Classification of Northern Hemisphere stratospheric ozone and water vapor profiles by meteorological regime

摘要

The subtropical and polar upper troposphere fronts and the polar vortexserve as the boundaries to divide the Northern Hemisphere into fourmeteorological regimes. These regimes are defined as (1) the arctic regime– within the polar vortex, (2) the polar regime – between the polar frontand the polar vortex, or when the latter is not present, the pole, (3) themidlatitude regime – between the subtropical and polar fronts, and (4) thetropical regime – between the equator and the subtropical front.Data from the Halogen Occultation Experiment (HALOE) and the StratosphericAerosol and Gas Experiment II (SAGE II) were used to show that within eachmeteorological regime, ozone and water profiles are characterized by uniqueozonepause and hygropause heights. Daily measurements and seven-year(1997–2003) monthly climatologies showed that, within each meteorologicalregime, both constituents exhibited distinct profile shapes from thetropopause up to approximately 20 km. This distinction was most pronouncedin the winter and spring months, and weak in the summer and fall. Despitedifferences in retrieval techniques and sampling between the SAGE and HALOEinstruments, the seven-year monthly climatologies calculated for each regimeagreed well for both species below ~22 km.Given that profiles of ozone and water vapor exhibit unique profiles shapeswithin each regime in the UTLS, trends in this region will therefore be theresult of both changes within each meteorological regime, and changes in therelative contribution of each regime to a given zonal band over time.