“Diurnal variation of CH4 at the surface from spring to winter.The time units are in local time(+8 h UTC).The error bar is 1σfor all the observed hourly mean data within that season at that local time.”in the capti...“Diurnal variation of CH4 at the surface from spring to winter.The time units are in local time(+8 h UTC).The error bar is 1σfor all the observed hourly mean data within that season at that local time.”in the caption of Fig.8 on Page 604 should be“Diurnal variation of CH4 at the surface from spring to winter.The time units are in UTC.The error bar is 1σfor all the observed hourly mean data within that season at that local time.”展开更多
In this report we summarize the research results by Chinese scientists in 2012–2014. The focuses are placed on the researches of the middle and upper atmosphere, specifically the researches related to ground-based ob...In this report we summarize the research results by Chinese scientists in 2012–2014. The focuses are placed on the researches of the middle and upper atmosphere, specifically the researches related to ground-based observation capability development, dynamical processes, the property of circulation and chemistry-climate coupling of the middle atmospheric layers.展开更多
In this report the research results by Chinese scientists in 2014—2016 are summarized.The focuses are placed on the researches of the middle and upper atmosphere,specifically the researches associated with ground-bas...In this report the research results by Chinese scientists in 2014—2016 are summarized.The focuses are placed on the researches of the middle and upper atmosphere,specifically the researches associated with ground-based observation capabihty development,dynamical processes,and properties of circulation and chemistry-climate coupling of the middle atmospheric layers.展开更多
In this paper we summarize the research results by Chinese scientists in 2016–2018. The focuses are placed on the researches of the middle and upper atmosphere, specifically the researches associated with groundbased...In this paper we summarize the research results by Chinese scientists in 2016–2018. The focuses are placed on the researches of the middle and upper atmosphere, specifically the researches associated with groundbased observation capability development, dynamical processes, and properties of circulation and chemistryclimate coupling of the middle atmospheric layers.展开更多
Tropopause folds are one of the key mechanisms of stratosphere–troposphere exchange(STE) in extratropical regions,transporting ozone-rich stratospheric air into the middle and lower troposphere. Although there have b...Tropopause folds are one of the key mechanisms of stratosphere–troposphere exchange(STE) in extratropical regions,transporting ozone-rich stratospheric air into the middle and lower troposphere. Although there have been many studies of tropopause folds that have occurred over Europe and North America,a very limited amount of work has been carried out over northeastern Asia. Ozonesondes produced by the Institute of Atmospheric Physics were launched in Changchun(43.9?N,125.2?E),Northeast China,in June 2013,and observed an ozone-enriched layer with thickness of 3 km and an ozone peak of180 ppbv at 6 km in the troposphere. The circulation field from the European Centre for Medium-Range Weather Forecasts Interim Reanalysis(ERA-Interim) dataset shows that this ozone peak was caused by a tropopause fold associated with a jet stream at the eastern flank of the East Asian trough. By analyzing the ozone data from the ozone monitoring instrument and Weather Research and Forecasting model with Chemistry(WRF-Chem) simulations,it was found that a high ozone concentration tongue originating from the lower stratosphere at high latitude(near central Siberia) intruded into the middle troposphere over Changchun between 5 and 8 km on 12 June 2013. The high-resolution WRF-Chem simulation was capable of describing events such as the tropopause fold that occurred on the cyclonic shear side of the jet stream. In addition,the TRAJ3 D trajectory model was used to trace the origin of measured secondary ozone peaks in the middle troposphere back,for example,to stratospheric intrusion through the tropopause fold.展开更多
By using the radiosonde measurements collected at Shouxian,China,we examined the dynamics and thermodynamics of single- and two-layer clouds formed at low and middle levels.The analyses indicated that the horizontal w...By using the radiosonde measurements collected at Shouxian,China,we examined the dynamics and thermodynamics of single- and two-layer clouds formed at low and middle levels.The analyses indicated that the horizontal wind speed above the cloud layers was higher than those within and below cloud layers.The maximum balloon ascent speed(5.3 m s^(-1)) was located in the vicinity of the layer with the maximum cloud occurrence frequency(24.4%),indicating an upward motion(0.1-0.16 ms^(-1)).The average thickness,magnitude and gradient of the temperature inversion layer above single-layer clouds were117±94 m,1.3±1.3℃ and 1.4±1.5℃(100 m)^(-1),respectively.The average temperature inversion magnitude was the same(1.3℃) for single-low and single-middle clouds;however,a larger gradient[1.7±1.8℃(100 m)^(-1)]and smaller thickness(94±67 m) were detected above single-low clouds relative to those above single-middle clouds[0.9±0.7℃(100 m)^(-1) and157±120 m].For the two-layer cloud,the temperature inversion parameters were 106±59 m,1.0±0.9℃ and 1.0±1.0℃(100 m)^(-1) above the upper-layer cloud and 82 ± 60 m,0.6±0.9℃ and 0.7±0.6℃(100 m)^(-1) above the low-layer cloud.Absolute differences between the cloud-base height(cloud-top height) and the lifting condensation level(equilibrium level)were less than 0.5 km for 66.4%(36.8%) of the cases analyzed in summer.展开更多
