Development of Solar Spectroradiometer for Meteorological Observation

A newgeneration of solar spectroradiometer has been developed by CUST/JRSI to improve solarirradiance observation data under hyperspectral resolution. It is based on the grating spectroradiometer with a back-thinned CCD linear image sensor and is operated in a hermetically sealed enclosure. The solar spectroradiometer is designed to measure the solar spectral irradiance from300 nm to 1100 nm wavelength range with the spectral resolution of 2 nm( the full width at half maximum). The optical bench is optimized to minimize stray light. The Peltier device is used to stabilize the temperature of CCD sensor to 25℃,while the change of temperature of CCD sensor is controlled to ±1℃ by the dedicated Peltier driver and control circuit.

Design and Application of Integrated Monitoring Model for Provincial Meteorological Observation Data Transmission

With the development of meteorological services, there are more and more types of real-time observation data, and the timeliness requirements are getting higher and higher. The monitoring methods of existing meteorological observation data transmission can no longer meet the needs. This paper proposes a new monitoring model, namely the “integrated monitoring model” for provincial meteorological observation data transmission. The model can complete the whole network monitoring of meteorological observation data transmission process. Based on this model, the integrated monitoring system for meteorological observation data transmission in Guangdong Province is developed. The system uses Java as the programming language, and integrates J2EE, Hibernate, Quartz, Snmp4j and Slf4j frameworks, and uses Oracle database as the data storage carrier, following the MVC specification and agile development concept. The system development uses four key technologies, including simple network management protocol, network connectivity detection technology, remote host management technology and thread pool technology. The integrated monitoring system has been put into business application. As a highlight of Guangdong’s meteorological modernization, it has played an active role in many major meteorological services.

Influence of Irregular Coastlines on a Tornadic Mesovortex in the Pearl River Delta during the Monsoon Season. Part Ⅰ:Pre-storm Environment and Storm Evolution

The Pearl River Delta(PRD),a tornado hotspot,forms a distinct trumpet-shaped coastline that concaves toward the South China Sea.During the summer monsoon season,low-level southwesterlies over the PRD’s sea surface tend to be turned toward the west coast,constituting a convergent wind field along with the landward-side southwesterlies,which influences regional convective weather.This two-part study explores the roles of this unique land–sea contrast of the trumpet-shaped coastline in the formation of a tornadic mesovortex within monsoonal flows in this region.Part I primarily presents observational analyses of pre-storm environments and storm evolutions.The rotating storm developed in a lowshear environment(not ideal for a supercell)under the interactions of three air masses under the influence of the land–sea contrast,monsoon,and storm cold outflows.This intersection zone(or“triple point”)is typically characterized by local enhancements of ambient vertical vorticity and convergence.Based on a rapid-scan X-band phased-array radar,finger-like echoes were recognized shortly after the gust front intruded on the triple point.Developed over the triple point,they rapidly wrapped up with a well-defined low-level mesovortex.It is thus presumed that the triple point may have played roles in the mesovortex genesis,which will be demonstrated in Part II with multiple sensitivity numerical simulations.The findings also suggest that when storms pass over the boundary intersection zone in the PRD,the expected possibility of a rotating storm occurring is relatively high,even in a low-shear environment.Improved knowledge of such environments provides additional guidance to assess the regional tornado risk.

Comparison and Verification of Coherent Doppler Wind Lidar and Radiosonde Data in the Beijing Urban Area

As a new type of wind field detection equipment, coherent Doppler wind lidar(CDWL) still needs more relevant observation experiments to compare and verify whether it can achieve the accuracy and precision of traditional observation equipment in urban areas. In this experiment, a self-developed CDWL provided four months of observations in the southern Beijing area. After the data acquisition time and height match, the wind profile data obtained based on a Doppler beam swinging(DBS) five-beam inversion algorithm were compared with radiosonde data released from the same location. The standard deviation(SD) of wind speed is 0.8 m s^(–1), and the coefficient of determination R~2 is 0.95. The SD of the wind direction is 17.7° with an R~2 of 0.96. Below the height of the roughness sublayer(about 400 m), the error in wind speed and wind direction is significantly greater than the error above the height of the boundary layer(about 1500 m). For the case of wind speeds less than 4 m s^(–1), the error of wind direction is more significant and is affected by the distribution of surrounding buildings. Averaging at different height levels using suitable time windows can effectively reduce the effects of turbulence and thus reduce the error caused by the different measurement methods of the two devices.

