Two Decades of Precipitation

NASA has released its newest and most comprehensive estimate of rain and snow covering nearly 20 years. Version 6 of NASA's IMERG -- short for the Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (GPM) -- combines information from a constellation of satellties that are operating in Earth's orbit, at a given time, to estimate precipitation over the majority of the Earth's surface.

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Data Visualizations

  • IMERG Daily Climatology
    2019.10.15
    The daily climatology dataset covers January 2001 to December 2018, computed as a trailing 30-day average to reduce the random noise due to isolated big events. Notable features include the annual cycle of the InterTropical Convergence Zone (ITCZ) following the motion of the Sun (with a time lag) over both land and ocean, the seasonal shift of the Asian Monsoon between South Asia in the boreal summer and Australia in the boreal winter, the North American Monsoon in the late boreal summer in northern Mexico and southwestern U.S., and the dry summer/wet winter pattern in the Mediterranean Sea area and the west coast of the U.S.
  • Grand Average Climatology
    2019.10.16
    The Grand Average Climatology dataset covers June 2000 to May 2019. It shows the well-known structure of global precipitation: Intertropical Convergence Zone (ITCZ) near the Equator, South Pacific Convergence Zone (SPCZ) and smaller South Atlantic Convergence Zone (SACZ), relatively dry subtropical highs, and mid-latitude storm tracks. The relatively fine spatial resolution (0.1° lat./lon.) gives a more detailed picture than the previous NASA product (Tropical Rainfall Measuring Mission [TRMM] Multi-satellite Precipitation Analysis [TMPA], 0.25°), and its near-global coverage, better sampling in time, and improved algorithms provide wider coverage and more confidence in the results. The satellite input allows NASA researchers to estimate precipitation over both land and ocean, which networks of surface sensors do not provide. The most reliable estimates are provided over ocean; warm land is second-best, coastal areas are third, and snow/ice-covered regions are least certain.
  • Precipitation Diurnal Cycles
    2019.10.15
    This IMERG visualization depicts the average amount of rainfall every half-hours around the day during the winter months of December-January-February. The average precipitation varies weakly over the course of a day, but the coastal regions generally receive similar amounts of precipitation at any hour, day or night. Winter-time precipitation systems in this region are driven less by the daily cycle of heating from the sun and more by atmospheric rivers coming in from the Pacific. This detailed information on the diurnal cycle of precipitation over the globe can help improve numerical weather and climate models by providing a reliable dataset based on observations.
  • Precipitation Accumulation and Anomalies
    2019.10.16
    This visualization of the precipitation from IMERG, averaged over 90 days, shows how the broad patterns of global precipitation fluctuate during this particular time period. Unlike the climatology, the vigorous, relatively small-scale precipitation systems create a very "lumpy", continually evolving pattern. Most notably here, the 2015-2016 El Niño is one of the strongest on record. The changes in the atmospheric circulation shift the rainfall that typically falls in the western Pacific—over Southeast Asia and northern Australia—to the central or eastern Pacific.

    The anomalies show the deviation from the normal seasonal cycle of precipitation. These maps help interpret the accumulation maps by isolating attention on the changes. Most notably here, the 2015-2016 El Niño is one of the strongest on record. The changes in the atmospheric circulation shift the rainfall that typically falls in the western Pacific—over Southeast Asia and northern Australia—to the central or eastern Pacific. As well, there are dry conditions across the Caribbean, tropical Atlantic, and northern South America. This display reduces the welter of "ordinary" precipitation and focuses attention on the systematic changes that are persistent, but not necessarily large enough to be readily noticed in the accumulations.

Edited Features

  • NASA Remasters Nearly 20 Years of Global Rain
    2019.10.16
    NASA has just released its newest and most comprehensive estimate of rain and snow covering nearly 20 years. Version 6 of NASA's IMERG -- the Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (GPM) -- combines information from a constellation of satellties are operating in Earth orbit, at a given time, to estimate precipitation over the majority of the Earth's surface. This algorithm is particularly valuable over the majority of the Earth's surface that lacks precipitation-measuring instruments on the ground. What is new in Version 6 IMERG is that the algorithm can now fuse the early precipititation estimates collected in 2000-2014 during the operation of the TRMM satellite with more recent precipitation estimates collected during operation of the GPM satellite. The longer the record, the more valuable it is, as researchers and application developers will attest. TRMM and GPM are two satellites specially designed to provide the most reliable space-based estimates of preciptiation, and both satellites are joint missions between NASA and the Japan Aerospace Exploration Agency (JAXA).
  • NASA’s New View of the Daily Cycle of Rain
    2019.10.17
    The most detailed view of our daily weather has been created using NASA's newest extended precipitation record known as the Integrated Multi-satellitE Retrievals for GPM, or IMERG analysis. The IMERG analysis combines almost 20 years of rain and snow data from the Tropical Rainfall Measuring Mission (TRMM) and the joint NASA-JAXA Global Precipitation Measurement mission (GPM). The daily cycle of weather, also known as the diurnal cycle, shapes how and when our weather develops and is fundamental to regulating our climate.

