North Atlantic Climate Dynamics

Atmospheric blocking in the North Atlantic alters normal climates across Europe and Russia by shifting storm tracks. Typically associated with an anticyclone, the zonal wind pattern known as the jet stream deviates from its mean position and its westerly winds reroute north and south of the anticyclone. In addition, the normal meridional gradient of geopotential height is reversed. This results in anomalous temperature and precipitation events, such as the 2010 Russian heat wave and cold winter extremes in west Europe. The severity of these extreme weather events and their increased frequency is a cause for concern; therefore, influences that may amplify or weaken the frequency of blocking in addition to better forecasting blocking is an ongoing scientific investigation. Yet, The atmospheric jet and blocking distributions, especially in the North Atlantic sector, have been challenging features for a climate model to realistically reproduce.

One potential factor influencing blocking is the sea surface temperatures(SST). Research has been done on whether natural climate variations, anthropogenic influence, or a combination of both are causing the warming of sea surface temperatures (SST) in the North Atlantic. The Atlantic Multidecadal Oscillation (AMO), the natural variability of SST in the North Atlantic impacting regional climates across North America and the subtropics and tropics of the Northern Hemisphere, potentially plays a significant role in the variability of blocking.

This research examines the relationship between the AMO and atmospheric blocking in the North Atlantic using the CESM1LE Model.