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1.
TYPHOON:SCIENTIFIC/OPERATIONALEXPERIMENTSANDDYNAMICTHEORETICALSTUDY¥ChenLianshou(陈联寿)andXuXiangde(除祥德)TYPHOON:SCIENTIFIC/OPER...  相似文献   

2.
At 0430 Beijing summer Time7 September 1988, the first Chinese meteorological satellite.named Fengyun-1(FY-1 meaning observing the wind and clouds in the atmosphere) waslaunched into the near-polar sun-synchronous orbit successfully at the Taiyuan SatelliteLaunching Center, Shanxi Province by Long March-4 launching vehicle which was developedby the Ministry of Aeronautics and Astronautics.FY-1 satellite is a hexahedron of 1.4m×1.4m×1.2m (Fig.1). The attitude of satellite  相似文献   

3.
At 0430 Beijing summer Time 7 September 1988,the first Chinese meteorological satellite.named Fengyun-1(FY-1 meaning observing the wind and clouds in the atmosphere) was launched into the near-polar sun-synchronous orbit successfully at the Taiyuan Satellite Launching Center,Shanxi Province by Long March-4 launching vehicle which was developed by the Ministry of Aeronautics and Astronautics.FY-1 satellite is a hexahedron of 1.4m×1.4m×1.2m (Fig.1).The attitude of satellite is three-axis. stabilized.The satellite at an altitude of 900 km operates around the earth 14 passes per day with a period of 102.86 min.The main instruments aboard the satellite are two Advanced Very High Resolution Radsometer (AVHRR) and Space Environmental Monitor.Table 1 gives the major specifications of AVHRR.  相似文献   

4.
Since 1982, several modifications in the operational model in National Meteorological Center(NMC) of China have been made, such as the adoption of the lateral boundary condition formulated byHovermal, Shuman's economic time difference scheme in the 5-layer Northern Hemispheric Model,and the replacement of the convective adjustment scheme by Kuo's cumulus parameterization scheme1974) in the 5-layer FLM. Owing to these modifications, both the objective and subjective verificationsof the prediction show that the accuracy of operational NWP has been significantly improved.Finally, applications of NWP Products are briefly summarized and future prospects are given.  相似文献   

5.
It is not only meteorological problems for the medium-range numerical weather prediction(NWP) research to be in operation,but also engineering and technological problems.Here we gener-ally described the results of research,engineering construction,operation information and testing,inthe course of set-up of medium-range NWP operation system in the China National MeteorologicalCenter.  相似文献   

6.
With polar orbiting meteorological satellites FY-1 and NOAA,flooding was monitored in the areas of the HuaiheRiver basin and the Taihu Lake region during June and July 1991.All satellite images from FY-1 and NOAA for concerned areas before and during flooding were examined.Thoseof cloud-free,with small amount of cumulus or thin cirrus were selected to exam the situation.Navigation and projec-tion were carefully performed,to ensure the projected images at different time overlap accurately with each other in 1—2pixels.Channel 1 (CH1) and Channel 2 (CH2) data of FY-1 and NOAA satellites with wavelength of 0.58—0.68μm and0.725—1.1μm were used to monitor the flooding.Albedo of Channel 2 and normalized vegetation index (NDVI) wereadopted as indicators to identify water body from land.With histogram and man-machine interactive methods,analysiswas done.In cloud-free condition,the two indicators identified the same area and scope of the water body.Totally cloud-free image in a large area is quite rare.To understand flood process,it is necessary to use more fre-quent images.It was investigated to distinguish water from land in partly cloudy condition.The result showed that whenthere is small amount of cumulus or thin cirrus,satellite images are still valuable in monitoring water body.In case ofmonitoring area covered with cirrus,vegetation index is useful,and while there is small amount of cumulus on land,albedo of Channel 2 can be used.Ten images from May 16 to August 18 of 1991 were examined.The results show that in the Lixiahe area,JiangsuProvince,the area submerged in total was the largest;along main stream of the Huaihe River,the Chuhe River,andaround the Chaohu Lake,a large percentage of area submerged;while in the Taihu Lake area,less field submerged.Flood monitoring was performed for 87 counties in the region concerned.These counties were put in order accord-ing to the percentage of submerged area in total.This order showed the extent of disaster at one view point.  相似文献   

