Extreme temperature and precipitation response to solar dimming and stratospheric aerosol geoengineering

摘要: Abstract. We examine extreme temperature and precipitation under two potential geoengineering methods forming part of the Geoengineering Model Intercomparison Project (GeoMIP). The solar dimming experiment G1 is designed to completely offset global mean radiative forcing due to a CO2 -quadrupling (abrupt4  ×  CO2), while in GeoMIP G4, representative concentration pathway 4.5 (RCP4.5) scenario partly by a simulated layer aerosols in stratosphere. Both G4 geoengineering simulations lead lower minimum temperatures (TNn) at higher latitudes and on land, primarily through feedback effects involving high-latitude processes such as snow cover, sea ice soil moisture. There larger cooling TNn and maximum (TXx) over land compared with oceans, the land–sea contrast for TXx than TNn. Maximum 5-day precipitation (Rx5day) increases subtropical whereas warm spells (WSDI) decrease markedly tropics, number consecutive dry days (CDDs) decreases most deserts. during tropical cyclone (hurricane) seasons becomes less intense, whilst remainder the year wetter. Stratospheric aerosol injection more effective than solar moderating (and flooding). Despite the magnitude applied being ∼  7.7 times larger despite differences chemistry and transport schemes amongst models, two types show similar spatial patterns normalized temperatures changes. Large mainly occur northern high latitudes, where stratospheric effectively reduces TNn TXx. While the pattern more complex that temperatures, generally stratospheric aerosol injection reducing tropical Rx5day, dimming is extra-tropical regions.