ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 35,Issue 1,2009 Table of Contents
2009, 35(1):3-8.
DOI: 10.7519/j.issn.1000-0526.2009.1.001
Abstract:
For applying the radar velocity data to test the results of numerical model, a new method is presented to save the wind vectors of 3D numerical model as the radial velocity in the base data format of radar, and to get the simula ted radar velocity display as radar volume scan in different inclination with th e same color tab of the operational radar. Based on this method, the velocity pr oduct of radar can be used to test the 3D wind field simulated by the model. Thi s method can help the programmer to find directly the difference between simulat ions and observations during the simulation process.
For applying the radar velocity data to test the results of numerical model, a new method is presented to save the wind vectors of 3D numerical model as the radial velocity in the base data format of radar, and to get the simula ted radar velocity display as radar volume scan in different inclination with th e same color tab of the operational radar. Based on this method, the velocity pr oduct of radar can be used to test the 3D wind field simulated by the model. Thi s method can help the programmer to find directly the difference between simulat ions and observations during the simulation process.
2 On Groundbased Remote Sensing for Atmospheric Species by FTI
R Instrument and Retrieval Algorithm
Zhang Xingying
,
Zhang Peng
,
Liao Hong
,
Hu Xiuqing
,
Li Yuan
,
Zhang Lijun
,
Rong Zhiguo
,
Qiu Hong
2009, 35(1):9-17.
DOI: 10.7519/j.issn.1000-0526.2009.1.002
Abstract:
The FTIR instrument (IFS 120M) from BRUKER Co. Germany, usually used in NDACC, h as been used for the study on groundbased remote sensing for atmospheric speci es andthe retrieval algorithm. The construction of the observation lab is stated. The result about the calibration for the solar spectrum is explored. The retrieval algorithm of AOD from the data by this instrument is also discussed.
The FTIR instrument (IFS 120M) from BRUKER Co. Germany, usually used in NDACC, h as been used for the study on groundbased remote sensing for atmospheric speci es andthe retrieval algorithm. The construction of the observation lab is stated. The result about the calibration for the solar spectrum is explored. The retrieval algorithm of AOD from the data by this instrument is also discussed.
2009, 35(1):18-23.
DOI: 10.7519/j.issn.1000-0526.2009.1.003
Abstract:
The remote sensing result of blue algal bloom in Lake Tai from 2003 to 2007 shows that in resent years the blue algal bloom in Lake Tai has the follow ing characters: (1) The frequency and area of the bloom trend increasing; (2) Th e break out seasons of the bloom is tending to winter and spring; (3) The highes t frequency and the most serious areas of bloom appear mostly to be in the west and north of the Lake. Beside the contamination, meteorological characters can a lso impact on the break out of blue algal bloom. Through the analysis between field measurement and remote sensing data, it was found that the temperature, wind, li ght and precipitation can all impact on the bloom. In the above four factors, temperature and light ha ve a po sitive effect while wind and precipitation have a negative effect. It was also n oticed that because of the changing of pollution’s state, the degrees of effect are also changing.
The remote sensing result of blue algal bloom in Lake Tai from 2003 to 2007 shows that in resent years the blue algal bloom in Lake Tai has the follow ing characters: (1) The frequency and area of the bloom trend increasing; (2) Th e break out seasons of the bloom is tending to winter and spring; (3) The highes t frequency and the most serious areas of bloom appear mostly to be in the west and north of the Lake. Beside the contamination, meteorological characters can a lso impact on the break out of blue algal bloom. Through the analysis between field measurement and remote sensing data, it was found that the temperature, wind, li ght and precipitation can all impact on the bloom. In the above four factors, temperature and light ha ve a po sitive effect while wind and precipitation have a negative effect. It was also n oticed that because of the changing of pollution’s state, the degrees of effect are also changing.
2009, 35(1):24-36.