During August 2013,a mobile Rayleigh lidar was deployed in Lhasa,Tibet(29.6°N,91.0°E) for making measurements of middle atmosphere densities and temperatures from 30 to 90 km.In this paper,the authors presen...During August 2013,a mobile Rayleigh lidar was deployed in Lhasa,Tibet(29.6°N,91.0°E) for making measurements of middle atmosphere densities and temperatures from 30 to 90 km.In this paper,the authors present the initial results from this scientific campaign,Middle Atmosphere Remote Mobile Observatory in Tibet(MARMOT),and compared the results to the MSIS-00(Mass Spectrometer and Incoherent Scatter) model.This work will advance our understanding of middle atmosphere dynamic processes,especially over the Tibetan Plateau area.展开更多
The authors examined the Madden-Julian Oscillation(MJO) in stratospheric ozone during boreal winter using a simulation from the Specified Dynamics version of the Whole Atmosphere Community Climate Model(SD-WACCM) in 2...The authors examined the Madden-Julian Oscillation(MJO) in stratospheric ozone during boreal winter using a simulation from the Specified Dynamics version of the Whole Atmosphere Community Climate Model(SD-WACCM) in 2004 and 2010. Comparison with European Centre for Medium-Range Weather Forecasts Interim Reanalysis(ERA-Interim) data suggested that the model simulation represented well the three-dimensional structure of the MJO-related ozone anomalies in the upper troposphere and stratosphere(i.e., between 200 and 20 h Pa). The negative ozone anomalies were over the Tibetan Plateau and East Asia in MJO phases 3–7, when the MJO convective anomalies travelled from the equatorial Indian Ocean towards the equatorial western Pacific Ocean. Due to the different vertical structures of the MJO-related circulation anomalies, the MJO-related stratospheric ozone anomalies showed different vertical structure over the Tibetan Plateau(25–40°N, 75–105°E) and East Asia(25–40°N, 105–135°E). As a result of the positive bias in the model-calculated ozone in the upper troposphere and lower stratosphere, the amplitude of MJO-related stratospheric ozone column anomalies(10–16 Dobson Units(DU)) in the SD-WACCM simulation was slightly larger than that(8–14 DU) in the ERA-Interim reanalysis.展开更多
“Earth summit mission 2022”is one of the landmark scientific research activities of the Second Tibetan Plateau Scientific Expedition and Research(STEP).This scientific expedition firstly used advanced technology and...“Earth summit mission 2022”is one of the landmark scientific research activities of the Second Tibetan Plateau Scientific Expedition and Research(STEP).This scientific expedition firstly used advanced technology and methods to detect vertical meteorological elements and produce forecasts for mountain climbing.The“Earth summit mission 2022”Qomolangma scientific expedition exceeded an altitude of over 8000 meters for the first time and carried out a comprehensive scientific investigation mission on the summit of Mt.Qomolangma.Among the participants,the westerly–monsoon synergy and influence team stationed in the Mt.Qomolangma region had two tasks:1)detecting the vertical structure of the atmosphere for parameters such as wind,temperature,humidity,and pressure with advanced instruments for high-altitude detection at the Mt.Qomolangma base camp;and 2)observing extreme weather processes to ensure that members of the mountaineering team could successfully reach the top.Through this scientific expedition,a better understanding of the vertical structure and weather characteristics of the complex area of Mt.Qomolangma is gained.展开更多
To make a detailed test on the reliability and detection performance of the electrochemical concentration cell(ECC)type ozonesonde which had been developed and preliminarily evaluated by the authors,an intensive ozone...To make a detailed test on the reliability and detection performance of the electrochemical concentration cell(ECC)type ozonesonde which had been developed and preliminarily evaluated by the authors,an intensive ozonesonde release experiment was held at two sites in Beijing and Changchun in June 2013.The results showed that the mean background current and its standard deviation were 0.03(0.04)μA and 0.02(0.03)μA in Beijing(Changchun).The average response time and its standard deviation were 27.8 s(30.4 s)and 4.0 s(3.7 s)in Beijing(Changchun).The ozone partial pressure profiles at both sites showed a central peak in the stratosphere and a side peak in the boundary layer.Large variation in ozone partial pressure was observed at the middle levels of the atmosphere(10–17 km).A more marked gradient of ozone change was observed in Beijing(3.4 mPa km–1)at the lower atmosphere level,as compared to that in Changchun(0.4 mPa km–1).The results presented in this paper indicate that this self-developed ozonesonde shows a high level of reliability and good performance.The ozonsonde is expected to play an important role in operational observations of ozone profiles.展开更多
Visualizing lightning location data is necessary in analyzing and researching lightning activity patterns.This article uses C#and the cross-platform.NET framework to develop a lightning location data analysis class li...Visualizing lightning location data is necessary in analyzing and researching lightning activity patterns.This article uses C#and the cross-platform.NET framework to develop a lightning location data analysis class library and the data-driven client to help lightning researchers improve work efficiency by avoiding repeated wheel invention.Lightning Location System Data Analyzer(LLSDA)is a suite of software tools that includes a.NET class library for software developers and a desktop application for end users.It supports a wide range of lightning location data formats,such as the University of Washington Global Lightning Location System(WWLLN)and Beijing Huayun Dongfang ADTD Lightning Location System data format,and maintains scalability.The class library can easily read,parse,and analyze lightning location data,and combined with third-party frameworks can realize grid analysis.The desktop application can be combined with MeteoInfo(a GIS open-source project)for secondary development.展开更多
