ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 35,Issue 10,2009 Table of Contents
2009, 35(10):3-7.
DOI: 10.7519/j.issn.1000-0526.2009.10.001
Abstract:
The application of nonlinear time series analysis in climatology mainl y includes three aspects as follows: observation data processing, abrupt change of climate and climatological prediction. The results of summarizing many paper s s how that, a great deal of scholars contribute a lot to the application of nonlin ear time series analysis in climatology. Most of the papers have used new method s in nonlinear time series analysis and almost every method can come to the top in some fields. However, they are just results with case study on the whol e, the inclusions need more validation and more systemic illustration; it is nec essary to hunt methods used in operational prediction and enhancing forecast ski ll. There is still a long way to go.
The application of nonlinear time series analysis in climatology mainl y includes three aspects as follows: observation data processing, abrupt change of climate and climatological prediction. The results of summarizing many paper s s how that, a great deal of scholars contribute a lot to the application of nonlin ear time series analysis in climatology. Most of the papers have used new method s in nonlinear time series analysis and almost every method can come to the top in some fields. However, they are just results with case study on the whol e, the inclusions need more validation and more systemic illustration; it is nec essary to hunt methods used in operational prediction and enhancing forecast ski ll. There is still a long way to go.
2009, 35(10):8-24.
DOI: 10.7519/j.issn.1000-0526.2009.10.002
Abstract:
Based on the PMS data of an aircraft cloud seeding in stratiform cloud in Henan Province on March 21, 2005, the differences of macro and microphysical character istics between seeded and unseeded clouds are analyzed. The results indicate tha t the maximum concentration of small cloud particles is 1.36×108m-3 at the height of 4200m before seeding, and the corresponding mean diameter is abo ut 5μm. The concentration and liquid water content of small cloud particles de crease after seeding, and their change below the seeding layer is more obvious t han that at the seeding layer. The mean diameter of small cloud particles increases from 17.32μm to 18.07μm at 5000m height. The change of microphysical quantity after seeding is caused by cloud seeding. There are similar cloud particle spectra at different heights.
Based on the PMS data of an aircraft cloud seeding in stratiform cloud in Henan Province on March 21, 2005, the differences of macro and microphysical character istics between seeded and unseeded clouds are analyzed. The results indicate tha t the maximum concentration of small cloud particles is 1.36×108m-3 at the height of 4200m before seeding, and the corresponding mean diameter is abo ut 5μm. The concentration and liquid water content of small cloud particles de crease after seeding, and their change below the seeding layer is more obvious t han that at the seeding layer. The mean diameter of small cloud particles increases from 17.32μm to 18.07μm at 5000m height. The change of microphysical quantity after seeding is caused by cloud seeding. There are similar cloud particle spectra at different heights.
2009, 35(10):25-31.
DOI: 10.7519/j.issn.1000-0526.2009.10.003
Abstract:
Based on the conventional data, satellite image, Doppler radar echo an d wind profiler information, a consecutive convection process in the Pudong Int ernat ional Airport on June 22, 2006 is analyzed. The results show that the first seve re convection event in the process was a local heat convection, the second sever e co nvection event was a squall line triggered by cold front, and the third severe c onve ction event was caused by mesoscale depression circulation. During the time earl ier before the squa ll line occurs， an apparent vertical wind shear was shown by the wind profiler information of the Pudong International Airport. It was of early warning signif icance.
Based on the conventional data, satellite image, Doppler radar echo an d wind profiler information, a consecutive convection process in the Pudong Int ernat ional Airport on June 22, 2006 is analyzed. The results show that the first seve re convection event in the process was a local heat convection, the second sever e co nvection event was a squall line triggered by cold front, and the third severe c onve ction event was caused by mesoscale depression circulation. During the time earl ier before the squa ll line occurs， an apparent vertical wind shear was shown by the wind profiler information of the Pudong International Airport. It was of early warning signif icance.
2009, 35(10):32-39.
