Abstract:Energy exchanges at the airsea interface together with the ocean advection govern the formation,maintenance and decay of sea surface temperature(SST) anomalies.Several aspects of the surface heat flux(SHF) feedback and the relation between SST and heat flux／transport variability are reviewed in this paper,based primarily on some of our recent studies.The heat flux anomaly is approximated as a forcing term plus a feedback term which is linear in SST.The SHF feedback parameter is determined from the lagged crosscovariances between SST and the SHF together with the autocovariance of SST.Feedback represented in this way is generally negative and acts to damp SST anomalies.It is dominated by the surface turbulent component.The strongest feedback is found at midlatitudes in both hemispheres,with the largest values occurring in the western and central portions of the oceans with extensions to higher latitudes.SHF feedback strengthens in northern winter and fall and weakens in spring and summer.These feedback features are reasonably well simulated in the CMIP3 coupled climate models.Nevertheless,the strength of the feedback in most of the models is somewhat weaker than reanalysisbased estimates.The“mean model”feedback parameter has better pattern correlations and smaller mean square differences than individual models when compared to reanalysisbased values.Based on the surface energy budget,SST variance may be expressed as the product of three factors:the sum of the variances of surface radiative and turbulent fluxes and the ocean heat transport,a transfer factor G measuring the persistence of SST,and an efficiency factor e reflecting the covariance structure among the heat fluxes and heat transport.The geographical distribution of the SST variance follows that of the sum of the variances of surface heat fluxes and the ocean heat transport,but modified by the factors of G and e.

Abstract:In this paper,two measuring parameters (e.g.station domain area and network density) of heterogeneity network from 160 stations in China are defined,which are calculated for presetting the spherical coronary area S0=50×104 km2,and their rationality is demonstrated.By use of them,the first weight function is constructed for calculating mean climate value and mean square deviation of air temperature of the network from 160 stations in China in January,April,July and October,in such a way that a reasonable result is obtained.Meanwhile,the second weight function is constructed,which is used to adjust anomalous air temperature of time series,and EOF(empirical orthogonal functions) analysis are carried on the original and the adjusted data.It demonstrates that EOF analysis result of the adjusted data is superior to that of the original data.

Abstract:Based on the multipletype observational data,this paper preliminarily analyses the mesoscale convective systems(MCSs) and weather background producing an extremely heavy rain along the Meiyu front in Hubei and Anhui provinces during 29—30 June 2009,and investigates the multiscale structure features of the Meiyu frontal rainstorm system.Then the mesoscale numerical model WRF with large domain and 9 km horizontal resolution is used to carry out a 3domainnested fine simulation for the heavy rain process.Morlet wavelet transformation is carried out to do spatial bandpassing filter for the model outputs,and the meso〖WTBX〗α,β〖WTB1〗 and 〖WTBX〗γ〖WTB1〗scale systems are separated out,in such a way that the three dimensional spatial dynamic and thermodynamic characteristics of the mesoscale systems with different scales are studied.The results are as follows.The extremely Meiyu frontal heavy rain is directly resulted from several MCSs with different scales,which are of different features on satellite cloud images and radar echoes.On meso〖WTBX〗α,β〖WTB1〗 and 〖WTBX〗γ〖WTB1〗scales,the Meiyu frontal heavy rain system has obvious different dynamic and thermodynamic structure features in horizontal and vertical directions.The meso〖WTBX〗α〖WTB1〗 and 〖WTBX〗β〖WTB1〗scale systems have obvious vertical circulation,while meso〖WTBX〗γ〖WTB1〗scale system has some features of inertial gravity waves and usually develops in meso〖WTBX〗α〖WTB1〗 and 〖WTBX〗β〖WTB1〗scale system.Lastly,a physic conceptual model is advanced for the typical Meiyu frontal rainstorm system.

Abstract:Based on ground base radar data,the simulation algorithm of airborne radar is proposed and an ideal model of simulation scanning patterns is also established.The algorithm is quicker and precise with the geometrical projection of divided data levels.The algorithm can be used in both sector scanning and taper scanning.At ideal conditions,this paper also discusses the algorithm of the ground echo eliminating as well as the Doppler velocity dealiasing.The results show that simulated echo could be applied to the feasibility study of scanning types before the real flight observation of airborne Doppler weather radar,and helps analysis its cloud and rain echo characteristics.

