Calculation of tidal changes reveals that the MS 7. 0 Lushan County,Sichuan,China,earthquake of April 20,2013 occurred at the minimum phase point of tidal force. It indicates that the seismogenic fault on which the ti...Calculation of tidal changes reveals that the MS 7. 0 Lushan County,Sichuan,China,earthquake of April 20,2013 occurred at the minimum phase point of tidal force. It indicates that the seismogenic fault on which the tidal force acts on is of thrust type. The outgoing long-wave radiation( OLR) is the energy radiating from the Earth as infrared radiation at low energy to space. According to the tidal cycle,abnormal OLR change is analyzed based on NOAA satellite data around the whole of China before and after the earthquake. The result shows that the OLR changed evidently with the tide force change.Temporally,the change went through the course: initial OLR rise → s trengthening →reaching abnormal peak → a ttenuation → r eturning to normal; in space,the abnormal area was distributed along the Longmenshan fault and evolved as: scattering→ c onvergent→ s cattering. The process is similar to the change process of rock breaking under stress loading. It indicates that the celestial tidal force can trigger earthquakes when the tectonic stress reaches the critical break point of an active fault and the OLR anomaly is proportional to the seismic tectonic stress change. It is of practical value to combine OLR and tidal force anomaly with earthquake precursor studies.展开更多
In the context of August 1982- July 1983 radiation balance data of the Qinghai-Xizang Plateau, detailed study is made of the relation between the active-surface temperature and surface temperature, proposing two param...In the context of August 1982- July 1983 radiation balance data of the Qinghai-Xizang Plateau, detailed study is made of the relation between the active-surface temperature and surface temperature, proposing two parameterization schemes on surface long-wave radiation (SLWR) of the form U=kδσ(T_0 + 273)~4 and U=δσ[(T_0+273)~4+△T)]~4, where k and △T are indicated by parameterization equations, separately, others being in conventional notation. Retrieved verification shows the two formulae to be of the same fitting accuracy with the mean relative error of 3.6% and suitable for computing instantaneous and mean flux density, alongside analyzed daily and annual variations of k and △T. Eventually. SLWR in the target area is investigated and its climatic characteristics examined.展开更多
Based on the air-sea interface heat fluxes and related meteorological variables datasets recently released by Objectively Analyzed Air-Sea Fluxes(OA Flux) Project of Woods Hole Oceanographic Institution,as well as the...Based on the air-sea interface heat fluxes and related meteorological variables datasets recently released by Objectively Analyzed Air-Sea Fluxes(OA Flux) Project of Woods Hole Oceanographic Institution,as well as the outgoing longwave radiation and surface wind datasets from National Oceanic and Atmospheric Administration,the seasonal dependence of local air-sea interaction over the tropical western Pacific warm pool(referred to the region(1o-6oN,144o-154oE)) is revealed and the probable impacts of remote forcing on the air-sea interaction are examined.The results indicated the dominance of oceanic forcing with the significant impact of ENSO in March and that of atmospheric feedback without notable influence of remote forcing in June.While the interannual variability of sea surface temperature anomaly(SSTA) is larger than that of SSTA tendency when oceanic forcing is dominant,the opposite is true when atmospheric feedback is dominant.The magnitude of the oceanic forcing of the atmosphere tends to decrease in March with the occurrence of ENSO,though ENSO has little influence on the atmospheric feedback to the ocean in June.The local air-sea interaction is substantially the same before and after the removal of the effect of Indian Oceanic Dipole.The reduction of shortwave radiation fluxes into the western Pacific warm pool,due to the enhanced overlaying convection in March associated with ENSO,leads to the decline of SST tendency that will weaken the oceanic forcing of the atmosphere.展开更多
In this paper,two schemes proposed by Julian(1984)and Krishnamauti(1986)are used to retrieve the tropical divergent wind at 200 hPa and 850 hPa from the satellite observational Outgoing Long-wave Radiation(OLR).The co...In this paper,two schemes proposed by Julian(1984)and Krishnamauti(1986)are used to retrieve the tropical divergent wind at 200 hPa and 850 hPa from the satellite observational Outgoing Long-wave Radiation(OLR).The comparison study has been conducted among the OLR-derived divergent wind field and those directly from wind fields of ECMWF and CAC tropical analysis,and NCEP/NCAR reanalysis for examining their reliability.Then,the divergent wind retrieved from OLR by using Julian's scheme is used to composite the diagrams of the Walker circulation and the local Hadley circulation during 1982—1983 ENSO event.The possible linkage between the anomalies of summer rainfall in East China during this period and the anomalous Walker and local Hadley circulations is discussed. It is shown that it is practically feasible to use the satellite observed OLR data in the estimation of the tropical divergent wind.It is aiso indicated that NCEP/NCAR reanalysis has made a progress for improving the reliability of the