CHANGING CLIMATE IN POLAR REGIONS FROM MICROWAVE AND INFRARED DATA

Abstract. This study reveals that the climate in the polar region may be experiencing a transition towards a different phase of change than what has been expected only a few decades ago. In the Arctic basin, the rapid decline in the perennial ice cover has been regarded as an important indicator of anthropogenic climate change with a high value of about 8 × 106 km² in 1980 and low value of only 3.4 × 106 km² in 2012. Since 2012, however, the sea ice cover remained relatively low but did not change much suggesting a more stable perennial ice cover. On the other hand, the sea ice cover in the Antarctic has been reported as having a positive trend with a record high of more than 20 × 106 km² in 2014 but has been declining abruptly starting in 2015 with 2023 having record lows continuously every month including the current month of June 2023. Such phenomenon for both the Northern and Southern Hemispheres is intriguing and appears not to be very well correlated with observed changes in surface temperature as also derived from satellite data. These developments suggest a need to better understand the role of changes in other variables such the amount of freshwater, wind patterns, water circulation and tropospheric temperature as well as effects of ENSO and PDO on the observed changes and trends.