DOI: 10.7519/j.issn.1000-0526.2009.10.004
Abstract:
Using the data of Nanjing Doppler weather radar (WSR98D), the tornado occurrin g in Tianchang of Anhui Province and Gaoyou of Jiangsu Province on July 3, 2007 was analyzed. The characteristics such as mesocyclone (M) and tornadic vortex s ignature (TVS) were found.The tornado occurred in the strong development supercell located on the north of line echo wave pattern (LEWP), the strong shear of wind direction existed in the front of echo line, and it makes the mesocyclone continuously generated along the echo line. In the cell tornado, mesocyclone (M) products can be worked out 30 min before tornado occurrence, the M lasts for 7 volume scan time lengths (42 minutes), thus TVS products can be worked out at the 5th volume scan of M product appearance, it lasts 3 volume scans, and the combined shear products have also given out notable prompting. According to the field survey, the tornado occurred at the time that the 2nd TVS occurred, it is located on the south side of the TVS, and consistent with the southern fringe of mesocyclone. Although the TVS products may be false at time, but with the checking of reflectivity, the base radial velocity, mesocyclone, combined shear products etc., it is useful for making tornado warning.
Using the data of Nanjing Doppler weather radar (WSR98D), the tornado occurrin g in Tianchang of Anhui Province and Gaoyou of Jiangsu Province on July 3, 2007 was analyzed. The characteristics such as mesocyclone (M) and tornadic vortex s ignature (TVS) were found.The tornado occurred in the strong development supercell located on the north of line echo wave pattern (LEWP), the strong shear of wind direction existed in the front of echo line, and it makes the mesocyclone continuously generated along the echo line. In the cell tornado, mesocyclone (M) products can be worked out 30 min before tornado occurrence, the M lasts for 7 volume scan time lengths (42 minutes), thus TVS products can be worked out at the 5th volume scan of M product appearance, it lasts 3 volume scans, and the combined shear products have also given out notable prompting. According to the field survey, the tornado occurred at the time that the 2nd TVS occurred, it is located on the south side of the TVS, and consistent with the southern fringe of mesocyclone. Although the TVS products may be false at time, but with the checking of reflectivity, the base radial velocity, mesocyclone, combined shear products etc., it is useful for making tornado warning.
2009, 35(10):40-49.
DOI: 10.7519/j.issn.1000-0526.2009.10.005
Abstract:
Based on WRF model outputs， one airplane turbulence accident happening on July 6， 2007 was analyzed. The results show that the accident took place in the gravity wave around a cyclone. The alternation of the ascending and descending flows between spiral clouds led to the airplane turbulence. Indices Ri and EI have a good instruction to the occurrence of airplane turbulence.
Based on WRF model outputs， one airplane turbulence accident happening on July 6， 2007 was analyzed. The results show that the accident took place in the gravity wave around a cyclone. The alternation of the ascending and descending flows between spiral clouds led to the airplane turbulence. Indices Ri and EI have a good instruction to the occurrence of airplane turbulence.
2009, 35(10):50-57.
DOI: 10.7519/j.issn.1000-0526.2009.10.006
Abstract:
Based on the reliable output of the MM5 model, the heavy rain occurring in the w arm sector in Guangxi during 8-9 May 2005 was analyzed. Results show that the l ow level jets (LLJ) kept on strengthening and the upper level jet maintaining ar e responsible for the dynamical mechanism; and in the lower troposphere there is the appearance of the cores of the LLJ moving eastward from the upper to the lo wer levels, which is the key reason for the heavy rain happening far away from the front and occurring in the warm sector. The organized convective movements repeatedly developing in the warm sector make the precipitation amount and rainfall rate more and stronger than those in the front area.
Based on the reliable output of the MM5 model, the heavy rain occurring in the w arm sector in Guangxi during 8-9 May 2005 was analyzed. Results show that the l ow level jets (LLJ) kept on strengthening and the upper level jet maintaining ar e responsible for the dynamical mechanism; and in the lower troposphere there is the appearance of the cores of the LLJ moving eastward from the upper to the lo wer levels, which is the key reason for the heavy rain happening far away from the front and occurring in the warm sector. The organized convective movements repeatedly developing in the warm sector make the precipitation amount and rainfall rate more and stronger than those in the front area.
2009, 35(10):58-70.
