Sciences and Exploration Directorate

Jackson Tan


Jackson Tan's Contact Card & Information.
Phone: 301.614.6227
Org Code: 613
Mail Code 613
Greenbelt, MD 20771

Brief Bio

I am an Scientist with Universities Space Research Association working at NASA Goddard Space Flight Center. My work focuses on the development of the Integrated Multi-satellitE Retrievals for GPM (IMERG) gridded global precipitation product from the Global Precipitation Measurement (GPM) mission, creation of cloud regimes from the Moderate Resolution Imaging Spectroradiometer (MODIS) observations, and the study of the relationship between clouds and precipitation.

Current Projects

IMERG Algorithm Development


The Integrated Multi-satellitE Retrievals for GPM (IMERG) is the leading global gridded precipitation product from the NASA Global Precipitation Measurement (GPM) mission. A successor to the widely used TRMM Multisatellite Precipitation Analysis, the recently released IMERG V06 provides precipitation estimates over a 20-year record and features numerous improvements. IMERG V07, planned for a late-2021 release, will require continued development, including testing for the optimal variable(s) in deriving motion vectors and ensuring correct functioning under an equal-area global grid.

Unified ISCCP-MODIS Weather States


Weather states (or cloud regimes) are mesoscale categorization of cloud distributions from passive satellite observations that have provided useful insights into the large-scale state of the atmosphere. Currently defined separately from Moderate Resolution Imaging Spectroradiometer (MODIS) and International Satellite Cloud Climatology Project (ISCCP) observations, the goal of this project is to integrate both products in a consistent manner to create a long-term record of unified ISCCP-MODIS weather states dataset for scientific analysis.

Understanding Cloud-Precipitation Relationship


Understanding the relationship between clouds and precipitation is critical for an accurate representation of related processes in models, but our knowledge remains deficient. The goal of this project is to conduct a combined analysis of clouds and precipitation using IMERG and cloud regimes, leveraging the detailed insights gained during the creation of each product to achieve an informed understanding of the connections between clouds and precipitation.


Ph.D., Monash University, Mar 2011–Sep 2014
School of Earth, Atmosphere and Environment, Faculty of Science

M.Sc., The Australian National University, Feb 2010–Dec 2010
Research School of Earth Sciences, College of Physical & Mathematical Sciences

B.Sc. (Hon.), National University of Singapore, Aug 2005–Jun 2009
Department of Physics, Faculty of Science



2021. "Improving Cross-track Scanning Radiometers’ Precipitation Retrieval over Ocean by Morphing." Journal of Hydrometeorology 22 (9): 2393-2406 [10.1175/jhm-d-21-0038.1] [Journal Article/Letter]

2021. "How well do multi-satellite products capture the space-time dynamics of precipitation? Part I: five products assessed via a wavenumber-frequency decomposition." Journal of Hydrometeorology [10.1175/jhm-d-21-0075.1] [Journal Article/Letter]

2021. "Comparisons of IMERG Version 06 Precipitation At and Between Passive Microwave Overpasses in the Tropics." Journal of Hydrometeorology 22 (8): 2117-2130 [10.1175/jhm-d-20-0226.1] [Journal Article/Letter]

2021. "SHARPEN: A Scheme to Restore the Distribution of Averaged Precipitation Fields." Journal of Hydrometeorology 22 (8): 2105-2116 [10.1175/jhm-d-20-0225.1] [Journal Article/Letter]

2021. "Comparison of Monthly IMERG Precipitation Estimates with PACRAIN Atoll Observations." Journal of Hydrometeorology 22 (7): 1745-1753 [10.1175/jhm-d-20-0202.1] [Journal Article/Letter]

2021. "Cloud-Precipitation Hybrid Regimes and their Projection onto IMERG Precipitation Data." Journal of Applied Meteorology and Climatology 60 (6): 733-748 [10.1175/jamc-d-20-0253.1] [Journal Article/Letter]

2021. "Classifying planetary cloudiness with an updated set of MODIS Cloud Regimes." Journal of Applied Meteorology and Climatology [10.1175/jamc-d-20-0247.1] [Journal Article/Letter]

2020. "PPDIST, global 0.1° daily and 3-hourly precipitation probability distribution climatologies for 1979–2018." Scientific Data 7 (1): 302 [10.1038/s41597-020-00631-x] [Journal Article/Letter]

2020. "Integrated Multi-satellite Retrievals for the Global Precipitation Measurement (GPM) Mission (IMERG)." Satellite Precipitation Measurement 343-353 [10.1007/978-3-030-24568-9_19] [Article in Book]

2020. "Evaluation of V05 Precipitation Estimates from GPM Constellation Radiometers Using KuPR as the Reference." Journal of Hydrometeorology 21 (4): 705-728 [10.1175/jhm-d-19-0144.1] [Journal Article/Letter]

2020. "Large‐Scale Characteristics of Tropical Convective Systems Through the Prism of Cloud Regime." Journal of Geophysical Research: Atmospheres 125 (6): [10.1029/2019jd031157] [Journal Article/Letter]

