It is still not well understood if subseasonal variability of the local PM_(2.5) in the Beijing-Tianjin-Hebei(BTH)region is affected by the stratospheric state.Using PM_(2.5) observations and the ERA5 reanalysis,the e...It is still not well understood if subseasonal variability of the local PM_(2.5) in the Beijing-Tianjin-Hebei(BTH)region is affected by the stratospheric state.Using PM_(2.5) observations and the ERA5 reanalysis,the evolution of the air quality in BTH during the January 2021 sudden stratospheric warming(SSW)is explored.The subseasonal variability of the PM_(2.5) concentration after the SSW onset is evidently enhanced.Stratospheric circumpolar easterly anomalies lasted for 53 days during the January-February 2021 SSW with two evident stratospheric pulses arriving at the ground.During the tropospheric wave weakening period and the intermittent period of dormant stratospheric pulses,the East Asian winter monsoon weakened,anomalous temperature inversion developed in the lower troposphere,anomalous surface southerlies prevailed,atmospheric moisture increased,and the boundary layer top height lowered,all of which favor the accumulation of pollutant particulates,leading to two periods of pollution processes in the BTH region.In the phase of strengthened East Asian winter monsoon around the very beginning of the SSW and another two periods when stratospheric pulses had reached the near surface,opposite-signed circulation patterns and meteorological conditions were observed,which helped to dilute and diffuse air pollutants in the BTH region.As a result,the air quality was excellent during the two periods when the stratospheric pulse had reached the near surface.The increased subseasonal variation of the regional pollutant particulates after the SSW onset highlights the important role of the stratosphere in the regional environment and provides implications for the environmental prediction.展开更多
This study compares the climatology and long-term trend of northern winter stratospheric residual mean meridional circulation(RMMC), as well as its responses to El Ni?o-Southern Oscillation(ENSO), stratospheric Quasi ...This study compares the climatology and long-term trend of northern winter stratospheric residual mean meridional circulation(RMMC), as well as its responses to El Ni?o-Southern Oscillation(ENSO), stratospheric Quasi Biennial Oscillation(QBO), and solar cycle in ten reanalyses and a stratosphere-resolving model, CESM1-WACCM. The RMMC is a large-scale meridional circulation cell in the stratosphere, usually referred to as the estimate of the Brewer Dobson circulation(BDC). The distribution of the BDC is generally consistent among multiple reanalyses except that the NOAA twentieth century reanalysis(20RC) largely underestimates it. Most reanalyses(except ERA40 and ERA-Interim) show a strengthening trend for the BDC during 1979–2010. All reanalyses and CESM1-WACCM consistently reveal that the deep branch of the BDC is significantly enhanced in El Ni?o winters as more waves from the troposphere dissipate in the stratospheric polar vortex region. A secondary circulation cell is coupled to the temperature anomalies below the QBO easterly center at 50 hPa with tropical upwelling/cooling and midlatitude downwelling/warming, and similar secondary circulation cells also appear between 50–10 hPa and above 10 hPa to balance the temperature anomalies. The direct BDC response to QBO in the upper stratosphere creates a barrier near 30°N to prevent waves from propagating to midlatitudes, contributing to the weakening of the polar vortex. The shallow branch of the BDC in the lower stratosphere is intensified during solar minima, and the downwelling warms the Arctic lower stratosphere. The stratospheric responses to QBO and solar cycle in most reanalyses are generally consistent except in the two 20 CRs.展开更多
