Abstract:One of the most well known forms of anthropogenic climate modification is the phenomenon of urban heating. The ambient temperatures of numerous urban centers have been determined to be several degrees higher than the ambient air temperature of surrounding rural areas. This phenomena is referred to as the Urban Heat Island Effect (UHI), and is studied in many of the largest cities around the world. The relationships are very complicated between the intensity of the urban heat island and various effects. In order to describe its spatial and temporal characters with pinpoint accuracy, temperature measurements are acquired using various monitoring systems such as meteorological station data; conventional ground measurement at fixed location; mobile traverses survey , remote sensing as well as simulation. Because every measurement method has its limitation, integrated detective methods are suggested to be used.

Abstract:On the basis of average temperature from 78 meteorological stations in the Yellow River basin, the monotonic trends of temperature over the past more than 30 years are analyzed with linear trend method and Mann-Kendall method. The analysis is mainly made for 12 months and the annual average temperature with the emphasis on the result of Mann-Kendall method. The isogram for the long-term trend of annual temperature is given. The result shows that the average temperature exhibits an increasing trend, mainly because of the increase of temperature in December, January and February. The largest trend is shown in December, while the smallest in August. However, temperature from several stations and months show declining tendency. Large differences show in areas and months, and according to these differences, the Yellow River basin is further divided into four regions.

Abstract:Based on the runoff drought index, the spring wheat yield data of Jiuquan, Zhangye and Wuwei in Hexi area, the relationship between the grades of runoff drought index and spring wheat yield without natural growth tendency is studied. The result shows that runoff drought index and spring wheat climate output of Hexi irrigational area appears opposite variation tendency. So, the change tendency of runoff drought index can be used to predict the variation tendency of output of spring wheat of this area.

Abstract:A heave rain event appeared in the middle and southern area of HeBei Province accompanied with storm surge in Bohai Bay on 11th October 2003. This was very rare in North of China in autumn. Based on the MM5 and Doppler radar data, the event is analyzed. The results show that (1) MM5 is better in simulation of steam field, sea-level pressure field and precipitation. (2) The permanence of eastern wind over Bohai sea resulted in the heap of sea water and the rise of sea level. Folding with chronometer strong tide, the storm surge occurred. (3) The thick layer of E—NE wind near the surface in the period of storm surge was increased, and the meantime precipitation was decreased.

Abstract:Based on GMS-5 infrared satellite images from 1996 to 1999, NECP data, the actual (typhoon) data from Typhoon Annual and GOES-9 infrared satellite images, an experiment was made on quantificational forecasting of the typhoon motion by stepwise analogy. The result experiment indicates that GOES-9 data is compatible with GMS-5 data and it can quantificationally forecast the typhoon motion by the method of analog forecasting with grey field and geopotential height field. The analog method does well in typhoon track forecasting, and therefore it would have a well application perspective.

Abstract:Based on monthly precipitation, mean monthly temperature and relative humidity of 75 (meteorological) stations in Henan Province from 1961 to 2000, the wetness index and the water budget in the surface are calculated. The results show that all stations are divided into 5 types with cluster analysis method. The wetness index and water deficiency over the surface has obvious difference in the five areas. The tendency of the wetness index over the surface declines slowly. The dryness trend properly results in the reduction of precipitation and the increase of temperature.

Abstract:Based on the routine sounding and surface observation data, NCEP grids data, MM5 model output, a diagnosis of the moist potential vorticity of the heavy rain event in the southern of North China on 4—5 July, 2000 is made. The results show that the spatial and temporal variations of moist potential vorticity can give good indication of the development of mesoscale vortex and heavy rain. It is advantage to the development of the vortex rainstorm that plus positive zone just over minus one. The heavy rain is located near the zero line at the south of the positive value zone of the barotropic moist potential vorticity in lower troposphere. The negative value of the baroclinc moist potential vorticity zones has a very good correspondence with the location and movement of the heavy rain.

Abstract:A Mei-Yu heavy rain event in the middle reach of the Changjiang River during July 22—23, 2002 is simulated by use of PSU/NCAR mesoscale nonstatic numerical forecast model MM5. The simulation result describes successfully the spatial and temporal rainfall distribution of the event and the developing course of the concomitant meso-β-scale systems. The analysis shows the characters of the high and low level stream field in various stage of the life cycle of the meso-β-sclale system.

