Journal of the Korean earth science society (한국지구과학회지)

The Korean Earth Science Society (한국지구과학회)
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The Regional Dependency of Cloud-radiative Forcing on the Sea Surface Temperature in the Interannual and Seasonal Time Scales

경년과 계절 시간 규모하에서 해수면 온도에 대한 구름복사 강제력의 지역 의존도

  • Lee, Woo-Seop (Department of Atmospheric Science, Kongju National University) ;
  • Kwak, Chong-Heum (Department of Atmospheric Science, Kongju National University) ;
  • So, Seon-Sup (Department of Atmospheric Science, Kongju National University) ;
  • Suh, Myoung-Seok (Department of Atmospheric Science, Kongju National University) ;
  • Kim, Maeng-Ki (Department of Atmospheric Science, Kongju National University)
  • Published : 2003.10.31
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Abstract

The regional dependency of cloud-radiative forcing at the top of atmosphere is studied using ERBE (Earth Radiation Budget Experiment), ISCCP (International Satellite Cloud Climatology Project) and NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) reanalysis data for 60 months from January 1985 to December 1989 over tropical ocean. In the interannual time scale, the dependency of cloud-radiative forcing on the sea surface temperature over the equatorial eastern Pacific ocean is about 7.4Wm$^{-2}$K$^{-1}$ for longwave radiation and about -4.4Wm$^{-2}$K$^{-1}$ for shortwave radiation, respectively. This shows that the net cloud-radiative forcing due to the increase of sea surface temperature over the equatorial eastern Pacific ocean heats the atmosphere. But the dependency is reversed over tropical oceans with -3.4Wm$^{-2}$K$^{-1}$ for longwave and 1.9WmWm$^{-2}$K$^{-1}$ for shortwave radiation, indicating that the net cloud-radiative forcing cools the atmosphere over tropical oceans. In raw data including seasonal cycle, the dependency of cloud-radiative forcing over the equatorial eastern Pacific ocean is very similar to that in interannual time scale in both the magnitude and the sign. But the dependency of cloud-radiative forcing on the sea surface temperature over tropical oceans is about 0.2Wm$^{-2}$K$^{-1}$ for longwave and 2.7Wm$^{-2}$K$^{-1}$ for shortwave radiation, respectively. These results represent that the role of seasonal cycle on the cloud radiative forcing is gradually more important than role of interannual time scale as the ocean area is broadening from the tropical central Pacific to the tropical ocean.

해수면 온도에 대한 구름복사 강제력의 지역 의존도가 조사되었다. 이 조사는 경년 변동과 계절 시간규모에 대해서 각각 조사되었다. 적도 동태평양에서 경년 변동의 경우 해수면 온도가 1$^{\circ}$C 증가할 때 순 구름복사 강제력은 약 3Wm$^{-2}$가 증가하였으며, 계절변동이 포함된 경우 약 3.5Wm$^{-2}$가 증가하는 것으로 나타났다. 반면 열대 해양전체에서 경년 변동의 경우 해수면 온도가 1$^{\circ}$C 증가할 때 순 구름복사 강제력은 1.5Wm$^{-2}$ 감소하였으나, 계절변동이 포함된 경우 약 2.9Wm$^{-2}$로 증가하였다. 따라서 해수면 온도에 대한 구름복사 강제력의 의존도는 적도 동태평양에서 열대 해양으로 넓어질수록 경년 변동에 의해 영향에서 계절변동에 의한 영향이 더 지배적으로 작용한다. 계절 변동이 포함된 경우 해역에 관계없이 해수면온도가 1$^{\circ}$C 증가할 때, 순 구름복사 강제력은 약 2${\sim}$3Wm$^{-2}$ 증가하였다. 이러한 결과는 해수면 온도의 경년 변동이 뚜렷한 적도 동태평양에서는 경년 변동에 의한 구름복사 강제력이 대기를 가열하는 반면, 열대 해양 전체에서는 계절변동에 의한 구름복사 강제력이 대기를 가열한다는 것을 의미한다.

