Climate Change Impacts Around Pituffik Space Base, Greenland: Integration of In Situ Data and a CMIP6 Modeling Approach

Atmospheric blocking is an upper-atmosphere phenomenon where anticyclonic motion impedes the normal eastward flow over a region, resulting in greater meridional flow. Typically associated with high pressure, blocking can lead to changes in precipitation patterns, increased surface heating, and an influx of moisture to the affected region. Pituffik Space Base, located in northwest Greenland, is home to essential U.S. ballistic missile early warning systems and satellite communications networks. This base is under threat from changing surface conditions due to such extreme blocking events. In this region, blocking has often been quantified using the Greenland Blocking Index (GBI), which measures 500-hPa anomalies on a daily basis to determine whether a block is in place. Other methods exist, such as hierarchical and non-hierarchical cluster techniques, mixture model clustering, non-linear equilibrium methods, and measuring either strength of westerly flow or persistent height anomalies.

This project seeks to utilize a unique in situ data suite captured during an extreme atmospheric block, in conjunction with downscaled global climate model output to investigate how extreme blocking may impact Pituffik Space Base in both near-term and future climate scenarios. Multiple blocking metrics, in addition to GBI, were used to gain a robust understanding of how best to quantify blocking in this region. The CMIP6 model suite was used to explore connections between extreme blocks, precipitation patterns, Greenland ice sheet melt, and subsequent impacts on streamflow around Pituffik.