properties of dust storms would be welcome. As discussed in Chapter 4, a cooperative international program called the China and America Air-Sea Experiments (CHAASE), studying the compositions of aerosols and rain over eastern Asia, has been carried out since 1990 (Arimoto et al. 1990, Gao et al. 1992a,b). As part of the Tropical Ocean and Global Atmosphere (TOGA) program, compositions of rain and aerosol samples collected over the Pacific were analyzed under a collaborative experiment between the Chinese National Research Center for Marine Environment Forecasts at the State Oceanographic Administration and NOAA.

At least four institutions, the CAS Institute of Atmospheric Physics, SMA, the CAS University of Science and Technology of China, and Peking University, are engaged in the development of one- and two-dimensional models for stratospheric chemistry studies. The CAS Institute of Atmospheric Physics and SMA have sent scientists to work with modelers in the United States.³ Total O₃ is measured regularly by CAS Institute of Atmospheric Physics scientists at a station in Beijing and another in Yunnan Province. Ground-based remote sensing techniques for measuring stratospheric trace gases such as O₃ and nitrite (NO₂) are under development at Peking University, CAS Anhui Institute of Optics and Fine Mechanics, and CAMS. Of particular interest are the measurements of O₃ and NO₂ column abundances at the Chinese Great Wall Station in Antarctica (Mao 1990). NEPA has been collecting data on halon and chlorofluorocarbon (CFC) consumption over the past several years, which have been reported through the United Nations Development Program (UNDP 1992).

Because most of the stratospheric observations and laboratory measurements are carried out in the United States and Europe, Chinese modelers do not often have timely access to these data sets. Computer facilities are also somewhat inadequate to run fully coupled two-dimensional transport and chemical models efficiently. As a result, the status of stratospheric models in China is not as advanced as those in developed countries. In particular, lack of access to observational data is a serious limitation for the development of Chinese stratospheric models.

National-scale programs on the measurement of precipitation chemistry are being performed by NEPA and SMA and on the regional