The role of cloud microphysical processes in climate: An assessment from a one‐dimensional perspective

American Geophysical Union (AGU) - Tập 94 Số D6 - Trang 8599-8607 - 1989
Kuo‐Nan Liou1, Szu‐Cheng S. Ou2
1Utah Univ. Salt Lake City, UT, United States
2Utah, University Salt Lake City, United States

Tóm tắt

The potential link between cloud microphysical processes and climate is investigated and theorized. We base our theory on results simulated from a one‐dimensional climate model with an interactive cloud formation and precipitation program. This cloud program includes temperature‐dependent parameterization equations for condensation, evaporation, and precipitation derived from growth equations for water droplets. We show that the cloud liquid water content is directly related to precipitation processes, which are governed by the mean cloud particle radius. In particular, we illustrate that the rate of precipitation generation is directly proportional to the fourth power of this radius. A doubling of CO2 is used as the radiative forcing. If the perturbed mean cloud particle radii for model high, middle, and low clouds are less than the climatological mean values, precipitation decreases because of the presence of smaller cloud particles, leading to an increase in the cloud liquid water content. Cloud solar albedo effects are enhanced, resulting in a reduction of temperature increases due to CO2 doubling (negative feedback). If, however, the perturbed mean cloud particle radii are larger than the climatological mean values, the availability of larger cloud particles would increase precipitation, leading to a decrease in the cloud liquid water content. The temperature increase in the case of CO2 doubling is amplified because of a reduction of cloud solar albedo effects (positive feedback). In the model the particle sizes are not directly related to radiative transfer, but they are indirectly related through precipitation and condensation processes, which determine the cloud liquid water content. We hypothesize that there are uncertainties in cloud microphysical processes and that a possible key to climate stability due to external radiative perturbations is the availability of larger or smaller cloud droplets (in reference to the climatological mean values). Smaller cloud droplets may be produced by additional condensation nuclei over the oceans as a result of greenhouse warming and pollution over land. The existence of larger cloud droplets could be caused by the removal of cloud‐forming nuclei, resulting from enhanced precipitation due to greenhouse perturbations. It is critically important to have a global climatology of the cloud particle radii for various cloud types in the investigation of the role of clouds in climate.

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Tài liệu tham khảo

10.1175/1520-0469(1971)028<1455:AWTIOT>2.0.CO;2

10.1029/JD090iD03p05867

Braham R., 1974, Cloud physics of urban weather modification: A preliminary report, Bull. Am. Meteorol. Soc., 55, 100

Budyko M. I., 1982, The Earth's Climate: Past and Future

10.1364/AO.6.001209

10.1111/j.2153-3490.1982.tb01813.x

10.1175/1520-0469(1980)037<1136:ACRAC>2.0.CO;2

10.1038/326655a0

10.1126/science.237.4818.1020

Haltiner G. J., 1980, Numerical Weather Prediction and Dynamic Meteorology

10.1175/1520-0469(1974)031<1137:IOTPOV>2.0.CO;2

10.1029/GM029p0130

10.1175/1520-0469(1977)034<0367:PDISIC>2.0.CO;2

10.1126/science.183.4128.909

10.1175/1520-0469(1983)040<0480:EOCCOS>2.0.CO;2

Kessler E. On the distribution and continuity of water substance in atmospheric circulation Meteorol. Monogr. 10 1969.

10.1007/978-1-935704-18-8_71

10.1175/1520-0469(1974)031<1232:FSOTPO>2.0.CO;2

10.1175/1520-0469(1979)036<1261:POTRPO>2.0.CO;2

10.1175/1520-0469(1985)042<1969:ICFACT>2.0.CO;2

10.1175/1520-0469(1969)026<1283:NMOPAC>2.0.CO;2

London J. A study of the atmospheric heat balance final reportContract AF19(122)‐166 99New York University New York 1957.

10.1175/1520-0469(1967)024<0241:TEOTAW>2.0.CO;2

10.1175/1520-0469(1980)037<0099:OTDOCC>2.0.CO;2

10.1175/1520-0469(1948)005<0165:TDORWS>2.0.CO;2

10.1007/978-94-009-6360-3

10.1175/1520-0493(1971)099<0895:NSOTLC>2.3.CO;2

Oort A. H. Global atmospheric circulation statistics (1958–1973) NOAA Prof. Pap. 14 180 Natl. Oceanic and Atmos. Admin. Washington D. C. 1983.

10.1007/978-1-935704-18-8_64

Prabhakara C. D. A.Short Nimbus‐7 SMMR‐derived seasonal variation in the water vapor liquid water and surface winds over the global oceans NASA Tech. MemoNASA‐TM‐86080 20 1984.

10.1029/RG021i007p01607

10.1007/978-94-009-9905-3

Rogers R. R., 1979, A Short Course in Cloud Physics

10.1175/1520-0469(1978)035<2207:CAACFM>2.0.CO;2

Sellers W. D., 1965, Physical Climatology

10.1175/1520-0493(1969)097<0471:MOPCT>2.3.CO;2

Smagorinsky J., 1978, Studies in Geophysics: Energy and Climate, 133

10.1029/JD089iD06p09668

10.1175/1520-0469(1973)030<0879:ACBAAS>2.0.CO;2

10.1029/JC086iC10p09739

10.1002/qj.49710444110

10.1175/1520-0469(1989)046<0020:SRTICC>2.0.CO;2

10.1111/j.1600-0889.1984.tb00254.x

10.1175/1520-0469(1967)024<0704:TPOCNB>2.0.CO;2

10.1029/JD089iD06p09475

Weast R. C., 1977, Handbook.for Chemistry and Physics

10.1175/1520-0469(1980)037<1485:CCACS>2.0.CO;2

10.1175/1520-0469(1988)045<1397:CFPIAG>2.0.CO;2

10.1175/1520-0469(1984)041<1336:TEOVLD>2.0.CO;2

10.1175/1520-0469(1973)030<0611:DOBPOT>2.0.CO;2