Updated on 2021/03/21

写真a

 
MASUNAGA, Hirohiko
 
Organization
Nagoya University Institute for Space-Earth Environmental Research Meteorological and Atmospheric Research Division Associate professor
Title
Associate professor

Degree 1

  1. Ph.D. ( 1999.3   The University of Tokyo ) 

Research Interests 5

  1. Algorithm development for satellite data analysis

  2. Satellite remote sensing

  3. Climatology

  4. Precipitation

  5. Cloud

Research Areas 1

  1. Others / Others  / Meteorology/Climatology/Satellite remote sensing

Current Research Project and SDGs 2

  1. Intercomparison of global rainfall products

  2. Climatological study on tropical precipitating clouds primarily based on satellite observations

Research History 6

  1. Nagoya University   Associate professor

    2015.10

  2. Associate Professor, Hydrospheric Atmospheric Research Center, Nagoya University

    2006.7 - 2015.9

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    Country:Japan

  3. Research Scientist II, Department of Atmospheric Science, Colorado State University

    2004.5 - 2006.6

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    Country:United States

  4. Postdoctoral Fellow, Department of Atmospheric Science, Colorado State University

    2002.5 - 2004.4

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    Country:United States

  5. NASDA Research Fellow, Earth Observation Research Center, National Space Development Agency (NASDA) of Japan (currently Japan Aerospace Exploration Agency)

    1999.10 - 2002.4

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    Country:Japan

  6. Postdoctoral Fellow, Center for Climate Sytem Research, University of Tokyo

    1999.4 - 1999.9

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    Country:Japan

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Education 3

  1. The University of Tokyo   Graduate School, Division of Science   Astronomy

    1996.4 - 1999.3

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    Country: Japan

  2. The University of Tokyo   Graduate School, Division of Science   Astronomy

    1994.4 - 1996.3

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    Country: Japan

  3. The University of Tokyo   Faculty of Science   Astronomy

    1990.4 - 1994.3

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    Country: Japan

Professional Memberships 3

  1. American Geophysical Union

  2. American Meteorological Society

  3. Meteorological Society of Japan

Committee Memberships 5

  1. NASA Aerosol, Cloud, Convection and Precipitation (ACCP)   Science Community Cohort (SCC) team member  

    2019.10   

  2. JSPS/Royal Society UK-Japan Frontier of Science Symposium   Planning Group Member Co-chair  

    2016.11   

  3. Editorial Committee, Journal of the Meteorological Society of Japan   Editor  

    2010.7   

  4. Global Energy and Water Exchanges Project (GEWEX) Data and Analysis Panel (GDAP)   Member  

    2010.2   

  5. JSPS/CNRS Japan-France Frontiers of Science Symposium   Planning Group Member (2011 Co-chair)  

    2010.2 - 2012.1   

Awards 1

  1. The Award of the Meteorological Society of Japan

    2019   The Meteorological Society of Japan   Studies of tropical convective dynamics by combined analysis of satellite observations

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    Award type:International academic award (Japan or overseas)  Country:Japan

 

Papers 58

  1. Transient Aggregation of Convection: Observed Behavior and Underlying Processes

    Masunaga Hirohiko, Holloway Christopher E., Kanamori Hironari, Bony Sandrine, Stein Thorwald H. M.

    JOURNAL OF CLIMATE   Vol. 34 ( 5 ) page: 1685 - 1700   2021.3

  2. A Satellite-Based Estimate of Convective Vertical Velocity and Convective Mass Flux: Global Survey and Comparison With Radar Wind Profiler Observations

    Jeyaratnam Jeyavinoth, Luo Zhengzhao Johnny, Giangrande Scott E., Wang Die, Masunaga Hirohiko

    GEOPHYSICAL RESEARCH LETTERS   Vol. 48 ( 1 )   2021.1

  3. A Mechanism for the Maintenance of Sharp Tropical Margins

    Masunaga Hirohiko, Mapes Brian E.

    JOURNAL OF THE ATMOSPHERIC SCIENCES   Vol. 77 ( 4 ) page: 1181 - 1197   2020.4

  4. Inter-product biases in global precipitation extremes Reviewed

    Masunaga, H., M. Schröder, F. A. Furuzawa, C. Kummerow, E. Rustemeier, and U. Schneider

    Environmental Research Letters   Vol. 14   page: 125016   2019.12

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    DOI: 10.1088/1748-9326/ab5da9

  5. Vertical Modes and Effective Stability of Quasi-2-Day Waves

    Sumi Yukari, Masunaga Hirohiko

    JOURNAL OF THE ATMOSPHERIC SCIENCES   Vol. 76 ( 7 ) page: 2005 - 2022   2019.7

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1175/JAS-D-19-0092.1

    Web of Science

  6. Origins of Heavy Precipitation Biases in the TRMM PR and TMI Products Assessed with CloudSat and Reanalysis Data

    Sekaranom Andung Bayu, Masunaga Hirohiko

    JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY   Vol. 58 ( 1 ) page: 37-54   2019.1

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1175/JAMC-D-18-0011.1

    Web of Science

  7. Radiative Invigoration of Tropical Convection by Preceding Cirrus Clouds

    Masunaga Hirohiko, Bony Sandrine

    JOURNAL OF THE ATMOSPHERIC SCIENCES   Vol. 75 ( 4 ) page: 1327-1342   2018.4

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1175/JAS-D-17-0355.1

    Web of Science

  8. The Meandering Margin of the Meteorological Moist Tropics

    Mapes Brian E., Chung Eui Seok, Hannah Walter M., Masunaga Hirohiko, Wimmers Anthony J., Velden Christopher S.

    GEOPHYSICAL RESEARCH LETTERS   Vol. 45 ( 2 ) page: 1177-1184   2018.1

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1002/2017GL076440

    Web of Science

  9. New Observational Metrics of Convective Self-Aggregation: Methodology and a Case Study

    Kadoya Toshiki, Masunaga Hirohiko

    JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN   Vol. 96 ( 6 ) page: 535-548   2018

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.2151/jmsj.2018-054

    Web of Science

  10. Global precipitation measurements for validating climate models

    Tapiador F. J., Navarro A., Levizzani V., Garcia-Ortega E., Huffman G. J., Kidd C., Kucera P. A., Kummerow C. D., Masunaga H., Petersen W. A., Roca R., Sanchez J. -L., Tao W. -K., Turk F. J.

    ATMOSPHERIC RESEARCH   Vol. 197   page: 1 - 20   2017.11

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.atmosres.2017.06.021

    Web of Science

  11. Observing Convective Aggregation

    Holloway Christopher E., Wing Allison A., Bony Sandrine, Muller Caroline, Masunaga Hirohiko, L'Ecuyer Tristan S., Turner David D., Zuidema Paquita

    SURVEYS IN GEOPHYSICS   Vol. 38 ( 6 ) page: 1199-1236   2017.11

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1007/s10712-017-9419-1

    Web of Science

  12. Implications of Warm Rain in Shallow Cumulus and Congestus Clouds for Large-Scale Circulations

    Nuijens Louise, Emanuel Kerry, Masunaga Hirohiko, L'Ecuyer Tristan

    SURVEYS IN GEOPHYSICS   Vol. 38 ( 6 ) page: 1257-1282   2017.11

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1007/s10712-017-9429-z

    Web of Science

  13. Comparison of TRMM-Derived Rainfall Products for General and Extreme Rains over the Maritime Continent

    Sekaranom Andung Bayu, Masunaga Hirohiko

    JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY   Vol. 56 ( 7 ) page: 1867-1881   2017.7

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1175/JAMC-D-16-0272.1

    Web of Science

  14. Revisiting the iris effect of tropical cirrus clouds with TRMM and A-Train satellite data

    Choi Yong-Sang, Kim WonMoo, Yeh Sang-Wook, Masunaga Hirohiko, Kwon Min-Jae, Jo Hyun-Su, Huang Lei

    JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES   Vol. 122 ( 11 ) page: 5917-5931   2017.6

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1002/2016JD025827

    Web of Science

  15. A toy model of tropical convection with a moisture storage closure

    Masunaga Hirohiko, Sumi Yukari

    JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS   Vol. 9 ( 1 ) page: 647-667   2017.3

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1002/2016MS000855

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  16. Relationship between the direction of diurnal rainfall migration and the ambient wind over the Southern Sumatra Island

    Yanase A., Yasunaga K., Masunaga H.