DOI: 10.7519/j.issn.1000-0526.2009.1.004
Abstract:
The cloud microphysical data measured by the airborne PMS probes in a precipitating stratiform cloud on June 12, 2004 in Hexi Corridor region of Gansu Province are analyzed. The cloud microphysical characteristics in both horizont al and vertical direction are presented through analyzing number concentration, mean diameter, shape and size distribution of cloud particles sampled with FSSP 100 probe and OAP2DGA2 probe. The results show that the cloud is AcSc configuration, and dry layer between Ac and Sc clouds is deep. Both vertical and horizontal varieties of cloud microphysical parameter show obviously inhomogeneous features. Th e cloud particle number concentration measured by FSSP100 changes from 0.1cm-3 to 232.6cm-3, and the mean diameter is around 3.5～45.5μm. The cha nge scopes of corresponding data explored with OAP2DGA2 are respectively 0.0 1～1167L-1 and 32.2～995.7μm. The particle images indicate that the rimin g, accretion and aggregation of ice and snow crystals are quiet universal, and i t shows that the supercooled water content in cloud is high. There are high co ncentration regions above 6000m altitude. Growth of massive ice crystals consume s largely the supercooled water, sequentially restraining the production or gr owth of big particles. The cool cloud processes are dominant during precipitatio n, and warm cloud processes is not distinct in Sc cloud.
The cloud microphysical data measured by the airborne PMS probes in a precipitating stratiform cloud on June 12, 2004 in Hexi Corridor region of Gansu Province are analyzed. The cloud microphysical characteristics in both horizont al and vertical direction are presented through analyzing number concentration, mean diameter, shape and size distribution of cloud particles sampled with FSSP 100 probe and OAP2DGA2 probe. The results show that the cloud is AcSc configuration, and dry layer between Ac and Sc clouds is deep. Both vertical and horizontal varieties of cloud microphysical parameter show obviously inhomogeneous features. Th e cloud particle number concentration measured by FSSP100 changes from 0.1cm-3 to 232.6cm-3, and the mean diameter is around 3.5～45.5μm. The cha nge scopes of corresponding data explored with OAP2DGA2 are respectively 0.0 1～1167L-1 and 32.2～995.7μm. The particle images indicate that the rimin g, accretion and aggregation of ice and snow crystals are quiet universal, and i t shows that the supercooled water content in cloud is high. There are high co ncentration regions above 6000m altitude. Growth of massive ice crystals consume s largely the supercooled water, sequentially restraining the production or gr owth of big particles. The cool cloud processes are dominant during precipitatio n, and warm cloud processes is not distinct in Sc cloud.
2009, 35(1):37-47.
DOI: 10.7519/j.issn.1000-0526.2009.1.005
Abstract:
Based on the dataset of observations of precipitation and visibility r ange since 1954 at the top of Mountain Hua, the ratio between the precipitation at Mt. Hua and at the nearby plain stations, which is defined as the orographic enhancement factor Ro, and the relationship between Ro and visibility, were appl ied to quantitatively learn the ways that air pollution aerosols suppress orogra phic precipitation. Ro decreased gradually during the measurement period, and mo st of the decrease occurred after 1980, about 20%, matched with the decreasing v isibility and increasing aerosol, which indicates that enhanced pollution aero sols suppress the orographic precipitation. The decrement of average annual precip itation at Mt. Hua after 1980 was 132mm, 15%, compared with that before 1980, a nd while the decrease was about 16mm, 3%, at the plain stations. The decrease in Ro is mainly caused by days of the light and moderate rain (daily precipitati on of less than 30 mm), but not by days with more than 30 mm, which suggested th at the thin short living orographic clouds are much more susceptible to precipit ation suppression by air pollution aerosols. Under dynamical uplift, the suppres sion of aerosol to clouds on the mountain top is stronger than that to clouds at plains, and causes 20%-30% decrease of precipitation at Mt. Hua from 1980 to 20 04. On the contrary, for the thermo-dynamically driven clouds, the suppression o f aerosol is equivalent to clouds on the mountain top and at plains.