DOI: 10.7519/j.issn.1000-0526.2009.10.007
Abstract:
Based on the June-August 2007 cloudtoground (CG) lightning dataset provided by the Meteorological Observation Center of China Meteorological Administration , the distribution and spatiotemporal variations of CG lightning over the Yangtze Riv er Basin and adjacent areas during the summer of 2007 are analyzed and compared wi th the thunderstorm distribution, the lightning distribution from loworbit sat ellites and with the deep convection distribution denoted by TBB≤-52°C. The re sults show that the four distributions are, to some extent, consistent with each other. By comparing the 2007 CG lightning distribution with the lightning distr ibution from the loworbit satellites, the CG lightning was more active over the Ya ngtzeHuaihe River Basin, Sichuan, Chongqing, the Northwest Zhejiang Province, t he middle of the Wuyi Mountains during the summer of 2007. In addition, the CG li ghtning was more active in July and August than in June, and the location of act ive areas is farther north, however, the positive CG lightning is the most active in July. It shows that the mesoscale convective systems occurred more often in July 2007. Diurnal variations of CG lightning were different over different area s. Over the Sichuan Basin and the YangtzeHuaihe River Basin, the diurnal varia tions of CG lightning had multiple active peaks, but there was only one active pe riod of CG lightning all day long over ZhejiangJiangxiFujian area. The CG light ning was often more active in the afternoon over the YangtzeHuaihe River Basin and ZhejiangJiangxiFujian area, but it had an obvious nocturnal feature over the Sichuan Basin. In the Southwest Sichuan Basin, the CG lightning obviously pro pagated eastwards and northwards. It is also found that there is a marked differe nce between the diurnal variations of positive CG lightning and negative CG ligh tning over the western Sichuan Plateau, the middle YunnanGuizhou Plateau and t he coastal areas in Zhejiang. By comparing the diurnal variations of negative CG lightning with the positive CG lightning and the frequency of TBB≤-52℃ from the F Y-2C satellite, the active period of negative CG lightning was often ahead of t hat of positive CG lightning and the active period of positive CG lightning in t hose areas was ahead of the frequency of TBB≤-52℃. It implies that the diurnal variations of negative CG lightning reflected the diurnal variations of initial convection, and positive CG lightning and the frequency of TBB≤-52℃ reflected the diurnal variations of mature and dissipating convections.
Based on the June-August 2007 cloudtoground (CG) lightning dataset provided by the Meteorological Observation Center of China Meteorological Administration , the distribution and spatiotemporal variations of CG lightning over the Yangtze Riv er Basin and adjacent areas during the summer of 2007 are analyzed and compared wi th the thunderstorm distribution, the lightning distribution from loworbit sat ellites and with the deep convection distribution denoted by TBB≤-52°C. The re sults show that the four distributions are, to some extent, consistent with each other. By comparing the 2007 CG lightning distribution with the lightning distr ibution from the loworbit satellites, the CG lightning was more active over the Ya ngtzeHuaihe River Basin, Sichuan, Chongqing, the Northwest Zhejiang Province, t he middle of the Wuyi Mountains during the summer of 2007. In addition, the CG li ghtning was more active in July and August than in June, and the location of act ive areas is farther north, however, the positive CG lightning is the most active in July. It shows that the mesoscale convective systems occurred more often in July 2007. Diurnal variations of CG lightning were different over different area s. Over the Sichuan Basin and the YangtzeHuaihe River Basin, the diurnal varia tions of CG lightning had multiple active peaks, but there was only one active pe riod of CG lightning all day long over ZhejiangJiangxiFujian area. The CG light ning was often more active in the afternoon over the YangtzeHuaihe River Basin and ZhejiangJiangxiFujian area, but it had an obvious nocturnal feature over the Sichuan Basin. In the Southwest Sichuan Basin, the CG lightning obviously pro pagated eastwards and northwards. It is also found that there is a marked differe nce between the diurnal variations of positive CG lightning and negative CG ligh tning over the western Sichuan Plateau, the middle YunnanGuizhou Plateau and t he coastal areas in Zhejiang. By comparing the diurnal variations of negative CG lightning with the positive CG lightning and the frequency of TBB≤-52℃ from the F Y-2C satellite, the active period of negative CG lightning was often ahead of t hat of positive CG lightning and the active period of positive CG lightning in t hose areas was ahead of the frequency of TBB≤-52℃. It implies that the diurnal variations of negative CG lightning reflected the diurnal variations of initial convection, and positive CG lightning and the frequency of TBB≤-52℃ reflected the diurnal variations of mature and dissipating convections.