    EARTH AND SPACE SCIENCE   Vol. 4 ( 3 ) page: 117-127   2017.3

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1002/2016EA000181

    Web of Science

  17. A toy model of tropical convection with a moisture storage closure Reviewed

    Masunaga, H. and Y. Sumi

    J. Adv. Model. Earth Syst.   Vol. 9   2017

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    DOI: 10.1002/2016MS00085

  18. Convective and large-scale mass flux profiles over tropical oceans determined from synergistic analysis of a suite of satellite observations Reviewed

    Masunaga, H., and Z. J. Luo

    J. Geophys. Res. Atmos   Vol. 121   2016

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    DOI: 10.1002/2016JD024753

  19. A Moist Static Energy Budget Analysis of Quasi 2-day Wave Using Satelite and Reanalsyis Data Reviewed

    Sumi, Y. and H. Masunaga

      Vol. 73   page: 743-759   2016

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  20. Assessment of a Satellite-based Atmospheric Budget Analysis Method with CINDY2011/DYNAMO/AMIE and TOGA COARE Sounding Array Data Reviewed

    Masunaga, H.

    J. Meteor. Soc. Japan   Vol. 93A   page: 21-40   2015

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    DOI: 10.2151/jmsj.2015-032

  21. Assessment of the consistency among global microwave land surface emissivity products Reviewed

    Norouzi,H., M. Temimi, C. Prigent, J. Turk, R. Khanbilvardi, Y. Tian, F. A. Furuzawa, and H. Masunaga

    Atmos. Meas. Tech.   Vol. 8   page: 1197-1205   2015

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    DOI: 10.5194/amt-8-1197-2015

  22. Early evaluation of Ku- and Ka-band sensitivities for the Global Precipitation Measurement (GPM) Dual-frequency Precipitation Radar (DPR) Reviewed

    Toyoshima, K., H. Masunaga, and F. A. Furuzawa

    SOLA   Vol. 11   page: 14-17   2015

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    DOI: 10.2151/sola.2015-004

  23. Free-tropospheric moisture convergence and tropical convective regimes Reviewed

    Masunaga, H.

    Geophys. Res. Lett.   Vol. 41   page: 8611-8618   2014.12

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    DOI: 10.1002/2014GL062301

  24. A mechanism of tropical convection inferred from observed variability in the moist static energy budget Reviewed

    Masunaga, H., and Tristan S. L'Ecuyer

    J. Atmos. Sci.   Vol. 71   page: 3747-3766   2014

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  25. The potential roles of background surface wind in the SST variability associated with intraseasonal oscillations Reviewed

    Kanemaru, K. and H. Masunaga

    J. Climate   Vol. 27   page: 7053-7068   2014

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  26. Quantifying uncertainties in land surface microwave emissivity retrievals Reviewed

    Tian, Y., C. Peters-Lidard , K. W. Harrison, C. Prigent, H. Norouzi, F. Aires, S.-A. Boukabara, F. A. Furuzawa, and H. Masunaga

    IEEE Trans. Geosci. Remote Sens.   Vol. 52   page: 829-840   2014

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  27. A satellite study of tropical moist convection and environmental variability: A moisture and thermal budget analysis Reviewed

    Masunaga, H.

    J. Atmos. Sci.   Vol. 70   page: 2443-2466   2013

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  28. A satellite study of the relationship between sea surface temperature and column water vapor over tropical and subtropical oceans Reviewed

    Kanemaru, K. and H. Masunaga

    J. Climate   Vol. 26   page: 4204-4218   2013

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  29. An evaluation of microwave land surface emissivities over the continental United States to benefit GPM-era precipitation algorithms Reviewed

    Ferraro, R., C. Peters-Lidard , C. Hernandez, F. J. Turk, F. Aires, C. Prigent, X. Lin, S.-A. Boukabara, F. Furuzawa, K. Gopalan, K. Harrison, F. Karbou, L. Li, C. Li, H. Masunaga, L. Moy, S. Ringerud, G. Skofronik-Jackson, Y. Tian, and N.-Y. Wang

    IEEE Trans. Geosci. Remote Sens.   Vol. 51   page: 378-398   2013

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  30. Aerosol effects on cumulus congestus population over the tropical Pacific: A cloud-resolving modeling study Reviewed

    Li, X., W.-K. Tao, H. Masunaga, G. Gu, and X. Zeng

    J. Meteor. Soc. Japan   Vol. 91   page: 817-833   2013

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  31. Analysis of cloud properties associated with tropical convection in climate models and satellite data Reviewed

    Ichikawa, H., H. Masunaga, Y. Tsushima, and H. Kanzawa

    Journal of the Meteorological Society of Japan   Vol. 90   page: 629-646   2012

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  32. Short-term versus climatological relationship between precipitation and tropospheric humidity Reviewed

    Hirohiko Masunaga

    Journal of Climate   Vol. 25   page: 7983-7990   2012

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  33. Reproducibility by climate models of cloud radiative forcing associated with tropical convection Reviewed

    Ichikawa, H., H. Masunaga, Y. Tsushima, and H. Kanzawa

    Journal of Climate   Vol. 25   page: 1247-1262   2012

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  34. A satellite study of the atmospheric forcing and response to moist convection over tropical and subtropical oceans Reviewed

    Hirohiko Masunaga

    Journal of the Atmospheric Sciences   Vol. 69   page: 150-167   2012

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    Satellite data are analyzed to explore the thermodynamic evolution of tropical and subtropical atmospheres
    prior and subsequent to moist convection in order to offer an observational test bed for convective adjustment,
    which is central to the quasi-equilibrium hypothesis. Tropical Rainfall Measuring Mission (TRMM)
    and Aqua satellite measurements are projected onto a composite temporal sequence over an hourly to daily
    time scale by exploiting the temporal gap between the local satellite overpasses, which changes from one day
    to another. The atmospheric forcing and response to convection are investigated separately for deep convective
    and congestus clouds. In the deep tropics, systematic moisture transport from the atmospheric
    boundary layer (ABL) to the free troposphere is evident in association with deep convection. The quick ABL
    ventilation suggests a swift convective adjustment but is preceded by a steady buildup ofABLmoisture, which
    does not imply continuous adjustment to equilibrium. The evolution of convective available potential energy
    (CAPE) is controlled not only by the ABL moisture but also largely by a coincident ABL cooling linked with
    a bipolar anomaly of tropospheric temperature. The ABL moisture and temperature effects together lead to
    a rapid drop of CAPE for 12 h preceding convection, followed by a restoring phase that emerges as the cool
    anomaly recovers for a day or two. When moist convection is brought by congestus clouds with no deep
    convection nearby, CAPE gently increases over a period of 1-2 days until congestus occurs and then declines
    as slowly, suggestive of no efficient convective adjustment. The subtropical atmosphere shows no sign of
    convective adjustment whether or not vigorous convection is present.

  35. Equatorial asymmetry of the east Pacific ITCZ: Observational constraints on the underlying processes Reviewed

    Masunaga, H. and T. S. L'Ecuyer

    J. Climate   Vol. 24   page: 1784-1800   2011.3

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    DOI: 1784-1800

  36. Satellite Data Simulator Unit (SDSU): A multi-sensor, multi-spectral satellite simulator package Reviewed

    Masunaga, H., T. Matsui, W.-K. Tao, A. Y. Hou, C. D. Kummerow, T. Nakajima, P. Bauer, W. S. Olson, M. Sekiguchi, and T. Y. Nakajima

    Bull. Amer. Meteorol. Soc.   Vol. 91   page: 1625-1632   2010.12

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    DOI: 1625-1632

  37. Improving a spectral bin microphysical scheme using TRMM satellite observations Reviewed

    Li, X., W.-K. Tao, T. Matsui, C. Liu, and H. Masunaga

    Quart. J. Roy. Meteor. Soc.   Vol. 136   page: 382-399   2010

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    TRMM-observed mature-stage squall lines during late spring and early summer
    in the central USA over a 9-year period are compiled and compared with a case
    simulation by the Goddard Cumulus Ensemble (GCE) model with a spectral bin
    microphysical scheme. During the quasi-steady state of the simulation, a forward
    radiative transfer model calculates TRMM Precipitation Radar (PR) reflectivity
    and 85 GHz brightness temperatures from simulated particle size distributions.
    Comparisons between model and TRMM observations using radar Contoured
    Frequency with Altitude Diagrams (CFADs) and 85 GHz brightness temperature
    probability density distributions are performed, in addition to CFADs from a surface
    C-band radar for the same case. Radar CFADs comparisons reveal that the model
    overestimates sizes of snow/aggregates in the stratiform region.
    Three sets of sensitivity tests are carried out in order to improve the simulated
    radar reflectivity profiles: increase of aggregates' density and terminal fall velocity;
    changing temperature dependency of collection efficiency between ice-phase
    particles, particularly those of the plate-type; and adding a break-up scheme for
    large aggregates. While all three approaches mitigate the discrepancies, changing
    collection efficiency produces the best match in magnitudes and characteristics
    of radar CFADs. In addition, interactions between ice- and water-phase particles
    also need to be adjusted in order to have good comparisons in both radar CFADs
    and 85 GHz brightness temperature distributions. This study shows that long-term
    satellite observations, especially those with multiple sensors, can be very useful in
    constraining model microphysics.