Regional Climate Damage Quantification and Its Impacts on Future Emission Pathways Using the RICE Model

This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate impact module on future emission pathways.Results highlight varied damages depending on regional economic development and locations.Specifically,China and Africa could suffer the most serious comprehensive damages caused by temperature change and sea level rise,followed by India,other developing Asian countries(OthAsia),and other high-income countries(OHI).The comprehensive damage fractions for China and Africa are projected to be 15.1%and 12.5%of gross domestic product(GDP)in 2195,with corresponding cumulative damages of 124.0 trillion and 87.3 trillion United States dollars(USD)from 2005 to 2195,respectively.Meanwhile,the comprehensive damage fractions in Japan,Eurasia,and Russia are smaller and projected to be lower than 5.6%of GDP in 2195,with cumulative damages of 6.8 trillion,4.2 trillion,and 3.3 trillion USD,respectively.Additionally,coastal regions like Africa,the European Union(EU),and OHI show comparable damages for sea level rise and temperature change.In China,however,sea level-induced damages are projected to exceed those from temperature changes.Moreover,this study indicates that switching the damage modules on or off affects the regional and global emission trajectories,but the magnitude is relatively small.By 2195,global emissions under the experiments with all of the damage modules switched off,only the sea level damage module switched on,and only the temperature damage module switched on,were 3.5%,2.3%and 1.2%higher than those with all of the damage modules switched on,respectively.

Mechanism of Diabatic Heating on Precipitation and the Track of a Tibetan Plateau Vortex over the Eastern Slope of the Tibetan Plateau

Existing studies contend that latent heating(LH)will replace sensible heating(SH)to become the dominant factor affecting the development of the Tibetan Plateau vortex(TPV)after it moves off the Tibetan Plateau(TP).However,in the process of the TPV moving off the TP requires that the airmass traverse the eastern slope of the Tibetan Plateau(ESTP)where the topography and diabatic heating(DH)conditions rapidly change.How LH gradually replaces SH to become the dominant factor in the development of the TPV over the ESTP is still not very clear.In this paper,an analysis of a typical case of a TPV with a long life history over the ESTP is performed by using multi-sourced meteorological data and model simulations.The results show that SH from the TP surface can change the TPV-associated precipitation distribution by temperature advection after the TPV moves off the TP.The LH can then directly promote the development of the TPV and has a certain guiding effect on the track of the TPV.The SH can control the active area of LH by changing the falling area of the TPV-associated precipitation,so it still plays a key role in the development and tracking of the TPV even though it has moved out of the main body of the TP.

Erratum to:Deriving Temporal and Vertical Distributions of Methane in Xianghe Using Ground-based Fourier Transform Infrared and Gas-analyzer

“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.”

Influence of Irregular Coastlines on a Tornadic Mesovortex in the Pearl River Delta during Monsoon Season.Part II:Numerical Experiments

As demonstrated in the first part of this study(Part I),wind-shift boundaries routinely form along the west coast of the Pearl River Delta due to the land-sea contrast of a“trumpet”shape coastline in the summer monsoon season.Through multiple numerical simulations,this article(Part II)aims to examine the roles of the trumpet-shaped coastline in the mesovortex genesis during the 1 June 2020 tornadic event.The modeling reproduced two mesovortices that are in close proximity in time and space to the realistic mesovortices.In addition to the modeled mesovortex over the triple point where strong ambient vertical vorticity was located,another mesovortex originated from an enhanced discrete vortex along an airmass boundary via shear instability.On the fine-scale storm morphology,finger-like echoes preceding hook echoes were also reproduced around the triple point.Results from sensitivity experiments suggest that the unique topography plays an essential role in modifying the vorticity budget during the mesovortex formation.While there is a high likelihood of an upcoming storm evolving into a rotating storm over the triple point,the simulation's accuracy is sensitive to the local environmental details and storm dynamics.The strengths of cold pool surges from upstream storms may influence the stretching of low-level vertically oriented vortex and thus the wrap-up of finger-like echoes.These findings suggest that the trumpet-shaped coastline is an important component of mesovortex production during the active monsoon season.It is hoped that this study will increase the situational awareness for forecasters regarding regional non-mesocyclone tornadic environments.