Defining abnormal transmittance as the case where the magnitude of the shortwave flux transmittance is greater than 1.0,the authors used surface solar irradiance and all-sky images obtained at the Yangbajing site in T...Defining abnormal transmittance as the case where the magnitude of the shortwave flux transmittance is greater than 1.0,the authors used surface solar irradiance and all-sky images obtained at the Yangbajing site in Tibet to analyze the reasons for the occurrence of abnormal shortwave flux transmittance.Based on the International Intercomparision of Three-Dimensional Radiation Code(I3RC) Monte Carlo community model of three-dimensional radiative transfer,the authors also performed simulations at a nonabsorbing wavelength and an absorbing wavelength through a stratocumulus and a cumulus field.The results showed the detection of abnormal transmittance on more than half the days,and the maximum transmittance was 1.34.The probability of the occurrence of abnormal transmittance appeared to be largest in summer,and on a daily basis was mainly at about noon local time.Abnormal transmittance mainly appeared when clear sky and clouds co-existed,especially at the edges of broken clouds and nearby regions with clear-sky conditions.The flux transmittance decreased as the solar zenith angle increased.展开更多
High-quality and continuous radiosonde, aerosol and surface meteorology datasets are used to investigate the statistical characteristics of meteorological parameters and their effects on aerosols. The data were collec...High-quality and continuous radiosonde, aerosol and surface meteorology datasets are used to investigate the statistical characteristics of meteorological parameters and their effects on aerosols. The data were collected at the Atmospheric Radiation Measurement Southern Great Plains climate research facility during 2000–15. The parameters and vertical distribution of temperature inversion layers were found to have strong diurnal and seasonal changes. For surface-based temperature inversion (SBI), the mean frequency and depth of temperature inversion layers were 39.4% and 198 m, respectively. The temperature difference between the top and bottom of SBI was 4.8℃, and so the temperature gradient was 2.4℃(100 m)^-1. The detailed vertical distributions of temperature inversion had been determined, and only the temperature inversion layers below 1000 m showed diurnal and seasonal variations. Mean surface aerosol number concentrations increased by 43.0%, 21.9% and 49.2% when SBIs were present at 0530, 1730 and 2330 LST, respectively. The effect of SBI on surface aerosol concentration was weakest in summer (18.1%) and strongest in winter (58.4%). During elevated temperature inversion events, there was no noticeable difference in surface aerosol number concentrations. Temperature differences and temperature gradients across SBIs correlated fairly well with aerosol number concentrations, especially for temperature gradients. The vertical distribution of aerosol optical properties with and without temperature inversions was different. Surface aerosol measurements were representative of the air within (below), but not above, SBIs and EIs. These results provide a basis for developing a boundary layer aerosol accumulation model and for improving radiative transfer models in the lower atmosphere.展开更多
In situ measurements of the vertical structure of ozone were made in Changchun(43.53?N, 125.13?E), China, by the Institute of Atmosphere Physics, in the summers of 2010–13. Analysis of the 89 validated ozone profiles...In situ measurements of the vertical structure of ozone were made in Changchun(43.53?N, 125.13?E), China, by the Institute of Atmosphere Physics, in the summers of 2010–13. Analysis of the 89 validated ozone profiles shows the variation of ozone concentration in the upper troposphere and lower stratosphere(UTLS) caused by cut-off lows(COLs) over Changchun. During the COL events, an increase of the ozone concentration and a lower height of the tropopause are observed.Backward simulations with a trajectory model show that the ozone-rich airmass brought by the COL is from Siberia. A case study proves that stratosphere–troposphere exchange(STE) occurs in the COL. The ozone-rich air mass transported from the stratosphere to the troposphere first becomes unstable, then loses its high ozone concentration. This process usually happens during the decay stage of COLs. In order to understand the influence of COLs on the ozone in the UTLS, statistical analysis of the ozone profiles within COLs, and other profiles, are employed. The results indicate that the ozone concentrations of the in-COL profiles are significantly higher than those of the other profiles between ±4 km around the tropopause. The COLs induce an increase in UTLS column ozone by 32% on average. Meanwhile, the COLs depress the lapse-rate tropopause(LRT)/dynamical tropopause height by 1.4/1.7 km and cause the atmosphere above the tropopause to be less stable. The influence of COLs is durable because the increased ozone concentration lasts at least one day after the COL has passed over Changchun. Furthermore, the relative coefficient between LRT height and lower stratosphere(LS) column ozone is-0.62,which implies a positive correlation between COL strength and LS ozone concentration.展开更多