  38. The southeast Pacific warm band and double ITCZ Reviewed

    Masunaga, H. and T. S. L'Ecuyer

    J. Climate   Vol. 23   page: 1189-1208   2010

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    The east Pacific double intertropical convergence zone (ITCZ) in austral fall is investigated with particular
    focus on the growing processes of its Southern Hemisphere branch. Satellite measurements from the Tropical
    Rainfall Measuring Mission (TRMM) and Quick Scatterometer (QuikSCAT) are analyzed to derive 8-yr
    climatology from 2000 to 2007. The earliest sign of the south ITCZ emerges in sea surface temperature (SST)
    by January, followed by the gradual development of surface convergence and water vapor. The shallow
    cumulus population starts growing to form the south ITCZ in February, a month earlier than vigorous deep
    convection is organized into the south ITCZ. The key factors that give rise to the initial SST enhancement or
    the southeast Pacific warm band are diagnosed by simple experiments. The experiments are designed to
    calculate SST, making use of an ocean mixed layer ``model'' forced by surface heat fluxes, all of which are
    derived from satellite observations. It is found that the shortwave flux absorbed into the ocean mixed layer is
    the primary driver of the southeast Pacific warm band. The warm band does not develop in boreal fall because
    the shortwave flux is seasonally so small that it is overwhelmed by other negative fluxes, including the latent
    heat and longwave fluxes. Clouds offset the net radiative flux by 10–15 W m22, which is large enough for the
    warm band to develop in boreal fall if it were not for clouds reflecting shortwave radiation. Interannual
    variability of the double ITCZ is also discussed in brief.

  39. A 9-season TRMM observation of the Austral Summer MJO and Low-frequency Equatorial Waves Reviewed

    Masunaga, H.

    J. Meteor. Soc. Japan   Vol. 87A   page: 295-315   2009

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    A long-term observation from the Tropical Rainfall Measuring Mission (TRMM) is analyzed to investigate the Madden-Julian Oscillation (MJO), Kelvin wave, and equatorial Rossby (ER) wave in austral summer seasons. TRMM Precipitation Radar (PR) and Visible/Infrared Scanner (VIRS) measurements are jointly used to clarify convective progression associated with individual modes of the tropical oscillations. Variability in the dynamic and thermodynamic environment involving sea surface temperature (SST), column relative humidity (CRH), and moisture convergence is also examined. A sea surface warming is found to precede the peak MJO convection by ∼ 10 days, while a prior SST increase is not as evident for the Kelvin and ER waves. Moisture convergence and CRH exhibit a horseshoe-like pattern in the composite MJO map, constituted of a pair of off-equatorial maxima and a weak equatorial peak. The Kelvin wave has a moist anomaly on the equator leading the convective peak as theoretically expected, while the moist anomaly also extends poleward without being accompanied by moisture convergence. Moisture convergence leads CRH by a day or two for the Kelvin and ER waves. Moisture convergence is, in contrast, virtually concurrent with CRH for the MJO. The correlation between CRH and deep stratiform coverage is diverse among the three modes of the tropical oscillations. Shallow cumulus and cumulus congestus lead the MJO convective peak by ∼ 1 day, followed by lingering non-precipitating high clouds. ER wave convection is led by moisture convergence but lagged by CRH. The convective progression appears not to proceed in a monotonic way for the ER wave.
    A possible mechanism to explain MJO propagation is discussed as suggested by a synthesis of the present findings. The Kelvin wave guides the eastward migration of MJO convection onset over the Indian Ocean. The role of the Kelvin wave in MJO propagation diminishes as the MJO enters the west Pacific with the convective are

  40. An MJO simulated by the NICAM at 14-km and 7-km resolutions Reviewed

    Liu, P., M. Satoh, B. Wang, H. Fudeyasu, T. Nasuno, T. Li, H. Miura, H. Taniguchi, H. Masunaga, X. Fu, and H. Annamalai

    Mon. Wea. Rev.   Vol. 137   page: 3254-3268   2009

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    This study discloses detailed Madden–Julian oscillation (MJO) characteristics in the two 30-day integrations
    of the global cloud-system-resolving Nonhydrostatic Icosahedral Atmospheric Model (NICAM) using the allseason
    real-time multivariateMJO index ofWheeler and Hendon. The model anomaly is derived by excluding
    the observed climatology because the simulation is sufficiently realistic.Results showthat theMJOhas a realistic
    evolution in amplitude pattern, geographical locations, eastward propagation, and baroclinic- and westwardtilted
    structures. In the central IndianOcean, convection develops with the low-level easterlywind anomaly then
    matures where the low-level easterly and westerly anomalies meet. Anomalous moisture tilts slightly with
    height. In contrast, over the western Pacific, the convection grows with a low-level westerly anomaly.Moisture
    fluctuations, leading convection in eastward propagation, tilt clearly westward with height. The frictional
    moisture convergence mechanism operates to maintain the MJO. Such success can be attributed to the explicit
    representation of the interactions between convection and large-scale circulations. The simulated event, however,
    grows faster in phases 2 and 3, and peaks with 30%higher amplitude than that observed, although the 7-km
    version shows slight improvement. The fast-growth phases are induced by the fast-growing low-level convergence
    in the IndianOcean and the strongly biased ITCZ in the west Pacific when themodel undergoes a spinup.
    The simulated OLR has a substantial bias in the tropics. Possible solutions to the deficiencies are discussed.
    1. Introduction
    The Madden–Julian oscillation (MJO; Madden and
    Julian 1971, 1972, 1994) dominates tropospheric variability
    in the tropics on time scales of 30–60 days. The
    oscillation influences weather and climate variability
    substantially in both the tropics (e.g., Yasunari 1979;
    Hendon and Liebmann 1990; Lawrence and Webster
    2002) and

  41. Evaluation of Precipitation and High-level Cloud Areas Associated with Large-scale Circulation over the Tropical Pacific in the CMIP3 Models Reviewed

    Ichikawa, H., H. Masunaga, and H. Kanzawa

    J. Meteor. Soc. Japan   Vol. 87   page: 771-789   2009

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    Precipitation and high-level cloud (HLC) areas in association with the large-scale circulation over the tropical
    Pacific are analyzed for simulations of nineteen Coupled Model Intercomparison Project Phase 3 (CMIP3) models
    with observations for 16 years of 1984–1999. The distribution of rainfall and HLC areas are composited around
    the geographical center of tropospheric upper-level (200 hPa) divergence (DIV) along Intertropical Convergence
    Zone (ITCZ) using monthly anomaly data. Datasets with a finer temporal sampling than monthly means were
    not available for the present purposes. The most notable feature is that the horizontal spread of enhanced circulation
    and the related rainfall and HLC areas are all underestimated around the DIV center in the models compared
    to the observation. Particularly, the underestimation is pronounced in HLC, presumably owing to di‰culties
    in the physical processes relevant to the spatial distribution of HLC area. In general, a model with a higher
    correlation between the large-scale circulation field and rainfall tends to have a wider spread of HLC area around
    the DIV center.

