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Recent observed surface air temperature changes over the Arctic region are the largest in the world. Winter (DJF) rates of warming exceed 4 degrees C. over portions of the Arctic land areas (shown left). We provide Arctic temperature trends and changes of other primary surface variables (e.g., sea level pressure, precipitation, sea ice cover) archived in this climate summary, portions of which are published each year in the Bulletin of the American Meteorological Society.
Sea ice extent averaged over the Northern Hemisphere has decreased correspondingly over the past 50 years (shown right). The largest change has been observed in the summer months with decreases exceeding 30%. Decreases observed in winter are more modest. We maintain this updated archive of sea ice concentrations and extents at the University of Illinois Department of Atmospheric Sciences.
Current sea ice and snow conditions (shown left) are available from the Cryosphere Today, in which we provide ice concentrations and snow depth for a variety of map projections. Timeseries of Northern Hemisphere and regional sea ice area and anomalies are also provided and updated daily.
Links to our additional recent observed climate related research:
|Evaluation of the ERA40 reanalyses for the Arctic|
|Submitted paper: Seasonality of observed and projected climate change|
|Submitted paper: Antarctic temperature analyses|
|Surface air temperature distribution skewness|
|Evaluation of climatic conditions favoring Alaskan forest fires|
|Antarctic temperature analyses|
Analysis of output from 15 global climate models for use in the IPCC Fourth Assessment Report (due in 2007) can be seen here. We evaluate the sensitivity of the Arctic climate to three different greenhouse gas scenarios. The archive shows that variations of temperature projections using different greenhouse gas scenarios are similar to the inter-model variability projected by the 15 different models. Projected changes (from late 20th-century climate state) of surface air temperature, sea level pressure, and precipitation for 3 20-year timeslices of the 21st-century are included.
At the bottom of this link, we evaluate the biases of simulated temperature, sea level pressure, and precipitation fields from the corresponding variables in the ERA40 reanalysis for the 1958-2000 period. The biases in surface air temperature over the Arctic can exceed 15 deg. C over climatalogical sea ice regions (see right) and the Arctic-region biases often exceed those found anywhere else on the globe.
Our work on the IPCC report is an extension to our recent work on the Arctic Climate Impact Assessment report and past work identifying a fingerprint of enhanced greenhouse warming in the Arctic (left).
The seasonality of recent observed changes (1948-2003: from the NCEP reanalyses) with changes projected by a composite of 5 GCMs for the next century, correlate well for surface air temperature (right) and sea level pressure. The seasonality correlations drop off substantially for precipitation, however. We have created plots of recent observed changes and projected changes, as well as the correlations of the annual cycle of changes between observations and projections here.
These images of Alaska link to a set of climate change scenarios for created specifically for Alaska. The climate change scenarios are downscaled from a set of global climate model projections to a high resolution domain for Alaska and for approximately three hundred specific population centers and locations of interest.
Finally, this link provides access to an online set of animations of observed and projected changes of surface air temperature, precipitation, and sea ice that we created for the PBS series Scientific American Frontiers: Episode "Hot Times in Alaska". Alan Alda hosts this interesting series.
Additional recent modelling related research includes:
|Graphics and animations of current Alaska ETA forecasts|
|Graphics and animations of current US ETA forecasts|
|Stand. devs. and sfc. air temp. threshold violation frequencies for two GCMs|