Using four satellite data sets(TOMS/SBUV, OMI, MLS, and HALOE), we analyze the seasonal variations of the total column ozone(TCO) and its zonal deviation(TCO*), and reveal the vertical structure of the Ozone Low(OV) o...Using four satellite data sets(TOMS/SBUV, OMI, MLS, and HALOE), we analyze the seasonal variations of the total column ozone(TCO) and its zonal deviation(TCO*), and reveal the vertical structure of the Ozone Low(OV) over the Asian continent. Our principal findings are:(1) The TCO over the Asian continent reaches its maximum in the spring and its minimum in the autumn. The Ozone Low exists from May to September.(2) The Ozone Low has two negative cores, located in the lower and the upper stratosphere. The lower core is near 30 hPa in the winter and 70 hPa in the other seasons. The upper core varies from 10 hPa to 1 hPa among the four seasons.(3)The position of the Ozone Low in the lower and the upper stratosphere over the Asian continent shows seasonal variability.展开更多
Previous studies have reported a close relationship between the negative Arctic Oscillation(AO)and the PM_(2.5)(particulate matter with a diameter of 2.5μm or less)diffusion in North China in winter.Using the North C...Previous studies have reported a close relationship between the negative Arctic Oscillation(AO)and the PM_(2.5)(particulate matter with a diameter of 2.5μm or less)diffusion in North China in winter.Using the North China regional mean meridional wind at 850 hPa derived from the ERA5(ECMWF Reanalysis version 5)reanalysis data in 1979–2022 as a useful substitute for station observed PM_(2.5) concentration(since the latter is available only since 2014),our study detected strong/weak northerly events representing the abnormal PM_(2.5) diffusion/accumulation events,and revisited the AO–PM_(2.5) diffusion relationship in North China during 1979–2022.The results show that only when the AO was characterized by a 2-month continuously negative/positive phases and with twin peaks respectively before and after the diffusion/accumulation events,would there be higher occurrences of the abnormal PM_(2.5) diffusion/accumulation.The second peak of negative AO acted to prolong the strong northerly winds by an average of 2 days.Further analysis reveals that the AO with twin peaks always has a footprint in the stratospheric northern annular mode(NAM)during the abnormal PM_(2.5) events,and the coupling between the stratosphere and troposphere plays a critical role in the second peak of AO.Vertical propagation of baroclinically amplifying waves leads to changes in isentropic meridional mass fluxes in the stratosphere following the changes in the troposphere.The stronger/weaker poleward mass fluxes increase/decrease the polar mass in the stratosphere,which dominates the total column air mass changes and leads to the second peak of AO.Considering the subseasonal predictability of the stratospheric NAM based on existing evidence,particular attention should be paid to these AO-related abnormal PM_(2.5) diffusion and accumulation events in North China because they might be more predictable at a longer lead time.展开更多
油源对比微量元素地球化学示踪是油气地球化学领域的前沿科学问题.以准噶尔盆地二叠系风城组碱湖含油气系统为例,对此进行了探索研究.通过对烃源岩和原油样品的微量元素组成进行电感耦合等离子体质谱(inductively coupled plasma mass s...油源对比微量元素地球化学示踪是油气地球化学领域的前沿科学问题.以准噶尔盆地二叠系风城组碱湖含油气系统为例,对此进行了探索研究.通过对烃源岩和原油样品的微量元素组成进行电感耦合等离子体质谱(inductively coupled plasma mass spectrometry,ICP-MS)分析和系统对比,发现检出的33个常见微量元素中,过渡族金属元素(Ti、V、Cr、Ni、Cu、Zn、Mn和Zr)、碱土金属元素(Sr和Ba)和非金属元素(B和As)在烃源岩与原油间具有较好的继承性,展示出油源对比和示踪意义,但由源到油,元素含量下降0.3~1141倍,差异富集特征显著,表明不能直接简单应用于油源对比.分析认为,微量元素从源到油的差异富集主要受控于微量元素以有机络(螯)合物或无机盐离子形式在有机质成烃演化与成藏过程中的动态分配.Ni和部分V以N–Ni/V键合于卟啉化合物,受油气运移影响小,相对稳定;大部分V以难溶矿物相赋存,油气初次运移时优先富集于烃源岩;Cr、Cu和Zn与有机酸中O/S原子络合,但在油气二次运移过程中化学键容易破裂;Mn、Zr、Ti、Sr和Ba主要以矿物相赋存于烃源岩中,在油气运移中以离子形式存在,易受油-岩相互作用发生离子交换;B以矿物相赋存于烃源岩中,但在初次运移时易与有机酸络合且受二次运移影响有限;As主要以砷化物或砷酸根离子赋存,受二次运移影响较大.据此,Ni、V、B、Cr、Cu、Zn和As具有较好的示踪意义,形成了4组参数:Ni含量进行油源对比、V/Ni和Ni/B示踪初次运移、Cr–Cu+Zn–As三端元图示踪二次运移.油气形成演化过程中的元素地球化学行为复杂,可在深入剖析后遴选有效参数应用于油气示踪,是经典有机地球化学方法的有效补充.展开更多
