A study of Arctic cloud data and Arctic cloud variability

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Tuesday, 19 January 2010: 2:30 PM
B215 (GWCC)
Neil P. Barton, LLNL, Livermore, CA; and D. E. Veron

Arctic clouds are a climate component that is changing. Winter cloud percentage has decreased, while spring cloudiness has increased in the last 20 plus years. Multiple data sets are used for Arctic cloud climate studies, but what are the differences within these data? This study examines differences in Arctic cloud data for the years 1982 to 2001 and also discusses large-scale Arctic cloud variability. Two polar-pathfinder satellite data sets and surface observations are compared. The two satellite data sets examined are the Advance Very High Resolution Radiometer (AVHRR) and the Television Infrared Observation Satellite (TIROS) polar pathfinders. Cloud amount is larger in the TIROS data set than the AVHRR while cloud variability is larger in the AVHRR data set. Qualitatively, spatially variability in cloud amount and cloud amount standard deviation is similar. Agreements between the two satellite data sets and surface observations are better during the summer months than compared to the winter months. This study also examines large-scale Arctic cloud variability and the Arctic cloud response to climate changes. Large scale variability is examined through principal component analysis and multivariate regressions. Cloud variability is compared to other modes of Arctic large scale variability, such as the Arctic Oscillation and North Atlantic Oscillation. The correlation between the leading Arctic cloud Principal component and the Arctic Oscillation is statistical significant with a p-value less than 0.10.