Northern Hemisphere atmospheric stilling accelerates lake thermal responses to a warming world

Citation

Woolway RI, Merchant CJ, Van Den Hoek J, Azorin-Molina C, Nõges P, Laas A, Mackay EB & Jones ID (2019) Northern Hemisphere atmospheric stilling accelerates lake thermal responses to a warming world. Geophysical Research Letters, 46 (21), pp. 11983-11992. https://doi.org/10.1029/2019GL082752

Abstract
Climate change, in particular the increase in air temperature, has been shown to influence lake thermal dynamics, with climatic warming resulting in higher surface temperatures, stronger stratification, and altered mixing regimes. Less-studied is the influence on lake thermal dynamics of atmospheric stilling, the decrease in near-surface wind speed observed in recent decades. Here we use a lake model to assess the influence of atmospheric stilling, on lake thermal dynamics across the Northern Hemisphere. From 1980-2016, lake thermal responses to warming have accelerated as a result of atmospheric stilling. Lake surface temperatures and thermal stability have changed at respective rates of 0.33 and 0.38°C decade-1, with atmospheric stilling contributing 15 and 27% of the calculated changes, respectively. Atmospheric stilling also resulted in a lengthening of stratification, contributing 23% of the calculated changes. Our results demonstrate that atmospheric stilling has influenced lake thermal responses to warming.

Keywords
lake; climate; wind

Journal
Geophysical Research Letters: Volume 46, Issue 21