Control of interannual and longer‐term variability of stratospheric water vapor

作者：Stephan A. Fueglistaler, Peter Haynes · 发表于：Journal of Geophysical Research Atmospheres · 年份：2005 · DOI：10.1029/2005jd006019 · 被引用次数：240 · 研究领域：Atmospheric Ozone and Climate、Climate variability and models、Atmospheric chemistry and aerosols

We use trajectory calculations based on 40‐year European Reanalysis (ERA‐40) data to predict the water mixing ratio of air entering the stratosphere in the tropics ([H2O]e) and thereby to examine interannual and longer‐term changes. [H2O]e is determined from the saturation mixing ratio of the coldest point during ascent from the troposphere to the stratosphere (the Lagrangian cold point). These model predictions for the time variation of [H2O]e agree very well with a broad range of measurements (Stratospheric Aerosol and Gas Experiment (SAGE) II, Halogen Occultation Experiment (HALOE), Microwave Limb Sounder (MLS), and Atmospheric Trace Molecule Spectroscopy (ATMOS)). During periods when measurements are consistent among various sensors and ERA‐40 temperatures show good agreement with radiosondes (1995–2002), the correlation between model predictions and HALOE water vapor anomalies in the tropical lower stratosphere is r = 0.81, as high as that between HALOE and SAGE II (r = 0.8). The model predictions suggest that the stratospheric quasi‐biennial oscillation, El Niño–Southern Oscillation, and possibly volcanic eruptions all play a significant role in modulating [H2O]e, leading to interannual anomalies of order 0.5 ppmv with timescales of several months to years. Although the Lagrangian calculations show substantial interannual variability of transport pathways into the stratosphere, the results show that the interannual anomalies of [H2O]e are dominated by anomalies of the z...