  42. A Joint Satellite and Global Cloud-Resolving Model Analysis of a Madden-Jullian Oscillation Event: Model Diagnosis Reviewed

    Masunaga, H., M. Satoh, and H. Miura

    J. Geophys. Res.   Vol. 113 ( D17210 ) page: doi:10.1029/2008JD009986   2008.9

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    In this study, a methodology to diagnose a global cloud-resolving model (GCRM) is explored on the basis of a joint analysis with satellite measurements. The Madden-Julian Oscillation experiment carried out with the Nonhydrostatic Icosahedral Atmospheric Model (NICAM) is used as the test bed. The NICAM output is compared with Tropical Rainfall Measuring Mission (TRMM) and CloudSat measurements in terms of composite analysis, contoured frequency by altitude diagrams (CFADs), and the joint histogram of cloud top and precipitation top heights. It is found in the composite diagram that the GCRM reproduces a slow, eastward migration of a convective envelope well comparable
    to the satellite measurement. The GCRM CFAD qualitatively reproduces TRMM and CloudSat CFADs, except that the GCRM tends to overly produce snow in deep convection. The joint histograms reveal that, while the overproduction of snow is evident, NICAM-simulated snow is incapable of producing 94-GHz radar echoes higher than 5 dBZ. This deficiency can be mitigated by a modification to microphysical parameterization in the way that a proportion of small particles is enhanced in the snow mass spectrum.

  43. *Seasonality and Regionality of the Madden-Julian Oscillation, Kelvin Wave, and Equatorial Rossby Wave. Reviewed

    Masunaga, H.

    J. Atmos. Sci.   Vol. 64   page: 4400-4416   2007.12

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    The Madden–Julian oscillation (MJO), Kelvin wave, and equatorial Rossby (ER) wave—collectively
    called intraseasonal oscillations (ISOs)—are investigated using a 25-yr record of outgoing longwave radiation
    (OLR) measurements as well as the associated dynamical fields. The ISO modes are detected by
    applying bandpass filters to the OLR data in the frequency–wavenumber space. An automated wavetracking
    algorithm is applied to each ISO mode so that convection centers accompanied with the ISOs are
    traced in space and time in an objective fashion. The identified paths of the individual ISO modes are first
    examined and found strongly modulated regionally and seasonally. The dynamical structure is composited
    with respect to the convection centers of each ISO mode. A baroclinic mode of the combined Rossby and
    Kelvin structure is prominent for the MJO, consistent with existing work. The Kelvin wave exhibits a
    low-level wind field resembling the shallow-water solution, while a slight lead of low-level convergence over
    convection suggests the impact of frictional boundary layer convergence on Kelvin wave dynamics. A lagged
    composite analysis reveals that the MJO is accompanied with a Kelvin wave approaching from the west
    preceding the MJO convective maximum in austral summer. MJO activity then peaks as the Kelvin and ER
    waves constructively interfere to enhance off-equatorial boundary layer convergence. The MJO leaves a
    Kelvin wave emanating to the east once the peak phase is passed. The approaching Kelvin wave prior to the
    development of MJO convection is absent in boreal summer and fall. The composite ER wave, loosely
    concentrated around the MJO, is nearly stationary throughout. A possible scenario to physically translate
    the observed result is also discussed.

  44. *The Madden-Julian Oscillation Recorded in Early Observations from the Tropical Rainfall Measuring Mission (TRMM). Reviewed

    Masunaga, H., T. S. L'Ecuyer, and C. D. Kummerow

    J. Atmos. Sci.   Vol. 63   page: 2777-2794   2006.11

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    A satellite data analysis is performed to explore the Madden–Julian oscillation (MJO) focusing on the
    potential roles of the equatorial Rossby (ER) and Kelvin waves. Measurements from the Tropical Rainfall
    Measuring Mission (TRMM) Precipitation Radar (PR) and Visible/Infrared Scanner (VIRS) are analyzed
    in the frequency–wavenumber domain to identify and ultimately filter primary low-frequency modes in the
    Tropics. The space–time spectrum of deep-storm fraction estimated by PR and VIRS exhibits notable
    Kelvin wave signals at wavenumbers 5–8, a distinct MJO peak at wavenumbers 1–7 and periods of about 40
    days, and a signal corresponding to the ER wave. These modes are separately filtered to study the individual
    modes and possible relationship among them in the time–longitude space. In 10 cases analyzed here, an
    MJO event is often collocated with a group of consecutive Kelvin waves as well as an intruding ER wave
    accompanied with the occasional onset of a stationary convective phase. The spatial and temporal relationship
    between the MJO and Kelvin wave is clearly visible in a lag composite diagram, while the ubiquity
    of the ER wave leads to a less pronounced relation between the MJO and ER wave. A case study based on
    the Geostationary Meteorological Satellite (GMS) imagery together with associated dynamic field captures
    the substructure of the planetary-scale waves. A cross-correlation analysis confirms the MJO-related cycle
    that involves surface and atmospheric parameters such as sea surface temperature, water vapor, low clouds,
    shallow convection, and near-surface wind as proposed in past studies. The findings suggest the possibility
    that a sequence of convective events coupled with the linear waves may play a critical role in MJO
    propagation. An intraseasonal radiative–hydrological cycle inherent in the local thermodynamic conditions
    could be also a potential factor responsible for the MJO by loosely modula

  45. Observations of Tropical Precipitating Clouds Ranging from Shallow to Deep Convective Systems. Reviewed

    Masunaga, H., and C. D. Kummerow

    Geophys. Res. Lett.   Vol. 33 ( L16805 ) page: doi:10.1029/2006GL026547   2006.8

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    Regional and temporal variability in a broad spectrum
    of tropical precipitation systems is investigated in
    conjunction with the large-scale environment. The
    analysis utilizes four storm categories (Shallow, Cumulus
    Congestus, Deep Stratiform, and Deep Convective)
    determined from Tropical Rainfall Measuring Mission
    (TRMM) measurements. Deep Stratiform and Deep
    Convective systems are found to be clearly correlated
    with large-scale circulation deduced from a reanalysis data
    set, and are modulated by a distinct seasonal cycle over
    land. The Shallow category is practically the only
    component of tropical oceanic rainfall for cold sea
    surfaces, while it gives way to deeper systems as SST
    exceeds 28–29C. The cloud horizontal scale of organized
    rainfall systems tends to be increasingly extensive relative
    to the raining portion as the system becomes larger. The
    present results are discussed in light of existing relevant
    studies.

  46. Satellite-based Assessment of Marine Low Cloud Variability Associated with Aerosol, Atmospheric Stability, and the Diurnal Cycles. Reviewed

    Matsui, T., H. Masunaga, R. A. Pielke Sr., S. M. Kreidenweis, W.-K. Tao, M. Chin, and Y. J. Kaufman

    J. Geophys. Res.   Vol. 111 ( D17204 ) page: doi:10.1029/2005JD006097   2006

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    This study examines variability in marine low cloud properties derived from
    semiglobal observations by the Tropical Rainfall Measuring Mission (TRMM) satellite, as
    linked to the aerosol index (AI) and lower-tropospheric stability (LTS). AI is derived from
    the Moderate Resolution Imaging Spectroradiometer (Terra MODIS) sensor and the
    Goddard Chemistry Aerosol Radiation and Transportation (GOCART) model and is used
    to represent column-integrated aerosol concentrations. LTS is derived from the NCEP/
    NCAR reanalysis and represents the background thermodynamic environment in which
    the clouds form. Global statistics reveal that cloud droplet size tends to be smallest in
    polluted (high-AI) and strong inversion (high-LTS) environments. Statistical
    quantification shows that cloud droplet size is better correlated with AI than it is with LTS.
    Simultaneously, the cloud liquid water path (CLWP) tends to decrease as AI increases.
    This correlation does not support the hypothesis or assumption that constant or increased
    CLWP is associated with high aerosol concentrations. Global variability in corrected
    cloud albedo (CCA), the product of cloud optical depth and cloud fraction, is very well
    explained by LTS, while both AI and LTS are needed to explain local variability in
    CCA. Most of the local correlations between AI and cloud properties are similar to the
    results from the global statistics, while weak anomalous aerosol-cloud correlations
    appear locally in the regions where simultaneous high (low) AI and low (high) LTS
    compensate each other. Daytime diurnal cycles explain additional variability in cloud
    properties. CCA has the largest diurnal cycle in high-LTS regions. Cloud droplet size and
    CLWP have weak diurnal cycles that differ between clean and polluted environments.
    The combined results suggest that investigations of marine low cloud radiative forcing and
    its relationship to hypothesized aerosol indirect effects must consider the combined
    effects of a

