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Influence of solar variability on the infrared radiative cooling of the thermosphere from 2002 to 2014
Author(s) -
Mlynczak Martin G.,
Hunt Linda A.,
Mertens Christopher J.,
Thomas Marshall B.,
Russell James M.,
Woods Thomas,
Earl Thompson R.,
Gordley Larry L.
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl059556
Subject(s) - thermosphere , atmospheric sciences , radiative cooling , solar maximum , solar irradiance , radiative transfer , environmental science , solar cycle , irradiance , solar minimum , infrared , atmosphere (unit) , mesosphere , airglow , ionosphere , physics , meteorology , stratosphere , geophysics , solar wind , astronomy , optics , plasma , quantum mechanics
Infrared radiative cooling of the thermosphere by carbon dioxide (CO 2 , 15 µm) and by nitric oxide (NO, 5.3 µm) has been observed for 12 years by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere‐Ionosphere‐Mesosphere Energetics and Dynamics satellite. For the first time we present a record of the two most important thermospheric infrared cooling agents over a complete solar cycle. SABER has documented dramatic variability in the radiative cooling on time scales ranging from days to the 11 year solar cycle. Deep minima in global mean vertical profiles of radiative cooling are observed in 2008–2009. Current solar maximum conditions, evidenced in the rates of radiative cooling, are substantially weaker than prior maximum conditions in 2002–2003. The observed changes in thermospheric cooling correlate well with changes in solar ultraviolet irradiance and geomagnetic activity during the prior maximum conditions. NO and CO 2 combine to emit 7 × 10 18 more Joules annually at solar maximum than at solar minimum.