2009, 35(10):71-78.
DOI: 10.7519/j.issn.1000-0526.2009.10.008
Abstract:
Based on the routine weather chart data and NCEP 1°×1°FNL grid data, it was analyzed the upperair circulation and physical features for a rare continuous autumn rain occurring in Northwest Shandong from September 26 to October 7, 2007.It is shown that the largescale circulation over Eurasia was relatively stable, a stable blocking anticyclone had been maintained nearby the Ural Mountains, the subtropical high pressure of the West Pacific was extraordinary strong, tropical cyclones were generated in the lowlatitude zone frequently, the positions of South Asian high and subtropical westerlies jet stream were obviously further north than normal, the shortwave trough was continuously split up to move toward east in midlatitudes of Asia, and the southwest warm wet air currents of the northwest of the subtropical high continued to interact in the mid and lower reaches of the Yellow River, thus formed the 12 daylong overcast and rainy weather.
Based on the routine weather chart data and NCEP 1°×1°FNL grid data, it was analyzed the upperair circulation and physical features for a rare continuous autumn rain occurring in Northwest Shandong from September 26 to October 7, 2007.It is shown that the largescale circulation over Eurasia was relatively stable, a stable blocking anticyclone had been maintained nearby the Ural Mountains, the subtropical high pressure of the West Pacific was extraordinary strong, tropical cyclones were generated in the lowlatitude zone frequently, the positions of South Asian high and subtropical westerlies jet stream were obviously further north than normal, the shortwave trough was continuously split up to move toward east in midlatitudes of Asia, and the southwest warm wet air currents of the northwest of the subtropical high continued to interact in the mid and lower reaches of the Yellow River, thus formed the 12 daylong overcast and rainy weather.
2009, 35(10):79-83.
DOI: 10.7519/j.issn.1000-0526.2009.10.009
Abstract:
By the use of annual mean temperature data of 24 meteorological stations in Ning xia, the homogeneity test was studied for annual mean temperature time series with the Po tter method. The results showed that among the 24 series, the 9 series were inhomoge neous, and the other 15 series were homogeneous. The discontinuous points were mainly found in the years 2001-2 006 an d altogether had 7 discontinuous points (77.8%), in which 6 inhomogeneous series were caused by r elocated stations. Stations were relocated frequently in the 1950s, but the ti m es of relocated station were not the main causation of inhomogeneous series, a nd the environment changes of relocated station were the main factors. Moreover, the environment townish change of a station was also one of the factors, even though the station does not move.
By the use of annual mean temperature data of 24 meteorological stations in Ning xia, the homogeneity test was studied for annual mean temperature time series with the Po tter method. The results showed that among the 24 series, the 9 series were inhomoge neous, and the other 15 series were homogeneous. The discontinuous points were mainly found in the years 2001-2 006 an d altogether had 7 discontinuous points (77.8%), in which 6 inhomogeneous series were caused by r elocated stations. Stations were relocated frequently in the 1950s, but the ti m es of relocated station were not the main causation of inhomogeneous series, a nd the environment changes of relocated station were the main factors. Moreover, the environment townish change of a station was also one of the factors, even though the station does not move.
2009, 35(10):84-89.
DOI: 10.7519/j.issn.1000-0526.2009.10.010
Abstract:
After processings of installation, adjustment, localization and automation, the 3rd v ersion of city air pollution prediction system (CAPPS3) is used to establis h the regional air quality numerical forecast system suited to Liaoning to forca st city pollution index, pollution level and the daily mean concentration distri bution of pollutants in Liaoning. Comparisons between forecast results and obser vation data show that the forecast accuracy of SO2 and NO2 in the 14 main cities of Liaoning are higher than th at of PM10. The location and value of regional pollutant concentration ar e realistic and the change of hourly pollutant concentration is also consistent with the ch ange of real wind, indicating that the CAPPS3 is able to exactly forecast the genesis and develo pment of regional pollution in time.