Abstract:According to producing and sending procedure of CINRAD/SC radar picture, the reasons analysis of uploading data lack, overtime and the mistakes of the content etc. are made, and meanwhile, the corresponding methods are given.

Abstract:The solar activities might affect precipitation in the Yellow River Basin. The Morlet wavelet method is applied to analyze the changes of wavelet coefficients of precipitation and sunspots at same time scales. The research shows that there are negative correlations between precipitation and sunspots and they are most obvious in 9-year time scale. Furthermore, the precipitation lagged behind the sunspots by 1—2 years.

Abstract:Based on the data of atmospheric and oceanic temperature, the analysis of the abnormal winter temperature of Jiangnan area and its relationship with the sea surface temperature are made. The results are as below. Jiangnan's winter trends to warm in nearly 50 years, especially since the mid 1980's, its tend coefficient is 0.29 and its period is about 6.3-year and 3.3-year, otherwise, the California sea area is its crucial area.

Abstract:By using the Doppler radar data of the hail event April 12, 2003 in Jiangxi province, the development characteristics of severe convection weather are analyzed and several respects and indexes are put forward about nowcasting of severe convection weather. It's concluded that the bow echo, TBSS, adverse wind regions, low-layer mesoscale convergence line, VIL and the change of hail index can used for nowcasting of convectional weather.

Abstract:Base on regulating data of the temperature sensor of AWS in 2004 in Shandong Province, the cause of the result beyond measure is analyzed. The results show that the asymmetry of temperature field in detection equipment is influenced by super temperature in natural environment, and the standard temperature sensor and the ones regulated are not installed appropriately in the temperature equipment.

Abstract:A heavy rainfall event in the lower valley of Changjiang river on 25 June 2004 is simulated by the mesoscale numerical model MM5 and is analyzed with the synoptic charts and satellite imagine. The results indicate that under the favorable weather background, it is caused by the strengthening again of the southwest low level jet and the movement of the low level shear line. The analysis of helicity also revealed that under the updraft, the conversion from the horizontal whirlpool into the vertical whirlpool is one of the possible mechanisms of the event.

Abstract:An abnormal winter heavy rainfall event in the low-latitude plateau during Jan. 4—5 2003 was caused by a westerly macro-scale baroclinic system. Based on the physical field produced by T213 model, the synoptic diagnostic analysis of the event heavy is made. The result shows that the mechanism caused the heavy rainfall can be well explained by quasi-geotropic motion theory.

Abstract:Two severe convective weather events are analyzed. The results show that this two events are similar in many aspects, Such as, the effect system, physical element fields and the radar echo features etc. The couple of the dynamic fields in upper and lower layers provides the dynamic condition. Convective weather occurred in the place of low-level front zone of dew point, and the place of convergence in the lower level and divergence in the upper level as well. The larger the difference between the convergence and divergence in upper and lower layers is, the heavier the rainfall is. The descending inflow jet appears at the back of the bow echo on the map of Doppler radar base reflectivity fields, the larger the corresponding radial velocity is, and the more rapid the movement of radar echoes is, the larger the wind on the ground is.

Abstract:Comparative analysis of two heavy rain events is made. The results show that both convective heavy rain and continuous heavy rain in 2004 occurred with plenty of vapor and strong ascending movement, but occurred with different circulation background and cloudy systems and thermal structure. The most important reason causing different characters between the two heavy rain events is the different thermal structure prior to raining.

Abstract:The characteristics of the Western Pacific Subtropical High (WPSH) and the Blocking High (BH) in June 2004 as well as the differences of 500hPa height and OLR between the drought years and the flooding years are studied. The results show that the important reasons for the below normal precipitation in June 2004 in Jiangxi are that the position of the WPSH is eastward and northward, and Okhotsk BH is weaker. The pattern of “- + -” of 500hPa height anomaly along the East Asian coast leads to the below normal precipitation in Jiangxi. The correlation analysis shows that the strong ITCZ leads to the northern WPSH and the below normal precipitation in Jiangxi.