The Global Precipitation Measurement Mission

  • Near Real-Time Global Precipitation from the Global Precipitation Measurement Constellation
    2015.03.31
    The Global Precipitation Measurement (GPM) mission produces NASA's most comprehensive global rain and snowfall product to date, called the Integrated Multi-satellite Retrievals for GPM (IMERG). It is computed using data from the GPM constellation of satellites — a network of international satellites that currently includes the GPM Core Observatory, GCOM-W1, NOAA-18, NOAA-19, DMSP F-16, DMSP F-17, DMSP F-18, Metop-A, and Metop-B. The global IMERG dataset provides precipitation rates for the entire world every 30 minutes. Although the process to create the combined dataset is intensive, the GPM team creates a preliminary, near-real-time dataset of precipitation within several hours of data acquisition. This visualization shows the most currently available precipitation data from IMERG, depicting how rain and snowstorms move around the planet. As scientists work to understand all the elements of Earth's climate and weather systems, and how they could change in the future, GPM provides a major step forward in providing comprehensive and consistent measurements of precipitation for scientists and a wide variety of user communities.
  • Painting the World with Water (New Colorbar)
    2015.10.01
    The ten currently-flying satellites in the Global Precipitation Measurement Constellation provide unprecedented information about the rain and snow across the entire Earth. This visualization shows the constellation in action, taking precipitation measurements underneath the satellite orbits. As time progresses and the Earth's surface is covered with measurements, the structure of the Earth's preciptation becomes clearer, from the constant rainfall patterns along the Equator to the storm fronts in the mid-latitudes. The dynamic nature of the precipitation is revealed as time speeds up and the satellite data swaths merge into a continuous visualization of changing rain and snowfall. Finally, the video fades into an visualization of IMERG, the newly available data set of global precipitation every thirty minutes that is derived from this satellite data. This is a newer version of the animation and uses a modified version of the Liquid Precipitation Rate colorbar. This newer colorbar improves the display of higher rain rates.
  • GPM Core Spacecraft Beauty Passes
    2013.10.31
    A variety of animated beauty passes of the Global Precipitation Measurement (GPM) Core spacecraft.
  • Science On a Sphere: A Global Tour of Precipitation from NASA
    2016.05.16
    Precipitation (falling rain and snow) is our fresh water reservoir in the sky and is fundamental to life on Earth. A Global Tour of Precipitation from NASA shows how rain and snowfall moves around the world from the vantage of space using measurements from the Global Precipitation Measurement Core Observatory, or GPM. This is a joint mission between NASA and the Japanese Aerospace Exploration Agency (JAXA) and offers the most detailed and worldwide view of rain and snowfall ever created.

    This narrated movie is created for Science On a Sphere, a platform designed by NOAA that displays movies on a spherical screen. Audiences can view the movie from any side of the sphere and can see any part of Earth. During this show viewers will be guided through a variety of precipitation patterns and display features such as the persistent band of the heaviest rainfall around the equator and tight swirls of tropical storms in the Northern Hemisphere. At subtropical latitudes in both hemispheres there are persistent dry areas and this is where most of the major deserts reside. Sea surface temperature and winds are also shown to highlight the interconnectedness of the Earth system. The movie concludes with near real-time global precipitation data from GPM, which is provided to Science On a Sphere roughly six hours after the observation. To download this movie formatted for a spherical screen, visit NOAA's official Science On a Sphere website below: ‌• A Global Tour of Precipitation from NASA ‌• Near Real-Time Global Precipitation Data

NASA Earth Science

  • Earth Observing Fleet (October 2018)
    2018.12.09
    This animation shows the orbits of NASA's fleet of Earth observing spacecraft that are considered operational as of October 2018. New elements in this version include the ICESat-2 and Cloudsat/CALIPSO in new orbits. The clouds used in this version are from a high resolution GEOS model run at 10 minute time steps interpolated down to the per-frame level.
    Spacecraft included: Aqua Aura CALIPSO: Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation CYGNSS-1: Cyclone Global Navigation Satellite System 1 CYGNSS-2: Cyclone Global Navigation Satellite System 2 CYGNSS-3: Cyclone Global Navigation Satellite System 3 CYGNSS-4: Cyclone Global Navigation Satellite System 4 CYNGSS-5: Cyclone Global Navigation Satellite System 5 CYGNSS-6: Cyclone Global Navigation Satellite System 6 CYGNSS-7: Cyclone Global Navigation Satellite System 7 CYGNSS-8: Cyclone Global Navigation Satellite System 8 Cloudsat DSCOVR: Deep Space Climate Observatory GPM: Global Precipitation Measurement GRACE-FO-1: Gravity Recovery and Climate Experiment Follow On-1 GRACE-FO-2: Gravity Recovery and Climate Experiment Follow On-2 ICESat-2 ISS: International Space Station Jason 2 Jason 3 Landsat 7 Landsat 8 OCO-2: Orbiting Carbon Observatory-2 SMAP: Soil Moisture Passive Active SORCE: Solar Radiation and Climate Experiment Suomi NPP: Suomi National Polar-orbiting Partnership Terra