After processings of installation, adjustment, localization and automation, the 3rd v ersion of city air pollution prediction system (CAPPS3) is used to establis h the regional air quality numerical forecast system suited to Liaoning to forca st city pollution index, pollution level and the daily mean concentration distri bution of pollutants in Liaoning. Comparisons between forecast results and obser vation data show that the forecast accuracy of SO2 and NO2 in the 14 main cities of Liaoning are higher than th at of PM10. The location and value of regional pollutant concentration ar e realistic and the change of hourly pollutant concentration is also consistent with the ch ange of real wind, indicating that the CAPPS3 is able to exactly forecast the genesis and develo pment of regional pollution in time.
2009, 35(10):90-96.
DOI: 10.7519/j.issn.1000-0526.2009.10.011
Abstract:
Presently, it is unfamiliar to see the research of dynamic influences between meteorological factors and economic systems. Thus, first, by using the a nnual temperature, industry production value, GDP and labour force data, a multvariable SVAR model is built. Then, the dynamic impacts between temperature and industry economy are analyzed through impulse response function (IRF) method. At last, a variance decomposition technique is adopted to investigate the influence degree. The results show that temperature rising has a negative effect on the industry economy of Nanjing as a whole, but it tends to be unconspicuous, about 3.1% of the industry production value is affected by the negative influence resulting from temperature rising every year. And the positive effect from industry economy developing to the temperature rising is remarkable, the annual contribution rate is about 4.4%. It proves that the way introduced in this paper on the basis of SVAR model is a reasonable and useful method to study the impacts between meteorological factors and economic systems.
Presently, it is unfamiliar to see the research of dynamic influences between meteorological factors and economic systems. Thus, first, by using the a nnual temperature, industry production value, GDP and labour force data, a multvariable SVAR model is built. Then, the dynamic impacts between temperature and industry economy are analyzed through impulse response function (IRF) method. At last, a variance decomposition technique is adopted to investigate the influence degree. The results show that temperature rising has a negative effect on the industry economy of Nanjing as a whole, but it tends to be unconspicuous, about 3.1% of the industry production value is affected by the negative influence resulting from temperature rising every year. And the positive effect from industry economy developing to the temperature rising is remarkable, the annual contribution rate is about 4.4%. It proves that the way introduced in this paper on the basis of SVAR model is a reasonable and useful method to study the impacts between meteorological factors and economic systems.
2009, 35(10):97-102.
DOI: 10.7519/j.issn.1000-0526.2009.10.012
Abstract:
The analysis and comparison are carried out between GTS1 radiosonde an d RS92 radiosonde from both static performance indices and dynamic characteristi cs, and the results show that the time lag effect exists in the temperature meas urement of GTS1 radiosonde, and the RS92 radiosonde gets obviously better humidity measu rement eff ect and lower pressure measurement above 200hPa than the GTS1 radiosonde. Meanwh ile, the RS92 radi osonde owns a higher wind measurement precision and there exsit systematic erro rs a bout 1m/s when the GTS1 radiosonde is located below 850hPa and above 15 0hPa. On the whole, RS92 radiosonde owns better performance.
The analysis and comparison are carried out between GTS1 radiosonde an d RS92 radiosonde from both static performance indices and dynamic characteristi cs, and the results show that the time lag effect exists in the temperature meas urement of GTS1 radiosonde, and the RS92 radiosonde gets obviously better humidity measu rement eff ect and lower pressure measurement above 200hPa than the GTS1 radiosonde. Meanwh ile, the RS92 radi osonde owns a higher wind measurement precision and there exsit systematic erro rs a bout 1m/s when the GTS1 radiosonde is located below 850hPa and above 15 0hPa. On the whole, RS92 radiosonde owns better performance.
2009, 35(10):103-107.
