Future Changes in Northern Hemisphere Summer Weather Persistence Linked to Projected Arctic Warming

Abstract

Understanding the response of the large‐scale atmospheric circulation to climatic change remains a key challenge. Specifically, changes in the equator‐to‐pole temperature difference have been suggested to affect the midlatitudes, potentially leading to more persistent extreme weather, but a scientific consensus has not been established so far. Here we quantify summer weather persistence by applying a tracking algorithm to lower tropospheric vorticity and temperature fields to analyze changes in their propagation speeds. We find significant links between slower propagating weather systems and a weaker equator‐to‐pole temperature difference in observations and models. By end of the century, the propagation of temperature anomalies over midlatitude land is projected to decrease by −3%, regionally strongest in southern North America (−45%) under a high emission scenario (CMIP5 RCP8.5). Even higher decreases are found (−10%, −58%) in models which project a decreasing equator‐to‐pole temperature difference. Our findings provide evidence that hot summer weather might become longer‐lasting, bearing the risk of more persistent heat extremes.

Document Details

Document Type
Pub Defense Publication
Publication Date
Feb 22, 2021
Source ID
10.1029/2020gl091603

Entities

People

  • Kai Kornhuber
  • Talia Tamarin‐Brodsky

Organizations

  • Climate Program Office
  • Columbia University
  • National Science Foundation
  • Office of Naval Research
  • University of Reading

Tags

Fields of Study

  • Environmental science

Readers

  • Atmospheric Science/Meteorology
  • Joint Military Operations and Doctrine.