tropical divergent wind,though some biases still exist in the description of the intensity and position of the divergence(convergence)maximum centers over Asian monsoon region.The application of Julian's method to a diagnosis on the evolutions of the anomalous Walker and Hadley circulations during 1982—1983 ENSO event shows that the development of this ENSO event is not companied with the sudden reversal of the Walker circulation,but the propagation of the ascending branch over the western Pacific to the central- eastern Pacific and crossing through the date line,which results in a significant displacement of the vertical circulation over the West Pacific(WP)and the central-east Pacific(CEP).It is also indicated that there exists a close linkage between the change of local Hadley circulation in the WP and the Walker circulation in the CEP,implying that the Walker circulation possibly severs as a bridge between the anomalies of the SST in the CEP and the change of local Hadley circulation in Northwest Pacific.The latter is responsible for the climate anomaly over eastern China during this period.展开更多
GPS radio occultation（GPS RO） method,an active satellite-to-satellite remote sensing technique,is capable of producing accurate,all-weather,round the clock,global refractive index,density,pressure,and temperature pr...GPS radio occultation（GPS RO） method,an active satellite-to-satellite remote sensing technique,is capable of producing accurate,all-weather,round the clock,global refractive index,density,pressure,and temperature profiles of the troposphere and stratosphere.This study presents planetary-scale equatorially trapped Kelvin waves in temperature profiles retrieved using COSMIC（Constellation Observing System for Meteorology,Ionosphere,and Climate） satellites during 2006-2009 and their interactions with background atmospheric conditions.It is found that the Kelvin waves are not only associated with wave periods of higher than 10 days（slow Kelvin waves） with higher zonal wave numbers（either 1 or 2）,but also possessing downward phase progression,giving evidence that the source regions of them are located at lower altitudes.A thorough verification of outgoing longwave radiation（OLR） reveals that deep convection activity has developed regularly over the Indonesian region,suggesting that the Kelvin waves are driven by the convective activity.The derived Kelvin waves show enhanced（diminished） tendencies during westward（eastward） phase of the quasi-biennial oscillation（QBO） in zonal winds,implying a mutual relation between both of them.The El Nino and Southern Oscillation（ENSO） below 18 km and the QBO features between 18 and 27km in temperature profiles are observed during May 2006-May 2010 with the help of an adaptive data analysis technique known as Hilbert Huang Transform（HHT）.Further,temperature anomalies computed using COSMIC retrieved temperatures are critically evaluated during different phases of ENSO,which has revealed interesting results and are discussed in light of available literature.展开更多
基金supported by the science for earthquake resilience of China(No.XH15050)the Research on Determination and Announcement of the National Significant Seismic Monitoring and Protction Regions During 2015 to 2016(201508010)
文摘Calculation of tidal changes reveals that the MS 7. 0 Lushan County,Sichuan,China,earthquake of April 20,2013 occurred at the minimum phase point of tidal force. It indicates that the seismogenic fault on which the tidal force acts on is of thrust type. The outgoing long-wave radiation( OLR) is the energy radiating from the Earth as infrared radiation at low energy to space. According to the tidal cycle,abnormal OLR change is analyzed based on NOAA satellite data around the whole of China before and after the earthquake. The result shows that the OLR changed evidently with the tide force change.Temporally,the change went through the course: initial OLR rise → s trengthening →reaching abnormal peak → a ttenuation → r eturning to normal; in space,the abnormal area was distributed along the Longmenshan fault and evolved as: scattering→ c onvergent→ s cattering. The process is similar to the change process of rock breaking under stress loading. It indicates that the celestial tidal force can trigger earthquakes when the tectonic stress reaches the critical break point of an active fault and the OLR anomaly is proportional to the seismic tectonic stress change. It is of practical value to combine OLR and tidal force anomaly with earthquake precursor studies.
基金This work is the pre-research result of "Qinghai-Xizang Plateau Meteorological Experiment" as part of the National Scientific Scaling Project
文摘In the context of August 1982- July 1983 radiation balance data of the Qinghai-Xizang Plateau, detailed study is made of the relation between the active-surface temperature and surface temperature, proposing two parameterization schemes on surface long-wave radiation (SLWR) of the form U=kδσ(T_0 + 273)~4 and U=δσ[(T_0+273)~4+△T)]~4, where k and △T are indicated by parameterization equations, separately, others being in conventional notation. Retrieved verification shows the two formulae to be of the same fitting accuracy with the mean relative error of 3.6% and suitable for computing instantaneous and mean flux density, alongside analyzed daily and annual variations of k and △T. Eventually. SLWR in the target area is investigated and its climatic characteristics examined.
