The GPM Core Observatory is continuing with the environmental test program at NASA Goddard Space Flight Center. Following the completion of thermal vacuum testing in January 2013, the Core Observatory team started the Electromagnetic Interference (EMI) and Electromagnetic Compatibility (EMC) test phase. The Core Observatory has successfully completed the Radio Frequency (RF) Self-Compatibility test and is being prepared for the next step of EMI/EMC test program. The EMI/EMC test program is expected to be completed in April 2013.
The NASA Precipitation Measurement Missions (PMM) Science Team for the TRMM and GPM missions met on March 18-21, 2013 in Annapolis, MD. This meeting included oral, poster, and evening working group sessions covering mission/program status, algorithm development activities, international partner reports, science activities, field campaign results, and other science team business. More than 175 scientists from 11 countries participated. The TRMM satellite is now in its 16th year of on-orbit operation and the GPM Core Observatory is scheduled to launch in early 2014.
The GCPEx observing strategy framework is designed to use a combination of multi-frequency radar, particle imaging and water equivalent-measuring surface instrumentation in conjunction with airborne dual-frequency radar, high frequency radiometer and in situ microphysics observations arranged in stacked altitude patterns to provide the most complete coupled sampling of surface and in-cloud microphysical properties possible.
The primary objectives of GCPEx are to obtain coordinated high quality in situ and remote sensing observations of falling snow events in a northern latitude climate. Such systems are prevalent in the Ontario region in the December- February timeframe where monthly mean snowfall amounts are approximately 40, 30 and 25 cm/month for December, January and February, respectively. Furthermore, the primary choice for DC-8 operations (Bangor, Maine) will allow potential sampling of Nor’Eastern Blizzards and heavy snow events over St.
To augment the observations and provide additional test cases for synthetic algorithm development and satellite simulator testing, a number of modeling activities are also planned. Cloud resolving model simulate frozen precipitation events using the GSFC-Weather Research and Forecasting (WRF) will be performed, initialized and forced by appropriate NWP forecast models. The GSFC WRF has single-moment Goddard Microphysics and spectral-bin microphysics. All of the microphysical schemes have their own set of unique capabilities and assumptions, and all will be tested by the GPM groups.
Frozen precipitation is particularly difficult to measure from space due to the wide variability in snowflake shapes and behavior. Snowflakes can have different impacts on the active and passive instruments signals compared to liquid precipitation, which is further complicated by a weak signal to noise ratio resulting from different scattering properties of liquid verses frozen precipitation.
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.