首页 | 本学科首页   官方微博 | 高级检索  
     


The Impact of Arctic Ozone Depletion on Northern Middle Latitudes: Interannual Variability and Dynamical Control
Authors:Panos Hadjinicolaou  John A. Pyle
Affiliation:(1) Centre for Atmospheric Science, Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, U.K., E-mail
Abstract:We have investigated the effect of the export of Arctic ozone loss, or`dilution', on mid-latitude ozone depletion during the 1990s, and its relation tointerannual meteorological variability. A stratospheric chemical-transport modelincorporated a simple gas-phase ozone scheme with the addition of a parameterisation ofpolar depletion which depended only on temperature and duration of sunlight. Themodel was forced with the U.K. Meteorological Office analyses from 1991 to 1999 covering eight Northern Hemisphere winters. The modelled Arctic ozone column losses wereabout half the magnitude of those in the Antarctic and showed a considerablevariation from year to year. The northern middle latitudes (40°–60° N)were mainly affected through dilution and experienced a variable 5–20%depletion. Year-round there is a depletion of about 1% in northern middle latitudes due toactivation at the pole but there is no evidence that this depletion increases with timeduring this integration. A series of inert tracer experiments for the winters from 1996 to 1999 showed that the dilution occurs primarily at the 560 K and 465 K isentropic levels where up to 30% of the airoriginating northward of 67° N on 1 March is found at 47° N later in spring. Thestrength and persistence of the Arctic vortex were crucial in determining the severity and the timing of the ozone dilution every year by influencing, respectively, the magnitude of the high-latitude depletion and the effectiveness of mixing to lower latitudes. This spring dilution was correlated with the winter/spring planetary wave activity indicating the important role of dynamical processes in regulating the polar-driven mid-latitude ozone depletion.
Keywords:Arctic  middle latitudes  ozone depletion  interannual variability  waves
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号