Meteorological applications of precipitable water vapor measurements retrieved by the national GNSS network of China

In this study, the Global Navigation Satellite System （GNSS） network of China is discussed, which can be used to monitor atmospheric precipitable water vapor （PWV）. By the end of 2013, the network had 952 GNSS sites, including 260 belonging to the Crustal Movement Observation Network of China （CMONOC） and 692 belonging to the China Meteorological Administration GNSS network （CMAGN）. Additionally, GNSS observation collecting and data processing procedures are presented and PWV data quality control methods are investigated. PWV levels as determined by GNSS and radiosonde are compared. The results show that GNSS estimates are generally in good agreement with measurements of radio- sondes and water vapor radiometers （WVR）. The PWV retrieved by the national GNSS network is used in weather forecasting, assimilation of data into numerical weather prediction models, the validation of PWV estimates by radiosonde, and plum rain monitoring. The network is also used to monitor the total ionospheric electron content.

Relationship between onset of peptic ulcer and meteorological factors

AIM： To discuss the relationship between onset of peptic ulcer （PU） and meteorological factors （MFs）. METHODS： A total of 24 252 patients were found with active PU in 104 121 samples of gastroscoic examination from 17 hospitals in Nanning from 1992 to 1997. The detectable rate of PU （DRPU） was calculated every month, every ten days and every five days. An analysis of DRPU and MFs was made in the same period of the year. A forecast model based on MFs of the previous month was established. The real and forecast values were tested and verified. RESULTS： During the 6 years, the DRPU from November to April was 24.4 -28.8%. The peak value （28.8%） was in January. The DRPU from May to October was 20.0 -22.6%, with its low peak （20.0%） in June. The DRPU decreased from winter and spring to summer and autumn （P 〈 0.005）. The correlated coefficient between DRPU and average temperature value was -0.8704, -0.6624, -0.5384 for one month, ten days, five days respectively （P 〈 0.01）. The correlated coefficient between DRPU and average highest temperature value was -0.8000, -0.6470,-0.5167 respectively （P 〈0.01）. The correlated coefficient between DRPU and average lowest temperature value was -0.8091, -0.6617, -0.5384 respectively （P 〈0.01）. The correlated coefficient between DRPU and average dew point temperature was -0.7812, -0.6246, -0.4936 respectively （P 〈0.01）. The correlated coefficient between DRPU and average air pressure value was 0.7320, 0.5777, 0.4579 respectively （P 〈0.01）. The average temperature, average highest and lowest temperature, average air pressure and average dew point temperature value of the previous month, ten days and five days could forecast the onset of PU, with its real and forecast values corresponding to 71.8%, 67.9% and 66.6% respectively. CONCLUSION： DRPU is closely related with the average temperature, average highest and lowest temperature, average air pressure and average dew point temperature of each month, every ten days and every five days for the same period. When MFs are changed, the human body produces a series of stress actions. A long-term and median-term based medical meteorological forecast of the onset of PU can be made more accurately according to this.

EXPERIMENTAL APPLICATION OF A THINNING SCHEME FOR THE ASSIMILATION OF SURFACE OBSERVATION DATA IN GRAPES-3DVAR

To reduce the spatial correlation of representation error in observations and computational complexity, we propose a thinning scheme that can extract typical observations within a certain range. This scheme is applied to the Global/Regional Assimilation and Prediction System(GRAPES) with three-dimensional variation(3 DVAR) to study the effect of the thinning radius on the assimilation results. The assimilation experiments indicate that when the ratio of the model resolution to the observational resolution is 1:3, the simulated results for precipitation are relatively good and have a relatively high equitable threat score(ETS). Moreover, the analysis errors in the temperature and the specific humidity are the smallest, the dependence of the norm gradient vector of the objective function on the number of iterations is slow, gentle, and close to 0, and the minimization results in improved conditions.

