Interpretation of Mid-Stratospheric Arctic Ozone Measurements Using a Photochemical Box-Model     

Sinnhuber  B.-M.  Müller  R.  Langer  J.  Bovensmann  H.  Eyring  V.  Klein  U.  Trentmann  J.  Burrows  J. P.  Künzi  K. F. 《Journal of Atmospheric Chemistry》1999,34(3):281-290

In this study measurements of mid-stratospheric Arctic ozone are compared with model simulations. The measurements obtained at Spitsbergen (79°N, 12°E) by ground based millimeter-wave radiometry exhibit large day to day variabilities as well as periods with low ozone. To interpret these measurements, calculations were made using the new photochemical box-trajectory model BRAPHO, with air parcel trajectories calculated from analyzed wind fields. Using a relatively simple approach, the model reproduces the observed ozone variability well, including inter-annual variations. The explanation for the observed ozone behavior is that at these altitudes ozone is determined by what we call dynamically controlled photochemistry. This means that the photochemical evolution of the ozone volume mixing ratio is mainly controlled by the atmospheric dynamics, in particular the solar zenith angle the air parcel has experienced.  相似文献   

Impact of Accurate Photolysis Calculations on the Simulation of Stratospheric Chemistry     

Jörg Trentmann  Heinrich Bovensmann  Veronika Eyring  Richard W. Müller  John P. Burrows 《Journal of Atmospheric Chemistry》2003,44(3):225-240

The interpretation of atmospheric measurements and the forecasting of the atmospheric composition require a hierarchy of accurate chemical transport and global circulation models. Here, the results of studies using Bremens Atmospheric Photochemical Model (BRAPHO) are presented. The focus of this study is given to the calculation of the atmospheric photolysis frequencies It is shown that the spectral high resolved simulation of the O₂ Schumann–Runge bands leads to differences in the order of 10% in the calculated O₂ photolysis frequency when compared with parameterizations used in other atmospheric models. Detailed treatment of the NO absorption leads to even larger differences (in the order of 50%) compared to standard parameterizations. Refraction leads to a significant increase in the photolysis frequencies at large solar zenith angles and, under polar spring conditions, to a significant change in the nighttime mixing ratio of some trace gases, e.g., NO₃. It appears that recent changes in some important rate constants significantly alter the simulated BrO_x- and HO_x-budgets in the mid-latitude stratosphere.  相似文献