HAO Colloquium - Marty Mlynczak, NASA

Frontiers in satellite observation of the mesosphere and thermosphere

Satellite observations of the terrestrial mesosphere and thermosphere have experienced a “golden age” over the past 25 years. Beginning with the Upper Atmosphere Research Satellite in the early 1990’s and continuing today with the long-running TIMED satellite and the newly-launched GOLD instrument, complemented in-between by numerous international instruments and missions, the mesosphere and thermosphere are the “ignorosphere” no longer. Looking forward to the next 25 years, there are still several frontiers in this region to be explored and discovered. Two frontiers in particular stand out. The first is to close the “thermosphere gap” in terms of a comprehensive, focused global measurement of kinetic temperatures, vector winds, energy input, and energy output of the atmosphere from 110 km to 200 km altitude. New technology in detection of terahertz frequency radiation offers the potential for exploring this frontier with relatively small, lower power instrumentation. A second, related frontier, is the detection and attribution of trends in temperature and density in the mesosphere and thermosphere. These trends are being driven by the continued buildup on carbon dioxide throughout the entire atmosphere. Ultimately, trends in carbon will drive a substantial cooling of the thermosphere, substantially lowering density at satellite altitude, and increasing lifetime of all orbiting objects including orbital debris. These effects will have a substantial impact on international space policy for the balance of the 21st century regarding the very habitability of some regions of low earth orbit. In this talk we will discuss the new technology for observing the mesosphere and thermosphere as well as the factors that must be considered in accurately detecting long-term trends from satellite observations. A further challenge facing the community is to balance the needs for long-term measurements for trend detection with the many process-oriented missions typically recommended in Decadal Surveys and similar community-developed roadmaps.

Date and time: 
Wednesday, September 19, 2018 - 2:00pm to 3:00pm
2139 - Capt. Mary