Drivers of 2016 record Arctic warmth assessed using climate simulations subjected to Factual and Counterfactual forcing
| Autor: | Martin P. Hoerling, Lesley Smith, Judith Perlwitz, Lantao Sun, Don Murray, Dave Allured, Jon Eischeid |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Atmospheric Science
geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Geography Planning and Development Lead (sea ice) Climate change lcsh:QC851-999 Management Monitoring Policy and Law 010502 geochemistry & geophysics 01 natural sciences Arctic ice pack Arctic Climatology Sea ice thickness Sea ice Environmental science lcsh:Meteorology. Climatology Climate model Sea ice concentration 0105 earth and related environmental sciences |
| Zdroj: | Weather and Climate Extremes, Vol 19, Iss, Pp 1-9 (2018) |
| ISSN: | 2212-0947 |
| Popis: | A suite of historical atmospheric model simulations is described that uses a hierarchy of global boundary forcings designed to inform research on the detection and attribution of weather and climate-related extremes. In addition to experiments forced by actual variations in sea surface temperature, sea ice concentration, and atmospheric chemical composition (so-called Factual experiments); additional (Counterfactual) experiments are conducted in which the boundary forcings are adjusted by removing estimates of long-term climate change. A third suite of experiments are identical to the Factual runs except that sea ice concentrations are set to climatological conditions (Clim-Polar experiments). These were used to investigate the cause for extremely warm Arctic surface temperature during 2016.Much of the magnitude of surface temperature anomalies averaged poleward of 65°N in 2016 (3.2 ± 0.6 °C above a 1980–89 reference) is shown to have been forced by observed global boundary conditions. The Factual experiments reveal that at least three quarters of the magnitude of 2016 annual mean Arctic warmth was forced, with considerable sensitivity to assumptions of sea ice thickness change. Results also indicate that 30–40% of the overall forced Arctic warming signal in 2016 originated from drivers outside of the Arctic. Despite such remote effects, the experiments reveal that the extreme magnitude of the 2016 Arctic warmth could not have occurred without consideration of the Arctic sea ice loss. We find a near-zero probability for Arctic surface temperature to be as warm as occurred in 2016 under late-19th century boundary conditions, and also under 2016 boundary conditions that do not include the depleted Arctic sea ice. Results from the atmospheric model experiments are reconciled with coupled climate model simulations which lead to a conclusion that about 60% of the 2016 Arctic warmth was likely attributable to human-induced climate change. Keywords: Arctic, Climate, Extreme, Model, Attribution |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|