Featured Articles Archive

  • Observing the Intertropical Convergence Zone with IMERG
    The intertropical convergence zone or “ITCZ” roughly forms a band that circumnavigates the Earth near the Equator where the northeast trade winds in the Northern Hemisphere converge with the southeast trade winds in the Southern Hemisphere.  Sailors have often referred to it as the “doldrums” due to its generally light winds.  Yet, the ITCZ is an important part of the global circulation as it forms the ascending branch of the Hadley circulation.  This is ultimately driven by incoming solar radiation, which peaks near the Equator.  This warms the air and the ocean, causing...
  • 5 Year Anniversary of Hurricane Arthur
    June marks the official start of the Atlantic hurricane season. And although strong tropical cyclones are rare in June in the Atlantic, it will soon be the 5-year anniversary of Hurricane Arthur, which became a tropical depression in very late June 2014 before hitting the Outer Banks of North Carolina as a Category 2 hurricane in early July. As with most storms early in the season, Arthur formed not from a tropical wave moving off the coast of Africa but from an old frontal boundary that stalls off the coast and provides a focus for shower and thunderstorm activity over warm water. With...
  • How TRMM and GPM Study Latent Heating
    Latent heating (LH) arises predominantly from the release of heat associated with the condensation of water vapor into cloud droplets in clouds with active updrafts.  Other sources of LH include ice deposition and freezing, while evaporation, melting and sublimation induce cooling, but condensation is the dominant heating term.  Like a hot-air balloon, LH can keep air parcels warmer than their surrounding environment and therefore rising.  On a large scale, LH is responsible for driving the ascending branch of the Hadley Circulation.  LH is also an important component in...
  • The 2019 Atlantic "hurricane season" is officially upon us and runs through November 30th. Did you know that GPM data play a fundamental role in the ability to monitor existing storm activity such as capturing the location and intensity of rainfall inside a storm, as well as improving weather and precipitation forecasts through assimilation of instantaneous precipitation information? Here are a few applications of GPM data used to study hurricanes and how the data was then used for decision-making.
  • Finding Strong Storms with TRMM & GPM
    Spring is severe storms season here in the US, but not everyone has NEXRAD radar coverage; however, NASA’s TRMM and GPM satellites with their onboard radars have made it possible to search the entire global Tropics and midlatitudes and systematically identify areas where there are strong to intense thunderstorms. Researchers now headed by Dr. Chuntao Liu at Texas A&M University have built a comprehensive database of “precipitation features” based on regions of contiguous radar echoes from first the TRMM and now the GPM satellite. These precipitation features can then be mined to locate...
  • TMPA Shows El Niño Conditions in the Pacific
    An El Niño that began to form last fall has matured and is now fully entrenched across the Pacific. Changes in sea surface temperatures or SSTs brought about by an El Niño affect the atmosphere, resulting in distinctive changes in the rainfall pattern across the Pacific Basin. These changes show up as anomalies or deviations in NASA’s analysis of climatological rainfall. 
  • 5 Years of Global Precipitation Measurement
    Five years ago, on Feb. 27, 2014, the Global Precipitation Measurement (GPM) Core Observatory, a joint satellite project by NASA and the Japan Aerospace Exploration Agency (JAXA), lifted off aboard a Japanese H-IIA rocket. Since then, the cutting-edge instruments on GPM have provided advanced measurements about the rain and snow particles within clouds, Earth’s precipitation patterns, extreme weather and myriad ways precipitation around the world affects society. Among the uses of GPM data are helping to forecast disease outbreaks in developing countries, producing global crop reports and...
  • Top 5 GPM Research Highlights
    GPM celebrates its fifth anniversary since launching from Tanegashima Island, Japan on February 27, 2014. This milestone not only marks the launch but also the many scientific research accomplishments that GPM has made in advancing our understanding of precipitation, from light rain to intense thunderstorms, to further our understanding of the water cycle. Here are five of GPM’s most significant research accomplishments and their contributions to weather and climate science in its first five years in space.