Short-term Prediction Research
and Transition Center

Remote Sensing Techniques

AMSR-E Techniques

The Advanced Microwave Scanning Radiometer for EOS (AMSR-E) is a passive microwave radiometer on the Aqua polar orbiting satellite. It measures radiation reaching the instrument at six frequencies (6.925 - 89.0 GHz) which are ideal for studying many atmospheric and surface phenomena. Unlike passive infrared measurements, radiation at some of these microwave frequencies are not significantly affected by clouds, allowing a more contiguous observation of the ocean surface or precipitation within the clouds.

Currently five products (rain rate, convective percent, water vapor, wind speed, and sea surface temperature) derived from the AMSR-E satellite data are being sent in near real-time to several NWS forecast offices (Miami, Huntsville, and Mobile) for evaluation and use. The products are ingested into AWIPS at the Huntsville, Mobile, and Miami weather offices and used by the forecasters for diagnostic analysis and forecast preparation. These products are especially useful over regions void of more conventional land- and satellite-based observations. Forecasters regularly comment about the value of monitoring offshore weather systems beyond land-based radar coverage.

Operational:

AE_Rain
Rain Rate and Convective Percent

Operationally we use the official AMSR-E rain products which are rain rate and convective percent (Adler, et al.) Rain rate is an instantaneous estimate valid from 0 – 50 mm/hr. Convective percent ranges from 0 (completely stratiform) to 100 (completely convective). Both products have an approximate 5 km surface resolution.

AE_Ocean
Sea Surface Temperature, Wind Speed, and Water Vapor

Operationally we use 3 of the official AMSR-E ocean products which are sea surface temperature, wind speed, and water vapor (Wentz and Meissner). Sea surface temperature is an estimate valid from -3 – 34.5 C and is available at 38 and 56 km resolutions. Wind speed is an estimate valid from 0 – 50 m/s and is available at 21 and 38 km resolutions. Water vapor is an estimate valid from 0 – 75 mm and is available at 21 km resolution.

Research:

AE_Land

There are three official AMSR-E land products (Njoku, et al.) We are investigating the soil moisture and vegetation water products. The third product, land surface temperature, is currently not produced by the AMSR-E science team due to RFI at the 6.9 GHz frequency. Soil moisture is an estimate for the top 0 – 1 cm of soil and is valid from 0 – 0.5 g/cm3 and is available on an EASE-grid at 25 km resolution. Vegetation water is an estimate for the amount of water in the canopy (surface to top) and is valid from 0 – 1000 kg/m2 and is available on an EASE-grid at 25 km resolution.

Other:

AE_Ocean
Cloud Water

The official AMSR-E ocean product, cloud water (Wentz and Meissner), is available and may be used in the future. Cloud water is a integrated value through the atmospheric column and is an estimate valid from 0 – 2.5 mm and is available at 12 km resolution