Northern Hemispheric cryosphere response to volcanic eruptions in the Paleoclimate Modeling Intercomparison Project 3 last millennium simulations

Abstract

AbstractWe analyzed last millennium simulations (circa 850–1850 Common Era) from the Paleoclimate Modeling Intercomparison Project 3 (PMIP3) project to determine whether current state‐of‐the‐art models produce sudden changes and persistence of cold conditions after large volcanic eruptions as inferred from geological records and previous climate modeling. Snow cover over Baffin Island in the eastern Canadian Arctic shows large‐scale expansion (as seen in proxy records) in two of the five models with snow cover information available, although it is not sustained beyond a decade. Sea ice expansion in the North Atlantic is seen in some PMIP3 models after large eruptions, although none of these models produce significant centennial‐scale effects. Warm Baffin Island summer climates stunt snow expansion in some models completely, and model topography tends to miss the critical plateau elevations that could sustain snow on the island. Northern Hemisphere sea ice extent is lower in six of the eight models than in reconstructions over the past millennium. Annual average Northern Hemisphere mean climates have a range of 3 K across models, while Arctic summer land‐only climates span more than 6 K. This has critical consequences on ice and snow formation and persistence in regions such as the Arctic where temperatures are near the freezing point and small temperature changes affect ice and snow feedback that could induce further climate changes. Thus, it is critical that models accurately represent absolute temperature.