06 December 2016

Projected Intensification of Subseasonal Temperature Variability and Heat Waves in the Great Plains


Compared to changes in the climatological mean temperature, we have less confidence in how much and by what mechanisms temperature variability may be affected by anthropogenic climate change. Here based on a 30-member climate change projection from an earth system model, we find summertime subseasonal temperature variability in the US Great Plains is enhanced by approximately 20% in 2070-2100 relative to 1980-2010. 


In particular daily temperature departures from the new climatologies during future heat waves are on average 0.6°C warmer than are the corresponding departures under present-day conditions. 


Although in both periods heat waves in the Great Plains tend to be associated with planetary wave events, the amplification of future heat waves does not appear to be induced by changes in planetary wave variability in the mid-latitudes. Instead, in this experiment the strengthening appears to be primarily caused by enhanced local land-atmosphere feedbacks resulting from a warmer/drier future climate.

Haiyan Teng
National Center for Atmospheric Research (NCAR)