Arctic Weather Inititative

Introduction

The Arctic Weather Initiative addresses the relationships between climate change and weather in the Arctic.   There are several components to this initiative:   (1) an evaluation of extreme events (strong storms, unusually high and low temperatures, heavy precipitation) in terms or recent changes and projections for the future, (2) the use of indigenous community reports on weather variability and predictability to guide assessments of recent changes in arctic weather, and (3) a contribution to an Arctic Regional Reanalysis that will incorporate available observations into a comprehensive gridded database for the Arctic, spanning several decades at 6-hourly or finer temporal increments.

A recent finding from the evaluation of extreme events is that high temperature records have been set with much greater frequency than low temperature records in Alaska during the past few decades.   This asymmetry in temperature extremes is consistent with the general warming.   Model projections indicate that the frequencies of hot summer days and the occurrences of wintertime thaw events are likely to increase substantially during the present century.   The data also show that intense storms (cyclones) have increased in frequency over the Arctic Ocean in recent decades, although changes in the Alaskan region are primarily in storm tracks rather than intensity.  

The key factor for storm-induced coastal flooding and erosion in Alaska is the absence of sea ice, which permits wave build-up during storms in late summer and autumn.   The Nome flood of October 2004 was one such event (See figures).  

The increase of weather variability reported by many indigenous communities is supported by an analysis of daily high and low temperatures in Alaska and Canada, but only if variability is evaluated relative to the average for an evolving 30-day mean.   This finding represents a new insight into recent changes, and the finding is attributable to anecdotal information from arctic residents.   We have yet to find evidence of decreased predictability, although the analysis to date has only used persistence as a measure of predictability.

Extreme weather damage on Front Street, Nome (photo by J. Steiger, WSO Nome)

Principal Investigators

John Walsh, IARC, UAF

Participants

David Atkinson, IARC, UAF
Xingang Fan, IARC, UAF
Inna Shapiro, IARC, UAF
John Walsh, IARC, UAF
Christopher Young, IARC, UAF

Other Organizations Involved

The University of Illinois has been participating under support of an NOAA grant.

Collaborations

University of Illinois (Michael Timlin) has participated in analysis of extreme events in global climate model simulations; he does not have funding from IARC.

National Weather Service (Timothy Shy) has participated in analysis of variability and predictability based on historical data; has co-authored journal paper that is in press.

National Science Foundation Some of the material on this website is based upon work supported in part by the National Science Foundation under Agreement No. ARC-0327664. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.