Based on the dataset of observations of precipitation and visibility r ange since 1954 at the top of Mountain Hua, the ratio between the precipitation at Mt. Hua and at the nearby plain stations, which is defined as the orographic enhancement factor Ro, and the relationship between Ro and visibility, were appl ied to quantitatively learn the ways that air pollution aerosols suppress orogra phic precipitation. Ro decreased gradually during the measurement period, and mo st of the decrease occurred after 1980, about 20%, matched with the decreasing v isibility and increasing aerosol, which indicates that enhanced pollution aero sols suppress the orographic precipitation. The decrement of average annual precip itation at Mt. Hua after 1980 was 132mm, 15%, compared with that before 1980, a nd while the decrease was about 16mm, 3%, at the plain stations. The decrease in Ro is mainly caused by days of the light and moderate rain (daily precipitati on of less than 30 mm), but not by days with more than 30 mm, which suggested th at the thin short living orographic clouds are much more susceptible to precipit ation suppression by air pollution aerosols. Under dynamical uplift, the suppres sion of aerosol to clouds on the mountain top is stronger than that to clouds at plains, and causes 20%-30% decrease of precipitation at Mt. Hua from 1980 to 20 04. On the contrary, for the thermo-dynamically driven clouds, the suppression o f aerosol is equivalent to clouds on the mountain top and at plains.
2009, 35(1):48-54.
DOI: 10.7519/j.issn.1000-0526.2009.1.006
Abstract:
A comparative analysis is made with the application of the Doppler weather radar data of three strong convection precipitations at the night of June 12, in the wee hours and night of July 12, 2006 in Tianjin region. The results show that th e change of the radial velocity field often precedes that of echo intensity f ield of Doppler weather radar during the beginning and mature stage of precipita tion. It indicates that the effort on the shorttime forecast of precipitation should be focused on the change of radial velocity field and also refer to the f oreca st outcome of Autonowcasting system. The accuracy in the shorttime forecast of strong convection precipitation process can be improved through judging the i ntensity change and moving direction of radar echo.
A comparative analysis is made with the application of the Doppler weather radar data of three strong convection precipitations at the night of June 12, in the wee hours and night of July 12, 2006 in Tianjin region. The results show that th e change of the radial velocity field often precedes that of echo intensity f ield of Doppler weather radar during the beginning and mature stage of precipita tion. It indicates that the effort on the shorttime forecast of precipitation should be focused on the change of radial velocity field and also refer to the f oreca st outcome of Autonowcasting system. The accuracy in the shorttime forecast of strong convection precipitation process can be improved through judging the i ntensity change and moving direction of radar echo.
2009, 35(1):55-64.
DOI: 10.7519/j.issn.1000-0526.2009.1.007
Abstract:
A strong rainstorm is analysis which occurred in Xinghua located the north of Ji angsu province on 25 July 2007. Results show that wind disaster originated from two kinds of rainstorm. One kind was the gust front which occurred at the front of the storm. Strong wind of grade 7-9 was attained when it happened. Another ki nd was the downburst arose in the multicell storm. The original height of refl ectivity core was higher than -20℃ isotherm. It had the characteristics of conv ergence on the mid level and descending of reflectivity core. The strong wind ab ove grade 10 was attained, when the descending airflow diverged strongly on the ground. A new cell was combined with the former storm above the gust front, thus the storm enhanced. When the downburst happened, the storm weakened, and another new cell was combin ed with the former storm. The downburst happened continuously, and the impact of gust front persisted.
A strong rainstorm is analysis which occurred in Xinghua located the north of Ji angsu province on 25 July 2007. Results show that wind disaster originated from two kinds of rainstorm. One kind was the gust front which occurred at the front of the storm. Strong wind of grade 7-9 was attained when it happened. Another ki nd was the downburst arose in the multicell storm. The original height of refl ectivity core was higher than -20℃ isotherm. It had the characteristics of conv ergence on the mid level and descending of reflectivity core. The strong wind ab ove grade 10 was attained, when the descending airflow diverged strongly on the ground. A new cell was combined with the former storm above the gust front, thus the storm enhanced. When the downburst happened, the storm weakened, and another new cell was combin ed with the former storm. The downburst happened continuously, and the impact of gust front persisted.
2009, 35(1):65-73.