The unique geographical location and high altitude of the Tibetan Plateau can greatly influence regional weather and climate.In particular, the Asian summer monsoon(ASM) anticyclone circulation system over the Tibetan...The unique geographical location and high altitude of the Tibetan Plateau can greatly influence regional weather and climate.In particular, the Asian summer monsoon(ASM) anticyclone circulation system over the Tibetan Plateau is recognized to be a significant transport pathway for water vapor and pollutants to enter the stratosphere. To improve understanding of these physical processes, a multi-location joint atmospheric experiment was performed over the Tibetan Plateau from late July to August in 2018, funded by the fiveyear(2018–2022) STEAM(stratosphere and troposphere exchange experiment during ASM) project, during which multiple platforms/instruments—including long-duration stratospheric balloons, dropsondes, unmanned aerial vehicles, special sounding systems, and ground-based and satellite-borne instruments—will be deployed. These complementary methods of data acquisition are expected to provide comprehensive atmospheric parameters(aerosol, ozone, water vapor, CO_2, CH_4, CO, temperature, pressure,turbulence, radiation, lightning and wind); the richness of this approach is expected to advance our comprehension of key mechanisms associated with thermal, dynamical, radiative, and chemical transports over the Tibetan Plateau during ASM activity.展开更多
In this study,we introduce our newly developed measurement-fed-perception self-adaption Low-cost UAV Coordinated Carbon Observation Network(LUCCN)prototype.The LUCCN primarily consists of two categories of instruments...In this study,we introduce our newly developed measurement-fed-perception self-adaption Low-cost UAV Coordinated Carbon Observation Network(LUCCN)prototype.The LUCCN primarily consists of two categories of instruments,including ground-based and UAV-based in-situ measurement.We use the GMP343,a low-cost non-dispersive infrared sensor,in both ground-based and UAV-based instruments.The first integrated measurement campaign took place in Shenzhen,China,4 May 2023.During the campaign,we found that LUCCN’s UAV component presented significant data-collecting advantages over its ground-based counterpart owing to the relatively high altitudes of the point emission sources,which was especially obvious at a gas power plant in Shenzhen.The emission flux was calculated by a crosssectional flux(CSF)method,the results of which differed from the Open-Data Inventory for Anthropogenic Carbon dioxide(ODIAC).The CSF result was slightly larger than others because of the low sampling rate of the whole emission cross section.The LUCCN system will be applied in future carbon monitoring campaigns to increase the spatiotemporal coverage of carbon emission information,especially in scenarios involving the detection of smaller-scale,rapidly varying sources and sinks.展开更多
Based on a vector radiative transfer model of the atmosphere–ocean system,the influence of oceanic components on radiation processes,including polarization effects,was investigated in the wavelength region ranging fr...Based on a vector radiative transfer model of the atmosphere–ocean system,the influence of oceanic components on radiation processes,including polarization effects,was investigated in the wavelength region ranging from 0.380 to 0.865 μm.The components considered were phytoplankton,inorganic suspended material(sediment),and colored,dissolved organic matter.Due to their important roles in oceanic radiation processes,the sensitivity of the bidirectional reflectance to the rough ocean surface,represented by the wind velocity 10 m above the ocean surface,and aerosol,were taken into account.The results demonstrated that both radiance and polarized radiance just below the ocean surface were sensitive to the change of the concentrations of the considered components,while the dependence of polarized radiance on the observation geometry was more sensitive than radiance.Significant differences in the specular plane existed between the impacts of the phytoplankton and sediment on the degree of polarization just above the ocean surface at 670 nm.At the top of the atmosphere(TOA),polarization was relatively insensitive to changing concentrations of ocean particles at longer wavelengths.Furthermore,the radiance at the TOA in the solar plane was more sensitive to the aerosol optical thickness than wind velocity.In contrast,wind velocity strongly influenced the radiance at the TOA in the sun glint region,while the polarization degree showed less dependence in that region.Finally,a nonlinear optimal inversion method was proposed to simultaneously retrieve the aerosol and wind velocity using radiance measurement.展开更多
The improvement of the accuracy of simulated cloud-related variables,such as the cloud fraction,in global climate models(GCMs)is still a challenging problem in climate modeling.In this study,the influence of cloud mic...The improvement of the accuracy of simulated cloud-related variables,such as the cloud fraction,in global climate models(GCMs)is still a challenging problem in climate modeling.In this study,the influence of cloud microphysics schemes(one-moment versus two-moment schemes)and cloud overlap methods(observation-based versus a fixed vertical decorrelation length)on the simulated cloud fraction was assessed in the BCC_AGCM2.0_CUACE/Aero.Compared with the fixed decorrelation length method,the observation-based approach produced a significantly improved cloud fraction both globally and for four representative regions.The utilization of a two-moment cloud microphysics scheme,on the other hand,notably improved the simulated cloud fraction compared with the one-moment scheme;specifically,the relative bias in the global mean total cloud fraction decreased by 42.9%–84.8%.Furthermore,the total cloud fraction bias decreased by 6.6%in the boreal winter(DJF)and 1.64%in the boreal summer(JJA).Cloud radiative forcing globally and in the four regions improved by 0.3%−1.2% and 0.2%−2.0%,respectively.Thus,our results showed that the interaction between clouds and climate through microphysical and radiation processes is a key contributor to simulation uncertainty.展开更多
文摘“Diurnal variation of CH4 at the surface from spring to winter.The time units are in local time(+8 h UTC).The error bar is 1σfor all the observed hourly mean data within that season at that local time.”in the caption of Fig.8 on Page 604 should be“Diurnal variation of CH4 at the surface from spring to winter.The time units are in UTC.The error bar is 1σfor all the observed hourly mean data within that season at that local time.”
