Sea Ice

Sea Ice

Sea Ice Concentration (%) for 1981-2005. Top (a-b):  Observed Climatology from SSM/I/SSMR Satellites. Bottom (c-d): Ensemble Mean from CCSM4 Model. Black Line is the Ice Edge from SSM/I/SSMR Data.

The Arctic is an interesting place to examine model biases because the climate exhibits strong feedback due to the high albedo of snow and ice. These plots show sea ice concentration and extent from satellite observations and the CCSM4 climate model for the period 1981-2005. The annual sea ice maximum typically occurs in March, while the annual sea ice minimum typically occurs in September.

How do the observed and simulated sea ice concentration compare for March? (Choose the best answer.)

How do the observed and simulated sea ice concentration and extent compare for September? (Choose the best answer.)

For the sea ice maximum in the month of March, the observed sea ice extent appears to be nearly identical to the simulated.

For the sea ice minimum in the month of September, the observed sea ice extent appears to be slightly greater than the simulated.

From this we can see that the climate model appears to do a good job of replicating the conditions that prevail in this highly sensitive region.