DOI: 10.7519/j.issn.1000-0526.2009.1.008
Abstract:
By using the high resolution output data from mesoscale model WRF succ essfully simulating typhoon “Khanun”, with the diagnostic method of isentropic potential vorticity(IPV) and moist potential vorticity(MPV), the evolvement cha racteristic of mesoscale system is analyzed in the course of rainstorm and the m echanism of typhoon rainstorm development and maintenance is discussed. The resu lts show that the study of PV on isentropic surface reveals PV evolvement characteristic of typhoon low pressure and nearby, the rainstorm region lies i n the no rtheast part of high PV center on the lower isentropic surface or lies in the ri ght side of the maximum PV gradient on the upper isentropic surface. It also sho ws that high PV, including in dry and cold air, spreads downward from the upper layer to intensify the turbulence of lower layers along with the isentropic surf ace furling to the center of positive PV anomaly, which helps the release of pot ential instability energy and the amplification of rainstorm. Conditional symmet ry instability and convective instability can be considered as significant mecha nism of typhoon rainstorm development and maintenance. Meanwhile, the developmen t of mesoscale system in the rainstorm region agrees with slantwise vorticity de velopment theory.
By using the high resolution output data from mesoscale model WRF succ essfully simulating typhoon “Khanun”, with the diagnostic method of isentropic potential vorticity(IPV) and moist potential vorticity(MPV), the evolvement cha racteristic of mesoscale system is analyzed in the course of rainstorm and the m echanism of typhoon rainstorm development and maintenance is discussed. The resu lts show that the study of PV on isentropic surface reveals PV evolvement characteristic of typhoon low pressure and nearby, the rainstorm region lies i n the no rtheast part of high PV center on the lower isentropic surface or lies in the ri ght side of the maximum PV gradient on the upper isentropic surface. It also sho ws that high PV, including in dry and cold air, spreads downward from the upper layer to intensify the turbulence of lower layers along with the isentropic surf ace furling to the center of positive PV anomaly, which helps the release of pot ential instability energy and the amplification of rainstorm. Conditional symmet ry instability and convective instability can be considered as significant mecha nism of typhoon rainstorm development and maintenance. Meanwhile, the developmen t of mesoscale system in the rainstorm region agrees with slantwise vorticity de velopment theory.
2009, 35(1):74-79.
DOI: 10.7519/j.issn.1000-0526.2009.1.009
Abstract:
A heavy rainstorm happened in Qingdao from September 18 to 20, 2007, w hich exceeded the historical record. The realtime data, circulation characteri s tic and Doppler radar data were used to analyze the heavy rainstorm process. The results show that there was a strong vapor convergence at low level．At the beg inning the precipitation was caused by the strong pumping at high level and was rather weak. Typhoon Wipha strengthened the convergence lifting. The activity of cold air at high level strengthened the instability. The coupling among the wes tern trough, subtropical high and typhoon Wipha formed this torrential rainstorm . Doppler radar data shows that the disturbance is active at lowlevel air. A l i near convergence band with cyclonic curve is found near sea surface. It is a sea land front caused by sealand breeze, and is also a strong rain belt companyi ng with heavy rain and strong horizontal wind shear.
A heavy rainstorm happened in Qingdao from September 18 to 20, 2007, w hich exceeded the historical record. The realtime data, circulation characteri s tic and Doppler radar data were used to analyze the heavy rainstorm process. The results show that there was a strong vapor convergence at low level．At the beg inning the precipitation was caused by the strong pumping at high level and was rather weak. Typhoon Wipha strengthened the convergence lifting. The activity of cold air at high level strengthened the instability. The coupling among the wes tern trough, subtropical high and typhoon Wipha formed this torrential rainstorm . Doppler radar data shows that the disturbance is active at lowlevel air. A l i near convergence band with cyclonic curve is found near sea surface. It is a sea land front caused by sealand breeze, and is also a strong rain belt companyi ng with heavy rain and strong horizontal wind shear.
2009, 35(1):80-86.
