Estimate of Hydrofluorocarbon Emissions for 2012–16 in the Yangtze River Delta, China

Hydrofluorocarbons(HFCs)have been widely used in China as substitutes for ozone-depleting substances,the production and use of which are being phased out under the Montreal Protocol.China is a major consumer of HFCs around the world,with its HFC emissions in CO2-equivalent contributing to about 18%of the global emissions for the period2012-16.Three methods are widely used to estimate the emissions of HFCs-namely,the bottom-up method,top-down method and tracer ratio method.In this study,the tracer ratio method was adopted to estimate HFC emissions in the Yangtze River Delta(YRD),using CO as a tracer.The YRD region might make a significant contribution to Chinese totals owing to its rapid economic growth.Weekly flask measurements for ten HFCs(HFC-23,HFC-32,HFC-125,HFC-134 a,HFC-143 a,HFC-152 a,HFC-227 ea,HFC-236 fa,HFC-245 fa and HFC-365 mfc)were conducted at Lin’an Regional Background Station in the YRD over the period 2012-16,and the HFC emissions were 2.4±1.4 Gg yr-1 for HFC-23,2.8±1.2 Gg yr-1 for HFC-32,2.2±1.2 Gg yr-1 for HFC-125,4.8±4.8 Gg yr-1 for HFC-134 a,0.9±0.6 Gg yr-1 for HFC-152 a,0.3±0.3 Gg yr-1 for HFC-227 ea and 0.3±0.2 Gg yr-1 for HFC-245 fa.The YRD total HFC emissions reached 53 Gg CO2-e yr-1,contributing 34%of the national total.The per capita HFC CO2-equivalent emissions rate was 240 kg yr-1,while the values of per unit area emissions and per million GDP emissions reached 150 Mg km-2yr-1 and 3500 kg yr-1(million CNY GDP)-1,which were much higher than national or global levels.

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.

Erratum to:Estimate of Hydrofluorocarbon Emissions for 2012-16 in the Yangtze River Delta,China

In the original version of this article,the unit of the YRD total HFC emissions“Gg CO2-e yr^−1”in the abstract should be Tg CO2-e yr^−1.On Page 581,in the fifth line from the left bottom,the unit of the total CO2-equivalent emissions of HFCs“Gg yr^−1”should be Tg yr^−1.

Promotive Effects of Alginate-Derived Oligosaccharides on the Inducing Drought Resistance of Tomato

In order to determine the role of alginate-derived oligosaccharides (ADO) in drought stress resistance of tomato (Ly-copersicon esculentum Miller) seedlings, the leaves were exposed to different concentrations of ADO (0.05%, 0.10%, 0.20%, 0.30% and 0.50%) after drought stress was simulated by exposing the roots to 0.6 molL-1 PEG-6000 solution for 6 h. Changes in biomass, electrolyte leakage and malondialdehyde (MDA), free proline, total soluble sugars (TSS) and abscisic acid (ABA), the enzyme activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) and phenylalanine ammonia-lyase (PAL) were measured to investigate the effects of ADO treatment. The results showed that the treatment with an ADO concentration of 0.20% exhibited the highest performance of drought stress resistance in the tomato seedlings by decreasing the electrolyte leakage and the concentration of MDA, increasing the contents of free proline, TSS and ABA, and increasing the activities of CAT, SOD, POD and PAL after treatment with ADO. It is suggested that changes in electrolyte leakage, MDA, osmotic solutes, ABA, anti-oxidative enzyme and PAL activities were responsible for the increased drought stress resistance in tomato seedlings. To our best knowledge, this is the first report of the effect of ADO treatment on enhancing the drought stress resistance of tomato seedlings.

Temperature effect on the reference frequency of FDR soil moisture sensor

The FDR automatic soil moisture sensor must determine reference frequency in the air and water. Experimental studies show that the water reference frequency is influenced by water temperature. The variation of the reference frequency of the sensor is measured with the change of the water temperature,then analysis the influence of the volume water content measurement of the sensor,analysis found that the error is not more than 3% for the measurement of the volumetric water content of the temperature.

Uncertainty Evaluation for Comparison Result of National Radiometric Standardsand World Radiometric Reference

Theuse of data of National Radiometric Standardtook place in the WMO International Pyrheliometer Comparisons IPCXI to evaluate the expended uncertainty of the comparison resultbetweenN ational Radiometric Standards( NRS) and the World Radiometric Reference( WRR) in Davos/World Radiometric Center. The result of expended uncertaintyis 0.17%,which meets the requirements of the World Meteorological Organization( WMO) and has reached the world advanced level.In this paper,the method can be used as a reference and basis for evaluating the uncertainty of thecomparison results of the Provincial solar radiation standard.

