A preliminary cause analysis of extremely less precipitation in Heilongjiang Province in July 2020 was carried out by using the monthly precipitation data at 62 meteorological stations of Heilongjiang Province, reanalysis data from National Center for Environmental Prediction and circulation indices from National Climate Center of China Meteorological Administration, etc. Results are as follows: (1) The precipitation was abnormally less in Heilongjiang in July 2020, and the average precipitation in the whole province was only 75.0 mm, which was the second least since 1961. (2) When the precipitation was abnormally less in Heilongjiang Province in July, the negative phase distribution with East Asia-Pacific teleconnection (EAP) pattern appeared over the East Asian coast from low to high latitude at 500 hPa geopotential height anomaly field in the same period, the position of East Asian subtropical westerly jet (EASWJ) obviously leaned to south, and the anomalous anticyclone-cyclone circulation appeared over northeastern China to near the Yellow Sea at the lower level of troposphere, the integrated water vapor diverged over Heilongjiang Province. The circulation characteristics in July 2020 were similar to those in the same period of less rain years, but the intensity of the jet center and its negative anomaly areas on the north side was significantly stronger than those in less rain years, and the center of the jet moved slightly to the east, the meridional wave train in troposphere over East Asian coast was more clearly. The abnormally southerly EASWJ played an important role on abnormally less precipitation in Heilongjiang Province in July 2020. (3) The atmospheric heat source near the South China Sea in May 2020 was abnormally weak, and the distribution of the North Atlantic Oscillation (NAO) appeared negative phase in July 2020, which caused the EASWJ to move anomalously southward in July through the meridional wave train of EAP teleconnection over East Asian coast and zonal wave train over the middle-high latitude of Eurasia, respectively, and resulted in less precipitation in Heilongjiang Province.

Based on European Centre for Medium-Range Weather Forecasts （ECMWF） fifth-generation global atmospheric reanalysis （ERA5） every day from May to August during 1979-2020, three land-atmosphere indexes to investigate land-atmosphere coupling processes were calculated,characteristics of land-atmosphere coupling in climatology and their difference under different dry and wetsoil conditions were analyzed over eastern and southern Asia. The results show that Northeast and North China,the Tibetan plateau, India, Yunnan Province of China and Southeast Asia,the middle latitude arid zone were strong land-atmosphere coupling zones in climatology. In the middle latitude arid zone, land-atmosphere coupling had no significant difference under different soil conditions due to the low soil moisture and its little variability. In the other strong coupling zones, the coupling strength decreased with increasing soil moisture condition because of the bigger variability of soil moisture in these regions, and this law is applicable to the coupling processes between soil moisture（SM） and evapotranspiration （ET）, between ET and water vapor condition of boundary layer, between ET and instability condition of boundary layer. The land-atmosphere couplings over South China were weak in climatology, coupling between SM and ET was significant only under dry soil conditions, while the coupling between ET and atmospheric boundary layer were not significant under all soil moisture conditions.

The ozone mass concentration is affected by meteorological elements and emissions from air pollution sources. In order to quantitatively evaluate the effect of air pollution control measures, it is necessary to separate the contributions from air pollution sources. The Kolmogorov-Zurbenko filter was used to decompose the time series of daily ozone mass concentration during 2014-2019 as well as time series of meteorological factors in the same period in Guangzhou into long-term, short-term and seasonal components, and the variance contribution of each component to the total variance of the original ozone mass concentration data was calculated. Then multiple linear stepwise regression method was used to establish the relationship between ozone mass concentration data and meteorological variables for each time scale, the contributions of meteorological factors and pollutant emissions to ozone mass concentration were separated to obtain the contribution of ozone mass concentration influenced by meteorological conditions only. The results are as follows: (1) The long-term series of ozone mass concentration generally fluctuated and increased, the seasonal component showed a high value in late spring and early summer, a secondary peak in late summer and early autumn, and a trough in winter. (2) By analyzing the variance contribution rates of each component to the total variance of ozone mass concentration, the short-term component contributed the most, followed by the seasonal component, and the long-term component contributed the least, which indicated that the fluctuation of ozone mass concentration in Guangzhou was mainly caused by the short-term and seasonal changes of meteorological conditions and precursor emissions, and the long-term changes of emissions and climate conditions were not the main reasons for the fluctuation of ozone mass concentration. (3) In terms of explanatory variance, meteorological variables had the highest explanatory ability to the long-term component of ozone mass concentration, followed by the seasonal component. (4) The long-term component of ozone mass concentration which eliminated the influence of meteorological conditions by stepwise regression showed a fluctuating decreasing trend. Combined with the aggravation of ozone pollution from 2014 to 2019 in Guangzhou, the meteorological conditions were unfavorable for ozone diffusion in recent years.

Climatic changes will probably pose a threat to global food and nutrition security, especially in arid and semi-arid regions. In correlative reports of the available literatures, the bioavailability of micronutrients in crops was likely to have important and poorly understanding with climate change, which was of particular concern in soil improvement in drylands. The objective of this paper was to stimulate debate on a theme that bioavailability of micronutrients in foodstuff and food security had been either ignored or avoided in future research for its response to climatic change in semiarid area. In addition, there was a fairly good understanding of authors attempts to highlight potential consequences from experimental studies within process-based patterns of bioavailability of micronutrients in crops that should include interactions between climate and micronutrients accumulation. Furthermore, the authors gave some advices about prediction the bioavailability of micronutrients in crops or drylands soil improvement responses to future global climate change in arid and semi-arid area.

Using lightning data detected by the TRMM satellite between 25-38 0N and 74-100 0E from 1998 Jan. 1 to 2003 Dec.31,the yearly, seasonal and diurnal lightning number and their change with the longitude and latitude, the lightning density distribution and lightning climatic feature were calculated and analyzed in this paper. Results show that the total mean diurnal lightning number is about 7 600 in Tibetan Plateau Region of China, and it is 66.470l0 of the total number during day and 33.530lo during night，and their ratio is 2.0. The yearly variety of the diurnal flash number is the many peak value, the flash occurs primarily in April to September per year, and the number is 940l0 of total yearly lightning number .First peak occurs in Jun to Auguest, and the second peak in May and September, the flash number in summer season  (Jun to Aug) is 70.230l0, and it is only about 0.830l0 of total yearly lightning number in November to March of the next year. Diurnal variation presents the single peak value, and mean hourly flash  number is about 347 in a year, it reaches a maximum  at 18 PM and it'、about 12.10l0 of diurnal lightning number, it comes to mininn lm during 8一11 AM and it'、only 1.30l0 of the diurnal number, and the maximum is 100 times of the minimum，these show that lightning occurring frequently in Tibetan region is primarily in dusk. In Tibetan region, yearly mean flash number change with latitudd is bigger than that with longitude. Diurnal variation time of peak value occurring lightning in 4 seasons show that the time
with peak value of flash number during a day is different, in winter it is primarily in the evening，in autumn it is in the afternoon, while in spring it is at night and in summer it is at dusk. In Tibetan Plateau region the different yearly mean flash density distributions in daytime and nighttime and all day show that the density is higher in eastern region than that in western region, the hlgh  denStty  area  are  mOTe  COriCenttated  In  Tlhetan  Center  TeglOn  TelatlVely.  DLITlng  daytlme  In  Tlhetan  Center  TeglOn  1S  f1aSh  hlgh density area, and during nighttime it is flash low area. The flash density for different seasons is different, the flash high density area in
spring it is tend to northern, in autumn it is southward, in summer it is highest flash density area in Tibetan region, in winter it is rarelv flash densitv.