24 January 2017

Heat Budget Analysis of Northern Hemisphere High-Latitude Spring Onset Events

Atmospheric dynamics induces Arctic spring onset.

Science

The study provides a comprehensive quantitative analysis of the physical sources responsible for rapid near-surface air temperature increases that occur in association with regional spring onset events within the Arctic atmosphere.  It is concluded that Arctic spring onset is primarily due to heat transport associated with atmospheric dynamical processes.

Impact

The physical understanding of Arctic spring onset is of fundamental importance to the study of seasonal transitions and how such transitions are likely to vary in association with anthropogenic global change.  Our results imply that accurate model simulations of Arctic spring onset are dependent upon proper representations of regional atmospheric dynamical processes.

Summary

The study first isolates four categories of spring onset events occurring in the following regions: the primary (critical) region over North Siberia, Greenland-North America, East Asia, and Alaska. Local changes in near-surface air temperature anomalies are decomposed into distinct dynamic and thermodynamic contributions using a heat budget analysis. The spatial and temporal structures of these dynamic and thermodynamic processes and their relative contributions to the sequential regional changes in temperature anomalies are investigated.  It is concluded that anomalous dynamical processes associated with synoptic eddy activity and quasi-stationary wave patterns are the primary contributors to the rapid temperature increases observed to occur during Arctic spring onset, with minimal contributions coming from anomalous diabatic processes.

Contact
Robert X Black
Georgia Institute of Technology School of Earth and Atmospheric Sciences
Publications
He, J. & Black, R. "Heat Budget Analysis of Northern Hemisphere High-Latitude Spring Onset Events." Journal of Geophysical Research 121, 10,113-10,137 (2016). [10.1002/2015JD024681].