Observed trends in clouds and precipitation (1983–2009): implications for their cause(s)

Abstract. Satellite observations (International Cloud Climatology Project (ISCCP), 1983–2009) of linear trends in cloud cover are compared to those global precipitation (Global Precipitation (GPCP) pentad V2.2, 1983–2009), investigate possible cause(s) the both and precipitation. The spatial distributions total characterized primarily by a broadening major ascending zone Hadley circulation. Our correlation studies suggest that warming, Atlantic Multidecadal Oscillation (AMO) Pacific Decadal (PDO) can explain 67 %, 49 % 38 respectively, variabilities cover, but causality is harder establish. Further analysis circulation shows trend temperature, rather than AMO PDO, primary contributor observed 1983–2009. underlying mechanism driving this proposed be moisture–convection–latent-heat feedback cycle under warming conditions. extended investigating connections between clouds China, based on large number long-running, high-quality surface weather stations 1957–2005. This reveals quantitative matching relationship reduction light cover. Furthermore, our study suggests China driven temperature; PDO plays secondary role, while contribution from Niño3.4 insignificant, consistent with analysis.