Introduction to major achievements
SCAS/CERN is composed of a group of high-level researchers including professors, associate professors, engineers, Ph. D and Masters. SCAS is under the leadership of Institute of Atmospheric Physics. SCAS possesses advanced instruments and technique-supporting system, including automatic observation system for exchange study of surface and atmosphere that are listed below in detail:
 GC/MS for CFCs;
 NMHC and TVOCs;
 GC/AED;
 FTIR/ GC/FTIR;
 RCFP-IC for aerosol measurement;
 Routine observation instruments for CO2,O3,NOx,CO and SO2 measurement et al.;
 Solar radiation observation and calibration system;
 Routine meteorological and micro-meteorological observation and calibration system;
The hardware of SCAS includes workstation, server, disk array, tape machine, recorder, scanner, Auto CAD, digitizer, graph plotter. The information system is composed of four parts: Database, GIS, Image processing software, Statistical software. The researches of SCAS include not only field experiments, but also numerical model study. SCAS takes the state needs and international focuses into its major study field.
Research projects the Center has been carried out include High-Tech Research and Development Program, national Basic Research Priorities Program, international cooperation projects, National Natural Science Foundation et al. The important technique tasks include taking charge of radiometer calibration and data quality control of 36 stations of CERN; 16 greenhouses observation stations; 5 regional base stations. SCAS assumed three key research projects during 1991 to 1995 and four major projects and four international cooperation projects during 1996 to 2000. The key program ?Study on Measurement Technologies and Emission Process of Greenhouse Gases from the Agriculture Ecosystem? was awarded the second-class award of China National Progress in Sciences and Technology of 2001. We invented automatic observation system and obtained two national patents, in addition, a monograph was published in 2001 and nearly 100 research papers were published during the recent 5 years. Moreover, a large number of postgraduates were cultivated.
Major achievements:
 ?Automatically sampling and analyzing system for measurement of methane and N2O?, which was original and obtained National patent
 Four daily variation types in CH4 emission were discovered, which were decided by CH4 transportation channel including air bubble, molecule dispersion and crop emission, other than production ratio
 Cultivating system in China may decrease CH4 emission by 26 to 46 percent; and the increase of N2O emission due to cultivating is negligible. The quantitative relation between N2O within agricultural ecological system and soil water was discovered. Suitable water managements may decrease CH4 emission by 26 to 70 percent with no cost of decrease in rice production.
 The first generation of CH4 emission numeral model for rice paddy was created and total emission in China was calculated to be 9~13 Tg/a with the help of the model. Moreover, global total emission of CH4 was estimated to be 35~50Tg/a.
 Organic fertilizer was discovered to be an important reason for increasing CH4 emission, so decomposed organic fertilizer such as compost may decrease CH4 emission by 50%, in addition, combined use of organic and chemical fertilizer may reduce CH4 and N2O emission of rice paddy.
 Research on greenhouse gases emission and its effects on climate and environment is focus of international atmospheric chemistry. Many attentions were paid to CH4, N2O and NO emission in Chinese rice paddy by international society, especially, many developed countries demand unreasonably that China assume responsibility for greenhouse gases mitigation by using of , so it?s of significance to carry out research on greenhouse gases emission in China, not only for science, but for policy making ensuring sustainable development in our country and scientific foundation for diploma dialogue.