Trend uncertainty in the ozone valley over the Tibetan Plateau（OVTP）and the South Asian high（SAH）during1979–2009 in ERA-Interim（interim reanalysis data from the ECMWF）,JRA-55（55-yr reanalysis data from the Jap...Trend uncertainty in the ozone valley over the Tibetan Plateau（OVTP）and the South Asian high（SAH）during1979–2009 in ERA-Interim（interim reanalysis data from the ECMWF）,JRA-55（55-yr reanalysis data from the Japan Meteorological Agency）,and NCEP-CFSR（Climate Forecast System Reanalysis）datasets was evaluated.The results showed that the NCEP-CFSR OVTP became strong in the summers of 1979–2009,whereas it became weak according to ERA-Interim and JRA-55.Satellite data merged with TOMS（Total Ozone Mapping Spectrometer）and OMI（Ozone Monitoring Instrument）agreed with the OVTP trend of NCEP-CFSR.The OVTP strengthening in NCEP-CFSR may have been caused by SAH intensification,a rising tropopause,and increasing ozone over non-TP（non-Tibetan Plateau）areas（27°–37°N,〈75°E and〉105°E）.Analogously,the OVTP weakening in ERA-Interim and JRA-55 may have been affected by weakening SAH,descending tropopause,and decreasing non-TP ozone.展开更多
Maturity evaluation of highly evolved organic matter is an important problem in oil and gas geochemistry,because conventional organic geochemical proxies are not applicable due to hydrocarbon generation and expulsion....Maturity evaluation of highly evolved organic matter is an important problem in oil and gas geochemistry,because conventional organic geochemical proxies are not applicable due to hydrocarbon generation and expulsion.In this study,we investigated the pyrobitumen in the reservoirs of the Sinian Dengying Formation in the Sichuan Basin,China.We focused on aromatic hydrocarbon biomarkers,and the calibration and application of aromatic maturity proxies using pyrobitumen reflectance and Raman spectral parameters.Our results show that only the thiophene compounds are effective maturity indicators,such as MDR(4-/1-MDBT),MDR′(4-MDBT/(1-MDBT+4-MDBT)),MDR1(1-MDBT/DBT),4,6-/(1,4+1,6)-DMDBT,(2,6+3,6)-/(1,4+1,6)-DMDBT,and[2,1]BNT/([2,1]BNT+[1,2]BNT),as these are largely independent of the optical anisotropy of pyrobitumen.The condensation and incorporation of thiophene compounds can lead to an increase in the reflectance of pyrobitumen,which means the thiophene compound parameters are positively or negatively correlated with pyrobitumen reflectance.New potential maturity parameters were proposed,including DMDBTs/MDBTs,TeMDBTs/(DBT+MDBTs+DMDBTs+TMDBTs+TeMDBTs),1-MDBT/MDBTs,and[2,1]BNT/BNTs.This method and these parameters are universally applicable to maturity characterization,especially in rocks that lack vitrinite,contain strongly anisotropic organic matter,and have high contents of thiophene compounds.展开更多
To the Editor,A 66-year-old man with a history of microscopic polyangiitis,type 2 diabetes mellitus,bronchiectasis,and emphysema presented to Jiangxi Provincial People's Hospital on September 28,2021.The patient&#...To the Editor,A 66-year-old man with a history of microscopic polyangiitis,type 2 diabetes mellitus,bronchiectasis,and emphysema presented to Jiangxi Provincial People's Hospital on September 28,2021.The patient's major symptoms were fever,diarrhea,cough with sputum for the past month,and gangrene of the lip for the past 6 days.The patient was a farmer residing in Jiangxi Province,who was a nonsmoker with no travel history.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42088101 and 42175069)the National Key R&D Program of China(Grant No.2018YFC1505602).