DOI: 10.7519/j.issn.1000-0526.2009.1.010
Abstract:
Currently, under the background of the growing climate warming, extrem e weather events occur frequently. In order to understand the formation mechani sm of heavy rain and to improve the forecasting ability of heavy rain in the Hai he River basin, a synoptic diagnostic analysis for the heavy rainfall process in the Haihe river valley, especially in the east of Hebei Province, is performed with NCEP 6hourly reanalysis data with resolution 1°×1°, the routine observ ation data and FY2C satellite data. The results show that the heavy rain origin ated in the preliminary instable atmospheric convection region, and the stations which have 6hour precipitation of more than 20 mm from 20:00BT of August 25th to 02:00 BT of August 26th almost located in the negative value area of the moist potential vorticity (MPV) in the low and medium layer of the troposphere. Mass of instable energy, heat and momentum were conveyed by low level jet (LLJ) to th e heavy rain region, which provided sufficient energy and moisture for the forma tion of the rain. The heavy rain region located at the western edge of the great positive value center of helicity. In the upper air of the heavy rain region there were strong rotating updrafts, and in the period of rain, convergence in underly ing bed, divergence in highlevel and the suction function that the latter was stronger than the former were advantageous in strengthening the underlying bed co nvergence and the convective ascending movement, providing favorable dynamic con dition for the formation of heavy rain. Simultaneously, the vapor in the high tr oposphere also played a crucial role in the development of strong precipitation cloud cluster.
Currently, under the background of the growing climate warming, extrem e weather events occur frequently. In order to understand the formation mechani sm of heavy rain and to improve the forecasting ability of heavy rain in the Hai he River basin, a synoptic diagnostic analysis for the heavy rainfall process in the Haihe river valley, especially in the east of Hebei Province, is performed with NCEP 6hourly reanalysis data with resolution 1°×1°, the routine observ ation data and FY2C satellite data. The results show that the heavy rain origin ated in the preliminary instable atmospheric convection region, and the stations which have 6hour precipitation of more than 20 mm from 20:00BT of August 25th to 02:00 BT of August 26th almost located in the negative value area of the moist potential vorticity (MPV) in the low and medium layer of the troposphere. Mass of instable energy, heat and momentum were conveyed by low level jet (LLJ) to th e heavy rain region, which provided sufficient energy and moisture for the forma tion of the rain. The heavy rain region located at the western edge of the great positive value center of helicity. In the upper air of the heavy rain region there were strong rotating updrafts, and in the period of rain, convergence in underly ing bed, divergence in highlevel and the suction function that the latter was stronger than the former were advantageous in strengthening the underlying bed co nvergence and the convective ascending movement, providing favorable dynamic con dition for the formation of heavy rain. Simultaneously, the vapor in the high tr oposphere also played a crucial role in the development of strong precipitation cloud cluster.
2009, 35(1):87-96.
DOI: 10.7519/j.issn.1000-0526.2009.1.011
Abstract:
Based on monthly sea ice extent data from 1979 to 2006, the sesonal change and t endency of Antarctic and Arctic sea ice were statistically analyzed. The results show as follows: the seasonal change of Antarctic sea ice is more remarkable th an that of the Arctic. In recent 30 years, Arctic sea ice decreases rapidly, esp ecially in summer and autumn, and more quickly since the mid 1990s.The decline m ainly appears over the Arctic Ocean near the Pacific in summer and autumn, over north of the Pacific in winter and spring. Antarctic sea ice shows uptrend since the early 1980s, especially in summer and autumn. There is a decreasing centre near Antarctic Peninsula. In addition, there are two increasing centers over Ross Sea and south west of Indian Ocean. The centers move eastwards and go back around Antarctica w ith the seasonal transition from summer to spring.
Based on monthly sea ice extent data from 1979 to 2006, the sesonal change and t endency of Antarctic and Arctic sea ice were statistically analyzed. The results show as follows: the seasonal change of Antarctic sea ice is more remarkable th an that of the Arctic. In recent 30 years, Arctic sea ice decreases rapidly, esp ecially in summer and autumn, and more quickly since the mid 1990s.The decline m ainly appears over the Arctic Ocean near the Pacific in summer and autumn, over north of the Pacific in winter and spring. Antarctic sea ice shows uptrend since the early 1980s, especially in summer and autumn. There is a decreasing centre near Antarctic Peninsula. In addition, there are two increasing centers over Ross Sea and south west of Indian Ocean. The centers move eastwards and go back around Antarctica w ith the seasonal transition from summer to spring.
