Jun 2 2010
Researchers at the Huntsville-based University of Alabama have showcased a new technique to utilize satellite instruments to provide dependable surface temperatures at the Fourth International Climate Change Conference that was held recently in Chicago.
University of Alabama¡¦s scientists Dr. Danny Braswell and Dr. Roy Spencer at the Earth System Science Center had developed this technique that utilizes microwave sensors installed on board the NASA and NOAA satellites for gathering surface temperature data across almost all the land regions on the Earth. These scientists expect that this system will be able to offer a stable process to monitor change in climate without the associated problems posed by present surface thermometers network. Spencer was among the keynote speakers during the Chicago conference.
For years satellite installed sensors are being utilized for gathering temperature data from the atmosphere¡¦s deep layers and oceans. However, there have been problems while deducing such data, resulting in their non-usage for gathering surface temperature data across the land mass.
According to Spencer, variation in the land background renders it difficult to model the temperature measurement technique. Due to differences in their microwave emissions, a forest at 70„aF and a sandy desert at 70„aF sandy desert do note appear similar for satellite instruments due to their respective microwave emission differences, rendering it difficult for interpreting the instruments¡¦ viewing, thereby preventing researchers from measuring land temperatures.
To solve this problem Braswell and Spencer and Braswell divided the land surface of the Earth into 10 categories of basic microwave surfaces, ranging from arid desert to swampy wetland. Knowledge of the mix of land categories in every region scanned by satellite sensor helps in the estimation of the temperature of a particular region more accurately.
Coverage is among the greatest benefits of satellite-based temperature monitoring. These satellite sensors gather temperature data across more than 95% land area of the Earth. Realistic surface temperature data is unavailable at present across most of the Earth¡¦s surface including parts of Northern Canada, Siberia, Russia, South America and Australia and most of the Antarctic and Africa. Relative brevity is among the largest drawbacks of the satellite-enabled dataset. The best satellite-based microwave sensor data utilized by Braswell and Spencer dates back to 2002, though earlier sensors might permit temperature data to be gathered back to 1987.
Source: http://www.uah.edu