Contributions of Anthropogenic and Natural Forcing to Recent Tropopause Height Changes

摘要: Observations indicate that the height of tropopause—the boundary between stratosphere and troposphere—has increased by several hundred meters since 1979. Comparable increases are evident in climate model experiments. The latter show human-induced changes ozone well-mixed greenhouse gases account for80% simulated rise tropopause over 1979–1999. Their primary contributions through cooling (caused ozone) warming troposphere gases). A modelpredicted fingerprint is statistically detectable two different observational (“reanalysis”) data sets. This positive detection result allows us to attribute overall a combination anthropogenic natural external forcings, with component predominating. represents marked large thermal, dynamical, chemical structure atmosphere (1–3). Increases past decades have been iden