Analysis of China's Haze Days in the Winter Half-Year and the Climatic Background during 1961–2012

The characteristics of haze days and the climatic background are analyzed by using daily observations of haze,precipitation,mean and maximum wind speed of 664 meteorological stations for the period of 1961–2012.The results show that haze days occur significantly more often in eastern China than in western China.The annual number of haze days is 5–30 d in most parts of central-eastern China,with some areas experiencing more than 30 d,while less than 5 d are averagely occurring in western China.Haze days are mainly concentrated in the winter half-year,with most in winter,followed by autumn,spring,and then summer.Nearly 20%of annual haze days are experienced in December.The haze days in central-eastern China in the winter half-year have a significant increasing trend of 1.7 d per decade during 1961–2012.There were great increases in haze days in the 1960s,1970s and the beginning of the 21st century.There was also significant abrupt changes of haze days in the early 1970s and 2000s.From 1961 to 2012,haze days in the winter half-year increased in South China,the middle-lower reaches of the Yangtze River,and North China,but decreased in Northeast China,eastern Northwest China and eastern Southwest China.The number of persistent haze is rising.The Longer the haze,the greater the proportion to the number persistent haze.Certain climatic conditions exacerbated the occurrence of haze.The correlation coefficient between haze days and precipitation days in the winter half-year is mainly negative in central-eastern China.The precipitation days show a decreasing trend in most parts of China,with a rate of around–4.0 d per decade in central-eastern China,which reduces the sedimentation capacity of atmospheric pollutants.During the period of 1961–2012,the correlation coefficients between haze days and mean wind speed and strong wind days are mainly negative in central-eastern China,while there exists positive correlation between haze days and breeze days in the winter half-year.The mean wind speed and strong wind days are decreasing,while breeze days are increasing in most parts of China,which is benefitial to the reduction of the pollutants diffusion capacity.As a result,haze occurs more easily.

IMPACT OF ENSO ON THE PRECIPITATION OVER CHINA IN WINTER HALF-YEARS

In this paper, the impact of ENSO on the precipitation over China in the winter half-year is investigated diagnostically. The results show that positive precipitation anomalies with statistical significance appear over southern China in El Nio episodes, which are caused by the enhanced warm and humid southwesterlies along the East Asian coast in the lower troposphere. The enhanced southwesterlies transport more water vapor to southern China, and the convergence of water vapor over southern China increases the precipitable water and specific humidity. In La Nia episodes,although atmospheric elements change reversely, they are not statistically significant as those in El Nio periods. The possible physical mechanism of the different impact of ENSO cycle on the precipitation over southern China is investigated by analyzing the intraseasonal oscillations(ISOs) in El Nio and La Nia winter half-years, respectively. By comparing the characteristics of ISOs in El Nio and La Nia, a physical mechanism is proposed to explain the different responses of the precipitation over China to ENSO in the winter half-year. In El Nio episodes, over western North Pacific(WNP) and South China Sea(SCS) the ISOs are inactive and exert little effect on water vapor transport and convergence, inducing positive precipitation anomalies with statistical significance over southern China in El Nio episodes. In La Nia episodes, however, the ISOs are active, which weaken the interannual variation signals of ENSO over WNP and southern China and lead to the insignificance of the interannual signals related to ENSO. Therefore, the different responses of precipitation over China to ENSO in the winter half-year are possibly caused by the difference of intraseasonal oscillations over WNP and SCS between El Nio and La Nia.

Progress in China's geological exploration in the first half year of 2018

In the first half year of 2018,there were changes in China's economic,industrial structure and the changes in government's policy on land and mineral resources.China's geological exploration is continued to maintain a trend of the growth.The fund investment in geological exploration declined and the impetus for investment in initial exploration was insufficient.The mining market showed a good development trend and the social investment depicted a slight rise.In the first half of the year,the investments in hydrogeologic exploration,environmental geology exploration and geological disaster investigation increased on the year-onyear basis.

Reconstruction of Sub-Decadal Winter Half-Year Temperature during 1651-2010 for the North China Plain Using Records of Frost Date

We extracted 374 pieces of records of frost date from historical documents. Using these records, we reconstructed winter half-year (October to next April) temperature series, with a resolution of 5-year, for the North China Plain during 1651-2010. The results show that the temperature changes in the North China Plain were divided into four phases. With the reference period of 1951-1980, two cold phases, 1651-1700 and 1781-1900, have cold anomaly of 0.83°C and 0.60°C respectively. However, between the two cold phases, 1701-1780 was a relative warm phase with the cold anomaly of 0.36°C referring to the mean of 1951-1980. After the 1900, the climate came into a warm phase. The mean temperature of 1901-2010 was 0.11°C higher than the mean of 1951-1980. During 1651-2010, the 1996-2000 is the warmest 5-year with the warm anomaly of 1.25°C than that of the reference period of 1951-1980.

Two and a Half Thousand Years of Navigation on the Dead Sea

Today there is a single ship on the Dead Sea:a vessel that makes monthly research cruises.But in earlier periods many kinds of boats sailed the waves of the saltiest of all lakes.Stone and wooden anchors found on the newly

Status Quo in the First Half Year of 2010

The first half year of 2010 has already been one part of the history. Usually, for textile industry, we would like to give some summary words about the economic operation for the first six months: the whole textile industry saw a stable development; however, confronting with the complicated external and internal economic environment, several unstable elements would still challenge the comprehensively stable industrial development.

Technical Textiles: 30% Growth in the First Half Year

Cinte Techtextil China 2010 will return to Shanghai from October 19th–21st, presenting opportunities for China’s ever-growing nonwovens and technical textiles industries. What’s about the status quo of the technical textile industry in China in the first half year of

Scanning the Year's Half:Hotspot Issues

The textile industry is growing at a slow speed against backdrop of outrageous rise in raw materials, energy, wages, yuan’s appreciation etc.. Three hot issues are more obviously brought into spotlight to be seen as most important factors that weigh a lot on the economic growth during the first half of the year and defi nitely the second half to come.A half of 2008 has elapsed, and the fore part of the year is mingled with hopes and worries, but the industry has managed to voyage on in the troubled waters. Reviewing the situation in perspectives, [[China Textile]] has summed up three hotspot issues that played protagonists in China’s textile industry: Firstly, outside-in sales from outbound shipment to homebound march on, secondly, the industry’s development is restricted by fund shortage; thirdly, the industrial adjustment and production relocation are still in progress.