Observation and modeling of vertical carbon dioxide distribution in a heavily polluted suburban environment

The vertical distribution of carbon dioxide(CO2)is important for the calibration and validation of transport models and remote sensing measurements.Due to the large mass and volume of traditional instruments as well as supporting systems,in-situ measurements of the CO2 vertical profile within the boundary layer are rare.This study used a miniaturized CO2 monitoring instrument based on a low-cost non-dispersive infrared(NDIR)sensor to measure the CO2 vertical profile and meteorological parameters of the lower troposphere(0–1000 m)in southwestern Shijiazhuang,Hebei Province,China.The sensors were onboard a tethered balloon with two processes:the ascending process and the descending process.The results showed that the overall trend of CO2 concentration decreased with height.Weather conditions and CO2 emission sources caused fluctuations in CO2 concentrations.The CO2 concentration varied from morning to afternoon due mainly to the faster spread of air mass during daytime,with strong convections and the accumulation of emissions at night.The low-cost sensor produced results consistent with the traditional gas chromatography method.The Weather Research and Forecasting model could not capture the CO2 profiles well due mainly to the bad performances in boundary layer height and the potential outdated fossil fuel emissions around the experimental site.This experiment is the first successful attempt to observe the CO2 vertical distribution in the lower troposphere by using lowcost NDIR sensors.The results help us to understand the vertical structure of CO2 in the boundary layer,and provide data for calibrating and validating transport models.

Editorial: Special issue on meteorological instruments

The earth we live in is a wonderful and complicated system,meteorology is a science of researching the earth and serving the public,so every country in the world is putting its attention on meteorological observation,and World Meteorological Organization always putting its emphasis on weather,climate

Direct Radiative Forcing of Anthropogenic Aerosols over Oceans from Satellite Observations

Anthropogenic aerosols play an important role in the atmospheric energy balance. Anthropogenic aerosol optical depth （AOD） and its accompanying shortwave radiative forcing （RF） are usually simulated by nu- merical models. Recently, with the development of space-borne instruments and sophisticated retrieval algorithms, it has become possible to estimate aerosol radiative forcing based on satellite observations. In this study, we have estimated shortwave direct radiative forcing due to anthropogenic aerosols over oceans in all-sky conditions by combining clouds and the Single Scanner Footprint data of the Clouds and Earth’s Radiant Energy System （CERES/SSF） experiment, which provide measurements of upward shortwave fluxes at the top of atmosphere, with Moderate Resolution Imaging Spectroradiometer （MODIS） aerosol and cloud products. We found that globally averaged aerosol radiative forcing over oceans in the clear-sky conditions and all-sky conditions were -1.03±0.48 W m-2 and -0.34 ±0.16 W m-2, respectively. Direct radiative forcing by anthropogenic aerosols shows large regional and seasonal variations. In some regions and in particular seasons, the magnitude of direct forcing by anthropogenic aerosols can be comparable to the forcing of greenhouse gases. However, it shows that aerosols caused the cooling effect, rather than warming effect from global scale, which is different from greenhouse gases.

Direct Observations of Atmospheric Transport and Stratosphere-Troposphere Exchange from High-Precision Carbon Dioxide and Carbon Monoxide Profile Measurements

The balloon-borne Aircore campaign was conducted in Inner Mongolia,China,on June 13 and 142018,which detected carbon dioxide(CO2)and carbon monoxide(CO)profiles from surface to 24 km,showing strong positive and negative correlations between 8 km and 10 km on 13 and 14 June,respectively.Backward trajectories,meteorological analyses,and CO2 horizontal distributions were combined to interpret this phenomenon.The results indicated that the source region experienced a stratospheric intrusion and exhibited a large horizontal CO2 gradient;namely,lower CO concentrations corresponded to higher CO2 concentrations and vice versa.The laminar structure with multiple origins resulted in the highly negative correlation between CO2 and CO in the upper troposphere on 14 June.The contribution of stratospheric air mass to the upper troposphere and that of tropospheric air mass to the lower stratosphere were 26.7%and24.3%,respectively,based on a mass balance approach.Another interesting phenomenon is that CO2 and CO concentrations increased substantially at approximately 8 km on 13 June.An analysis based on the backward trajectory implied that the air mass possibly came from anthropogenic sources.The slope of CO2/CO representing the anthropogenic sources was 87.3 ppm ppm-1.In addition,the CO2 profile showed that there was a large CO2 gradient of 4 ppm km-1 within the boundary layer on 13 June,and this gradient disappeared on 14 June.

