THE ARCTIC

Abstract

Disruptive environmental change in the Arctic continued in 2021. While few indicators were at record levels, the ongoing trends provide a stark illustration of an Arctic that is a very different place than the Arctic of the twentieth century. Air and ocean temperatures in the Arctic are intimately linked with sea ice and are directly connected to the biological productivity of the region. Terrestrial snow cover, or the lack thereof, plays an important role in modulating air temperatures and the hydrologic cycle. During the winter, lower latitude drivers such as the El Niño-Southern Oscillation, the Madden-Julian Oscillation, and the evolution of the stratospheric polar vortex affect regional conditions and sub-seasonal variability. These processes add to the complexity of annually assessing the state of the Arctic, despite numerous examples of observed broadscale directional change across the region.