Variations in western Arctic temperatures in response to cloud radiative and synoptic‐scale influences

Abstract

The analysis focuses on Barrow, Alaska, a site that is sensitive to changing conditions because it is located near cryospheric boundaries and is influenced by both extratropical and Arctic synoptic activity. Surface and upper air meteorological data for a 31‐year period (1965–1995) are used to evaluate temperature variations as they relate to dynamical and radiative processes. Both annual and monthly analyses indicate a tendency toward warming overall. However, the annual warming is not monotonic over time and varies seasonally. Comparisons of temperature time series from four sites along the Siberian‐Alaskan coastline show that Barrow is a representative site to evaluate climate change in the western Arctic coastal zone. Regionally, the warming is dominated by significant temperature increases during winter and spring, but cooling is indicated for autumn. These results are not entirely consistent with model predictions of a more uniform high‐latitude warming during the cold season in response to increasing concentrations of greenhouse gases in the atmosphere. Rather, the observed changes are attributed to well‐known natural processes that affect regional cloud distributions in response to changing circulation patterns. Coincident daily and hourly meteorological and radiation data are also used to demonstrate empirically how clouds modulate Arctic temperatures.