  47. Variability in the Characteristics of Precipitation Systems in the Tropical Pacific.Part II: Implications for Atmospheric Heating Reviewed

    TRISTAN S. L'ECUYER, HIROHIKO MASUNAGA, AND CHRISTIAN D. KUMMEROW

    J. Cliamte   Vol. 19   page: 1388-1406   2006

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    This paper explores changes in the principal components of observed energy budgets across the tropical
    Pacific in response to the strong 1998 El Niño event. Multisensor observations from the Tropical Rainfall
    Measuring Mission (TRMM) Microwave Imager (TMI), Visible and Infrared Scanner (VIRS), and precipitation
    radar (PR) instruments aboard TRMM are used to quantify changes in radiative and latent
    heating in the east and west Pacific in response to the different phases of the El Niño–Southern Oscillation.
    In periods of normal east–west SST gradients there is substantial heating in the west Pacific and cooling in
    the east, implying strong eastward atmospheric energy transport. During the active phase of the El Niño,
    both the east and west Pacific tend toward local radiative–convective equilibrium resulting in their temporary
    energetic decoupling. It is further demonstrated that the response of these regions to ENSO-induced
    SST variability is directly related to changes in the characteristics of clouds and precipitation in each region.
    Through quantitative analysis of the radiative and latent heating properties of shallow, midlevel, and deep
    precipitation events and an equivalent set of nonprecipitating cloud systems, times of reduced atmospheric
    heating are found to be associated with a shift toward shallow and midlevel precipitation systems and
    associated low-level cloudiness. The precipitation from such systems is typically less intense, and they do not
    trap outgoing longwave radiation as efficiently as their deeper counterparts, resulting in reduced radiative
    and latent heating of the atmosphere. The results also suggest that the net effect of precipitating systems on
    top-of-the-atmosphere (TOA) fluxes and the efficiency with which they heat the atmosphere and cool the
    surface exhibit strong dependence on their surroundings. The sensitivity of cloud radiative impacts to the
    atmospheric and surface properties

  48. *Variability in the Characteristics of Precipitation Systems in the Tropical Pacific. Part I. Spatial Structure. Reviewed

    Masunaga, H., T. S. L'Ecuyer, and C. D. Kummerow

    J. Climate   Vol. 18   page: 823-840   2005

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    Regional and temporal variability in the vertical and horizontal characteristics of tropical precipitating
    clouds are investigated using the Precipitation Radar (PR) and the Visible and Infrared Scanner (VIRS) on
    board the Tropical Rainfall Measuring Mission (TRMM) satellite. The present study focuses on the three
    oceanic regions (west, central, and east Pacific) together with two continental regions for comparison and
    the two separate time periods (February 1998 and February 2000) under different phases of the El Niño–
    Southern Oscillation (ENSO) in order to examine regional and ENSO-related variations. The height
    spectrums of storms are investigated in terms of radar echo-top height and infrared brightness temperature.
    The variability in the spectrum clearly correlates with the large-scale circulation and its ENSO-related
    change. On the basis of the height spectrum, storm systems are classified into the four categories of shallow,
    cumulus congestus, deep stratiform, and deep convective. The deep stratiform and deep convective categories,
    both of which have very cold cloud tops, are differentiated by radar echo-top heights so that deep
    convective systems are accompanied with an appreciable amount of large frozen particles aloft. While
    shallow events are dominant in the probability of occurrence over relatively cold oceans, deep convective
    systems take their place for warmer sea surface temperatures (SSTs). The turnover occurs at the SST
    threshold of 28°–29°C for all the oceanic regions and years investigated except the west Pacific in 2000, for
    which deep convective systems prevail over the entire range of SST. Rain correlation-scale length (RCSL)
    and cloud correlation-scale length (CCSL) are introduced as statistical indicators of the horizontal scale of
    storms. While the RCSL is 8–18 km for shallow- and cumulus congestus–type clouds without significant
    regional and temporal variations, the RCSL and CCSL associate

  49. *Combined Radar and Radiometer Analysis of Precipitation Profiles for a Parametric Retrieval Algorithm. Reviewed

    Masunaga, H. and C. D. Kummerow

    J. Atmos. Oceanic Tech.   Vol. 22   page: 909-929   2005

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    A methodology to analyze precipitation profiles using the Tropical Rainfall Measuring Mission (TRMM)
    Microwave Imager (TMI) and precipitation radar (PR) is proposed. Rainfall profiles are retrieved from PR
    measurements, defined as the best-fit solution selected from precalculated profiles by cloud-resolving
    models (CRMs), under explicitly defined assumptions of drop size distribution (DSD) and ice hydrometeor
    models. The PR path-integrated attenuation (PIA), where available, is further used to adjust DSD in a
    manner that is similar to the PR operational algorithm. Combined with the TMI-retrieved nonraining
    geophysical parameters, the three-dimensional structure of the geophysical parameters is obtained across
    the satellite-observed domains. Microwave brightness temperatures are then computed for a comparison
    with TMI observations to examine if the radar-retrieved rainfall is consistent in the radiometric measurement
    space. The inconsistency in microwave brightness temperatures is reduced by iterating the retrieval
    procedure with updated assumptions of the DSD and ice-density models. The proposed methodology is
    expected to refine the a priori rain profile database and error models for use by parametric passive
    microwave algorithms, aimed at the Global Precipitation Measurement (GPM) mission, as well as a future
    TRMM algorithms.

  50. Impact of aerosols and atmospheric thermodynamics on cloudproperties within the climate system Reviewed

    Toshihisa Matsui, Hirohiko Masunaga, and Roger A. Pielke Sr.

    Geophys. Res. Lett.   Vol. 31 ( L06109 ) page: doi:10.1029/2003GL019287   2004

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    A combination of cloud-top and columnar droplet sizes
    derived from the multi Tropical Rainfall Measurement
    Mission (TRMM) sensors reveals the sensitivity of the
    aerosols effect on cloud-precipitation processes due to
    environmental vertical thermodynamic structure. First, the
    magnitude of aerosol indirect effect could be larger with
    the analysis of columnar droplet sizes than that derived from
    the cloud-top droplet sizes since column-droplet size can
    account for the broader droplet spectra in the cloud layers.
    Second, a combination of cloud-top and columnar droplet
    sizes reveals that the warm rain process is prevented
    regardless of the aerosols concentration under high static
    stability such as when a strong temperature inversion exists,
    while a high aerosol concentration suppresses the warm rain
    formulation under low static stability.

  51. Physical Properties of Maritime Low Clouds as Retrieved by Combined Use of TRMM Microwave Imager and Visible/Infrared Scanner. Algorithm. Reviewed

    Masunaga, H., T. Y. Nakajima, T. Nakajima, M. Kachi, R. Oki, and S. Kuroda

    J. Geophys. Res.   Vol. 107 ( D10 ) page: doi:10.1029/2001JD000743   2002

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    Satellite remote sensing studies on the microphysical and optical properties of clouds have
    constructed an active research field in the last decades. Clouds are observed over a wide spectral
    range from the visible/infrared to the microwave, and either shortwave or microwave measurement
    is used to evaluate the liquid water path (LWP). On the other hand, to date, there have been few
    cloud studies based on combined measurement by a visible/infrared imager and a microwave
    radiometer aboard the same platform. In this paper a physical inversion algorithm for the combined
    use of visible/infrared and microwave sensors is proposed to retrieve the cloud physical quantities
    such as LWP and the effective droplet radius, each of which is determined in two different ways.
    The current version of the algorithm has been developed for application to the Tropical Rainfall
    Measurement Mission (TRMM) sensors, i.e., Visible and Infrared Scanner (VIRS) and TRMM
    Microwave Imager (TMI). The cloud top temperature obtained from the VIRS analysis is used as an
    input to the TMI analysis to reduce uncertainties in estimation of LWP. Total errors in LWP are
    estimated to range from 11 to 30 g /m2. In the algorithm the beam-filling efficiency of clouds for
    TMI footprints is corrected by the cloud fraction evaluated from the VIRS measurements. For
    application, global analysis is performed with 3-monthly data from January to March 2000. The
    scatter diagram of the shortwave-retrieved LWP (LWPshrt) versus the microwave-retrieved LWP
    (LWPmicr) shows characteristic trends for both precipitating and nonprecipitating clouds. Vertical
    inhomogeneity of the cloud droplet size accounts for small excess of LWPshrt over LWPmicr for
    nonprecipitating clouds, while precipitating clouds produce LWPmicr larger than LWPshrt, owing to
    the presence of raindrops. These tendencies are reinforced by examination of the global
    distributions of the shortwave-retrieved droplet radius Re (NV) and the microwa

