Observed and Modeled Cloud Responses to Interannual Climate Variability

Clouds play a crucial role in Earth’s radiative energy budget, but remain a major source of uncertainty in climate predictions. Studying how clouds respond to interannual variability provides a validation metric for climate models and may provide insight into how clouds and cloud feedbacks might be altered in a changing climate. Here, cloud interactions with the Southern Annular Mode, North Atlantic Oscillation, El Nino Southern Oscillation, North Pacific Index, and Pacific Decadal Oscillation are examined using 15 years of MISR cloud observations, ERA-Interim reanalysis, and a 25 year historical HadGEM 2.0 climate simulation. We use regression and clustering techniques to identify regions with distinct cloud responses to these sources of climate variability in the context of cloud occurrence histograms, we examine the observed cloud and meteorological changes in these regions in response to these modes of climate variability, and finally compare the observed responses to those produced by HadGEM.