Cloud Changes in the Period of Global Warming: The Results of the International Satellite Project

We present the results of an analysis of climatic series of global and regional cloudiness for 1983-2009. The data were obtained as part of the ISCCP international satellite project. A technique of statistical time series analysis that includes a smoothing algorithm and wavelet analysis is described. Both methods are intended for the analysis of nonstationary series. According to the results of analysis, both global and regional cloudiness show a decrease of 2-6%. The greatest decrease is observed in the tropics and over the oceans, while the decrease is minimal over land. The correlation coefficient between the global cloud series on the one hand and the global air and ocean surface temperature series on the other hand reaches values between -0.84 and -0.86. The coefficient of determination that characterizes the regression accuracy for the prediction of global temperature variations based on the variations in the lower cloud cover in this case is 0.316.