Other
Scientific paper
May 2001
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001agusm..sa31b11o&link_type=abstract
American Geophysical Union, Spring Meeting 2001, abstract #SA31B-11
Other
0340 Middle Atmosphere--Composition And Chemistry, 0341 Middle Atmosphere--, Onstituent Transport And Chemistry (3334), 2439 Ionospheric Irregularities, 3332 Mesospheric Dynamics
Scientific paper
The first observations of infrared emission from polar mesospheric clouds (PMCs) were recorded by the Spatial Infrared Imaging Telescope (SPIRIT) III radiometer on the Midcourse Space Experiment (MSX) satellite during the operational period of the infrared sensor, April 1996 through February 1997. Infrared emissions from PMCs were observed in views of the earth limb, were detected with high spatial variability at latitudes greater than 54 degrees in both hemispheres, and were evident in each of the four instances the northern polar mesosphere was observed from 13 July to 16 August 1996. In addition to the infrared signatures, the solar illuminated clouds were detected simultaneously as noctilucent features by ultraviolet and visible sensors co-aligned with the SPIRIT III radiometer on the MSX spacecraft. Infrared measurements in the northern polar region recorded on 22 July 1996 are presented for two long wavelength infrared (LWIR) radiometer bands, 11.1 to 13.2 and 18.1 to 26.0 μ m. The infrared signature is due to thermal self-emission of the cloud ice particles which is much greater than the infrared signature due to Rayleigh scatter of earthshine or sunlight at these wavelengths. The 22 July 1996 MSX data shows the PMC infrared emission is highly structured and is readily apparent at latitudes greater than 54 degrees north. A maximum infrared PMC radiance in this MSX observation was detected at a latitude of 84.8 degrees north and longitude of 325.6 degrees at 03:13:25 UT, equivalent to a local solar time of approximately 00:56. The PMC radiance profile at 03:13:25 UT appears to uniformly fill the line of sight and with this assumption was inverted to determine an altitude dependent volume emission rate. The 11.1 to 13.2 μ m band has a peak volume emission rate at an altitude of 83.8 +/- 0.2 km and a decrease in volume emission rate with altitude that is much more rapid below than above the peak emission rate. The ratio of the LWIR radiometer band radiance was used to provide a measure of the cloud temperature and a temperature of 136K has been calculated for the peak emission altitude of 83.8 km for the observation at 03:13:25 UT on 22 July 1996. These and other results from the analysis of the infrared signatures will be presented.
Gardner M. E.
Humphrey Charles H.
O'Neil Robert R.
Richards E. N.
Stair A. T.
No associations
LandOfFree
MSX: Infrared Emission From Polar Mesospheric Clouds does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with MSX: Infrared Emission From Polar Mesospheric Clouds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and MSX: Infrared Emission From Polar Mesospheric Clouds will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1272931