Comparison of ozone profiles between DIAL observations and chemical transport model simulations over Río Gallegos, Argentina in the 2009 Antarctic spring

T. SUGITA; H. AKIYOSHI; M. KADOWAKI; H. NAKAMURA, E. WOLFRAM, J. SALVADOR, AND A. MIZUNO

Kobe

Conferencia; The 13 th Atmospheric Sciences and Application to Air Quality (ASAAQ13); 2015

Meteorological Society of Japan, National Institute for Environmental Studies, and RIKEN Advanced Institute for Computational Science et al.,

We have started a project on research of ozone/UV and aerosol in South America since 2013. This project is supported by Japan Science and Technology Agency (JST) and Japan International Cooperation Agency (JICA) under SATREPS program in collaboration with CEILAP in Argentina and Magellan University in Chile. The monitoring of ozone at the South Patagonian Atmospheric Observatory (OAPA , 51.6S, 69.3W) in Río Gallegos, Argentina is one of the essential part of this project. Whereas in NIES, a chemical transport model (CTM) has been developed to study chemical and dynamical processes in the stratosphere. This model, the MIROC3.2-CTM, incorporates a chemical module into the MIROC3.2-GCM using horizontal winds (and temperature) nudged toward ECMWF Reanalysis (ERA)-Interim data. To examine a performance of the model simulation, the calculated ozone profiles were compared with those observed by a DIfferential Absorption Lidar (DIAL) at OAPA between 300 hPa and 5 hPa. We focus on a period of November 2009 when a persistent ozone decrease was found (e.g., de Laat et al., Geophys. Res. Lett., 2010; Wolfram et al., Ann. Geophys., 2012). In general, the calculated ozone values in the lower stratosphere (below ~30 hPa) are larger than those of DIAL on the seven measurement days. Above ~30 hPa, the calculated ozone values are smaller than those of DIAL; the differences exceed 2 ppmv at the most. To further examine such discrepancies, we verify latitudinal differences (within ±5) of the ozone profiles using the Microwave Limb Sounder (MLS) measurements (http://mls.jpl.nasa.gov/). In some cases below ~30 hPa where the model/DIAL difference is found, the model agrees with MLS. It may suggest small scale differences that are difficult to capture either by model or MLS. The large differences between the model and DIAL (or MLS) are still evident in early Nov. above ~30 hPa where the latitudinal change in MLS is small, suggesting a larger ozone destruction or a weaker transport in the model. The measurement of high vertical resolution ozone profiles in the southern high latitude is very unique, so that such comparisons give us a good opportunity for validating vertical structures of ozone reproduced in the model.