Using Climate Divisions to Analyze Variations and Trends in Alaska Temperature and Precipitation

Abstract

By extending the record of Alaskan divisional temperature and precipitation back in time, regional variations and trends of temperature and precipitation over 1920-2012 are documented. The use of the divisional framework highlights the greater spatial coherence of temperature variations relative to precipitation variations.The divisional time series of temperature are characterized by large interannual variability superimposed upon low-frequency variability, as well as by an underlying trend. Low-frequency variability corresponding to the Pacific decadal oscillation (PDO) includes Alaska's generally warm period of the 1920s and 1930s, a cold period from the late 1940s through the mid-1970s, a warm period from the late 1970s through the early 2000s, and a cooler period in the most recent decade. An exception to the cooling of the past decade is the North Slope climate division, which has continued to warm. There has been a gradual upward trend of Alaskan temperatures relative to the PDO since 1920, resulting in a statewide average warming of about 18C.In contrast to temperature, variations of precipitation are less consistent across climate divisions and have much less multidecadal character. Thirty-year trends of both variables are highly sensitive to the choice of the subperiod within the overall 93-yr period. The trends also vary seasonally, with winter and spring contributing the most to the annual trends.

Seasonal flows of international British Columbia-Alaska rivers: The nonlinear influence of ocean-atmosphere circulation patterns

“…To the extent that the outcomes from this study can be compared to prior literature for the region, the streamflow, temperature, and precipitation findings are broadly consistent with earlier teleconnection analyses (e.g., [4,20,61]). Many of the specific hydroclimatic processes inferred, such as higher autumn-winter streamflows or earlier snowmelt freshets under warmer air temperatures, have been widely observed either in this region, or alternatively in other areas of western North America (e.g., [3,22,25,68]).…”

“…Teleconnections to such climate modes have, with the possible exception of the Pacific Decadal Oscillation, enjoyed relatively little scrutiny in southeast Alaska and northwest British Columbia in comparison to other areas of western North America and, indeed, even other areas of Alaska and British Columbia. Nonetheless, prior teleconnection analyses within and near this border region (e.g., [4,5,16,20,32,48,61]) provide encouraging signs that this should be a fruitful approach to conceptualizing and characterizing the interannual streamflow variability of transboundary rivers in the area.…”

Changing times, changing stories: generational differences in climate change perspectives from four remote indigenous communities in Subarctic Alaska

“…Looking specifically at the maritime Arctic, Polyakov et al (2003) determined that a mean temperature increase of 1.2°C had occurred between the years 1875 and 2000. Bieniek et al (2014) found a mean temperature increase of 1.7°C between 1949 and 2012 specifically in Alaska with winter and spring temperatures having the largest increases (Wendler et al 2012). Additionally, temperature increases started in Alaska around 1977 with a high correlation to the Pacific Decadal Oscillation (Hartmann and Wendler 2005).…”

“…The river provides livelihood to the residents of the basin in the form of food, transportation, water, firewood, and building supplies. Over the past 60 years in Alaska, Bieniek et al (2014) found a 1.7°C increase in mean annual temperatures. Increased temperature will likely change water chemistry, alter permafrost distribution (Jorgenson et al 2006, Romanovsky et al 2008, Frey and McClelland 2009, increase glacier melt, increase discharge, and alter inputs to the eastern Bering Sea Streigl 2007, Walvoord et al 2012).…”

Hydrologic Regime Changes in a High-Latitude Glacierized Watershed under Future Climate Conditions

“…A primary source of uncertainty is the limited availability of meteorological stations in Alaska to form the basis for extrapolation to unmonitored areas [45]. The downscaling of coarse-resolution CMIP5 global circulation models introduces bias, and some deficiencies are known to exist in CMIP5 simulations of northern latitudes, such as incomplete simulation of the effects of aerosols on clouds [1], overestimation of active layer thickness and the permafrost-carbon feedback, and generally poor representation of the pacific decadal oscillation [46].…”