DOI: 10.7519/j.issn.1000-0526.2009.10.013
Abstract:
In order to accurately measure the temperature, it can be taken platinum res istance (Pt100) as a sensor of temperature measurement device, but it brings about the temperatureresistance nonlinear characteri stics. A unique precise algorithm for the conversion of platinum resistance nonl inear signals into air temperature is put forward by introducing platinum resist ance characteristics, and it is also the software table look up law and the method of average which carry out the two levels of error adjustm ents. The realization of this unique algorithm consists of the hardware and soft w are parts. The hardware is based on the good performance of A/D co n verter for the core component of the selfcalibration and system ca libration features in the precision conversion circuit, and the software is give n by the principa l source code, to achieve precision temperature measurement. The method is well applied in the temperature measurement devices.
In order to accurately measure the temperature, it can be taken platinum res istance (Pt100) as a sensor of temperature measurement device, but it brings about the temperatureresistance nonlinear characteri stics. A unique precise algorithm for the conversion of platinum resistance nonl inear signals into air temperature is put forward by introducing platinum resist ance characteristics, and it is also the software table look up law and the method of average which carry out the two levels of error adjustm ents. The realization of this unique algorithm consists of the hardware and soft w are parts. The hardware is based on the good performance of A/D co n verter for the core component of the selfcalibration and system ca libration features in the precision conversion circuit, and the software is give n by the principa l source code, to achieve precision temperature measurement. The method is well applied in the temperature measurement devices.
2009, 35(10):108-112.
DOI: 10.7519/j.issn.1000-0526.2009.10.014
Abstract:
The transmitter is an important part in CINRAD/SA radar. Because of its comp lex structure and running in the state of uninterrupted high voltage, a highest failurerate occurs among several extensions of radar system. Generally, th e rad ar system will be forced to halt once this fatal failure occurred. Based on an a b normal CINRAD/SA radar transmitter power decline, we find out that the failure lie s in the highfrequency pulse generator, which makes the pulse width depressed. And also, some maintenance methods are summed up here, from which the rad ar maintenance professional could take as reference.
The transmitter is an important part in CINRAD/SA radar. Because of its comp lex structure and running in the state of uninterrupted high voltage, a highest failurerate occurs among several extensions of radar system. Generally, th e rad ar system will be forced to halt once this fatal failure occurred. Based on an a b normal CINRAD/SA radar transmitter power decline, we find out that the failure lie s in the highfrequency pulse generator, which makes the pulse width depressed. And also, some maintenance methods are summed up here, from which the rad ar maintenance professional could take as reference.
2009, 35(10):113-118.
DOI: 10.7519/j.issn.1000-0526.2009.10.015
Abstract:
The RF Generator is the core component of Coherent Doppler weather rad ar, and the components are the highpriced due to high level technics. It prov ides all ne cessary radar working signals of benchmark, and has altogether 5output signals , na mely the 9.6 MHz master clock signals, COHO signal, RF DRIVE signal, STALO signa l , and RF TEST SIGNAL. Because different regions use different working frequenc y of ra dar’s transmitters, then the RF Generator can not be universal, and a compon ent backup is unrealistic in stations. On the other hand, radar manufacturers d id not provide the RF Generator drawings, and it brought difficulties to determine fau lt reasons. For the more than 10 CINRAD/SA radar RF Generator failures, the pape r divides three types of failures and analyzes the specific repairing methods. Finally, b y analyzing the frequency internal structure, we put forward the method or techn ique of resolving failures which the radar operator and maintenance professional should master so as to enhance the station’s security capacity.
The RF Generator is the core component of Coherent Doppler weather rad ar, and the components are the highpriced due to high level technics. It prov ides all ne cessary radar working signals of benchmark, and has altogether 5output signals , na mely the 9.6 MHz master clock signals, COHO signal, RF DRIVE signal, STALO signa l , and RF TEST SIGNAL. Because different regions use different working frequenc y of ra dar’s transmitters, then the RF Generator can not be universal, and a compon ent backup is unrealistic in stations. On the other hand, radar manufacturers d id not provide the RF Generator drawings, and it brought difficulties to determine fau lt reasons. For the more than 10 CINRAD/SA radar RF Generator failures, the pape r divides three types of failures and analyzes the specific repairing methods. Finally, b y analyzing the frequency internal structure, we put forward the method or techn ique of resolving failures which the radar operator and maintenance professional should master so as to enhance the station’s security capacity.
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ISSN:1000-0526 CN:11-2282/P