2009, 35(1):97-101.
DOI: 10.7519/j.issn.1000-0526.2009.01.012
Abstract:
Based on the climatic data of Puyang,Henan and the data of flood disaster during 1995-2004, the spatial and temporal characteristic of flood dis aster and the urban economical loss were analyzed. By using regression analysis, weighted average and parameter statistics according to the rank and type of res ources, the assessment steps and technique of flood disaster loss are discussed, and a quantitative assessment model of urban disaster loss was established. The feasibility of the model was validated by analyzing flood cases during 2005-200 6, one of which was a typhoon precipitating process on July 22-24, 2005 with pre cipitation amount of 215.9mm. The result indicates that the quantitatively calc ulated loss of flood disaster is quite agreement with the statistics of flood di saster loss investigation. It shows that the model can quickly and accurately ev aluate the loss of flood disaster. Meanwhile, the technique is feasible and oper ational, and is valuable for the authority to prevent and mitigate the flood dis aster.
Based on the climatic data of Puyang,Henan and the data of flood disaster during 1995-2004, the spatial and temporal characteristic of flood dis aster and the urban economical loss were analyzed. By using regression analysis, weighted average and parameter statistics according to the rank and type of res ources, the assessment steps and technique of flood disaster loss are discussed, and a quantitative assessment model of urban disaster loss was established. The feasibility of the model was validated by analyzing flood cases during 2005-200 6, one of which was a typhoon precipitating process on July 22-24, 2005 with pre cipitation amount of 215.9mm. The result indicates that the quantitatively calc ulated loss of flood disaster is quite agreement with the statistics of flood di saster loss investigation. It shows that the model can quickly and accurately ev aluate the loss of flood disaster. Meanwhile, the technique is feasible and oper ational, and is valuable for the authority to prevent and mitigate the flood dis aster.
2009, 35(1):102-107.
DOI: 10.7519/j.issn.1000-0526.2009.1.013
Abstract:
Based on the analyses of the spectral characteristic of dust storm, cl oud, snow and desert using the several MODIS data during the period from 2002 to 2004, two dust indices were constructed, which can determine quantitatively the scope and intensity of dust storm. The test results in several storms from 2 002 to 2007 indicated that the abovebuilt dust indices could effectively deter mine the scope and intensity of dust storms, and are proved to be simple and ope rable. In order to solve the actual issue that the present service product of re mote sensing monitoring of dust storm is mainly simple and qualitative images, a new evaluating system was developed to monitor the dust storm based on MODIS dat a, which can offer not only MODIS image of dust storm, but the remote sensing mo nitoring image of the scope and intensity of dust storm, the plot of land classi fications affected by dust storm, the statistics of dust area in different provi nce, the statistics of area affected by dust storm for different land classifica tion in China, and the statistics of area affected by dust storm for different c ounty and different land classification in Gansu province. The new system is abl e to provide various products for the monitoring of dust storm in quantitative a nd fine service way.
Based on the analyses of the spectral characteristic of dust storm, cl oud, snow and desert using the several MODIS data during the period from 2002 to 2004, two dust indices were constructed, which can determine quantitatively the scope and intensity of dust storm. The test results in several storms from 2 002 to 2007 indicated that the abovebuilt dust indices could effectively deter mine the scope and intensity of dust storms, and are proved to be simple and ope rable. In order to solve the actual issue that the present service product of re mote sensing monitoring of dust storm is mainly simple and qualitative images, a new evaluating system was developed to monitor the dust storm based on MODIS dat a, which can offer not only MODIS image of dust storm, but the remote sensing mo nitoring image of the scope and intensity of dust storm, the plot of land classi fications affected by dust storm, the statistics of dust area in different provi nce, the statistics of area affected by dust storm for different land classifica tion in China, and the statistics of area affected by dust storm for different c ounty and different land classification in Gansu province. The new system is abl e to provide various products for the monitoring of dust storm in quantitative a nd fine service way.
