An inquiry into the cirrus-cloud thermostat effect for tropical sea surface temperature

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · Geophysical Research Letters

DOI:https://doi.org/10.1029/94GL00222· OSTI ID:79504

Lau, K M; Sui, C H; Chou, M D; Tao, W K ^[1]

---

1. NASA, Goddard Space Flight Center, Greenbelt, MD (United States)

In this paper, we investigate the relative importance of local vs remote control on cloud radiative forcing using a cumulus ensemble model. It is found that cloud and surface radiation forcings are much more sensitive to the mean vertical motion assoicated with large scale tropical circulation than to the local SST (sea surface temperature). When the local SST is increased with the mean vertical motion held constant, increased surface latent and sensible heat flux associated with enhanced moisture recycling is found to be the primary mechanism for cooling the ocean surface. Large changes in surface shortwave fluxes are related to changes in cloudiness induced by changes in the large scale circulation. These results are consistent with a number of earlier empirical studies, which raised concerns regarding the validity of the cirrus-thermostat hypothesis (Ramanathan and Collins, 1991). It is argued that for a better understanding of cloud feedback, both local and remote controls need to be considered and that a cumulus ensemble model is a powerful tool that should be explored for such purpose.

• Research Organization: National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center
• OSTI ID: 79504
• Journal Information: Geophysical Research Letters, Journal Name: Geophysical Research Letters Journal Issue: 12 Vol. 21; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ATMOSPHERIC CIRCULATION
EARTH ATMOSPHERE
GREENHOUSE EFFECT
HEAT FLUX
RADIANT HEAT TRANSFER
TROPICAL REGIONS