A New X-band Weather Radar System with Distributed Phased-Array Front-ends: Development and Preliminary Observation Results

A novel weather radar system with distributed phased-array front-ends was developed. The specifications and preliminary data synthesis of this system are presented, which comprises one back-end and three or more front-ends. Each front-end, which utilizes a phased-array digital beamforming technology, sequentially transmits four 22.5°-width beams to cover the 0°–90° elevational scan within about 0.05 s. The azimuthal detection is completed by one mechanical scan of0°–360° azimuths within about 12 s volume-scan update time. In the case of three front-ends, they are deployed according to an acute triangle to form a fine detection area(FDA). Because of the triangular deployment of multiple phased-array front-ends and a unique synchronized azimuthal scanning(SAS) rule, this new radar system is named Array Weather Radar(AWR). The back-end controls the front-ends to scan strictly in accordance with the SAS rule that assures the data time differences(DTD) among the three front-ends are less than 2 s for the same detection point in the FDA. The SAS can maintain DTD < 2 s for an expanded seven-front-end AWR. With the smallest DTD, gridded wind fields are derived from AWR data, by sampling of the interpolated grid, onto a rectangular grid of 100 m ×100 m ×100 m at a 12 s temporal resolution in the FDA. The first X-band single-polarized three-front-end AWR was deployed in field experiments in 2018 at Huanghua International Airport, China. Having completed the data synthesis and processing, the preliminary observation results of the first AWR are described herein.

Measuring and comparing in-situ CO2 and CO profiles with satellite observations and model data

Accurate measurements of the vertical distribution of carbon dioxide(CO2)in the atmosphere are critical to validate the vertical columns recorded by satellite and ground-based spectrometers and to estimate sources and sinks of CO2.This work describes an in-situ air-sampler system(Aircore).Profiles of CO2 and carbon monoxide(CO)were retrieved from two soundings of this system in Xilin Hot on 13 and 14 June 2018,and compared with observations from the Tropospheric Monitoring Instrument(TROPOMI),Orbiting Carbon Observatory-2(OCO-2),and Copernicus Atmosphere Monitoring Service(CAMS).The column-averaged mixing ratio of CO(XCO)monitored by TROPOMI agreed well with that calculated from the in-situ CO pro le,with a small mean diffierence of 5±1.89 ppb.The column-averaged mixing ratio of CO2(XCO2)monitored by OCO-2 also agreed well with that calculated from the in-situ CO2 profile,with a slight bias of 0.4±0.6 ppm.The OCO-2 a posteriori profile had an obvious bias compared with the in-situ CO2 pro le on 13 June,with an underestimation between 600 hPa and 250 hPa and an overestimation below 600 hPa.CAMS also had the same bias compared with the in-situ CO profile;however,CAMS agreed well with the in-situ CO profile on 14 June in the troposphere because a weak cold vortex passed Xilin Hot on 13 June and disappeared on 14 June.In the stratosphere,there were significant biases in the vertical degradation.The striking agreement between the column-averaged mixing ratios and the diffierences in the vertical distribution suggests new exciting applications for the profile product.

