Professor Umran S. Inan

Winter 1997-98

Date: Wednesday, January 28, 1998

Time: 4:15 PM Refreshments at 4:00

Location: Gesb 124 (Green Earth Sciences Bldg.)

Examples of space borne infrared instrumentation for sounding the stratosphere and mesosphere

Dr. Jack Kumer

Lockheed Martin Advanced Research Center


In this presentation we address 2 topics in atmospheric science that benefit from remote sounding data obtained by space borne infrared instrumentation. The first is the, by now somewhat venerable, problem of understanding the morphology of ozone in the stratosphere, and its response to natural and manmade perturbations. The second is the new and exciting problem of verifying predictions (Picard et al, Geophys. res. Lett. 24, pg 2635-2638, 1997) of enhanced mesospheric CO2 4.3 um airglow due to nitrogen vibration excitation as the result of sustained heating of lower ionospheric electrons by thundercloud fields (Inan et al, Geophys. res. Lett. 23, pg 1067-1070, 1996).

On the first topic we'll begin with a review of ozone chemistry, and the critical components of the stratosphere, gases and aerosols, that impact this chemistry. (This sets requirements to measure these components ). We'll review the requirements on infrared remote sounding instrumentation to measure these components. The Cryogenic Limb Array Etalon Spectrometer (CLAES) was a state of the art instrument designed to meet these measurement requirements. It was selected for such measurements in response to the 1978 NASA Announcement of Opportunity (AO) to provide instrumentation for the Upper Atmosphere Research Satellite (UARS), and it performed very successfully during its 19 month mission on UARS. We'll report on some of the highlights of the CLAES measurements. We'll also present for comparison an instrument we are currently developing to provide measurements similar to the CLAES in some respects, and considerably improved in others. This instrument exploits technology advances since 1978 to pursue the current NASA "smaller, cheaper, better" instrumentation goal. For example, the new instrument has a mass of less than 50 kg compared to the CLAES 1200 kg launch mass. It has been accepted as a candidate for space flight validation by the NASA New Millenium Program.

On the second topic we'll define a minimum set of observations required to demonstrate the predictions for enhanced CO2 4.3 um airglow above thundercloud fields. We'll also present strawman suites of instrumentation to verify the effect. We'll consider applications that would use earthlimb viewing geometry, as well as the more difficult, but.perhaps scientifically richer, nadir imaging viewing geometry. Use of low cost technology will be emphasized.

Brief Biography: The speaker has been with the Lockheed Martin Advanced technology Center (LMATC) since 1971, and is presently a Senior Staff Scientist and a Senior Member of the Research Laboratory. He has extensive experience in modeling atmospheric airglow and thermal emission in the XUV through the infrared, and in measuring these. His work in non-LTE 4.3 um CO2 emissions in the mesosphere, as Principal Scientist for the Cryogenic limb Array Etalon Spectrometer (CLAES) deployed on the NASA Upper Atmospheric Research Satellite, and in recent years on instrumentation including initial development of the current NMP flight candidate instrument is the part of his background relevant to todays presentation.