文摘It is still not well understood if subseasonal variability of the local PM_(2.5) in the Beijing-Tianjin-Hebei(BTH)region is affected by the stratospheric state.Using PM_(2.5) observations and the ERA5 reanalysis,the evolution of the air quality in BTH during the January 2021 sudden stratospheric warming(SSW)is explored.The subseasonal variability of the PM_(2.5) concentration after the SSW onset is evidently enhanced.Stratospheric circumpolar easterly anomalies lasted for 53 days during the January-February 2021 SSW with two evident stratospheric pulses arriving at the ground.During the tropospheric wave weakening period and the intermittent period of dormant stratospheric pulses,the East Asian winter monsoon weakened,anomalous temperature inversion developed in the lower troposphere,anomalous surface southerlies prevailed,atmospheric moisture increased,and the boundary layer top height lowered,all of which favor the accumulation of pollutant particulates,leading to two periods of pollution processes in the BTH region.In the phase of strengthened East Asian winter monsoon around the very beginning of the SSW and another two periods when stratospheric pulses had reached the near surface,opposite-signed circulation patterns and meteorological conditions were observed,which helped to dilute and diffuse air pollutants in the BTH region.As a result,the air quality was excellent during the two periods when the stratospheric pulse had reached the near surface.The increased subseasonal variation of the regional pollutant particulates after the SSW onset highlights the important role of the stratosphere in the regional environment and provides implications for the environmental prediction.
基金supported by grants from the National Natural Science Foundation of China(41705024,41875048)the National Key R&D Program of China(2016YFA0602104)+1 种基金the Planning and Budgeting Committee of the Council for Higher Education in Israelthe Startup Foundation for Introducing Talent of NUIST(2016r060)
文摘This study compares the climatology and long-term trend of northern winter stratospheric residual mean meridional circulation(RMMC), as well as its responses to El Ni?o-Southern Oscillation(ENSO), stratospheric Quasi Biennial Oscillation(QBO), and solar cycle in ten reanalyses and a stratosphere-resolving model, CESM1-WACCM. The RMMC is a large-scale meridional circulation cell in the stratosphere, usually referred to as the estimate of the Brewer Dobson circulation(BDC). The distribution of the BDC is generally consistent among multiple reanalyses except that the NOAA twentieth century reanalysis(20RC) largely underestimates it. Most reanalyses(except ERA40 and ERA-Interim) show a strengthening trend for the BDC during 1979–2010. All reanalyses and CESM1-WACCM consistently reveal that the deep branch of the BDC is significantly enhanced in El Ni?o winters as more waves from the troposphere dissipate in the stratospheric polar vortex region. A secondary circulation cell is coupled to the temperature anomalies below the QBO easterly center at 50 hPa with tropical upwelling/cooling and midlatitude downwelling/warming, and similar secondary circulation cells also appear between 50–10 hPa and above 10 hPa to balance the temperature anomalies. The direct BDC response to QBO in the upper stratosphere creates a barrier near 30°N to prevent waves from propagating to midlatitudes, contributing to the weakening of the polar vortex. The shallow branch of the BDC in the lower stratosphere is intensified during solar minima, and the downwelling warms the Arctic lower stratosphere. The stratospheric responses to QBO and solar cycle in most reanalyses are generally consistent except in the two 20 CRs.