基金Fundamental Research Funds for the Central Universities(WK2080000037)Natural Science Foundation of Anhui Province(1208085QD75)Open Fund of the Key Laboratory of Ocean Circulation and Waves from Chinese Academy of Sciences(KLOCAW1204)
文摘Based on the air-sea interface heat fluxes and related meteorological variables datasets recently released by Objectively Analyzed Air-Sea Fluxes(OA Flux) Project of Woods Hole Oceanographic Institution,as well as the outgoing longwave radiation and surface wind datasets from National Oceanic and Atmospheric Administration,the seasonal dependence of local air-sea interaction over the tropical western Pacific warm pool(referred to the region(1o-6oN,144o-154oE)) is revealed and the probable impacts of remote forcing on the air-sea interaction are examined.The results indicated the dominance of oceanic forcing with the significant impact of ENSO in March and that of atmospheric feedback without notable influence of remote forcing in June.While the interannual variability of sea surface temperature anomaly(SSTA) is larger than that of SSTA tendency when oceanic forcing is dominant,the opposite is true when atmospheric feedback is dominant.The magnitude of the oceanic forcing of the atmosphere tends to decrease in March with the occurrence of ENSO,though ENSO has little influence on the atmospheric feedback to the ocean in June.The local air-sea interaction is substantially the same before and after the removal of the effect of Indian Oceanic Dipole.The reduction of shortwave radiation fluxes into the western Pacific warm pool,due to the enhanced overlaying convection in March associated with ENSO,leads to the decline of SST tendency that will weaken the oceanic forcing of the atmosphere.
基金This research is supported by the Chinese Ninth Five-Year National Project"Short-Range Climate Prediction System" the National Natural Science Foundation of China project for the young scientists,Grant No.49705061.
文摘In this paper,two schemes proposed by Julian(1984)and Krishnamauti(1986)are used to retrieve the tropical divergent wind at 200 hPa and 850 hPa from the satellite observational Outgoing Long-wave Radiation(OLR).The comparison study has been conducted among the OLR-derived divergent wind field and those directly from wind fields of ECMWF and CAC tropical analysis,and NCEP/NCAR reanalysis for examining their reliability.Then,the divergent wind retrieved from OLR by using Julian's scheme is used to composite the diagrams of the Walker circulation and the local Hadley circulation during 1982—1983 ENSO event.The possible linkage between the anomalies of summer rainfall in East China during this period and the anomalous Walker and local Hadley circulations is discussed. It is shown that it is practically feasible to use the satellite observed OLR data in the estimation of the tropical divergent wind.It is aiso indicated that NCEP/NCAR reanalysis has made a progress for improving the reliability of the tropical divergent wind,though some biases still exist in the description of the intensity and position of the divergence(convergence)maximum centers over Asian monsoon region.The application of Julian's method to a diagnosis on the evolutions of the anomalous Walker and Hadley circulations during 1982—1983 ENSO event shows that the development of this ENSO event is not companied with the sudden reversal of the Walker circulation,but the propagation of the ascending branch over the western Pacific to the central- eastern Pacific and crossing through the date line,which results in a significant displacement of the vertical circulation over the West Pacific(WP)and the central-east Pacific(CEP).It is also indicated that there exists a close linkage between the change of local Hadley circulation in the WP and the Walker circulation in the CEP,implying that the Walker circulation possibly severs as a bridge between the anomalies of the SST in the CEP and the change of local Hadley circulation in Northwest Pacific.The latter is responsible for the climate anomaly over eastern China during this period.
基金Supported by the Science Council of Taiwan(NSC-101-2811-M-008-012)
文摘GPS radio occultation（GPS RO） method,an active satellite-to-satellite remote sensing technique,is capable of producing accurate,all-weather,round the clock,global refractive index,density,pressure,and temperature profiles of the troposphere and stratosphere.This study presents planetary-scale equatorially trapped Kelvin waves in temperature profiles retrieved using COSMIC（Constellation Observing System for Meteorology,Ionosphere,and Climate） satellites during 2006-2009 and their interactions with background atmospheric conditions.It is found that the Kelvin waves are not only associated with wave periods of higher than 10 days（slow Kelvin waves） with higher zonal wave numbers（either 1 or 2）,but also possessing downward phase progression,giving evidence that the source regions of them are located at lower altitudes.A thorough verification of outgoing longwave radiation（OLR） reveals that deep convection activity has developed regularly over the Indonesian region,suggesting that the Kelvin waves are driven by the convective activity.The derived Kelvin waves show enhanced（diminished） tendencies during westward（eastward） phase of the quasi-biennial oscillation（QBO） in zonal winds,implying a mutual relation between both of them.The El Nino and Southern Oscillation（ENSO） below 18 km and the QBO features between 18 and 27km in temperature profiles are observed during May 2006-May 2010 with the help of an adaptive data analysis technique known as Hilbert Huang Transform（HHT）.Further,temperature anomalies computed using COSMIC retrieved temperatures are critically evaluated during different phases of ENSO,which has revealed interesting results and are discussed in light of available literature.