2019. "IMERG V06: Changes to the Morphing Algorithm." Journal of Atmospheric and Oceanic Technology 36 (12): 2471-2482 [10.1175/jtech-d-19-0114.1] [Journal Article/Letter]

2019. "Diurnal Cycle of IMERG V06 Precipitation." Geophysical Research Letters 46 (22): 13584-13592 [10.1029/2019gl085395] [Journal Article/Letter]

2019. "Subgrid Precipitation Properties of Mesoscale Atmospheric Systems Represented by MODIS Cloud Regimes." Journal of Climate 32 (6): 1797-1812 [10.1175/jcli-d-18-0570.1] [Journal Article/Letter]

2018. "Evaluating TMPA Rainfall over the Sparsely Gauged East African Rift." Journal of Hydrometeorology 19 (9): 1507-1528 [10.1175/jhm-d-18-0103.1] [Journal Article/Letter]

2018. "Evaluating rainfall errors in global climate models through cloud regimes." Climate Dynamics 50 3301–3314 [10.1007/s00382-017-3806-7] [Journal Article/Letter]

2018. "Contrasting the Co-variability of Daytime Cloud and Precipitation over Tropical Land and Ocean." Atmospheric Chemistry and Physics 1-31 [] [Journal Article/Letter]

2018. "Evaluation of Global Precipitation Measurement Rainfall Estimates against Three Dense Gauge Networks." Journal of Hydrometeorology 19 (3): 517-532 [10.1175/jhm-d-17-0174.1] [Journal Article/Letter]

2017. "Evaluation of GPM IMERG Early, Late, and Final rainfall estimates using WegenerNet gauge data in southeastern Austria." Hydrology and Earth System Sciences 21 (12): 6559-6572 [10.5194/hess-21-6559-2017] [Journal Article/Letter]

2017. "Evaluation of GPM IMERG Early, Late, and Final rainfall estimates with WegenerNet gauge data in southeast Austria." Hydrology and Earth System Sciences Discussions 1-21 [10.5194/hess-2017-256] [Journal Article/Letter]

2017. "Validation of the Version 05 Level 2 precipitation products from the GPM Core Observatory and constellation satellite sensors." Quarterly Journal of the Royal Meteorological Society 144 (S1): 313-328 [10.1002/qj.3175] [Journal Article/Letter]

2017. "Performance of IMERG as a Function of Spatiotemporal Scale." Journal of Hydrometeorology 18 (2): 307-319 [10.1175/jhm-d-16-0174.1] [Journal Article/Letter]

2016. "A Novel Approach to Identify Sources of Errors in IMERG for GPM Ground Validation." Journal of Hydrometeorology 17 (9): 2477–2491 [10.1175/jhm-d-16-0079.1] [Journal Article/Letter]

2015. "Increases in tropical rainfall driven by changes in frequency of organized deep convection." Nature 519 451-454 [10.1038/nature14339] [Journal Article/Letter]

2015. "The Consequences of a Local Approach in Statistical Models of Convection on its Large-Scale Coherence." Journal of Geophysical Research: Atmosphere 120 (3): 931-944 [10.1002/2014JD022680] [Journal Article/Letter]

2013. "On the Identification of the Large-Scale Properties of Tropical Convection Using Cloud Regimes ." J. Clim. 26 (17): 6618-6632 [10.1175/JCLI-D-12-00624.1] [Journal Article/Letter]

2013. "A three-hourly dataset of the state of tropical convection based on cloud regimes." Geophys. Res. Lett. 40 (7): 1415–1419 [10.1002/grl.50294] [Journal Article/Letter]


  • Outstanding Performance – Science, NASA GSFC 610AT, 16 Oct 2020
  • Editor's Award, AMS (Journal of Hydrometeorology), 23 Jul 2020
  • 2019 Robert H. Goddard Honor Award for Science Teams, NASA GSFC, 23 Jun 2020
  • Best First-Authored Paper, NASA GSFC Climate and Radiation Laboratory, 21 Jan 2020
  • PMM Science Team Award, NASA Precipitation Measurement Missions, 08 Oct 2018
  • Scientific Leadership Award, NASA GSFC Climate and Radiation Laboratory, 19 Jan 2018

Professional Societies

American Geophysical Union

Regular member

2015 - Present

American Meteorological Society

Regular member

2016 - Present

Australian Meteorological and Oceanographic Society

Student member

2012 - 2014

Professional Service

  • Editor, American Meteorological Society Journal of Hydrometeorology, 1 Feb 2024 – present
  • Associate Editor, American Meteorological Society Journal of Hydrometeorology, 5 Oct 2020 – 31 Jan 2024
  • Chair, AGU Fall Meeting 2020, H200. Space-Based Precipitation Observations and Estimation: Innovations for Science and Applications IV Posters
  • OSPA Judge, AGU Fall Meeting 2015, 2016, 2018, 2020
  • Member, AGU Precipitation Technical Committee