  52. Comparison of Rainfall Products Derived from TRMM Microwave Imager and Precipitation Radar. Reviewed

    Masunaga, H., T. Iguchi, R. Oki, and M. Kachi

    J. Applied Meteor.   Vol. 41   page: 849-862   2002

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    Satellite remote sensing is an indispensable means of measuring and monitoring precipitation on a global scale.
    The Tropical Rainfall Measuring Mission (TRMM) is continuing to make significant progress in helping the global
    features of precipitation to be understood, particularly with the help of a pair of spaceborne microwave sensors,
    the TRMM Microwave Imager (TMI) and precipitation radar (PR). The TRMM version-5 standard products,
    however, are known to have a systematic inconsistency in mean monthly rainfall. To clarify the origin of this
    inconsistency, the authors investigate the zonal mean precipitation and the regional trends in the hydrometeor
    profiles in terms of the precipitation water content (PWC) and the precipitation water path (PWP) derived from
    the TMI profiling algorithm (2A12) and the PR profile (2A25). An excess of PR over TMI in near-surface PWC
    is identified in the midlatitudes (especially in winter), whereas PWP exhibits a striking excess of TMI over PR
    around the tropical rainfall maximum. It is shown that these inconsistencies arise from TMI underestimating the
    near-surface PWC in midlatitude winter and PR underestimating PWP in the Tropics. This conclusion is supported
    by the contoured-frequency-by-altitude diagrams as a function of PWC. Correlations between rain rate and PWC/
    PWP indicate that the TMI profiling algorithm tends to provide a larger rain rate than the PR profile under a given
    PWC or PWP, which exaggerates the excess by TMI and cancels the excess by PR through the conversion from
    precipitation water to rain rate. As a consequence, the disagreement in the rainfall products between TMI and PR
    is a combined result of the intrinsic bias originating from the different physical principles between TMI and PR
    measurements and the purely algorithmic bias inherent in the conversion from precipitation water to rain rate.

  53. Physical Properties of Maritime Low Clouds as Retrieved by Combined Use of TRMM Microwave Imager and Visible/Infrared Scanner. II. Climatology of Warm Clouds and Rain. Reviewed

    Masunaga, H., T. Y. Nakajima, T. Nakajima, M. Kachi, and K. Suzuki

    J. Geophys. Res   Vol. 107 ( D19 ) page: doi:10.1029/2001JD001269   2002

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    In this paper, we investigate characteristics of low clouds and warm-rain production in
    terms of droplet growth based on the effective droplet radii retrieved by a combined use of
    visible, infrared, and microwave satellite remote sensing. We propose to categorize low
    clouds into the following groups: (1) nondrizzling, nonraining clouds; (2) nonraining
    clouds with drizzling near the cloud top; (3) raining clouds; and (4) clouds with no clear
    interpretation in terms of the effective radii derived using two different schemes. This
    categorization is supported by examination of the correlation between static stability and
    the retrieved results in the three ``precipitating regions'' (the Middle Pacific, South Pacific
    Convergence Zone [SPCZ], and Intertropical Convergence Zone [ITCZ] cumulus regions)
    and in the four ``nonprecipitating regions'' (the Californian, Peruvian, Namibian, and
    eastern Asian stratus regions). The rain rate derived by Precipitation Radar (PR) provides
    global characteristics consistent with our results. Californian and Peruvian stratus clouds
    are found to frequently have the drizzle mode near the cloud top, whereas Namibian strati
    have fewer chances to drizzle. The drizzle mode almost completely disappears in the
    eastern Asian region in the winter. The cloud–aerosol interaction is a promising candidate
    for suppressing the drizzle mode formation in nonprecipitating clouds.

  54. The Effective Cloud Fraction of Broken Clouds Obtained by Multi-stream Radiative Transfer. I. Longwave Radiation Reviewed

    Masunaga, H. and T. Nakajima

    J. Atmos. Sci.   Vol. 58   page: 2455-2467   2001

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    The influence of broken clouds on radiative flux has provided a major source of uncertainty in radiative
    transfer models of the atmosphere because plane-parallel approximations are assumed in most of the current
    atmospheric models, where horizontal inhomogeneity cannot be adequately taken into account. In this paper,
    effects by cloud inhomogeneity on longwave radiation fields are investigated, using a simple model of a cloud
    array that consists of identical cuboids following some past studies. In contrast to past work that adopted simplified
    formulations of radiative transfer, multistream radiative transfer is considered to obtain the exact solutions of
    radiative flux, which enable us to consider semitransparent clouds as well as optically thick clouds in desirable
    accuracy. Applicability to semitransparent clouds is important because cirrus clouds, which are considered to
    play significant roles for longwave radiation, are often semitransparent to infrared radiation.
    The computational results show that the empirical formula previously derived by Harshvardhan and Weinman
    systematically underestimates the effective cloud fraction. An alternative formula is proposed for the effective
    cloud fraction to supply a better fit to the exact solution of radiative flux. Furthermore, new formulas are derived
    to approximate the exact solutions including the dependence on the optical thickness of clouds. They are useful
    to convert plane-parallel flux to 3D flux passing through broken clouds, either for optically thick or thin clouds.

  55. A Radiation Hydrodynamic Model for Protostellar Collapse II. The Second Collapse and The Birth of a Protostar. Reviewed

    Masunaga, H. and Inutsuka, S.

    Astrophys. J.   Vol. 531   page: 350-365   2000

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    carry out radiation hydrodynamic calculations to study physical processes in the formation of a 1
    M protostar. Following our previous work, calculations pursue the whole evolution from the beginning _
    of the Ðrst collapse to the end of the main accretion phase. The adiabatic core formed after the initial
    collapse (i.e., the Ðrst core) experiences further gravitational collapse triggered by dissociation of molecular
    hydrogen, which leads to the formation of the second core, i.e., the birth of a protostar. The protostar
    grows in mass as accreting the infalling material from the circumstellar envelope, while the protostar
    keeps its radius at D4 R during the main accretion phase. These typical features in the evolution are in _
    good agreement with previous studies. We consider two di†erent initial conditions for the density distribution
    : homogeneous and hydrostatic cloud cores with the same central density of 1.415]10~19 g
    cm~3 . The homogeneous core has the total mass of 1 M while the hydrostatic core has 3.852 For _ M_.
    the initially homogeneous model, the accretion luminosity rapidly rises to the maximum value of 25 L _
    just after the birth of a protostar, and declines gradually as the mass accretion rate decreases. In contrast,
    the luminosity increases monotonically with time for the initially hydrostatic model. This di†erence
    arises because the mass accretion rate varies depending on the inward acceleration at the initial stage,
    which a†ects the luminosity curve. A less massive hydrostatic core would possess the similar properties
    in the luminosity curve to the 3.852 M case, because a hydrostatic cloud core with mass lower than _
    3.852 M can be shown to provide a smaller mass accretion rate after the birth of a protostar and a _
    more gradual rise in the luminosity curve. Our numerical code is designed to provide the evolution of
    the spectral energy distribution (SED) along with the dynamical evolution in our spherically sym

  56. Infall Signatures in Molecular Line Spectra of Protostellar Envelopes. Reviewed

    Masunaga, H. and Inutsuka, S.

    Astrophys. J.   Vol. 536   page: 406-415   2000

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    A double-peaked proÐle with a stronger blue peak in a molecular line spectrum is considered strong
    evidence for the infall motion in the gas envelope surrounding a protostar. Some past studies performed
    model calculations for reproducing observed spectral proÐles using simpliÐed dynamical models such as
    isothermal similarity solutions. However, validity of the similarity solutions for spectral line synthesis
    should be examined in comparison with more realistic dynamical models.
    In this paper we carry out theoretical modeling of molecular line spectra, adopting a spherically symmetric
    radiation hydrodynamical model for protostar formation taken from a recent work by the
    authors. This study concentrates on how infall motions could account for the asymmetric line proÐles
    observed toward protostellar sources. We do not explicitly consider the e†ects of rotation and outÑows
    on the generation of line proÐles. In our numerical code for the non-LTE line transfer, the level populations
    are fully consistent with the radiation Ðeld under an arbitrary physical structure in spherical symmetry,
    and hence, reliable spectral synthesis has been enabled and compared to the LTE, large velocity
    gradient (or Sobolev), and microturbulence approximations.
    Contrary to the remarks by Zhou, we do not Ðnd an overestimation of line widths, although the
    dynamical evolution resembles the Larson-Penston solution rather than the expansion-wave solution.
    Furthermore, the infall motion produces wings extending to v\^2 km s~1 in line spectra, in contrast
    to previous works where wings could not be produced by infall models. These results imply that simpli-
    Ðed infall models, such as the isothermal similarity solutions adopted by previous authors, are not
    always suitable to the detailed modeling of line spectra.