基金funded by the National Science Foundation of China (91537213, 91837311, 41675039, 41875048)
文摘Using four satellite data sets(TOMS/SBUV, OMI, MLS, and HALOE), we analyze the seasonal variations of the total column ozone(TCO) and its zonal deviation(TCO*), and reveal the vertical structure of the Ozone Low(OV) over the Asian continent. Our principal findings are:(1) The TCO over the Asian continent reaches its maximum in the spring and its minimum in the autumn. The Ozone Low exists from May to September.(2) The Ozone Low has two negative cores, located in the lower and the upper stratosphere. The lower core is near 30 hPa in the winter and 70 hPa in the other seasons. The upper core varies from 10 hPa to 1 hPa among the four seasons.(3)The position of the Ozone Low in the lower and the upper stratosphere over the Asian continent shows seasonal variability.
基金Supported by the National Natural Science Foundation of China(42375060)Creative Research Group Fund of the National Natural Science Foundation of China(42021004)Natural Science Foundation of Jiangsu Province of China(BK20211288)。
文摘Previous studies have reported a close relationship between the negative Arctic Oscillation(AO)and the PM_(2.5)(particulate matter with a diameter of 2.5μm or less)diffusion in North China in winter.Using the North China regional mean meridional wind at 850 hPa derived from the ERA5(ECMWF Reanalysis version 5)reanalysis data in 1979–2022 as a useful substitute for station observed PM_(2.5) concentration(since the latter is available only since 2014),our study detected strong/weak northerly events representing the abnormal PM_(2.5) diffusion/accumulation events,and revisited the AO–PM_(2.5) diffusion relationship in North China during 1979–2022.The results show that only when the AO was characterized by a 2-month continuously negative/positive phases and with twin peaks respectively before and after the diffusion/accumulation events,would there be higher occurrences of the abnormal PM_(2.5) diffusion/accumulation.The second peak of negative AO acted to prolong the strong northerly winds by an average of 2 days.Further analysis reveals that the AO with twin peaks always has a footprint in the stratospheric northern annular mode(NAM)during the abnormal PM_(2.5) events,and the coupling between the stratosphere and troposphere plays a critical role in the second peak of AO.Vertical propagation of baroclinically amplifying waves leads to changes in isentropic meridional mass fluxes in the stratosphere following the changes in the troposphere.The stronger/weaker poleward mass fluxes increase/decrease the polar mass in the stratosphere,which dominates the total column air mass changes and leads to the second peak of AO.Considering the subseasonal predictability of the stratospheric NAM based on existing evidence,particular attention should be paid to these AO-related abnormal PM_(2.5) diffusion and accumulation events in North China because they might be more predictable at a longer lead time.
文摘油源对比微量元素地球化学示踪是油气地球化学领域的前沿科学问题.以准噶尔盆地二叠系风城组碱湖含油气系统为例,对此进行了探索研究.通过对烃源岩和原油样品的微量元素组成进行电感耦合等离子体质谱(inductively coupled plasma mass spectrometry,ICP-MS)分析和系统对比,发现检出的33个常见微量元素中,过渡族金属元素(Ti、V、Cr、Ni、Cu、Zn、Mn和Zr)、碱土金属元素(Sr和Ba)和非金属元素(B和As)在烃源岩与原油间具有较好的继承性,展示出油源对比和示踪意义,但由源到油,元素含量下降0.3~1141倍,差异富集特征显著,表明不能直接简单应用于油源对比.分析认为,微量元素从源到油的差异富集主要受控于微量元素以有机络(螯)合物或无机盐离子形式在有机质成烃演化与成藏过程中的动态分配.Ni和部分V以N–Ni/V键合于卟啉化合物,受油气运移影响小,相对稳定;大部分V以难溶矿物相赋存,油气初次运移时优先富集于烃源岩;Cr、Cu和Zn与有机酸中O/S原子络合,但在油气二次运移过程中化学键容易破裂;Mn、Zr、Ti、Sr和Ba主要以矿物相赋存于烃源岩中,在油气运移中以离子形式存在,易受油-岩相互作用发生离子交换;B以矿物相赋存于烃源岩中,但在初次运移时易与有机酸络合且受二次运移影响有限;As主要以砷化物或砷酸根离子赋存,受二次运移影响较大.据此,Ni、V、B、Cr、Cu、Zn和As具有较好的示踪意义,形成了4组参数:Ni含量进行油源对比、V/Ni和Ni/B示踪初次运移、Cr–Cu+Zn–As三端元图示踪二次运移.油气形成演化过程中的元素地球化学行为复杂,可在深入剖析后遴选有效参数应用于油气示踪,是经典有机地球化学方法的有效补充.