文摘In this report we summarize the research results by Chinese scientists in 2012–2014. The focuses are placed on the researches of the middle and upper atmosphere, specifically the researches related to ground-based observation capability development, dynamical processes, the property of circulation and chemistry-climate coupling of the middle atmospheric layers.
文摘In this report the research results by Chinese scientists in 2014—2016 are summarized.The focuses are placed on the researches of the middle and upper atmosphere,specifically the researches associated with ground-based observation capabihty development,dynamical processes,and properties of circulation and chemistry-climate coupling of the middle atmospheric layers.
文摘In this paper we summarize the research results by Chinese scientists in 2016–2018. The focuses are placed on the researches of the middle and upper atmosphere, specifically the researches associated with groundbased observation capability development, dynamical processes, and properties of circulation and chemistryclimate coupling of the middle atmospheric layers.
基金co-funded by the Key Project of the National Natural Science Foundation of China [grant number 42230609 and 41630425]the National Key Research and Development Plan projects [grant number 2022YFC3004101]
基金supported by the National Basic Research Program of China under Grant No.2010CB428602the National Natural Science Foundation of China (Grant No. 41175040)
文摘Tropopause folds are one of the key mechanisms of stratosphere–troposphere exchange(STE) in extratropical regions,transporting ozone-rich stratospheric air into the middle and lower troposphere. Although there have been many studies of tropopause folds that have occurred over Europe and North America,a very limited amount of work has been carried out over northeastern Asia. Ozonesondes produced by the Institute of Atmospheric Physics were launched in Changchun(43.9?N,125.2?E),Northeast China,in June 2013,and observed an ozone-enriched layer with thickness of 3 km and an ozone peak of180 ppbv at 6 km in the troposphere. The circulation field from the European Centre for Medium-Range Weather Forecasts Interim Reanalysis(ERA-Interim) dataset shows that this ozone peak was caused by a tropopause fold associated with a jet stream at the eastern flank of the East Asian trough. By analyzing the ozone data from the ozone monitoring instrument and Weather Research and Forecasting model with Chemistry(WRF-Chem) simulations,it was found that a high ozone concentration tongue originating from the lower stratosphere at high latitude(near central Siberia) intruded into the middle troposphere over Changchun between 5 and 8 km on 12 June 2013. The high-resolution WRF-Chem simulation was capable of describing events such as the tropopause fold that occurred on the cyclonic shear side of the jet stream. In addition,the TRAJ3 D trajectory model was used to trace the origin of measured secondary ozone peaks in the middle troposphere back,for example,to stratospheric intrusion through the tropopause fold.
基金the ARM program sponsored by the U.S. DOEsupported by the National Natural Science Foundation of China (Grant Nos. 40975001 and 61327810)+2 种基金the Special Fund for Public Welfare Industry (Meteorology) (Grant No. GYHY201106046)the support of a grant (to SUNYA) from the Office of Science (BER),U.S. DOEthe Key National Basic Research Program on Global Change (Grant No. 2013CB955803)
文摘By using the radiosonde measurements collected at Shouxian,China,we examined the dynamics and thermodynamics of single- and two-layer clouds formed at low and middle levels.The analyses indicated that the horizontal wind speed above the cloud layers was higher than those within and below cloud layers.The maximum balloon ascent speed(5.3 m s^(-1)) was located in the vicinity of the layer with the maximum cloud occurrence frequency(24.4%),indicating an upward motion(0.1-0.16 ms^(-1)).The average thickness,magnitude and gradient of the temperature inversion layer above single-layer clouds were117±94 m,1.3±1.3℃ and 1.4±1.5℃(100 m)^(-1),respectively.The average temperature inversion magnitude was the same(1.3℃) for single-low and single-middle clouds;however,a larger gradient[1.7±1.8℃(100 m)^(-1)]and smaller thickness(94±67 m) were detected above single-low clouds relative to those above single-middle clouds[0.9±0.7℃(100 m)^(-1) and157±120 m].For the two-layer cloud,the temperature inversion parameters were 106±59 m,1.0±0.9℃ and 1.0±1.0℃(100 m)^(-1) above the upper-layer cloud and 82 ± 60 m,0.6±0.9℃ and 0.7±0.6℃(100 m)^(-1) above the low-layer cloud.Absolute differences between the cloud-base height(cloud-top height) and the lifting condensation level(equilibrium level)were less than 0.5 km for 66.4%(36.8%) of the cases analyzed in summer.