Abstract:Since the hyperspectral atmospheric infrared sounder (AIRS) has 2 378 channels,it is essential to select the main useful information from all those channels.The paper proposes a method of channel selection based on the cumulative effect coefficient of principal component.Firstly,it was the preprocessing of the channels.Then,for the channels combination during the daytime,the principal component analysis of temperature and humiditys Jacobi was made respectively to get the cumulative effect coefficient of each channel on the principal component.Finally,for the channels combination during the nighttime,the channels affected by sunlight were added in.Thus,the subset of selected channels both during the daytime and nighttime was obtained.It is shown that the method is feasible according to the profile retrieval experiments of temperature and humidity.

Abstract:By analyzing the summer satellite data from 2000 to 2007,it shows that some of mesoscale cloud clusters resulting in regional or largescale rainstorm in Shandong province experience the process from nonorganized system to organized system,from irregular cloud pattern to regular cloud pattern.To study the features of the evolution,six typical events are studied.The results show that the cloud clusters selforganization causing the heavy rainstorm in Shandong province occurs in July,there are 5 pieces of cloud clusters on average at the beginning,the average distance between the cloud clusters is 200 km,most cloud clusters build in the west of Shandong province and in the boundary of Shandong,Henan and Hebei provinces,the 1hr strongest precipitation generally happens within three hours before or after the completion of selforganization,and the cloud clusters lasts for about 11 hours from building over selforganization to extinction.

Abstract:According to the analyses on the synoptic situation,satellite image,radar echo and AWS data,it is found that there is a vortex selforganization process during a recordbreaking torrential rainfall in Shanghai on 25 August 2008.A surface mesoscale low develops during the heavy rainfall,which has a close connection with the organization and combination of meso and microscale vortices.Growing of the surface low stirs up the intensive precipitation and brings Shanghai city with the recordbreaking heavy rainfall.The process that forecasters applied the vortex selforganization theory on the forecast of the heavy rainfall is also detailed,which promises the theorys broad prospect on operational forecasting.

Abstract:An observation was carried out in the winter in 2006 at Pancheng,northern suburb of Nanjing,using tethered balloon system,automatic weather station and other instruments.The boundary layer structures on fog and fogfree days are analyzed and compared.Results show that on the fogfree days the temperature inversions are mainly singlelayer ones,sometimes with short duration doublelayer structures,while the fog mature stage inversions are free from the ground.Compared with the fogfree days,the temperature diurnal range above the average fog top on fog days is larger while the below one is smaller.The timeheight cross section of average wind speed on the fog days is similar to that on the fogfree days.In the stable boundary layer,the wind speed profiles have one or two maximum values.The average wind speed profiles on fog days are similar to those on the fogfree days.No remarkable relationship exists between the temperature and specific humidity profiles on the fogfree days.Differently,these two parameters have a good correspondence between each other in the fog body whereas they vary oppositely during the ascent and descent of the fog top.The stronger temperature inversion,lower temperature and smaller nearsurfacelayer wind speed are background for the winter fog formation in Nanjing.

Abstract:Based on the mean air temperature,mean wind speed,precipitation,cloud cover and visibility data at Shengyang and Xinchengzi stations at 02:00,08:00,14:00 and 20:00 BST from 1992 to 2008,the effect of urban heat island (UHI) was analyzed under different weather conditions.Results show that UHI intensity in Shenyang region is the lowest at 08:00 BST under light and heavy fog conditions,while it is the highest at 20:00 BST and the lowest at 14:00 BST under other weather conditions.UHI intensity is higher in night than in daytime under different weather conditions.Difference of UHI intensity between nighttime and daytime is the largest under the clear and calm wind condition,with the value of 073 ℃.Under the light fog condition,UHI intensity is the strongest in autumn,but under other weather conditions,it is the strongest in winter.Under the heavy rain condition,UHI intensity is the lowest in spring,and under the other precipitation conditions,it is the lowest in summer.UHI intensity decreases with the precipitation increase,wind speed increases,and visibility decrease.The UHI intensity difference (UHI20:00-UHI02:00) is larger in night than that (UHI08:00-UHI14:00) in daytime under the condition from the first to third wind levels,and the rule is contrary under the other wind levels.There are not obvious rules under other weather conditions.

