Articles

Falling snow is critically important for society in terms of freshwater resources, atmospheric water and energy cycles, and ecosystems. However, there are few archives of falling snow around the world that can be used to improve measurements from satellites. GCPEx will make detailed in situ observations of cloud and frozen precipitation microphysics to improve these databases. Falling snow represents a primary contribution to regional atmospheric and terrestrial water budgets, particularly at high latitudes. While often overlooked, precipitation falling in the form of snow is critically...

NASA technicians spun the GPM satellite up to just over 10 RPM in Goddard Space Flight Center’s High-Capacity Centrifuge facility March 31 2011. Put Some Spin On It If you've ever taken a fast curve in a car, you've felt your body pushed outward, away from the curve. That outward push is centrifugal force, and the faster you turn, the more it pushes you away from the center. Spinning on the centrifuge does the same thing to the satellite -- except the centrifugal forces are a lot bigger -- capable of going up to 30 times the force of gravity, or "g's." GPM's test went up to seven g's. But...

In the clean room at NASA Goddard Space Flight Center in Greenbelt Md., the Global Precipitation Measurement (GPM) mission's Core satellite is steadily taking shape. Set to measure rainfall worldwide after launch in 2014, GPM's two solar panels are the latest components currently undergoing rigorous testing before being integrated with the spacecraft, a process that began seven months ago when the main structural elements went on an unusual ride. GPM moves from the clean room to the test chamber on a dolly without wheels. Compressed air is pumped out under airpads that float the Spacecraft on...

UPDATE: Monday, August 29th, 2011 Irene Drenches Northeastern United States UPDATE: Friday, August 26th, 2011 Irene Passes Through the Bahamas, Heads Towards Cape Hatterus Wednesday, August 24th, 2011 After becoming a small hurricane while passing over Puerto Rico, Irene re-emerged over the warm, open waters of the western Atlantic northwest of the Dominican Republic on the morning of August 22nd. The storm quickly showed signs of intensifying as deep convective towers arose near the center of Irene, releasing heat into the core of the system. In response, Irene's central pressure fell and...

A key component of the TRMM project is the Ground Validation (GV) effort which consists of collecting data from ground-based radar, rain gauges and disdrometers. The data is quality-controlled, and then validation products are produced for comparison with TRMM satellite products. The four primary GV sites are Darwin, Australia; Houston, Texas; Kwajalein, Republic of the Marshall Islands; and, Melbourne, Florida. A significant effort is also being supported at NASA Wallops Flight Facility (WFF) and vicinity to provide high quality, long-term measurements of rain rates (via a network of rain...