Seasonal distribution of ozone and radiation field at the stratosphere

The coupled chemistry-climate model WACCM3 (Whole Atmosphere Community Climate Model) developed by NCAR is applied to study the seasonal variations of the stratospheric temperature, wind, ozone and radiation fields. The stratospheric quasi-zero wind layer at around 20～22km (i.e., atmosphere pressure range is 50～30hPa), where the wind speed is less than 5m·s^-1 and is stable to the north of 40°N during July and August, is suitable for long-term stay of airships. There appears a belt of ozone at 30hPa over China and ozone concentrations are greater in the mid-latitudes than in the lower latitudes below 30hPa. There are significant seasonal spatial variations in solar heating rates in the stratosphere. In the upper stratosphere, the maximum solar heating rate reaches 100×10^-6K·s^-1 while in the lower stratosphere the maximum solar heating rate is only 10×10^-6K·s^-1. The solar heating rate is greater in June to August than in September over China. The solar heating rate is greater in the mid-latitudes than in the lower latitudes between 100hPa and 30hPa and is greater in the lower latitudes than in the mid-latitudes above 30hPa. The change of solar heating rate is small in August and September at 30hPa and 40hPa. The maximum diurnal variation of solar heating rate appears at 40°N at 30hPa. At 50hPa, the diurnal variation of solar heating rate is smaller than that at 40hPa and the maximum variation occurs farther south. The longwave heating rate is smaller in the lower latitudes than in the mid-latitude stratosphere. In particular condition of terrain, the ozone concentration, solar heating rate and longwave heating rate are smaller over Tibetan Plateau than other areas at the same latitude.