Arctic and Antarctic ice Surface Temperatures from AVHRR thermal Infrared satellite sensors, 1982-2015.

The new version of the Arctic and Antarctic ice Surface Temperatures from thermal Infrared satellite sensors (AASTI v2) Climate Data Record (CDR) is produced. AASTI v2 covers high latitude Seas, Marginal Ice Zone, Sea Ice and Ice Cap surface temperatures North of 50 degree North and South of 50 degree South for the period 1982 to 2015. The data set is based on Global Area Coverage (GAC) data from AVHRR instruments on board NOAA and METOP satellites. AASTI is produced as a swath based surface temperature CDR in satellite view projection (level 2) and as a daily mean surface temperature CDR in a fixed regular grid (level-3). The resolution of the level-2 data set is multiple daily coverage with 4 km spatial resolution and the level-3 data are daily values in 0.25 arc degree resolution. The level 3 data set also contains 3 hourly mean temperature fields in order to preserve a high degree of the diurnal temperature variability.

The Ice and Sea Surface Temperature (IST/SST) retrieval algorithms are adapted from the operational integreted IST/SST product from EUMETSAT's Ocean and Sea Ice Satellite Application Facility (OSISAF). The Standard Deviation of errors (std) and biases of the data set are estimated for three environments: For Arctic sea ice, std=3.0 K and bias=-2.1 K; in open North Atlantic water, std=0.7 K and bias=-0.3 K and at Greenland Summit, std=2.6 K and bias=-3.1 K. The in situ measurements used for Greenland Summit are 2 meter air temperatures and the applied in situ measurements for the Arctic sea ice were measurements by traditional drifting buoys. It has previously been documented that temperatures from these platforms may deviate largely from the actual surface temperature and therefore also from the radiometric temperatures measured from space.

Based on the AASTI v2 CDR the first satellite based Sea Ice Surface Temperature climatology is presented. Monthly mean sea ice surface temperature climatology and trends for the Arctic Ocean and Southern Ocean are presented, as well as a comparison with corresponding ERA Interim surface temperatures.