基金supported by the National Natural Science Foundation of China (NSFC) (Grant No.41127901)the National Basic Research Program of China (973 program,Grant No.2010CB428601)the "100 Technical Talents" Program of the Chinese Academy of Sciences (CAS)
文摘During August 2013,a mobile Rayleigh lidar was deployed in Lhasa,Tibet(29.6°N,91.0°E) for making measurements of middle atmosphere densities and temperatures from 30 to 90 km.In this paper,the authors present the initial results from this scientific campaign,Middle Atmosphere Remote Mobile Observatory in Tibet(MARMOT),and compared the results to the MSIS-00(Mass Spectrometer and Incoherent Scatter) model.This work will advance our understanding of middle atmosphere dynamic processes,especially over the Tibetan Plateau area.
基金funded by the National Natural Science Foundation of China (Grant No. 41105025)the Dragon 3 Programme (ID: 10577)
文摘The authors examined the Madden-Julian Oscillation(MJO) in stratospheric ozone during boreal winter using a simulation from the Specified Dynamics version of the Whole Atmosphere Community Climate Model(SD-WACCM) in 2004 and 2010. Comparison with European Centre for Medium-Range Weather Forecasts Interim Reanalysis(ERA-Interim) data suggested that the model simulation represented well the three-dimensional structure of the MJO-related ozone anomalies in the upper troposphere and stratosphere(i.e., between 200 and 20 h Pa). The negative ozone anomalies were over the Tibetan Plateau and East Asia in MJO phases 3–7, when the MJO convective anomalies travelled from the equatorial Indian Ocean towards the equatorial western Pacific Ocean. Due to the different vertical structures of the MJO-related circulation anomalies, the MJO-related stratospheric ozone anomalies showed different vertical structure over the Tibetan Plateau(25–40°N, 75–105°E) and East Asia(25–40°N, 105–135°E). As a result of the positive bias in the model-calculated ozone in the upper troposphere and lower stratosphere, the amplitude of MJO-related stratospheric ozone column anomalies(10–16 Dobson Units(DU)) in the SD-WACCM simulation was slightly larger than that(8–14 DU) in the ERA-Interim reanalysis.
基金funded by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0103)the Strategic Priority Research Program of Chinese Academy of Sciences(XDA20060101)the National Natural Science Foundation of China(Grant Nos.91837208,41830650).
文摘“Earth summit mission 2022”is one of the landmark scientific research activities of the Second Tibetan Plateau Scientific Expedition and Research(STEP).This scientific expedition firstly used advanced technology and methods to detect vertical meteorological elements and produce forecasts for mountain climbing.The“Earth summit mission 2022”Qomolangma scientific expedition exceeded an altitude of over 8000 meters for the first time and carried out a comprehensive scientific investigation mission on the summit of Mt.Qomolangma.Among the participants,the westerly–monsoon synergy and influence team stationed in the Mt.Qomolangma region had two tasks:1)detecting the vertical structure of the atmosphere for parameters such as wind,temperature,humidity,and pressure with advanced instruments for high-altitude detection at the Mt.Qomolangma base camp;and 2)observing extreme weather processes to ensure that members of the mountaineering team could successfully reach the top.Through this scientific expedition,a better understanding of the vertical structure and weather characteristics of the complex area of Mt.Qomolangma is gained.
基金supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No.XDB05020503)the Special Fund for Public Welfare Industry (Meteorology) (Grant No.GYHY201106041)
文摘To make a detailed test on the reliability and detection performance of the electrochemical concentration cell(ECC)type ozonesonde which had been developed and preliminarily evaluated by the authors,an intensive ozonesonde release experiment was held at two sites in Beijing and Changchun in June 2013.The results showed that the mean background current and its standard deviation were 0.03(0.04)μA and 0.02(0.03)μA in Beijing(Changchun).The average response time and its standard deviation were 27.8 s(30.4 s)and 4.0 s(3.7 s)in Beijing(Changchun).The ozone partial pressure profiles at both sites showed a central peak in the stratosphere and a side peak in the boundary layer.Large variation in ozone partial pressure was observed at the middle levels of the atmosphere(10–17 km).A more marked gradient of ozone change was observed in Beijing(3.4 mPa km–1)at the lower atmosphere level,as compared to that in Changchun(0.4 mPa km–1).The results presented in this paper indicate that this self-developed ozonesonde shows a high level of reliability and good performance.The ozonsonde is expected to play an important role in operational observations of ozone profiles.
文摘Visualizing lightning location data is necessary in analyzing and researching lightning activity patterns.This article uses C#and the cross-platform.NET framework to develop a lightning location data analysis class library and the data-driven client to help lightning researchers improve work efficiency by avoiding repeated wheel invention.Lightning Location System Data Analyzer(LLSDA)is a suite of software tools that includes a.NET class library for software developers and a desktop application for end users.It supports a wide range of lightning location data formats,such as the University of Washington Global Lightning Location System(WWLLN)and Beijing Huayun Dongfang ADTD Lightning Location System data format,and maintains scalability.The class library can easily read,parse,and analyze lightning location data,and combined with third-party frameworks can realize grid analysis.The desktop application can be combined with MeteoInfo(a GIS open-source project)for secondary development.
