Tuesday, November 13, 2012

New paper finds clouds cool the climate

A new paper published in Environmental Research Letters examines satellite data over Eurasia to find that total cloud cover acts as a net negative feedback to cool the climate. The finding contradicts the assumptions programmed into climate models that clouds act as a net positive feedback to cause warming.

Damped summer warming accompanied with cloud cover increase over Eurasia from 1982 to 2009

Qiuhong Tang1 and Guoyong Leng1,2
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1 Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
2 Graduate University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China 


The relationship between summer temperature, total cloud cover and precipitation over Eurasia was investigated using observation-based products of temperature and precipitation, and satellite-derived cloud cover and radiation products. We used a partial least squares regression approach to separate the local influences of cloud cover and precipitation on temperature variations. Our results suggest that the variance of summer temperature is partly explained by changes in summer cloudiness. The summer temperature dependence on cloud cover is strong at the high latitudes and in the middle latitude semi-humid area, while the dependence on precipitation is strong in the Central Asia arid area and the southern Asia humid area. During the period 1982–2009, the damped warming in extended West Siberia was accompanied with increases in cloud cover, and the pronounced warming in Europe and Mongolia was associated with a decrease in cloud cover and precipitation. Our results suggest that cloud cover may be the important local factor influencing the summer temperature variation in Eurasia while precipitation plays an important role at the middle latitudes.


  1. http://link.springer.com/article/10.1007%2Fs00704-012-0607-0

  2. https://docs.google.com/viewer?a=v&q=cache:E8JoDwTwITcJ:www.cmsaf.eu/bvbw/generator/CMSAF/Content/Publication/atbd__pdf/SAF__CM__DWD__ATBD__CRE__1.1,templateId%3Draw,property%3DpublicationFile.pdf/SAF_CM_DWD_ATBD_CRE_1.pdf+&hl=en&gl=us&pid=bl&srcid=ADGEESi1KMbRY5E1RZqroKVYV3WNZzAbgTL5Yvzm_TqOQxf3TJ9yeAh9yJzH-vCH6itWl-eBESldS44G1wdDKtmcFUdDPbBBNoMAS4chAZpXPBFPwjcHsDKxlYbYKnjEikQk5PsZhnjm&sig=AHIEtbTW59nAkLZxzj7le5y50ZeCcvk16w

  3. http://journals.ametsoc.org/doi/abs/10.1175/JAMC-D-12-025.1?af=R