2009, 35(1):108-113.
DOI: 10.7519/j.issn.1000-0526.2009.1.014
Abstract:
Based on the monthly precipitation data of 88 observing stations in Gua ngxi from 1961 to 2006, drought and flood grades in winter and autumn are divide d with the method of Z index, and the annual change and spatial-temporal charact eristics are obtained with EOF. The results show that the overall dry in Guangxi is the main type. There exists a positive correlation between the frequency of flood and drought and the time coefficient. The circulation characteristic at 50 0 hPa in the same season is analyzed. The results show that in flooding autum n, the trough at the eastern part of Ural is deeper, the high pressure in the So uth Sea is stronger and the subtropical high is weaker than in drought autumn. W hile in flooding winter, the high pressure is in North and the low pressure in S outh. The cold air path inclined to the south, and the geo-potential height is l ow at the Tibetan Plateau, which can lead small trough moving eastward and affec ting Guangxi.
Based on the monthly precipitation data of 88 observing stations in Gua ngxi from 1961 to 2006, drought and flood grades in winter and autumn are divide d with the method of Z index, and the annual change and spatial-temporal charact eristics are obtained with EOF. The results show that the overall dry in Guangxi is the main type. There exists a positive correlation between the frequency of flood and drought and the time coefficient. The circulation characteristic at 50 0 hPa in the same season is analyzed. The results show that in flooding autum n, the trough at the eastern part of Ural is deeper, the high pressure in the So uth Sea is stronger and the subtropical high is weaker than in drought autumn. W hile in flooding winter, the high pressure is in North and the low pressure in S outh. The cold air path inclined to the south, and the geo-potential height is l ow at the Tibetan Plateau, which can lead small trough moving eastward and affec ting Guangxi.
2009, 35(1):114-118.
DOI: 10.7519/j.issn.1000-0526.2009.01.015
Abstract:
Based on power load information and weather data from 2005 to 2006, it is conclu ded that the annual and seasonal variations of power load in agricultural region correspond statistically to the cycle of agricultural activity. The time of sec ond peak power load of daily variation is consistent with the peak of daily ma ximum temperature and minimum air humidity. Relationship is analyzed not only be tween daily average power load and atmospheric pressure, temperature, humidity, wind, precipitation, but variation of power load and meteorological element as w ell. Rainy day and clear days are counted in sections. The results show that var iations of precipitation, air humidity, temperature have better correlation with the power load. Four different models are established to simulate fluctuation o f power load by using stepwise regression equation. The better simulated result is element-difference model after error analysis, so the forecast of power load fluctuation is tested and error is analyzed in May of 2007. The result is t hat?in rainy day the error in?common power load forecast method error is 63.2% , but the forecast error in the element-difference model is 18.7%. In addition t he monthly average forecast error of power load for the common power load foreca st model and the element-difference model are 26.0% and 13.4%, respectively.
Based on power load information and weather data from 2005 to 2006, it is conclu ded that the annual and seasonal variations of power load in agricultural region correspond statistically to the cycle of agricultural activity. The time of sec ond peak power load of daily variation is consistent with the peak of daily ma ximum temperature and minimum air humidity. Relationship is analyzed not only be tween daily average power load and atmospheric pressure, temperature, humidity, wind, precipitation, but variation of power load and meteorological element as w ell. Rainy day and clear days are counted in sections. The results show that var iations of precipitation, air humidity, temperature have better correlation with the power load. Four different models are established to simulate fluctuation o f power load by using stepwise regression equation. The better simulated result is element-difference model after error analysis, so the forecast of power load fluctuation is tested and error is analyzed in May of 2007. The result is t hat?in rainy day the error in?common power load forecast method error is 63.2% , but the forecast error in the element-difference model is 18.7%. In addition t he monthly average forecast error of power load for the common power load foreca st model and the element-difference model are 26.0% and 13.4%, respectively.
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ISSN:1000-0526 CN:11-2282/P