Abstract:The timefrequency characteristics of four intensity indices Ii(i=1,4〖TX-〗)and two center position indices (〖WTBX〗λ〖WTB1〗i,〖WTBX〗φ〖WTB1〗i;i=3,4〖TX-〗)of the Aleutian low(AL) proposed by different scholars since the 1990s are analyzed and compared in this paper,and their correlation relationships with the sea surface temperature(SST) of the Pacific Ocean,air temperature and precipitation in the Northern Hemisphere during the same period are investigated.The results show that evolutionary features of Ii(i=2,4〖TX-〗) are mostly similar:the AL was weaker before the mid1970s,then stronger,and becomes weaker again in recent years;larger differences existed between I1 and Ii(i=2,4〖TX-〗) probably because I1 is defined according to the 5month mean pressure field.The geographic distributive range of the appearance of the center position of the AL determined by (〖WTBX〗λ〖WTB1〗c3,〖WTBX〗φ〖WTB1〗c3) is larger than that by (〖WTBX〗λ〖WTB1〗c4,〖WTBX〗φ〖WTB1〗c4),which might be caused by the differences in the length of average time period and the different definitions of the center position between them;and it is about 5yr earlier for 〖WTBX〗λ〖WTB1〗c4 to turn from the negative position anomaly phase to the positive one than the time when 〖WTBX〗λ〖WTB1〗c3 did,and the tuning time of 〖WTBX〗λ〖WTB1〗c4 is also more consistent with the transition time of intensity indices Ii(i=2,4〖TX-〗).In strong EI Ni〖AKn~D〗o events,the AL strengthened with its center shifting eastward;and vice versa in La Ni〖AKn~D〗a events.In this respect,intensity indices I2 and I4 and position indices〖WTBX〗 λ〖WTB1〗c4 and 〖WTBX〗λ〖WTB1〗c3 are comparatively better.When the AL was stronger (〖WTBX〗〖AKI~〗′〖WTB1〗i<0) and lay eastward of its normal position (〖WTBX〗〖AKλ~〗〖WTB1〗′ci>0),it was colder and drier in the midlatitude North Pacific region and the southern area of North America,but warmer and wetter in the northeast area of North Pacific,and vice versa.

Abstract:Due to the enormous disaster caused by the heavy rainfall in Henan and Anhui on 9 July 2005,the process is simulated by using mesoscale model(MM5) and is studied based on NCEP／NCAR reanalysis data and product of MM5.The results show that the Baikal blocking,cold vortex over Northeastern China and the highlevel trough were propitious to the heavy rainfall.The lowlevel jet and shear were the main systems leading to the rainfall.According to the change of divergence,vorticity,vertical velocity,helicity and equivalent potential temperature,it is obviously found that atmosphere converged and ascended,and lowmidlevel stratification instability was very apparent in heavy rainfall area.Additionally,uplowlevel matter exchange was intense.The vertical profile of helicity over heavy rainstorm area was positive in the lowmiddlelevel and negative in upperlevel of troposphere.The large positive helicity area corresponded to the center of the rainstorm.Distribution of moist flux divergence presented that there was strong moisture convergence in the rainstorm area.Moreover,frontogenetic condition provided energy and vapor for the rainfall and its reinforcement.

Abstract:Sky and terrain factors are elements influencing the Diffuse Solar Radiation(DSR) over rugged terrain.By using DEM data and the extraterrestrial solar radiation model and the terrain openness model,influences of terrain factors on the diffuse solar radiation are comprehensively evaluated.By using the horizontal diffuse solar radiation model simulated by routine meteorological observation data,influences of sky factors on DSR are evaluated.Thus,a model to calculate the diffuse solar radiation over rugged terrains in Zhejiang province was developed and the monthly spatial distribution of DSR was calculated.The results show that:the geographical and topographical factors,the monsoon influence and the atmosphere transparence exert effects on spatial distribution of DSR;the annual DSR presents a decreasing trend form south to north;the order of seasonal DSR is summer>spring>autumn>winter;the maximum(minimum) DSR lie in the open areas(shaded areas) and has little to do with the slope and aspect.It varies in different seasons.The results can provide data for researches of climate change and environmental resources.

Abstract:According to the continuous heavy rainfall events in the ChangjiangHuaihe River valley in summer 2003 and in South China in summer 1998,the ICTP Regional Climate Model (RegCM3) is used to simulate the effect of the heating anomalies over the ChangjiangHuaihe River valley,South China and the Bay of Bengal on the shortterm E/W and N/S positions of the Western Pacific Subtropical High (WPSH) during the heavy rainfall.The simulations confirm that the shortterm position variations of WPSH are closely associated with the atmospheric heating fields and their patterns.The heat source over the Bay of Bengal to far west of WPSH may induce an anomalous westward extension of WPSH during the continuous heavy rainfall.During the torrential rain in South China,the configuration of heating fields over South China and the Bay of Bengal may lead to a shortterm eastward withdrawal of WPSH during its seasonal westward extension.During the torrential rain in ChangjiangHuaihe River valley,the heat sources over ChangjiangHuaihe River valley and the Bay of Bengal may induce an anomalous westward extension of WPSH.But the effect is not evident in the simulation of the N/S position variation of WPSH,which can not approve that the WPSHs N/S position variation can be hindered individually by the heating source over South China or ChangjiangHuaihe River valley.