基金Supported by the National Natural Science Foundation of China(41305039,41675039,91537213,41375047,41375092,41475140,41641042,and 41575057)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Trend uncertainty in the ozone valley over the Tibetan Plateau（OVTP）and the South Asian high（SAH）during1979–2009 in ERA-Interim（interim reanalysis data from the ECMWF）,JRA-55（55-yr reanalysis data from the Japan Meteorological Agency）,and NCEP-CFSR（Climate Forecast System Reanalysis）datasets was evaluated.The results showed that the NCEP-CFSR OVTP became strong in the summers of 1979–2009,whereas it became weak according to ERA-Interim and JRA-55.Satellite data merged with TOMS（Total Ozone Mapping Spectrometer）and OMI（Ozone Monitoring Instrument）agreed with the OVTP trend of NCEP-CFSR.The OVTP strengthening in NCEP-CFSR may have been caused by SAH intensification,a rising tropopause,and increasing ozone over non-TP（non-Tibetan Plateau）areas（27°–37°N,〈75°E and〉105°E）.Analogously,the OVTP weakening in ERA-Interim and JRA-55 may have been affected by weakening SAH,descending tropopause,and decreasing non-TP ozone.
基金supported by the National Natural Science Foundation of China(Grant Nos.42230808 and 41830425).
文摘Maturity evaluation of highly evolved organic matter is an important problem in oil and gas geochemistry,because conventional organic geochemical proxies are not applicable due to hydrocarbon generation and expulsion.In this study,we investigated the pyrobitumen in the reservoirs of the Sinian Dengying Formation in the Sichuan Basin,China.We focused on aromatic hydrocarbon biomarkers,and the calibration and application of aromatic maturity proxies using pyrobitumen reflectance and Raman spectral parameters.Our results show that only the thiophene compounds are effective maturity indicators,such as MDR(4-/1-MDBT),MDR′(4-MDBT/(1-MDBT+4-MDBT)),MDR1(1-MDBT/DBT),4,6-/(1,4+1,6)-DMDBT,(2,6+3,6)-/(1,4+1,6)-DMDBT,and[2,1]BNT/([2,1]BNT+[1,2]BNT),as these are largely independent of the optical anisotropy of pyrobitumen.The condensation and incorporation of thiophene compounds can lead to an increase in the reflectance of pyrobitumen,which means the thiophene compound parameters are positively or negatively correlated with pyrobitumen reflectance.New potential maturity parameters were proposed,including DMDBTs/MDBTs,TeMDBTs/(DBT+MDBTs+DMDBTs+TMDBTs+TeMDBTs),1-MDBT/MDBTs,and[2,1]BNT/BNTs.This method and these parameters are universally applicable to maturity characterization,especially in rocks that lack vitrinite,contain strongly anisotropic organic matter,and have high contents of thiophene compounds.
基金supported by Jiangxi Province Medical Leading Discipline Construct Project(Rheumatology)Provincial and Municipal Joint Construction Projects of Medical Disciplines in Jiangxi Province(Rheumatology)National Natural Science Foundation of China(No.81960296).
文摘To the Editor,A 66-year-old man with a history of microscopic polyangiitis,type 2 diabetes mellitus,bronchiectasis,and emphysema presented to Jiangxi Provincial People's Hospital on September 28,2021.The patient's major symptoms were fever,diarrhea,cough with sputum for the past month,and gangrene of the lip for the past 6 days.The patient was a farmer residing in Jiangxi Province,who was a nonsmoker with no travel history.