  57. Does "t @ 1" Terminate the Isothermal Evolution of Collapsing Clouds? Reviewed

    Masunaga, H. and Inutsuka, S.

    Astrophys. J.   Vol. 510   page: 822-827   1999

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    We examine when gravitationally collapsing clouds terminate their isothermal evolution. According to
    our previous work, the condition with which isothermality is broken down is classiÐed into three cases,
    i.e., when (1) the compressional heating rate overtakes the thermal cooling rate, (2) the optical depth for
    thermal radiation reaches unity, or (3) the compressional heating rate becomes comparable with the
    energy transport rate because of radiative di†usion. In the present paper this classiÐcation is extended to
    dmiseoontrhseietirgemesnawelrieatvhl ovwluahltuiiocehns otchef eatssheeesciwonnhitdeiiantlioccnalsoseuad1retoesrma3tpiseiÐsreasdtau.triFesÐoTeridnp,itlaaanundsdibcloaepseavca2iltuyheasis,onfaonTdisniigtwnaeinÐddceatine,cremw. eiWneÐentdehmethpcahrtiatsitcihzaeel
    that the condition of ““qB1 ÏÏ never terminates isothermality, but nonisothermal evolutions begin either
    earlier or later depending on the initial temperature and opacity. This result contrasts with the conventional
    idea that opaqueness breaks isothermality. On the basis of the critical density discussed above, the
    minimum Jeans mass for fragmentation, MF, is reconsidered. In contrast to the results by previous
    authors that MF is insensitive to Tinit and i, we Ðnd that MF can be substantially larger than the typical
    value of D10~2 M depending on and i. In particular, increases with decreasing metallicity, _ Tinit MF
    MFPi~1, for low-metal clouds. A cloud with i\10~4 cm2 g~1 and Tinit\10 K yields MF\3.7 M_.
    Finally, our critical densities would be helpful for hydrodynamic simulations that are intended to simply
    handle the hardening of the equation of state.

  58. A Radiation Hydrodynamic Model for Protostellar Collapse I. The First Collapse. Reviewed

    Masunaga, H., Miyama, S.M., and Inutsuka, S.

    Astrophys. J.   Vol. 495   page: 346-369   1998

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    Dynamical collapse of a molecular cloud core and the formation of a star are investigated by performing
    radiation hydrodynamic calculations in spherical symmetry. The angle-dependent and
    frequency-dependent radiative transfer equation is solved without any di†usion approximations, and the
    evolution of the spectral energy distribution (SED) is examined.
    In the present paper, as the Ðrst step in a series of our work, evolutions before hydrogen molecules
    begin to dissociate (the so-called Ðrst collapse) are examined for di†erent masses and initial temperatures
    of the parent cloud cores and for di†erent opacities. Numerical results for a typical case [Tinit\10 K
    and iP(10 K)D0.01 cm2 g~1] show that the radius and mass of the Ðrst core are D5 AU and D0.05
    M respectively. These values are independent both of the mass of the parent cloud core and of the _,
    initial density proÐle. The analytical expressions for the radius, mass, and accretion luminosity of the
    Ðrst core are also obtained. The SED contains only cold components of a few times 10 K throughout
    the Ðrst collapse phase, because the opaque envelope veils the Ðrst core from observers. We suggest that
    the molecular cloud cores with luminosities higher than D0.1 L should contain young protostars deep _
    in the center, even if they show no evidence for the existence of central stars in near-infrared and optical
    observations.

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Books 3

  1. Temporal and Spatial Variability of Clouds and Related Aerosols in "Clouds in the Perturbed Climate System: Their Relationship to Energy Balance, Atmospheric Dynamics, and Precipitation", Ed. by Heintzenberg, J., and R. J. Charlson

    Anderson, T. L. (Rapporteur), A. Ackerman, D. L. Hartmann, G. A. Isaac, S. Kinne, H. Masunaga, J. R. Norris, U. Pöschl, K. S. Schmidt, A. Slingo, and Y. N. Takayabu( Role: Joint author)

    The MIT Press  2009 

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    Language:English

  2. Clouds and Precipitation: Extreme Rainfall and Rain from Shallow Cloudsin "Clouds in the Perturbed Climate System: Their Relationship to Energy Balance, Atmospheric Dynamics, and Precipitation", Ed. by Heintzenberg, J., and R. J. Charlson

    Takayabu, Y. N., and H. Masunaga( Role: Joint author)

    The MIT Press  2009 

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    Language:English

  3. A Next-generation Microwave Rainfall Retrieval Algorithms for use by TRMM and GPM

    Kummerow, C. D., H. Masunaga, and P. Bauer( Role: Joint author)

    Springer  2007 

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    Language:English

Presentations 18

  1. A Satellite Study of the Atmospheric Forcing and Response to Moist Convection International conference

    Hirohiko Masunaga

    IUGG general assembly 

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    Event date: 2011.6 - 2011.7

    Language:English   Presentation type:Oral presentation (general)  

    Country:Australia  

  2. 熱帯湿潤対流に対する大規模強制力および大気応答に関する衛星観測研究

    増永浩彦

    日本気象学会2011年度春季年会 

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    Event date: 2011.5

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:東京都渋谷区   Country:Japan  

  3. A Satellite Study of the Atmospheric Forcing and Response to Moist Convection International conference

    MASUNAGA, H.

    Dpt. of Atmospheric Science Colloquium, Colorado State University, 

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    Event date: 2011.2

    Language:English   Presentation type:Oral presentation (general)  

    Country:United States  

  4. The southeast Pacific warm band and double ITCZ International conference

    MASUNAGA, H., AND T. S. L'ECUYER

    The 29th Conference on Hurricanes and Tropical Meteorology 

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    Event date: 2010.5

    Language:English   Presentation type:Oral presentation (general)  

    Country:United States  

  5. 東太平洋ITCZ の赤道非対称性:衛星観測に基づく再検討

    増永浩彦, Tristan L'Ecuyer

    日本気象学会2010年度春季年会 

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    Event date: 2010.5

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:東京都渋谷区   Country:Japan  

  6. Satellite Data Simulator Unit version 2 International conference

    MASUNAGA, H.,

    American Geophysical Union Fall Meeting 

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    Event date: 2009.12

    Language:English   Presentation type:Oral presentation (general)  

    Country:United States  

  7. Origins of moisture development leading MJO convective burst International conference

    MASUNAGA, H.

    MOCA-09 (the IAMAS/IAPSO/IACS 2009 joint assembly) 

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    Event date: 2009.7

    Language:English   Presentation type:Oral presentation (general)  

    Country:Canada  

  8. On the development of the eastern Pacific double ITCZ. International conference

    MASUNAGA, H., AND T. S. L'ECUYER

    89th American Meteorological Society Annual Meeting 

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    Event date: 2009.1

    Language:English   Presentation type:Oral presentation (general)  

    Country:United States  

  9. 東太平洋double ITCZの発達過程について

    増永浩彦, Tristan L'Ecuyer

    日本気象学会2008年度秋季年会 

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    Event date: 2008.11

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:宮城県仙台市   Country:Japan  

  10. TRMMおよびCloudSat衛星データを用いた全球雲解像モデル検証

    増永浩彦、佐藤正樹、三浦裕亮

    日本気象学会2008年度春季年会 

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    Event date: 2008.5

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue: 神奈川県横浜市   Country:Japan  

  11. A Joint Satellite and Global CRM Analysis of the MJO. International conference

    JSPS-DFG Round Table on Climate System Research - Status and Perspective 

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    Event date: 2008.1

    Language:English   Presentation type:Oral presentation (invited, special)  

  12. A Joint Satellite and Global Cloud-Resolving Model Analysis of the 2006/07 Madden-Julian Oscillation International conference

    2007 American Geophysical Union Fall Meeting 

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    Event date: 2007.12

    Language:English   Presentation type:Oral presentation (general)  

  13. TRMM observations of convective variability associated with the austral summer MJO, Kelvin wave, and equatorial Rossby wave. International conference

    New Approaches to Meet the Challenge of the Madden-Julian Oscillation 

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    Event date: 2007.11

    Language:English   Presentation type:Poster presentation  

  14. 大規模赤道波に伴う対流システム発達過程の観測的研究

    増永浩彦

    日本気象学会2007年度秋季年会 

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    Event date: 2007.10

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  15. Satellite Data Analysis of the Madden-Julian Oscillation, Kelvin wave, and the Equatorial Rossby Wave. International conference

    MASUNAGA, H.

