2022 PMM Science Team Meeting Group Photo

PMM Science Team


The NASA Precipitation Measurement Missions (PMM) Science Team conducts scientific research (including algorithm development, mission implementation, product validation, and data utilization) in support of TRMM and GPM Missions. The team comprises scientists funded by NASA and international investigators selected by NASA on the basis of no exchange of funds.


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PMM Science Program Management Team

Name Organization Title
Dr. Will McCarty NASA Headquarters GPM Program Scientist
Dr. George Huffman NASA Goddard Space Flight Center GPM Project Scientist and PMM Science Team Lead
Dr. Erich F. Stocker NASA Goddard Space Flight Center GPM Deputy Project Scientist for Data and Precipitation Processing System Project Manager
Dr. Walter A. Petersen NASA Marshall Space Flight Center Deputy Project Scientist, Ground Validation
David B. Wolff NASA Wallops Flight Facility GPM Ground Validation System Manager
Andrea Portier NASA Goddard Space Flight Center GPM Senior Applications Lead

PMM Principal Investigators and Proposal Titles (2021 - 2022)


In-person attendees of the 2022 PMM Science Team Meeting. Credits: NASA

Last name First Name Affiliation Proposal Title




Quasi-Physical Representation of the Microphysics, Dynamics, and Single Scattering Properties of Falling Snow



Atmospheric & Environmental Research, Inc.

Use of GPM to Understand Production of Hail in Organized Multicellular Systems in Subtropical South America



North Carolina State University

Maintenance of Long-Lived Easterly Waves and Their Transformation to Tropical Cyclones: The Role of Precipitating Moist Convection and Scale Interactions



Marshall Space Flight Center

A Multi-Perspective Analysis of Hail Processes, Melting, and Their Environments



University of Arizona

Snowfall Analysis in High Latitudes to Advance NASA IMERG



Northeastern University

A Precipitation-Based Risk Index for Well Water Contamination



Jet Propulsion Laboratory

Using GPM to Resolve Plant Water Supply in Wet Tropical Soils



Georgia Tech Research Corporation

Using Satellite-Based Precipitation Estimates to Obtain the Conditional Probability Distribution of Soil Moisture


Chandra V.

Colorado State University

GPM Global Observations and Precipitation Microphysics: Algorithm Support, Enhancement, Cross Validation, and Adding the Third Dimension to the Classification Module



University of Maryland, College Park

Use of Satellite Observations and Global Cloud-Resolving Model Simulations to Study Precipitation Characteristics and Microphysical Processes



Pennsylvania State University

Understanding the Dynamics and Predictability of Tropical Cyclones Using PMM Microwave Observations



University of Minnesota

Extending Forecast Skills of Global Precipitation: A Deep Learning Framework for IMERG Data Assimilation over the Wasserstein Space



Columbia University

Constraining Drivers of Tropical Precipitating Cloud Shield Areas Across Scales to Inform Climate Model Development



University of California, Irvine

Enhancing the Representation of Precipitation Space-Time Dynamics in Satellite Products: Validation, Error Modeling and Improvement of Retrieval Algorithms



Atmospheric & Environmental Research, Inc.

Combining Satellite Observations of Rainfall, Numerical Weather Prediction, and Historical Satellite Flood Mapping to Forecast Flood Disasters for Humanitarian Mission Support



Morgan State University

Clustering-Based Quantification and Mitigation of Uncertainties in the GPM Combined Algorithm



Goddard Space Flight Center

Addressing Global Blind Zone Precipitation Estimate Errors from Space Using Observations and Modeling



Jet Propulsion Laboratory

Understanding and Predicting Tropical Cyclone Rapid Intensity Changes Using Passive Microwave Observations from GPM and TRMM



University of California, Davis

Assessing the Tropical Two-Layer Moisture-Precipitation Paradigm



University of Maryland, College Park

A Framework for Precipitation Retrievals from the Evolving GPM Constellation



Colorado State University

GPROF and Regime Dependent Uncertainties



Marshall Space Flight Center

Investigating Cloud-to-Precipitation Transitions with Airborne Passive Microwave Observations



Texas A&M University - Corpus Christi

Upgrade Precipitation Feature Databases and Assess Uncertainties in PMM Products



University of Wyoming

Constraints on Extratropical Cloud Feedback Through Analysis of Cyclone Precipitation Structure



University of Maryland, College Park

Snowfall Type Classification for Improving Passive Microwave Falling Snow Estimation/Retrieval



Florida State University

The Monitoring and the Predictability of Regional Tropical Rainy Seasons Using GPM Products



University of Wisconsin, Madison

High-Latitude Precipitation Characteristics During Atmospheric River Events Utilizing GPM and Ground-Based Observations



