Modeling the Arctic climate

In February, polar climate researchers gathered at the National Center for Atmospheric Research in Boulder, Colorado to discuss the newest updates to models of the Earth’s climate system. The researchers are working together to create better models of the Arctic and Antarctic climates, which will feed into larger models of the whole Earth that help scientists understand how climate will change in the future. What goes into a climate model, and what can scientists learn from models that they cannot learn from observations?

This image shows several aspects of climate, including sea ice, surface winds, and sea surface temperature. This image came from data simulated from {a href=http://www.cesm.ucar.edu/}NCAR's Community Earth System Model{/a}. ||Credit: ©UCAR. Image courtesy Gary Strand, NCAR|{a href=http://nsidc.org/icelights/files/2012/03/CESM_model_NCAR.jpg}High Resolution Image{/a}

What’s in a model?
Computer climate models are based on scientists’ understanding of Earth’s climate. The models use mathematical relationships to try to quantify the relationships between parts of the climate system. If you tweak one factor in climate, how does the simulated climate system respond? Models that bring many factors together help scientists learn how the climate system works, and let them run simulations on Earth’s climate. They also allow scientists to assess how climate may be affected by present and future changes in greenhouse gases and solar forcing, and how much of a role natural variability plays. Continue reading

Summer predictions for Arctic sea ice

graph of estimates from the SEARCH sea ice outlook

Last week, an international group of researchers released their best estimates for Arctic sea ice extent over the summer melt season. The scientists are compiling their estimates so that they can better predict changes in Arctic sea ice. Credit: SEARCH Sea Ice Outlook

Average Arctic sea ice extent this May was the third lowest in the satellite record. Does that mean that ice extent will reach a new record low this summer? Or will it recover somewhat over recent years?

Last week sea ice scientists from around the world shared their best answers to those questions, in the June report of the Sea Ice Outlook. For the report, the researchers used a variety of methods to predict how sea ice will behave this summer, such as statistical methods or computer models. Continue reading