On board measurement of black carbon aerosols over the Arctic Ocean in summer

This paper presents aerosol black carbon (BC) concentrations measured at deck level on board the R/V XUE LONG icebreaker. The vessel cruised the Arctic Ocean carrying an in situ aethalometer during the summers of 2008 and 2010. The courses of the third Chinese National Arctic Research Expedition (3rd CHINARE-Arctic, August 2008) and fourth Chinese National Arctic Research Expedition (4th CHINARE-Arctic, from late July to August 2010) were bounded by 173°W-143°W and 178°E-150°W, with northernmost points 85°25'N and 88°26'N, respectively. Results show low surface BC concentrations over the ocean throughout the courses, with means (standard error) of 6.0 (±4.7) ngm-3for 3rd CHINARE-Arctic, and 8.4(±7.1) ngm-3for 4th CHINARE-Arctic. It is clear that these onboard BC concentrations are similar to reported data from coastal stations in the Arctic region. The latitude-average BC concentration varied from 3.0-26.2 ng·m-3for 3rd CHINARE-Arctic,to 4.2-20.5 ng·m-3for 4th CHINARE-Arctic. At latitudes higher than 72°N for 3rd CHINARE-Arctic and 75°N for 4th CHINARE-Arctic, BC concentrations were lower and had negligible latitudinal gradients. Analysis indicates that the presence of the Arctic front isolates the lower atmosphere of the high-latitude Arctic Ocean from low-latitude terrestrial transport. This maintains the very low BC concentrations and negligible concentration gradients at high latitudes of the Arctic Ocean during summer. Calculated airmass backward trajectories for the two expeditions show that the Arctic front in 2010 was further north than in 2008, which caused different latitudinal variation of BC concentration in the two years.

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.

Measurement and analysis of ozone, ultraviolet B and aerosol light scattering coefficients in the Arctic

Tropospheric ozone (O3), ultraviolet B (UVB) radiation and aerosol light scattering coefficients (SC)were investigated on a cruise ship during the fourth Chinese National Arctic Research Expedition from July 1-September 20, 2010. The results showed that O3, UVB and SC decreased with increasing latitude, with minimum values recorded in the central Arctic Ocean. Average O3 concentrations were 15.9 ppbv and 15.1 ppbv in the Bering Sea and Arctic Ocean, respectively. Ozone concentrations increased to 17.5 ppbv in the high Arctic region.Average UVB values were 0.26 W·m-2and 0.14 W·m-2in the Bering Sea and Arctic Ocean, respectively. Theaverage SC in the Bering Sea was 4.3 M·m-1, more than twice the value measured in the Arctic Ocean, which had an average value of 1.7 M·m-1. Overall, UVB and SC values were stable in the central Arctic Ocean.

Impacts of aerosol chemical compositions on optical properties in urban Beijing,China

The optical properties of aerosols and their chemical composition,including water-soluble ions,organic carbon(OC),and elemental carbon(EC) in PM_(2.5) and PM_(10),were measured from 26 May to 30 June of 2012 at an urban site in Beijing.The daily average concentrations of PM_(2.5) and PM_(10) were 103.2 and 159.6 μg/m^3,respectively.On average,the OC and EC contributed 20.1% and 4.3% ,respectively,to PM_(2.5) and 16.3% and3.9% ,respectively,to PM_(10).Secondary ions(SO_4^(2-),NO_3^-,and NH_4^+) dominated the water-soluble ions and accounted for 57.9% and 62.6% of PM_(2.5) and PM_(10),respectively.The wind dependence of PM_(2.5),OC,SO_4^(2-),and NO_3^- implied that the pollution sources mainly came from south and southeast of Beijing during the summer.The monthly mean values of the scattering coefficient(σ_(sc)) and absorption coefficient(σ_(ab)) at525 nm were 312.9 and 28.7 Mm^(-1),respectively,and the mean single-scattering albedo(ω) was 0.85.The wind dependence of σ_(sc) revealed that this value was mainly influenced by regional transport during the summer,and the relationship between σ_(ab) and wind indicated that a high σ_(ab) resulted from the joint effects of local emissions and regional transport.The reconstructed σ_(sc) that was derived from the revised IMPROVE equation agreed well with the observations.The contribution of different chemical species toσ_(sc) was investigated under different pollution levels,and it was found that secondary inorganic aerosols accounted for a large part of σ_(sc) during pollution episodes(35.7% ),while organic matter was the main contributor to σ_(sc) under clean conditions(33.6% ).