7.
Surface O_3 concentration and its precursors have been observed at Longfengshan station,Heilongjiang Province for a period of one year from August 13,1994 to July 30,1995.Relationship between surface O_3 and the meteorological conditions during this period is analyzed inthis study.Observation results show that diurnal variation of surface O_3 follows a pattern ofdouble-peaks with amplitude of 27—28 ppb under fine days in summer and autumn.Although thediurnal variation is small(14 ppb),it is still detectable when it is overcast.Diurnal variation of O_3is irregular under rainy days.Surface O_3 concentration rises when wind speed starts to increase at0800 BT(Beijing Time)from 0 to 6 m s~(-1)in autumn,winter and summer.Relative high surfaceO_3 concentration is noticed frequently when S,SSW,SW and WSW wind are encountered at thestation during all seasons.At 0800 BT and 1400 BT the surface O_3 concentration increases with theincrease of global radiation accordingly during fine days in winter,spring and autumn.During finedays average peak of O_3 concentration in summer is 20 ppb higher than that in winter while theaverage peak of global radiation in summer is almost twice as high as that in winter.The averagesurface O_3 concentration under fine days in autumn at Longfengshan station is 14 ppb lower incomparison to the observation results from Lin'an station where Lin'an is at about the samelongitude and lower latitude,with same environment,which is mainly caused by the difference ofglobal radiation due to different latitudes in these two areas(difference of average peak globalradiation about 100 W m~(-2)).  相似文献   

8.
THESCIENTIFICWATERMANAGEMENTINWINTERWHEATPRODUCTIONANDITSECONOMICBENEFITSINNORTHCHINAAnShunqing(安顺清)andLiuGengshan(刘庚山)Resear...  相似文献   

9.
Based on China's observational data in 1951-1990,after minimizing the possible biases caused by station relocation and urban heat island,the spatial and temporal distributions of trends for maximum and minimum temperatures are studied.The results show that increasing trends of maximum temperatures are in the areas west to 95°E,and north to the Huanghe (Yellow) River,while decreasing trends exist in eastern China south to the Yellow River.Minimum temperatures are generally increasing throughout China,with dominant warming trends at the higher latitudes.This resulted in very obvious decreasing trends in diurnal temperature ranges.The periodic cycles are consistent between the maximum and minimum temperatures,but asymmetric trends are very obvious.The significant increase of minimum(nighttime) temperatures reflects the evidence of enhancement of greenhouse effect.Further analysis shows that the changes of maximum and minimum temperatures are mainly related to sunshine duration and atmospheric water vapor content.  相似文献   

10.
Based on improvement of a distributed hydrology-soil-vegetation model (DHSVM for short)and its application to North China,a nested regional climatic-hydrologic model system is developedby connecting DHSVM with RegCM2/China.The simulated climate scenarios,including controland 2×CO_2 outputs,are downscaled to 8 stations in Luanhe River and Sanggan River Basins todrive the hydrology model.According to simulation results,under double CO_2 scenarios,annualmean temperature and evapotranspiration will increase 2.8C and 29 mm,respectively;precipitation also increase but with different value for each basin,6 mm for Luanhe River Basinwhile 46 mm for Sanggan River Basin;runoff change for the two basins is different too,27 mmdecrease for Luanhe River Basin while 26 mm increase for Sanggan River Basin.As a result,therunoff in future for Luanhe River Basin and Sanggan River Basin will be 74 mm and 71 mm,respectively,which is approximately a quarter of annual mean runoff(284 mm)of the wholecountry.Total streamflow for the two basins will decrease about 2.5×10~8m~3.All these indicatethat the warm and dry trend will continue in the two river basins under double CO_2 scenarios.Thenested model system,with both climatic and hydrologic prediction ability,could also be applied toother basins in China by parameter adjustment.  相似文献   

11.
E1 Nino Modoki, similar to but different from canonical E1 Nino, has been observed since the late 1970s. In this paper, using HadlSST and NCEP/NCAR wind data, we analyze the relationship between E1 Nifio Modoki and Sea Surface Temperature (SST) in the offshore area of China and its adjacent waters for different seasons. Our results show a significant negative correlation between E1 Nifio Modoki in summer and SST in autumn in the offshore area of China and its adjacent waters, particularly for regions located in the east of the Kuroshio. It is also found that during E1 Nifio Modoki period, anomalous northerlies prevail over the regions from the northern part of the Philippines to the offshore area of China, indicating that the northerlies are unfavorable for the transport of warm water from the western tropical Pacific to the mid-latitude area. Consequently, E1 Nifio Modoki in summer may play a substantial role in cold SST anomalies in the offshore area of China and its adjacent waters in autumn through the influence of the Kuroshio, with a lagged response of the ocean to the atmospheric wind field.  相似文献   

12.
It is presented that there is a pumping effect at its base in the development process of a cumulus.In the strongest stage of cumulus development,the pumping is mainly produced by the buoyance at the base,and may be taken as the first approximation of the ascending speed at the base.The results of numerical calculations and simulations of four observed radar echoes show that as the first approximation,the height of air-mass cumulus may be simulated by Haltiner model in the absence of observed ascending speeds at the base,and the Haltiner model can be characterized by the sensitivity of the cumulus development to the virtual temperature excess over environment at the base.  相似文献   

13.
The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region.  相似文献   

14.
This paper is an extension of the author's paper (Xie,1982) to the spherical earth.It is found that the similar results are obtained under the assumption of isotropic distribution of horizontal kinetic energy along the zonal and meridional directions.It points out the limitation of the results already obtained and paves the path for the approach of anisotropie semi-eddy or quasi-eddy motion of the atmosphere.  相似文献   