University of Wisconsin, Madison

A 70-Year Climatology of Ocean Precipitation from Shipboard Present-Weather Observations Calibrated Using GPM



Jet Propulsion Laboratory

A Study of the Influence of Convection on Atmospheric River Genesis, Evolution, and Precipitation Production



Colorado State University

The Nature of Global Convection from GPM: Extratropical Cyclones to Tropical Convection



Texas A&M, College Station

Gravity Wave Impacts on Convection Near Complex Terrain (ROSES21)



Goddard Space Flight Center

Characterizing Extreme Storms to Better Inform Hydrometeorological Hazard Assessment



Jet Propulsion Laboratory

Investigating the Double-ITCZ Bias in CMIP6 Models



Jet Propulsion Laboratory

Enhancements to Passive MW Algorithm Coverage and Representation of Vertical Precipitation Structure, Towards Future Improvements to Level-3 Precipitation Products



University of Colorado, Boulder

Characterizing Precipitation Vertical Structure in the Satellite Radar Near-Surface Blind Zone



University of Wisconsin, Madison

Global Multiscale Uncertainty Estimation for Satellite Precipitation Products to Improve Hydrologic Prediction

PMM Principal Investigators funded under NASA Internal Work Packages

GPM Algorithm Work Packages (Jan 2018 Summary)

NASA Headquarters has authorized a new funding strategy called "Work Packages" whereby key Principal Investigators at NASA centers who are repeatedly funded under ROSES calls are preselected outside of the ROSES call. This is a listing of the approved Work Package Principal Investigators and their topics for the 10th PMM ROSES Science Team (nominally 2018-2020).

Principal Investigator Title Task Summary
Cecil, Daniel Better Understanding GPM Radiometer Measurements Using Ground-Based Radar GPM, TRMM and related satellites have observed a huge number of precipitating systems around the globe. Pairing high-quality ground-based radar data with coincident satellite observations helps us learn to better interpret the satellite data, and to apply that understanding to satellite observations from otherwise data-sparse regions. This work aims to (a) improve understanding of how different hydrometeor types (and their vertical profiles and amounts) relate to observed satellite measurements; (b) investigate precipitation retrieval quality (error characteristics and biases) associated with particular hydrometeor types or profiles; (c) investigate characteristics of precipitation systems (and their related weather and climate patterns) around the globe.

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Huffman, George Extending the IMERG Multi-Sensor Level 3 Precipitation Product into Polar Regions

Comprehensive science algorithm development, implementation, maintenance, and validation, including user support, for quasi-global combined-satellite precipitation estimates at fine time/space scales, both in near-real and post-real time. This work includes extending the Integrated Multi-satellitE Retrievals for GPM (IMERG) to polar regions.

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Meneghini, Robert Path Attenuation Estimates from the Dual-Frequency Precipitation Radar

Development, scientific enhancement and validation of the Dual-Frequency Precipitation Radar (DPR) Surface Reference Technique (SRT) will be pursued by extending the dual-frequency version of the method (DSRT) to the new proposed scan geometry.  In addition, hybrid path attenuation estimates will be formulated by merging the SRT with the the Hitschfeld-Bordan (HB) method of attenuation correction, which performs well at light rain rates. Tests of the performance of the hybrid estimates will be done by adding new code and new output variables to existing operational codes.

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Munchak, Stephen   Improved Representation of Active and Passive Surface Characteristics in the GPM DPR-GMI Combined Precipitation Algorithm

Continue to improve representation of surface properties through physical and statistical models that account for correlated properties of emissivity and radar backscatter in the CORRA forward model. Integrate retrievals of surface and atmospheric state (including ocean surface wind, land emissivity, water vapor, clouds, and light precipitation) in regions where DPR does not detect precipitation.

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Olson, William Continued Development and Validation of Ice- and Mixed-Phase Precipitation Models for the GPM Combined Radar-Radiometer Algorithm

The overall effort is aimed at the development, delivery, maintenance, and validation of the Combined Radar-Radiometer Algorithm (CORRA) by improving the physical parameterizations of precipitation in all phases.  The science emphasis will be on the further exploitation of non-spherical ice and mixed-phase precipitation particle models, as well as particle size/habit distribution evolution simulations, to support improved descriptions of the bulk radiative properties of these precipitation types in the algorithm. Precipitation phase transitions in stratiform, convective, and near-convective regimes will be addressed. Validation of particle models will employ airborne remote sensing and in situ data from recent field campaigns, as well as GPM DPR-GMI data and coincident ground observations.

