The Effect of Sea Surface Temperature and 2m Air Temperature on Precipitation Events in the Southern Coasts of Caspian Sea

Authors
H. Nouri 1
H. Ghayour 2
A. Masoodian 2
M. Azadi 3
A. Ildoromi 1
1 Department of Watershed Management, University of Malayer, Malayer, Iran.
2 Department of Geography and climatology, University of Isfahan, Isfahan, Iran.
3 Atmospheric Science and Meteorological Research Center, Tehran, Iran.
Abstract
There are a number of ideas to generate cloud and precipitation in the southern coasts of Caspian Sea, but none of them explain the cause of precipitation particularly heavy and super heavy precipitations precisely. This study describes main thermodynamic factors when the situation and location of synoptic patterns are effective. On the basis of daily data, monthly regimes and monthly trends of the Sea Surface Temperature (SST), difference between 2m air temperature and SST over the Caspian Sea as well as the SST gradients in different distances on latitude and its anomaly were calculated. For recognition of synoptic conditions, humidity advection, geopotential and sea level pressure maps were drawn. The results showed that there are three thermodynamic factors over the Caspian Sea to produce precipitation particularly from September to December. The first factor is arrangement and well organized of the SST gradients as it decreases from the south to the north of Caspian Sea. Also, the SST over the Sea must be enough warm to produce clouds and precipitation. The last factor is the difference between 2m air temperature and SST. When the synoptic patterns in different pressure levels are suitable for instability, the air-sea interaction process is the most important factor to produce the advection humidity, clouds and precipitation particularly heavier precipitation events in the north of Iran.
Keywords
Air temperature
Caspian sea
Precipitation
SST
Ahmedoua, O., Yasudab, H., Wangb, K. and Hattorid, K., Characteristics of precipitation in northern Mauritania and its links with sea surface temperature, J. Arid. Environ., 2008; 72: 2243-2250.
Alijani, B. Synoptic climatology, SAMT Publications, Tehran, Iran.2002; 1: 112-114.
Bertrand, S. Co variability of precipitation and sea surface temperature changes in Northern Chilean Patagonia during the last 2000 years, Quaternary International, XVIII INQUA Congress, 21st–27th July, 2011, Bern, Switzerland, 2012; 279-280: 50.
Biasutti, M., Battisti, D.S. and Sarachik, E.S. Mechanisms Controlling the Annual Cycle of Precipitation in the Tropical Atlantic Sector in an Atmospheric GCM. J. Climate.2004; 17: 4708-4723.
Chan, J.C.L. and Zhou, W. PDO, ENSO and the early summer monsoon rainfall over south China. J. Geophysics. 2005; 15: 156-169.
Chan, J.C.L., Liu, Y.M., Chow, K.C.Y., Ding, H.W., Lau, K.M., and Chan, K.L., Design of a regional climate model for the simulation of South China summer monsoon rainfall. J. Meteor. Soc. Japan.2004; 82: 1645-1665.
Chang, C.P., Zhang, Y. and Li, T. Interannual and interdecadal variations of the East Asian summer monsoon and tropical Pacific SSTs. Part II: Meridional structure of the monsoon. J. Climate. 2000; 13: 4326-4340.
Chen, L.T., Impact of the SST anomalies in the equatorial eastern Pacific on the tropical atmospheric circulation and rainfall during the rainy period in China. Chinese J. Atmosphere. 1977; 1: 1-12.
Ghaemi, H. General Meteorology, SAMT Publication, Tehran, Iran. 2007; 4: 570-573.
Giannini, A., Saravanan, R. and Chang, P. Dynamics of the boreal summer African monsoon in the NSIPP1 atmospheric model. J. Climate Dynamic. 2005; 25: 517-535.
Herrmann, S.M. and Hutchinson, C.F. The changing contexts of the certification debate. J. Arid. Environ., 2005; 18: 87-99.
Hong, X., Paul M., Wang, S. and Rowley, C. High SST variability south of Martha's Vineyard: Observation and modeling study, J. Marine Syst.,2009; 78: 59-76.
Huang, R.H. and Wu, Y.F. The influence of ENSO on the summer climate change in China and its mechanisms. J. Adv. Atmos. Sci., 1989; 6: 21-32.
Huang, R.H. and Zhou, L.T. Research on the characteristics, formation mechanism and prediction of severe climate disasters in China. J. NDS., 2002; 11: 1-9.
Huang, R.H., Zhou, L. T. and Chen, W. The progresses of recent studies on the variability of the East Asian monsoon and their causes. J. Adv. Atmos. Sci., 2003; 20: 55-69.
Hunt. B.G. Natural climate variability and Sahel precipitation trends. J. Global Planet Change. 2000; 24: 107-131.
Kawai, Y. and Wada, A. Diurnal sea surface temperature, variation and its impact on the atmosphere and ocean: A review. J. Oceanography. 2007; 63: 721-744.
Khalili, A. Precipitation patterns of central Elburz. J. Climatol., 1973; 21: 215-232.
Landsea, C.W., Gray, W.M., Mielke, P.W. and Berry, k.J. Long-term Variations of western Sahelian monsoon rainfall and intense U.S. Land falling hurricanes. J. Climate. 1992; 5: 1528-1534.
Lau, K.M. and Weng, H.Y. Coherent model of global SST and summer rainfall over China: An assessment of the regional impacts of the 1997-98 El Niño. J. Climate. 2001; 14: 1294-1208.
Lin, Z.D. and Lu, R.Y. The ENSO’s effect on Eastern China rainfall in the following early summer. J. Adv. Atmos. Sci., 2009; 26: 33-342.
Masoodian, S.A. Climatic regions of Iran. J. Geogr. Develop., 2003; 2: 171-183.
Loubere, P.,  Creamer, W. and Haas, H. Evolution of the El Nino-Southern Oscillation in the late Holocene and insulation driven change in the tropical annual SST cycle, Global and Planetary Change, 2013; 100: 129-144.
Moradi H. The role of Caspian Sea in the southern coasts precipitation, J. Marin sci. Iran, 2003; 2: 14-15.
Stammerjohn, S., Maksym, T., Heil, P., Massom, R. and Vancoppenolle, M. The influence of winds, sea-surface temperature and precipitation anomalies on Antarctic regional sea-ice conditions during IPY 2007, Deep Sea Research Part II: Topical Studies in Oceanography, 2011; 58: 999-1018. begin_of_the_skype_highlighting.
Woodman, R. Model statistical forecast of precipitation in the north of Peru, The phenomenon El Niño. Investigation for a prognosis, encounter universities of the south Pacific. 1999; 6: 93-108.
Wu, R., Hu, Z. and B. Kirtman, Evolution of ENSO-related rainfall anomalies in East Asia and the processes. J. Climate. 2003; 16: 3741-3757.
Yang, F.L. and Lau, K.M. Trend and variability of China precipitation in spring and summer: linkage to sea-surface temperatures. Int. J. Climatol., 2004; 10: 1094-1105.
Yang, S. and Lau, K.M. Influences of sea surface temperature and ground wetness on Asian summer monsoon. J. Climate, 1998; 11: 3230-3246.
Zhou, L.T. and Wu, R. Respective impacts of East Asian winter monsoon and ENSO on winter rainfall in China, J. Geophys. Res., 2009; 5: 67-81.
Zhou L.T, Chi-Yung T., Wen, Z. and Johnny C. Influence of South China Sea SST and the ENSO on Winter Rainfall over South China. J. Natural Disasters. 2009; 31: 19-29.
ECOPERSIA
Volume 1, Issue 4 - Serial Number 6
December 2013
Pages 369-383