Influence of high-latitude blocking and the northern stratospheric polar vortex on cold-air outbreaks under Arctic amplification of global warming

Environmental Research Climate, Journal Year: 2024, Volume and Issue: 3(4), P. 042004 - 042004

Published: Nov. 18, 2024

Abstract It is widely accepted that Arctic amplification (AA)—enhanced warming relative to global warming—will increasingly moderate cold-air outbreaks (CAOs) the midlatitudes. Yet, some recent studies also argue AA over last three decades rest of present century may contribute more frequent severe winter weather including disruptive cold spells. To prepare society for future extremes, it necessary resolve whether and midlatitude are coincidental or physically linked. Severe events in northern continents often related a range stratospheric polar vortex (SPV) configurations atmospheric blocking, but these dynamical drivers complex still not fully understood. Here we review research advances paradigms nonlinear theory blocking helps explain location, timing duration AA/midlatitude connections, vortex’s zonal asymmetric intra-seasonal variations, its southward migration continents, surface impacts. We highlight novel understanding SPV variability—polar stretching stratosphere–troposphere oscillation—that have remained mostly hidden predominant focus on sudden warmings. A physical explanation two-way vertical coupling process between highs, taking into account local conditions, remains elusive. conclude evidence exists tropical preconditioning Arctic-midlatitude climate linkages. Recent using very large-ensemble modelling provides an emerging opportunity robustly quantify internal variability when studying potential response CAOs sea-ice loss.

Language: Английский

Emergence of Arctic Extremes

Climate, Journal Year: 2024, Volume and Issue: 12(8), P. 109 - 109

Published: July 27, 2024

Recent increases in extreme events, especially those near and beyond previous records, are a new index for Arctic global climate change. They vary by type, location, season. These record-shattering events often have no known historical analogues suggest that other surprises store. Twenty-six unprecedented from 2022, 2023, early 2024 include record summer temperatures/heatwaves, storms, major Canadian wildfires, continental snow melt, Greenland sea temperatures of 5–7 °C above normal, drought Iceland, low northern Alaskan salmon runs. Collectively, such diverse extremes form consilience, the principle evidence independent, unrelated sources converge as strong indicator ongoing behaviors represent emergent phenomenon. Emergence occurs when multiple processes interact to produce properties, interaction amplification with normal range weather events. Examples typhon Merbok resulted extensive coastal erosion Bering Sea, melt Svalbard. The can now be considered different state before fifteen years ago. Communities must adapt intermittent avoid worst-case scenarios.

Language: Английский