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Petersen, Walter Validation of GPM Precipitation Retrieval Algorithms across the Precipitation Continuum

Existing GPM-GV field and Validation Network datasets collected in warm and cold-season regimes are used to relate 3-D precipitation character and process variability to GPM retrieval algorithm constraints and performance. GV polarimetric radar and disdrometer-derived quantities of precipitation rate/content, type (rain, snow, convective, stratiform), and size distribution are processed and analyzed to relate dominant inter- and intra-footprint scale precipitation process/parameter variability to performance and improvement of key GPM algorithm components including path integrated attenuation, non uniform beam filling, retrieval of the rain drop size distribution, and estimation of rain and snow water-equivalent rates.

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Peters-Lidard, Christa Dynamic Emissivity Estimates to Support Physical Precipitation Retrievals for GPM (continued)

This work will provide dynamic emissivity estimates over land surfaces to support physical precipitation retrievals for GPM. The dynamic emissivity approaches include physical variables such as leaf area index and soil moisture as well as empirical combinations of channel brightness temperatures, including their time variations. These global emissivity estimates are to be integrated and tested within the GMI GPROF algorithm.

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Tao, Wei-Kuo Advancing the Retrieval of Latent Heating for PMM with Improved Simulations of Convective, Synoptic, and Cold Season Systems and their Associated Microphysical and Precipitation Processes

This work includes improving simulations/models for a wide range of precipitating cloud systems, from weak, unorganized isolated rain showers to intense mesoscale convective precipitation systems to large-scale synoptic snow storms, and their associated precipitation structures, latent heat release profiles and cloud microphysical processes.  Data from GPM field campaigns will be used to validate and improve the microphysical processes in the high-resolution numerical models.  Consequently, this work also expands and improves the performance of the Goddard Convective-Stratiform Heating (CSH) algorithm for the TRMM and GPM eras by using the improved model simulated latent heating, radiation and surface rain/snowfall data.

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PMM / GPM International Collaborator Team

Leveraging of GPM international partner research activities and infrastructure enables coordinated global precipitation remote sensing research and ground validation activities to be conducted. Here “global” refers to both geography and precipitation regime- enabling gap-filling observations and complementary research to more completely validate satellite observations around the globe. Within this framework specific collaborations between PMM Science Team investigators, GPM GV, and international partners have been sought. Currently active * collaborations are outlined in the below table.

Country Investigators Focus
Argentina P. Salio Ground validation of in a sub-tropical convective precipitation environment
Australia P. May, A. Protat Land/Sea-based direct GV, precipitation process studies and field measurements in the southern hemisphere tropics and mid-latitudes
Austria J. Fuchsberger, G. Kirchenghast, S. O Ground validation and rain variability in the mid-latitudes using the dense WegenerNet network
Belgium S. Lhermitte Snow process studies and measurement, Antarctica
Brazil L. Machado, D. Vila, C. Angelis Ground validation and storm system process studies in the tropics/sub-tropics, field measurements
Canada D. Hudak, P. Joe (WMO) Ground validation, snow process studies and field measurements in the mid and high-latitudes
Colombia G. Poveda Validation of the TRMM and GPM precipitation products using information from raingauges in Colombia
European Union (ECMWF) P. Bauer, A. Geer GPM data for model data assimilation
Finland A.-M. Harri, D. Moisseev, A. von Lerber Ground validation, snow process studies and field measurements, High-Latitudes
France R. Roca, N. Viltard, F. Aires Megha Tropiques Mission, data and algorithms, global land surface emission (Aires)
France G. Delrieu Cooperation in the Hydrological Cycle Mediterranean Experiment
Italy G. Pannegrossi, V. Levizzani (IPWG), L. Baldina, S. Puca, G. Vulpiani HSAF precipitation retrieval algorithms, ground-validation, GV radar calibration/measurement practices, mid-latitude Mediterranean region
Korea G. Ryu, G. Lee, S. Joo Ground validation, precipitation process studies and field measurement (rain, orographic snow), mid-latitudes land/sea.
Korea KD. Ahn, G. Lee and S. Joo  ICE-POP collaboration in study of winter precipitation


H. Leijnse (KNMI), R. Uijlenhoet Validation of Satellite Based Precipitation Estimates in the Netherlands
Portugal Vasco Mantas Ground validation, ecologic applications, dissemination tools.
Spain F. Tapiador Ground Validation, precipitation character and variability, field measurements, mid-latitudes
Switzerland A. Berne Ground validation, precipitation field measurements, Alpine orographic snow processes, mid-latitudes
Turkey K. Yilmaz   Ground Validation of GPM-Era Precipitation Products over Complex Topography of Turkey and the Mediterranean with a focus on Modeling Hydrologic Extremes        
United Kingdom A. Battaglia Active/passive radiative modeling, multiple scattering processes, field measurements, physical ground-validation
United Kingdom J. Crosier GPM Validation in the United Kingdom

* Note: The formal list of collaborators is dynamic, often a function of partner funding status and guided research focus.

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