Simulation of Stratospheric Ozone in the KIAPSGM NWP model using linear photochemistry parameterization

Abstract:

Stratospheric ozone plays important roles in the Earth’s weather and climate systems due to its physiochemical properties and a wide range of spectral absorption. Because of complicated chemical equations and expensive computational cost, NWP community has introduced a linear photochemistry parameterization (LPP) that Cariolle and Déqué suggested in 1986 with an insight of ozone-temperature relationships, to weather forecasting system. In this study, we simulated stratospheric ozone using recent LPP coefficients in a numerical weather prediction (NWP) model, the KIAPS-GM (Korea Institute of Atmospheric Prediction Systems - Global Model), and evaluated model results with observations.

The KIAPS-GM uses three dimensional hydrostatic dynamical core based on the High-Order Method Modeling Environment (HOMME) in cubed sphere with a horizontal resolution of ne30np4 and 70 vertical layers up to 85km. LPP scheme was fully implemented into the KIAPS-GM including the ozone tracer advection. Prognostic ozone was estimated through interaction with local ozone field, temperature field, and radiation field as those physics fields were updated while climatological ozone (Fortuin and Kelder, 1998) was constantly fed into radiation fields in every month. ERA-interim ozone and meteorological data (Dee et al., 2011) were used as initial data. Simulation period was year 2008 when larger ozone hole events occurred than usual. We compared interactive ozone case with climatological ozone case. For the sensitivity studies to initial ozone fields and LPP coefficients, ERA-interim hourly and monthly ozone data were used; and LPP coefficients such as Cariolle and Teyssadre (2007) and Monge-Sanz et al. (2011) were interpolated into instantaneous pressure levels, respectively. Preliminary results show that the ozone concentration in interactive ozone case is higher than climatological one in the lower stratosphere and troposphere while the former is lower than the latter in the upper atmosphere. It leads to the cooler in the upper atmosphere but the warmer in the lower stratosphere and troposphere. We analyzed the discrepancies between our simulation results and observations such as ozone sonde data, SBUV-2 (Solar Backscattering UV radiometer) and MLS (Microwave Lim Sounder).