15.
We developed a volume-to-biomass method based on age groups representative of forest development stages to estimate live tree biomass, C, and biomass and C accumulation rates of Chinas forests between 1973 and 1993. The data were from plot-level forest inventory, national-level inventory statistics, and ecological site studies specified to estimate biomass in different tree components. Our results indicate that carbon storage in Chinas forests was 4.34 Pg C in the early 1990s, an increase of 13% since the early 1970s. The annual forest C sequestration rate from the late 1980s to early 1990s was 0.068 Pg C/yr and approximately four- to five-times higher than in the 1970s and 1980s. The large C sink in Chinas forests in the early 1990s was likely related to age structure changes that had developed to more productive stages, a consequence of reforestation and afforestation programs from the 1960s. The results were compared with other C store estimates, which were based on the same inventory data. Various methods can produce estimates that differ in the direction of C flux as well as its magnitude. Separating age groups with the volume–biomass method could cause a 27% difference in estimated carbon pools but an 89% difference in C sequestration rates whereas the biomass density method would provide an estimate that differs by 65% in the C pools.  相似文献   

16.
We developed a volume-to-biomass method based on age groups representative of forest development stages to estimate live tree biomass, C, and biomass and C accumulation rates of Chinas forests between 1973 and 1993. The data were from plot-level forest inventory, national-level inventory statistics, and ecological site studies specified to estimate biomass in different tree components. Our results indicate that carbon storage in Chinas forests was 4.34 Pg C in the early 1990s, an increase of 13% since the early 1970s. The annual forest C sequestration rate from the late 1980s to early 1990s was 0.068 Pg C/yr and approximately four- to five-times higher than in the 1970s and 1980s. The large C sink in Chinas forests in the early 1990s was likely related to age structure changes that had developed to more productive stages, a consequence of reforestation and afforestation programs from the 1960s. The results were compared with other C store estimates, which were based on the same inventory data. Various methods can produce estimates that differ in the direction of C flux as well as its magnitude. Separating age groups with the volume–biomass method could cause a 27% difference in estimated carbon pools but an 89% difference in C sequestration rates whereas the biomass density method would provide an estimate that differs by 65% in the C pools.  相似文献   

17.
On the basis of the analysis of atmospheric carbon dioxide concentration variations and the annual mean air temperature at Syowa Station, Antarctica in the period of 1984-1988, the following results are easily obtained:(1) The annual mean values of the atmospheric carbon dioxide concentration are gradually increased and equal to 342.59, 343.80, 345.15, 346.83 and 348.82 ppmv for 1984, 1985, 1986, 1987 and 1988, respectively. Its annual in-crease rates are 1.21, 1.35, 1.68 and 1.99 ppmv/yr. For 1984-1985, 1985-1986, 1986-1987 and 1987-1988, respectively and are raised year by year.The seasonal variations are observed and the maximum concentration is in spring and the minimum one is in late-summer or early-autumn.(2)The increasing tendency of the concentration of the atmospheric carbon dioxide is consistent with that of the air temperature.  相似文献   

18.
The simple linear relationship between clear-sky planetary and surface albedo can be adopted for certain accuracy.There are different parameterization schemes of atmospheric correction for different retrieval models.In this paper,several representative retrieval models are compared and tested with observational data from HEIhe basin Field Experiment(HEIFE) in western China.Some evaluations and suggestions on improvement are proposed for models which would be more applicable to plateau and arid areas.  相似文献   

19.
20.
Climate change leads to more frequent and severe flooding, urging cities to adapt to protect their populations and assets. Despite exacerbated hazards, governments repeatedly draw on ‘tried-and-true’ approaches to protect the status quo, often with serious adverse effects for the poor and vulnerable. Yet, such dominant approaches do not go unchallenged as the media and other actors prompt public debate to assess flood impacts, scrutinise government decisions, and perhaps even promote alternative practices. News outlets are not, however, balanced or value-free; the events portrayed and the voices (and knowledges) recognised and included in media coverage deeply influence whether and how flooding is incorporated in policy. Focusing on São Paulo, Brazil, we examine how the media framed flood events and conveyed solutions during the city’s worst floods in recorded history. We demonstrate how competing media outlets largely depicted flooding as a natural phenomenon to be solved by governments and experts through existing techno-managerial practices, mirroring governmental partisan plans for adaptive action. In doing so, the media failed to offer a democratic space for public discussion, citizen contestation, and the advancement of alternative trajectories for adaptation. We posit that inclusive trajectories that address entrenched vulnerabilities and projected climate change will benefit from rigorous ethical debates around the media’s role in disaster coverage while strategically leveraging alternative media outlets as public pedagogy and agenda-setting tools.  相似文献   

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