PM_(10)Observed at a Meteorological Station in Beijing:Historical Trend and Implications

Inhalable particles(PM_(10)),with aerodynamic equivalent diameters that are generally 10 micrometers or smaller,are basic pollutants in many areas,especially in northern China,and thus the pollution from PM_(10)inhalable particulate matter is a growing concern for public health.Independent long-term observations are necessary to evaluate the efficacy of PM_(10)reduction actions.Variations in the PM_(10)concentration from 2006 to 2017 at an observation station(NJ)in Beijing were recorded and analyzed.The average value±1 standard deviation of daily mean PM_(10)concentrations was 138.8±96.1μg m^(-3)for 1307 days(accounting for 34.7%of the total days),showing PM_(10)concentration exceeding the National Ambient Air Quality Standard(NAAQS)24-h average of 150μg m^(-3).Particulate concentration depended upon various meteorological conditions as also observed in this work:at low wind speed(<4 m s^(-1)),the concentrations of PM_(10) revealed a downward trend with-19μg m^(-3)per unit of wind speed,but when wind speed rose(>4 m s^(-1)),the values increased by 49μg m^(-3)per unit of wind speed.In Beijing,air masses from northwest China,especially from the Gobi Desert and other desert areas,had net contributions to long-range transport of natural dust,enhancing the PM_(10)concentrations by up to 29%.Overall,PM_(10)mass concentration showed a significant downward trend with-8.0μg/m3/yr from 2006 to 2017.Although with higher fluctuations in recorded data,similar downward trends derived from the government released data were also found at the nearby districts.The result delivered a proof of efficacy for the reduction actions recently adopted to limit PM_(10)concentrations in Beijing.Very significant difference of diurnal changes in PM_(10) concentrations was also found in two periods of 2006-2011 and 2012-2017,which might be due to the different contributions of fugitive dust.Nevertheless,further efforts,especially on controlling fugitive dust,should be planned as the PM_(10) concentration annual mean value(94μg m^(-3))in 2017 still exceeded the NAAQS standard.The results showed that there is still a long way to go to reduce PM_(10)in Beijing.

Analysis of Essential Meteorological Elements Surrounding Typhoon Sinlaku by Unmanned Aerial Vehicle

In this paper, a successful flight with an unmanned aerial vehicle (UAV) surrounded Typhoon Sinlaku on 15 Sept., 2008 and the preliminary analysis of all the collected data during the observation period has been presented. It is the first time to adopt surrounding method to observe typhoon in mainland of China. During the 3 h field campaign, the flight altitude is about 500 m to observe the essential meteorological elements in boundary layer of typhoon. The average temperature is 22.57&#176C and ranged from 21.50&#176C to 25.80&#176C, while about the relative humidity, the maximum is 100%, the minimum is 80.60% and the average is 97.98%. As for the wind, the average wind speed is 19.68 m/s and the maximum is 30.03 m/s. The typhoon center is a warm structure, the closer to the center, the higher the temperature is and the lower the wind speed is. In conclusion, the mini-UAV has the capability to observe the boundary layer of typhoon.

Contrastive Observation of Solar Thermal and Photovoltaic Resource

Solar thermal and photovoltaic applications are the most w idely used and the most successful w ay of commercial development in solar energy applications. Observation and assessment of solar thermal and photovoltaic resources are the basis and key of their large-scale development and utilization. Using the observational data carried out from Beijing southern suburbs observation station of China M eteorological Administration in summer of 2009,preliminary solar thermal and photovoltaic resources characteristics for different w eather conditions,different angle and different directions are analyzed. The results show that:(1) In sunny,cloudy or rainy w eather conditions,both of solar thermal and photovoltaic sensors daily irradiance have consistent change in trend. Solar thermal irradiance is larger than photovoltaic. Under sunny conditions,solar thermal global radiation has about 2.7%higher than the photovoltaic global radiation. Under cloudy w eather conditions,solar thermal global radiation has about 3. 9%higher than the photovoltaic. Under rainy w eather conditions,solar thermal global radiation has about 20% higher than the photovoltaic.(2) For different inclined plane daily global radiation,southern latitude-15 °incline is the maximum and southern vertical surface is the minimum. The order from large to small is southern latitude-15 ° incline,southern latitude incline,southern latitude+15 °incline,horizontal surface and southern vertical surface. Southern latitude-15 °incline global radiation has about 41% higher than the southern vertical surface.(3) For different orientation vertical surface daily global radiation,southern vertical surface is the maximum and w estern vertical surface is the minimum,w hich eastern vertical surface is in the middle. Southern vertical surface global radiation has about 20% higher than the w estern vertical surface.