The importance of dynamical feedback on doubled CO{sub 2}-induced changes in the thermal structure of the mesosphere

Journal Article · Sat Jul 01 04:00:00 EDT 1995 · Geophysical Research Letters

DOI:https://doi.org/10.1029/95GL01432· OSTI ID:250026

Portmann, R W; Thomas, G E ^[1]; Solomon, S ^[2]; Garcia, R R ^[3]

---

1. Univ. of Colorado, Boulder, CO (United States)
2. Aeronomy Lab., Boulder, CO (United States)
3. National Center for Atmospheric Research, Boulder, CO (United States)

The Garcia-Solomon two-dimensional model was used to study the effect of doubled carbon-dioxide on the middle atmosphere. The model has been improved to include non-LTE CO{sub 2} cooling in the 15 micron band above 70 km and new chemical heating and heating efficiencies. The effect of doubling CO{sub 2} on the temperature is found to be large at the stratopause (about 10-12K cooling) and at the mesopause (about 6-12K cooling). In the stratosphere, dynamical feedbacks on the heating rate caused by the temperature changes are small compared to the radiative changes while in the mesosphere they can be large. In fact, calculations with the present dynamical heating rate used in the doubled CO{sub 2} energy equation indicate that the radiative forcing alone could cause a temperature increase of about 10K in the polar summer mesopause region. The dynamical feedbacks which oppose this positive radiative forcing are discussed. 18 refs., 3 figs.

• OSTI ID: 250026
• Journal Information: Geophysical Research Letters, Journal Name: Geophysical Research Letters Journal Issue: 13 Vol. 22; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CARBON DIOXIDE
CLIMATE MODELS
ECOLOGICAL CONCENTRATION
HEATING
MESOSPHERE