基金supported by the National Natural Science Foundation of China (Grant No.41275040)
文摘Defining abnormal transmittance as the case where the magnitude of the shortwave flux transmittance is greater than 1.0,the authors used surface solar irradiance and all-sky images obtained at the Yangbajing site in Tibet to analyze the reasons for the occurrence of abnormal shortwave flux transmittance.Based on the International Intercomparision of Three-Dimensional Radiation Code(I3RC) Monte Carlo community model of three-dimensional radiative transfer,the authors also performed simulations at a nonabsorbing wavelength and an absorbing wavelength through a stratocumulus and a cumulus field.The results showed the detection of abnormal transmittance on more than half the days,and the maximum transmittance was 1.34.The probability of the occurrence of abnormal transmittance appeared to be largest in summer,and on a daily basis was mainly at about noon local time.Abnormal transmittance mainly appeared when clear sky and clouds co-existed,especially at the edges of broken clouds and nearby regions with clear-sky conditions.The flux transmittance decreased as the solar zenith angle increased.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA17010101)the National Natural Science Foundation of China (Grant Nos. 41305011, 41775033, 41575033 and 41675034)+1 种基金the China Postdoctoral Science Foundation (Grant No.2014M550797)the National Key R&D Program of China (Grant No. 2017YFA0603504)
文摘High-quality and continuous radiosonde, aerosol and surface meteorology datasets are used to investigate the statistical characteristics of meteorological parameters and their effects on aerosols. The data were collected at the Atmospheric Radiation Measurement Southern Great Plains climate research facility during 2000–15. The parameters and vertical distribution of temperature inversion layers were found to have strong diurnal and seasonal changes. For surface-based temperature inversion (SBI), the mean frequency and depth of temperature inversion layers were 39.4% and 198 m, respectively. The temperature difference between the top and bottom of SBI was 4.8℃, and so the temperature gradient was 2.4℃(100 m)^-1. The detailed vertical distributions of temperature inversion had been determined, and only the temperature inversion layers below 1000 m showed diurnal and seasonal variations. Mean surface aerosol number concentrations increased by 43.0%, 21.9% and 49.2% when SBIs were present at 0530, 1730 and 2330 LST, respectively. The effect of SBI on surface aerosol concentration was weakest in summer (18.1%) and strongest in winter (58.4%). During elevated temperature inversion events, there was no noticeable difference in surface aerosol number concentrations. Temperature differences and temperature gradients across SBIs correlated fairly well with aerosol number concentrations, especially for temperature gradients. The vertical distribution of aerosol optical properties with and without temperature inversions was different. Surface aerosol measurements were representative of the air within (below), but not above, SBIs and EIs. These results provide a basis for developing a boundary layer aerosol accumulation model and for improving radiative transfer models in the lower atmosphere.
基金jointly supported by the National Basic Research Program of China (Grant No.2010CB428602)the National Natural Science Foundation of China (Grant Nos.41275046 and 41025017)
文摘In situ measurements of the vertical structure of ozone were made in Changchun(43.53?N, 125.13?E), China, by the Institute of Atmosphere Physics, in the summers of 2010–13. Analysis of the 89 validated ozone profiles shows the variation of ozone concentration in the upper troposphere and lower stratosphere(UTLS) caused by cut-off lows(COLs) over Changchun. During the COL events, an increase of the ozone concentration and a lower height of the tropopause are observed.Backward simulations with a trajectory model show that the ozone-rich airmass brought by the COL is from Siberia. A case study proves that stratosphere–troposphere exchange(STE) occurs in the COL. The ozone-rich air mass transported from the stratosphere to the troposphere first becomes unstable, then loses its high ozone concentration. This process usually happens during the decay stage of COLs. In order to understand the influence of COLs on the ozone in the UTLS, statistical analysis of the ozone profiles within COLs, and other profiles, are employed. The results indicate that the ozone concentrations of the in-COL profiles are significantly higher than those of the other profiles between ±4 km around the tropopause. The COLs induce an increase in UTLS column ozone by 32% on average. Meanwhile, the COLs depress the lapse-rate tropopause(LRT)/dynamical tropopause height by 1.4/1.7 km and cause the atmosphere above the tropopause to be less stable. The influence of COLs is durable because the increased ozone concentration lasts at least one day after the COL has passed over Changchun. Furthermore, the relative coefficient between LRT height and lower stratosphere(LS) column ozone is-0.62,which implies a positive correlation between COL strength and LS ozone concentration.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant Nos. XDA17010101, XDA17010102, XDA17010103, XDA17010104 and XDA17010105)
文摘The unique geographical location and high altitude of the Tibetan Plateau can greatly influence regional weather and climate.In particular, the Asian summer monsoon(ASM) anticyclone circulation system over the Tibetan Plateau is recognized to be a significant transport pathway for water vapor and pollutants to enter the stratosphere. To improve understanding of these physical processes, a multi-location joint atmospheric experiment was performed over the Tibetan Plateau from late July to August in 2018, funded by the fiveyear(2018–2022) STEAM(stratosphere and troposphere exchange experiment during ASM) project, during which multiple platforms/instruments—including long-duration stratospheric balloons, dropsondes, unmanned aerial vehicles, special sounding systems, and ground-based and satellite-borne instruments—will be deployed. These complementary methods of data acquisition are expected to provide comprehensive atmospheric parameters(aerosol, ozone, water vapor, CO_2, CH_4, CO, temperature, pressure,turbulence, radiation, lightning and wind); the richness of this approach is expected to advance our comprehension of key mechanisms associated with thermal, dynamical, radiative, and chemical transports over the Tibetan Plateau during ASM activity.