Keywords

References

  1. 김맹기, 강인식, 1998, 지표온난화에 미치는 구름-복사 피드백의 계절의존도. 한국기상학회 추계학술대회 초록집. 194-197
  2. 손병주, 1996, 구름이 지표 장파복사 수지에 미치는 영향.한국기상학회지 , 32(2), 229-242
  3. Arking, A. and Ziskin, D., 1994, Relationship between clouds and sea surface temperatures in the western trop-ical Pacific. Journal of Climate, 7, 988-1000 https://doi.org/10.1175/1520-0442(1994)007<0988:RBCASS>2.0.CO;2
  4. Bony, S., K. Lau, M., and Sud, Y. C., 1997, Sea surface temperature and large-scale circulation influences on tropical greenhouse effect and cloud radiative forcing. Joumal of Climate, 10, 2055-2077 https://doi.org/10.1175/1520-0442(1997)010<2055:SSTALS>2.0.CO;2
  5. Bergman, J. and Hendon, H. H., 2000, The impact of clouds on the seasonal cycle of radiative heating over the Pacific. Joumal of the Atmospheric Science, 57, 545-566 https://doi.org/10.1175/1520-0469(2000)057<0545:TIOCOT>2.0.CO;2
  6. Harrison, E. F, Barkstorm, B. R., Ramanathan, V, Cess, R. D., and Gibson, G. G. 1990, Seasonal variation of cloud radiative forcing derived from the Earth radiation Budget Experiment. Joumal of Geophysical Research, 95, 18687-18703 https://doi.org/10.1029/JD095iD11p18687
  7. Hartmann, D. L. and Michelsen, M., 1993, Large-scale effects on the regulation of tropical sea surface tempera-ture. Joumal of Climate, 6, 2049-2062 https://doi.org/10.1175/1520-0442(1993)006<2049:LSEOTR>2.0.CO;2
  8. Ho, C.-H., Chou, M.-D., and Sui, C.-H. 2002, Compari-son of different earth radiation budget experiment data sets over tropical oceans, International Journal of Clima-tology, 22, 263-270 https://doi.org/10.1002/joc.734
  9. Lau, K.-M., Wu, H.-T, and Bony, S., 1997, The Role of Large-Scale Atmospheric Circulation in the Relation-ship Between Tropical Convection and Sea Surface Temperature. Joumal of Climate, 10, 381-392 https://doi.org/10.1175/1520-0442(1997)010<0381:TROLSA>2.0.CO;2
  10. Pai, D. S. and Rajeevan, M., 1998, Clouds and cloud radi-ative forcing over tropical Indian ocean and their rela-tionship with sea surface temperature. Current Science, 75, 372-381
  11. Preisendorfer, R. W. and Mobley, C. D., 1988, Principalcomponent analysis in meteorology and oceanography.Elsevier Science Publication, 425 pp
  12. Ramanathan, V, Cess, R. D., Hamson, E. R, Minnis, R, Barkstomn, B. R., Ahmad, E., and Hartmann, D., 1989, Cloud-radiative forcing and climate: Results from the Earth Radiation Budget Experiment. Science, 243, 57-63 https://doi.org/10.1126/science.243.4887.57
  13. Rossow, W. B., Brest, C. L., and Roiter, M., 1996, Intema-tional Satellite Cloud Climatology Project (ISCCP) Update of Radiance Calibrations. WMO/TD.-No. 736. World Meteorological Organization
  14. Song, B.-G. and Kim, Y.-S., 2002, Interrelationship between sea surface temperature and clouds over the Tropical ocean. Journal of the Korean Meteorological Society, 38 (3), 225-235
  15. Zhang, M. H., Cess, R. D., and Xie, S. C., 1996, Relation-ship between Cloud Radiative Forcing and Sea Surface Temperatures over the Entire Tropical Oceans, Joumal of Climate 9, 1374-1384 https://doi.org/10.1175/1520-0442(1996)009<1374:RBCRFA>2.0.CO;2