    International Union of Geodesy and Geophysics 

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    Event date: 2007.7

    Language:English   Presentation type:Oral presentation (general)  

  16. Prospective Meteorological Studies Using Next-Generation Earth-Observing Satellites

    The Meteorological Society of Japan 125th Anniversary International Symposium, Toward Next Generation of Atmospheric Sciences 

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    Event date: 2007.5

    Language:English   Presentation type:Oral presentation (invited, special)  

    Country:Japan  

  17. Tropical Rainfall Climatology analyzed from satellite measurements International conference

    European Geosciences Union General Assembly 

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    Event date: 2007.4

    Language:English   Presentation type:Oral presentation (general)  

  18. 対流と結合したケルビン波、赤道ロスビー波、およびMadden-Julian振動の観測的研究

    増永浩彦、Tristan L’Ecuyer, Christian Kummerow

    日本気象学会2006年度秋季年会 

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    Event date: 2006.10

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

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Research Project for Joint Research, Competitive Funding, etc. 5

  1. Inter-comparison of global rainfall datasets for the improvement of satellite rainfall algorithms

    2019.4 - 2022.3

    Cooperative Research within Japan 

  2. Inter-comparison of global rainfall data products for the improvement of satellite rainfall algorithms

    2017.4 - 2019.3

    Commissioned Research 

  3. Development of a microwave land surface emissivity algorithm for combined DPR/GMI algorithms

    2013.4 - 2016.3

    Commissioned Research 

  4. Development of a combined DPR and GMI precipitation algorithm

    2010.4 - 2013.3

    Funded Research from Enterprise 

  5. Development of a precipitation retrieval algorithm for combined use of DPR and GMI

    2007.8 - 2010.3

    Funded Research from Enterprise 

KAKENHI (Grants-in-Aid for Scientific Research) 11

  1. Uncertainties of climate variability and change and future projection in mid-latitudes

    Grant number:19H05704  2019.6 - 2024.3

    Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

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    Authorship:Coinvestigator(s) 

  2. A thermodynamic mechanism for the maintenance of the moist-tropical margins

    Grant number:19H01966  2019.4 - 2022.3

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    Authorship:Principal investigator 

    Grant amount:\17030000 ( Direct Cost: \13100000 、 Indirect Cost:\3930000 )

  3. 衛星データシミュレータを用いた雲解像モデル検証手法の開拓(国際共同研究強化)

    2016.4 - 2019.3

    科学研究費補助金  国際共同研究加速基金

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    Authorship:Principal investigator 

  4. Intense investigation of the oxidation capacity of global atmosphere and its changes

    Grant number:16H02937  2016.4 - 2019.3

    Sudo Kengo

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    Authorship:Coinvestigator(s) 

    This study improves the estimate of global distributions of hydroxy radical (OH) which controls oxidation and removal processes of various compounds in the atmosphere, and evaluates the recent change in the atmospheric oxidation capacity and its controlling mechanism. The estimate of OH distributions is improved by validating and elaborating the calculations of clouds, aerosols, and stratospheric ozone with combining a chemistry climate model simulation with the observational data as from satellite measurements. This study further investigates contributions of individual controlling factors of OH changes such as anthropogenic and natural emissions of nitrogen oxides (NOx), carbon monoxide (CO), volatile organic compounds (VOCs), in addition to the distributions of clouds, water vapor (H2O), and ozone.

  5. Exploring methods to evaluate cloud-resolving models using satellite data simulators(Fostering Joint International Research)

    Grant number:15KK0157  2016 - 2018

    Fund for the Promotion of Joint International Research (Fostering Joint International Research)

    Masunaga Hirohiko

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    Authorship:Principal investigator 

    Grant amount:\13390000 ( Direct Cost: \10300000 、 Indirect Cost:\3090000 )

    Radiative-convective interactions, although known to be a critical physical element of the Earth’s atmosphere, are not understood in the context of the development of individual convective systems. This work seeks evidence for convective-radiative interactions in satellite measurements, with focus on the variability over the life cycle of tropical convection. Cirrus cloud cover begins to increase, accompanied by a notable reduction of LW cooling, in moist atmospheres even 1-2 days before deep convection is invigorated. A possible mechanism to support this observational implication is discussed using a simple conceptual model. The model suggests that the preceding cirrus clouds could radiatively promote the moistening with the aid of the congestus-mode (or a vertical mode with a lower-tropospheric updraft) dynamics within a short period of time (about 2 days) as observed.

  6. Exploring methods to evaluate cloud-resolving models using satellite data simulators

    Grant number:26287113  2014.4 - 2018.3

    MASUNAGA Hirohiko

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    Authorship:Principal investigator 

    Grant amount:\16640000 ( Direct Cost: \12800000 、 Indirect Cost:\3840000 )

    This study is aimed at developing novel process-oriented methods based on satellite data, as represented by satellite data simulators, in order to evaluate numerical weather models. The meteorological parameters such as the precipitation efficiency and cumulus mass flux, known traditionally to be difficult to estimate from satellite observations, are successfully retrieved from a combined use of cutting-edge Earth-observing satellites including CloudSat, Aqua, and TRMM. The findings would open a new pathway for the observational assessment of, for example, cumulus parameterizations implemented in climate models.

  7. 多衛星データ複合解析に基づく熱帯大気循環場の全球観測:「見えない風」を見る

    2014.4 - 2017.3

    科学研究費補助金 

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    Authorship:Principal investigator 

  8. 衛星データシミュレータを用いた雲解像モデル検証手法の開拓

    2014.4 - 2017.3

    科学研究費補助金  基盤研究(B)

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    Authorship:Principal investigator 

  9. Interactions between tropical atmosphere and convection explored by combined use of multiple satellites

    2011.4 - 2014.3

    Grant-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists(B)

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    Authorship:Principal investigator 

  10. さまざまな大規模赤道波に伴う対流雲発達過程の観測研究:統一的理解に向けて

    2008.6 - 2011.3

    科学研究費補助金  若手研究(B),課題番号:20740269

    増永 浩彦

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    Authorship:Principal investigator 

  11. 熱帯降水時空間変動の衛星データベース作成と熱帯季節内振動の観測的研究

    2007.10 - 2009.3

    科学研究費補助金  若手研究(スタートアップ)

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    Authorship:Principal investigator 

    熱帯域の対流活動は大規模大気循環において中心的な役割を果たし、また熱帯季節内振動の物理機構のさらなる理解においても熱帯降水システムの広域観測は本質的に重要である。本研究では、熱帯降雨観測衛星(TRMM)赤外輝度温度とレーダ降雨頂高度を用いて熱帯降水システム時空間変動の気候学的理解を深めることを目的とする。 とくに、熱帯気象学の代表的な研究課題として、本研究では熱帯季節内振動の駆動・伝搬特性に着目する。熱帯季節内振動の主要なモードとして知られるマデン・ジュリアン振動(MJO)は、熱帯気象のみならず熱帯低気圧発生への影響という観点から台風の予測にも間接的なかかわりを持つが、その振動・伝播機構は未だ解明されていない点も多い。本研究では、研究代表者のこれまでの研究成果をさらに発展させ、ケルビン波や赤道ロスビー波といった他の赤道波モード間の相互作用によりMJOの物理機構を説明する可能性を追求する。また、作成したTRMM衛星データセットを研究コミュニティに公開し、関連分野の研究者との幅広い連携を図ることも目的とする。

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Teaching Experience (On-campus) 1

  1. First Year Seminar B

    2011