 |
| Titel |
Middle atmosphere response to different descriptions of the 11-yr solar cycle in spectral irradiance in a chemistry-climate model |
| VerfasserIn |
W. H. Swartz, R. S. Stolarski, L. D. Oman, E. L. Fleming, C. H. Jackman |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 13 ; Nr. 12, no. 13 (2012-07-12), S.5937-5948 |
| Datensatznummer |
250011307
|
| Publikation (Nr.) |
 copernicus.org/acp-12-5937-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| The 11-yr solar cycle in solar spectral irradiance (SSI) inferred from
measurements by the SOlar Radiation & Climate Experiment (SORCE) suggests a
much larger variation in the ultraviolet than previously accepted. We present
middle atmosphere ozone and temperature responses to the solar cycles in
SORCE SSI and the ubiquitous Naval Research Laboratory (NRL) SSI
reconstruction using the Goddard Earth Observing System chemistry-climate
model (GEOSCCM). The results are largely consistent with other recent
modeling studies. The modeled ozone response is positive throughout the
stratosphere and lower mesosphere using the NRL SSI, while the SORCE SSI
produces a response that is larger in the lower stratosphere but out of phase
with respect to total solar irradiance above 45 km. The modeled responses in
total ozone are similar to those derived from satellite and ground-based
measurements, 3–6 Dobson Units per 100 units of 10.7-cm radio flux
(F10.7) in the tropics. The peak zonal mean tropical temperature
response using the SORCE SSI is nearly 2 K per 100 units F10.7 – 3
times larger than the simulation using the NRL SSI. The GEOSCCM and the
Goddard Space Flight Center (GSFC) 2-D coupled model are used to examine how
the SSI solar cycle affects the atmosphere through direct solar heating and
photolysis processes individually. Middle atmosphere ozone is affected almost
entirely through photolysis, whereas the solar cycle in temperature is caused
both through direct heating and photolysis feedbacks, processes that are
mostly linearly separable.
This is important in that it means that chemistry-transport models should
simulate the solar cycle in ozone well, while general circulation models without
coupled chemistry will underestimate the temperature response to the solar cycle
significantly in the middle atmosphere.
Further, the net ozone response results from the
balance of ozone production at wavelengths less than 242 nm and destruction
at longer wavelengths, coincidentally corresponding to the wavelength regimes
of the SOLar STellar Irradiance Comparison Experiment (SOLSTICE) and Spectral
Irradiance Monitor (SIM) on SORCE, respectively. A higher
wavelength-resolution analysis of the spectral response could allow for a
better prediction of the atmospheric response to arbitrary SSI variations. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|