Middle Atmosphere Dynamics by Sub-Millimeter Radiometry

Oberlin College, Oberlin OH

Investigators

Abstract

This proposal requests funding for the analysis and distribution of middle atmospheric data taken using the Antarctic Sub-millimeter Telescope / Remote Observatory (AST/RO), a separately funded NSF OPP project. AST/RO is a 1.7 m diameter, offset Gregorian telescope located at Amundsen-Scott South Pole Station capable of observing at wavelengths between 200 microns and 1.3 mm. The mesosphere lies at the boundary between the denser stratosphere and the tenuous thermosphere, over 60 km above the Earth's surface. The mesosphere lies at the bottom of the region in which the particles from the Sun deposit much of their energy, while also being at the top end of planetary-scale atmospheric gravity waves and tides. In this key position, the mesosphere plays an important part in our planet's overall atmospheric balance. The project's objectives are the following: (1) measure wind velocities in the polar mesosphere year-round, (2) measure carbon monoxide mixing ratios and density in the polar mesosphere and lower thermosphere, (3) combine data with other projects to develop a more complete understanding of polar atmospheric dynamics, (4) create an automatic data pipeline to allow results to be placed on the web within 24 hours of observations, (5) provide an opportunity for involvement by undergraduates in active and approachable science research, and (7) develop Web based activities using near real time data to explain to the general public the properties of the polar atmosphere. While it might be possible to construct a small instrument in Antarctica to measure the properties of the mesosphere discussed in this proposal, significant cost savings are possible by taking advantage of resources already available on the continent. While AST/RO has primarily focused on observations of astrophysical phenomena, the instrumentation is also well suited to making observations of the Earth's atmosphere. In much the same way that carbon monoxide (CO) is currently used as a tracer for astrophysical processes, CO can also be used as a tracer for transport processes in the upper atmosphere. By measuring the emission from rotational transitions of CO, the AST/RO data can be used to determine the mesospheric wind velocity and CO mixing profile of the atmosphere in the region 40 km to 130 km above the Earth's surface. This data can then be used to study the dynamics of the polar mesosphere, especially when combined with data from other research projects in Antarctica and in space.