华北地区兴隆站二氧化碳浓度观测（英文）

基于兴隆站Picarro G2301观测资料,本文分析了2016年5月至2017年12月近地面二氧化碳浓度变化趋势以及远距离输送的影响。采用背景值筛选方法,提取了兴隆站二氧化碳背景浓度和污染浓度。分析表明,兴隆站二氧化碳背景浓度和污染浓度有相似的季节变化特征,夏季最低,冬季和早春较高。冬季和早春的高背景值主要由于正的生物通量,即更强的植物呼吸作用和更弱的植物光合作用;夏季则相反,夏季和初秋污染浓度与背景浓度差值均较大,主要是本地源排放增加,而72小时后向轨迹的聚类分析以及PSCF分析也表明,夏季由于来自北京,天津,河北和山东的气流输送,携带有高浓度二氧化碳气团也会使兴隆地区的二氧化碳污染浓度升高。远距离输送结果也表明,京津冀区域人为排放二氧化碳对兴隆地区四个季节的二氧化碳浓度均有正的贡献,冬季来自内蒙古和张家口的气团输送也会带来正的贡献。二氧化碳浓度的日变化在所有季节都很显著,10:00至14:00左右二氧化碳浓度较低。中午较强的边界层对流将高空低浓度的二氧化碳向下输送到近地面大气,下午则相反,而高值通常发生在夜间。

Study on Solar Spectral Radiation Standard revising Based on Smart

The ISO9845-1-1992( E) standard has been issued for more than 20 years,the various factors that affect the solar spectral radiation have been undergone many changes over the years. The standard data cannot satisfy the current needs. According to the opinions of international experts on the revision of ISO9845-1-1992( E) : in the revised standard,the spectral irradiation of different inclined surface should be added,Accordingly,China land center and European land average latitude should be calculated. In this paper,the geometric average latitude and weighted average latitude of China land are calculated respectively. The direct normal irradiance and hemispherical irradiance are calculated by using SMART model at the two tilt angle that corresponding to the latitudes.

Impact of Beijing’s“Coal to Electricity”program on ambient PM_(2.5) and the associated reactive oxygen species(ROS)

The Beijing“Coal to Electricity”program provides a unique opportunity to explore air quality impacts by replacing residential coal burning with electrical appliances.In this study,the atmospheric ROS(Gas-phase ROS and Particle-phase ROS,abbreviated to G-ROS and P-ROS)were measured by an online instrument in parallel with concurrent PM_(2.5) sample collections analyzed for chemical composition and cellular ROS in a baseline year(Coal Use Year-CUY)and the first year following implementation of the“Coal to Electricity”program(Coal Ban Year-CBY).The results showed PM_(2.5) concentrations had no significant difference between the two sampling periods,but the activities of G-ROS,P-ROS,and cellular ROS in CBY were 8.72 nmol H_(2)O_(2)/m^(3),9.82 nmol H 2 O 2/m 3,and 2045.75μg UD/mg PM higher than in CUY.Six sources were identified by factor-analysis from the chemical components of PM_(2.5).Secondary sources(SECs)were the dominant source of PM_(2.5) in the two periods,with 15.90%higher contribution in CBY than in CUY.Industrial Emission&Coal Combustion sources(Ind.&CCs),mainly from regional transport,also increased significantly in CBY.The contributions of Aged Sea Salt&Residential Burning sources to PM_(2.5) decreased 5.31% from CUY to CBY.The correlation results illustrated that Ind.&CCs had significant positive correlations with atmospheric ROS,and SECs significantly associated with cellular ROS,especially nitrates(r=0.626,p=0.000).Therefore,the implementation of the“Coal to Electricity”program reduced PM_(2.5) contributions from coal and biomass combustion,but had little effect on the improvement of atmospheric and cellular ROS.

Preliminary Calibration of GPS Signals and Its Effects on Soil Moisture Estimation

In recent years, Global Navigation Satellite Systems Reflectometry (GNSS-R) is developed to estimate soil moisture content (SMC) as a new remote sensing tool. Signal error of Global Positioning System (GPS) bistatic radar is an important factor that affects the accuracy of SMC estimation. In this paper, two methods of GPS signal calibration involving both the direct and reflected signals are introduced, and a detailed explanation of the theoretical basis for such methods is given. An improved SMC estimation model utilizing calibrated GPS L-band signals is proposed, and the estimation accuracy is validated using the airborne GPS data from the Soil Moisture Experiment in 2002 (SMEX02). We choose 21 sites with soybean and corn in the Walnut Creek region of the US for validation. The sites are divided into three categories according to their vegetation cover: bare soil, mid-vegetation cover (Mid-Veg), and high-vegetation cover (High-Veg). The accuracy of SMC estimation is 11.17% for bare soil and 8.12% for Mid-Veg sites, much better than that of the traditional model. For High-Veg sites, the effect of signal attenuation due to vegetation cover is preliminarily taken into consideration and a linear model related to Normalized Difference Vegetation Indices (NDVI) is adopted to obtain a factor for rectifying the "over-calibration", and the error for High-Veg sites is finally reduced to 3.81%.