Abstract

Influencing factors, and variations and trends of Antarctic ozone hole in recent decades are analyzed, and sudden change processes of ozone at Zhongshan station and the effect of atmospheric dynamic processes on ozone changes are also discussed by using the satellite ozone data and the ground-measured ozone data at two Antarctic stations as well as the NCEP/NCAR reanalysis data. The results show that equivalent effective stratospheric chlorine (EESC) and stratospheric temperature are two important factors influencing the ozone hole. The column ozone at Zhongshan and Syowa stations is significantly related with EESC and stratospheric temperature, which means that even though the two stations are both located on the edge of the ozone hole, EESC and stratospheric temperature still played a very important role in column ozone changes, and mean while verifies that EESC is applicable on the coast of east Antarctic continent. Decadal changes in EESC are similar with those of the ozone hole, and inter-annual variations of ozone are closely related with stratospheric temperature. Based on the relation of EESC and ozone hole size, it can be projected that the ozone hole size will gradually reduce to the 1980’s level from 2010 to around 2070. Of course there might exist many uncertainties in the projection, which therefore needs to be further studied. Bian, L.-G., Z. Lin, X.-D. Zheng, et al., 2012: Trend of Antarctic ozone hole and its influencing factors. Adv. Clim. Change Res., 3 (2), doi: 10.3724/SP.J.1248.2012.00068.

Abstract

The annual and seasonal trends in pan evaporation in the lower Yellow River Basin based on quality-controlled data from 10 meteorological stations in 1961–2010 are analyzed. The causes for the changes in annual and seasonal pan evaporation are also discussed. The results suggest that, despite the 1.15°C increasing in annual mean surface air temperature over the past 50 years (0.23°C per decade), the annual pan evaporation has steadily declined by an average rate of −7.65 mm per year. By comparison, this change is greater than those previously reported in China. Significant decreasing trends in annual pan evaporation have been observed at almost all stations. As a whole, seasonal pan evaporation decreased significantly, especially in summer, whereas seasonal temperature increased significantly, except in summer. Thus, the pan evaporation paradox exists in the lower Yellow River Basin. The trend analysis of other meteorological factors indicates significant decrease in sunshine duration and wind speed, but no significant variations in precipitation and relative humidity at annual and seasonal time scales. By examining the relationship between precipitation and pan evaporation, it did not show a concurrent decrease in pan evaporation and increase in precipitation. The partial correlation analysis discovered that the primary cause of decrease in annual and seasonal pan evaporation is the decrease in wind speed. A further examination using a stepwise regression shows that decrease in wind speed and sunshine duration, and increase in mean temperature are likely to be the main meteorological factors affecting the annual and seasonal pan evaporation in the lower Yellow River Basin over the past 50 years. Ji, X.-J., J.-J. Wang, W.-L. Gu, et al., 2012: Trends in annual and seasonal pan evaporation in the lower Yellow River Basin from 1961 to 2010. Adv. Clim. Change Res., 3 (4), doi: 10.3724/SP.J.1248.2012.00195.

Abstract

The emission control of non-CO2 greenhouse gases is conducive to slowing down global warming. It is also helpful in controlling environmental pollution, and beneficial in improving the local health benefits. This paper aims at six kinds of non-CO2 greenhouse gases under United Nations Framework Convention on Climate Change, namely methane (CH4 ), nitrous oxide (N2 O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6 ), and nitrogen trifluoride (NF3 ). This paper analyzes the emission status and trend of China’s non-CO2 greenhouse gases, and provides some technology selections for non-CO2 emission reduction. Through strategic policy arrangements and appropriate technology choices, China can gain environmental protection and greenhouse gas control. Zhou, Y.-M., and Y.-S. Feng, 2014: The strategy and technology selection for non-CO2 greenhouse gas emission control. Adv. Clim. Change Res ., 5(1), doi: 10.3724/SP.J.1248.2014.028.

Abstract

The study investigated the trend of extreme flood events in the Pearl River basin during 1951–2010. Stream flow data at 23 gauging stations were used for the study. The Pearson type III distribution was selected for the flood frequency analysis. Results indicate that extreme flood events increase significantly in the Pearl River Basin since 1980. At the 23 gauging stations, there are 16 (70%) stations show positive (increasing) trends in 1981–2010. Most of the 16 stations are located along the West River and North River. While 7 (30%) stations show negative (decreasing) trends, and are found in the East River and the southeast region of the West River Basin. Wu, Z.-Y., G.-H. Lu, Z.-Y. Liu, et al., 2013: Trends of extreme flood events in the Pearl River Basin during 1951–2010. Adv. Clim. Change Res., 4 (2), doi: 10.3724/SP.J.1248.2013.110.