Abstract:Based on the satellite data and stratocumulus mixed cloud microphysical data measured by three airplanes in Beijing,Shanxi and Hebei,the stratocumulus mixed cloud spatial microphysical structure characteristics around Beijing area are analyzed.The results show that the spatial distribution of cloud microphysical parameters in front of cold front is nonuniform,it is bigger above 2 700 m,the vertical particles concentration and diameter is inverse correlation,the extreme of cloud particles concentration has 7 orders of magnitudes,the differnce of big particles concentration is 7 magnitudes,the difference of precipitation particles is 6 magnitudes.Cloud particles concentration and diameter in horizontal is ununiform and anticorrelation.The vertical cloud microphysical parameters in middle of cold front are ununiform and the peak values appears in 2 500—3 600 m and above 4 000 m.The concentration and diameter of cloud particles present inverse correlation,the extreme difference of cloud particles concentration is 6 magnitudes,the difference of big particles concentration is 7 magnitudes,the difference of precipitation particles is 5 magnitudes.The cloud particles concentration and diameter in horizontal is ununiform,presenting inverse correlation.The cloud particles spectrum is unimodal in front of cold front on 4 800 m,multimodal on 4 200 m and bimodal on 3 600.The cloud precipitation particles spectrum is monotone decreasing on 4 800 m,peak value is in droplet(≤100 〖WTBZ〗μ〖WTB1〗m).The spectrum patterns on 4 200 m and 3 600 m are bimodal,the peak value are separately in 100 〖WTBZ〗μ〖WTB1〗m and 230 〖WTBZ〗μ〖WTB1〗m.The precipitation particles spectrum patterns on three layers are unimodal and the peak values are similar.The cloud particles spectrum patterns on three layers in the middle of cold front appears a big difference.The spectrum patterns on 4 800 m and 4 200 m are unimodal while peak values appear in droplet and 15 〖WTBZ〗μ〖WTB1〗m,separately.The spectrum patterns on 3 600 m is bimodal,peak values are in 7 〖WTBZ〗μ〖WTB1〗m and 30 〖WTBZ〗μ〖WTB1〗m,separately.The cloud precipitation spectrums on three height layer is a little differece.It is monotone decreasing spectrum on 4 800 m,peak value appears in droplet(≤100 〖WTBZ〗μ〖WTB1〗m).The spectrums are bimodal on 4 200 m and 3 600 m,peak values appear in less than 100 〖WTBZ〗μ〖WTB1〗m and 200 〖WTBZ〗μ〖WTB1〗m,separately.The precipitation spectrums on three layers are similar.They are unimodal.

Abstract:The characteristics of electricity consumption and maximum electrical load,and their relationships with meteorological elements were analyzed by calculating the change rate of daily electricity consumption (〖WTB1X〗l〖WTB1〗ml) and maximum electrical load (〖WTB1X〗l〖WTB1〗mh) in Huzhou City,China from 2006 to 2008.This paper emphatically introduced the effects of mean temperature,minimum temperature and maximum temperature on the electricity consumption and maximum electrical load,and established the forecast model of electricity consumption and maximum electrical load.Results show that the daily electricity consumption and maximum electrical load have interannual variation characteristics and increasing trends from 2006 to 2008,but with obvious monthly differences.The effects of different meteorological elements on electricity consumption and maximum electrical load are different in each month,and the relations between 〖WTB1X〗l〖WTB1〗ml(〖WTB1X〗l〖WTB1〗mh)and meteorological elements are significantly from June to October.In different temperature range,the influences of temperature on electricity consumption and maximum electrical load are different,and the electricity consumption and maximum electrical load have maximum change rate of 20%.The values of 〖WTB1X〗l〖WTB1〗ml〖WTB1X〗 〖WTB1〗and 〖WTB1X〗l〖WTB1〗mh can reach 2%—5% when temperature increases 1 ℃ in July and August.