基金supported by the National Key Research and Development Plan(Grant No.2021YFB3901000)the Chinese Academy of Sciences Project for Young Scientists in Basic Research(YSBR-037)+2 种基金the International Partnership Program of the Chinese Academy of Sciences(060GJHZ2022070MI)the MOST-ESA Dragon-5 Programme for Monitoring Greenhouse Gases from Space(ID.59355)the Finland–China Mobility Cooperation Project funded by the Academy of Finland(No.348596)。
文摘In this study,we introduce our newly developed measurement-fed-perception self-adaption Low-cost UAV Coordinated Carbon Observation Network(LUCCN)prototype.The LUCCN primarily consists of two categories of instruments,including ground-based and UAV-based in-situ measurement.We use the GMP343,a low-cost non-dispersive infrared sensor,in both ground-based and UAV-based instruments.The first integrated measurement campaign took place in Shenzhen,China,4 May 2023.During the campaign,we found that LUCCN’s UAV component presented significant data-collecting advantages over its ground-based counterpart owing to the relatively high altitudes of the point emission sources,which was especially obvious at a gas power plant in Shenzhen.The emission flux was calculated by a crosssectional flux(CSF)method,the results of which differed from the Open-Data Inventory for Anthropogenic Carbon dioxide(ODIAC).The CSF result was slightly larger than others because of the low sampling rate of the whole emission cross section.The LUCCN system will be applied in future carbon monitoring campaigns to increase the spatiotemporal coverage of carbon emission information,especially in scenarios involving the detection of smaller-scale,rapidly varying sources and sinks.
基金supported by the "Strategic Priority Research Program" of the Chinese Academy of Sciences(Grant No.XDA05100300)the National Basic Research Program of China(Grant No.2013CB955801)+2 种基金the National Natural Science Foundation of China(Grant Nos.41175030 and 41475136)the National Basic Research Program of China(Grant No.2014CB953703)funds from MOEJ/GOSAT&GOSAT2,JST/CREST/EMS/TEEDDA,JAXA/ Earth CARE&GCOM-C,MEXT/RECCA/SALSA,MEXT/Kakenhi/ Innovative Areas 2409,and MOEJ/ERTDF/S-12
文摘Based on a vector radiative transfer model of the atmosphere–ocean system,the influence of oceanic components on radiation processes,including polarization effects,was investigated in the wavelength region ranging from 0.380 to 0.865 μm.The components considered were phytoplankton,inorganic suspended material(sediment),and colored,dissolved organic matter.Due to their important roles in oceanic radiation processes,the sensitivity of the bidirectional reflectance to the rough ocean surface,represented by the wind velocity 10 m above the ocean surface,and aerosol,were taken into account.The results demonstrated that both radiance and polarized radiance just below the ocean surface were sensitive to the change of the concentrations of the considered components,while the dependence of polarized radiance on the observation geometry was more sensitive than radiance.Significant differences in the specular plane existed between the impacts of the phytoplankton and sediment on the degree of polarization just above the ocean surface at 670 nm.At the top of the atmosphere(TOA),polarization was relatively insensitive to changing concentrations of ocean particles at longer wavelengths.Furthermore,the radiance at the TOA in the solar plane was more sensitive to the aerosol optical thickness than wind velocity.In contrast,wind velocity strongly influenced the radiance at the TOA in the sun glint region,while the polarization degree showed less dependence in that region.Finally,a nonlinear optimal inversion method was proposed to simultaneously retrieve the aerosol and wind velocity using radiance measurement.
基金supported by the National Key R&D Program of China(2017YFA0603502)(Key)National Natural Science Foundation of China(91644211)S&T Development Fund of CAMS(2021KJ004).
文摘The improvement of the accuracy of simulated cloud-related variables,such as the cloud fraction,in global climate models(GCMs)is still a challenging problem in climate modeling.In this study,the influence of cloud microphysics schemes(one-moment versus two-moment schemes)and cloud overlap methods(observation-based versus a fixed vertical decorrelation length)on the simulated cloud fraction was assessed in the BCC_AGCM2.0_CUACE/Aero.Compared with the fixed decorrelation length method,the observation-based approach produced a significantly improved cloud fraction both globally and for four representative regions.The utilization of a two-moment cloud microphysics scheme,on the other hand,notably improved the simulated cloud fraction compared with the one-moment scheme;specifically,the relative bias in the global mean total cloud fraction decreased by 42.9%–84.8%.Furthermore,the total cloud fraction bias decreased by 6.6%in the boreal winter(DJF)and 1.64%in the boreal summer(JJA).Cloud radiative forcing globally and in the four regions improved by 0.3%−1.2% and 0.2%−2.0%,respectively.Thus,our results showed that the interaction between clouds and climate through microphysical and radiation processes is a key contributor to simulation uncertainty.
