Analysis of photosynthetically active radiation and applied parameterization model for estimating of PAR in the North China Plain     

Bo Hu  Yangchun Yu  Zirui Liu  Yuesi Wang 《Journal of Atmospheric Chemistry》2016,73(4):345-362

As photosynthetically active radiation (PAR) variability and PAR estimating methods play an important role in climate change and ecological process research, PAR variation trends and broadband global solar radiation (R _s ) ratios (PAR/R _s ) in the North China Plain (NCP) are examined using in situ PAR and R _s observed data for 2005 to 2011. The annual average PAR value found in the NCP is 22.9 mol m^?2 d^?1. The highest and lowest values were recorded at Changwu and Luancheng sites, respectively. The highest PAR/R _s value was found in Jiaozhouwan due to large water vapor volumes present in this area. PAR/R _s levels have increased in the NCP due to a decrease in fine aerosols and increase in water vapor concentration. From these analysis results, a parameterization model that can be applied to all sky conditions was checked. Empirical estimation model comparisons for obtaining PAR values indicate that model was least accurate when R _s was used independently. When the model included R _s, the clearness index (K _s) and the solar zenith angle, the model estimated PAR values with acceptable accuracy. A parameterization model was constructed by considering K _s and attenuation factors of PAR under clear weather conditions (ρ _clear). The improved parameterization model more accurately predicts values for local sites and for various observation sites.  相似文献   

城市化进程对北京区域气象场的影响模拟   总被引：7，自引：0，他引：7       下载免费PDF全文

高媛媛  何金海  王自发 《气象与环境学报》2007,23(3):58-64

城市化所导致的下垫面的改变会直接影响局地气象。根据北京城市测绘院提供的北京市楼房建筑平均高度资料,利用中尺度数值模式(MM5V3)模拟了城市化进程引起的气象效应,并与奥林匹克公园站等6个地面观测资料进行了比较。结果表明:MM5V3可以很好地模拟下垫面类型改变导致的气象效应,城市升温效果获得了较好的体现,风速模拟值减小,风向的模拟得到较明显的改善,气压和风速的统计偏差也明显减小。分析结果还揭示了稳定天气条件下北京地区气象场的模拟及实时预报必须考虑精细化的地形及下垫面状况。  相似文献   

Modeling the sudden decrease in CH4 growth rate in 1992     

Zhang Renjian  Wang Mingxing 《大气科学进展》1999,16(2):242-250

A two-dimensional global chemistry model is developed to study the distribution and long-term trends of methane. The model contains 34 species and 104 chemical and photochemical reactions. Using the model, the long-term trends of CH₄, CO and OH in atmosphere are simulated, comparison between the model and observations shows that the simulation is successful. Experiments are done to investigate the causes of dramatic decrease in the growth rate of CH₄ in 1992 such as OH increase due to stratospheric ozone depletion, decrease of temperature in the troposphere due to Mount Pinatubo eruption and descendent of CH₄ sources fluxes. A new explanation is proposed and verified by this model that the decrease of CO emission plays an important role for the abnormal growth rate of CH₄ in 1992. We find that the decreases of CH₄ and CO emissions are the main reasons for the sudden decrease of growth rate of CH₄ in 1992, which account for 73% and 27% respectively.  相似文献   

混沌理论与大气边界层湍流研究   总被引：6，自引：1，他引：5  

李昕 《地球科学进展》2000,15(2):178-183

简述了混沌理论的发展及其判别方法,阐明混沌理论的建立给大气科学中的湍流研究带来了新的启示;介绍了近期混沌理论在大气边界层湍流研究中的应用结果,这些结果表明大气边界层湍流具有很强的混沌特性,且存在低维奇怪吸引子。最后提出了有待进一步研究的问题。  相似文献   

Mitigation options for methane, nitrous oxide and nitric oxide emissions from agricultural ecosystems   总被引：9，自引：0，他引：9  

Zheng Xunhu  Wang Mingxing  Wang Yuesi  Shen Renxing  Li Jing  J. Heyer  M. Koegge  H. Papen 《大气科学进展》2000,17(1):83-92

1.IntroductionNitrousoxide(N,O)andmethane(CH.)arethemostimportantgreenhousegassesintheatmospherewithitscontributiontoglobalwarmingjustlowerthanCO2.Theirconcentrationsinatmospherehavebeennotedtoincreasecurrentlyattherateof0.25%yr--'andl.02%yr',respectively(IPCC,1995).Atpresent,theincreaseofNZOandCH4intheatmospherehasbeenestimatedtoaccountfor20--25%oftheglobalwarming(FAO&IAEA,1992;Bailes&Bridges,1992).NOdoesnotabsorbradiationdirectlyintheatmosphere,buttheincreasingconcentrationofNOmay…  相似文献   

Trends in particulate matter and its chemical compositions in China from 2013–2017     

Wang  Yuesi  Li  Wenjie  Gao  Wenkang  Liu  Zirui  Tian  Shili  Shen  Rongrong  Ji  Dongsheng  Wang  Shuai  Wang  Lili  Tang  Guiqian  Song  Tao  Cheng  Mengtian  Wang  Gehui  Gong  Zhengyu  Hao  Jiming  Zhang  Yuanhang 《中国科学:地球科学(英文版)》2019,62(12):1857-1871

Accurate determination of the atmospheric particulate matter mass concentration and chemical composition is helpful in exploring the causes and sources of atmospheric enthalpy pollution and in evaluating the rationality of environmental air quality control strategies.Based on the sampling and chemical composition data of PM_(2.5) in different key regions of China in the CARE-China observation network,this research analyzes the environmental air quality data released by the China National Environmental Monitoring Centre during the studied period to determine the changes in the particulate matter mass concentration in key regions and the evolution of the corresponding chemical compositions during the implementation of the Action Plan for Prevention and Control of Air Pollution from 2013-2017.The results show the following.(1) The particulate matter mass concentration in China showed a significant downward trend;however,the PM_(2.5) annual mass concentration in 64% of cities exceeds the New Chinese Ambient Air Quality Standard(CAAQS) Grade Ⅱ(GB3095-2012).The region to the east of the Taihang Mountains,the Fenhe and Weihe River Plain and the Urumqi-Changji regions in Xinjiang,all have PM_(2.5) concentration loading that is still high,and heavy haze pollution occurred frequently in the autumn and winter.(2) During the heavy pollution in the autumn and winter,the concentrations of sulfate and organic components decreased significantly.The mean SO_4~(2-) concentration in PM_(2.5) decreased by 76%,12%,81% and 38% in Beijing-Tianjin-Hebei(BTH),the Pearl River Delta(PRD),the Sichuan-Chongqing region(SC) and the Fenhe and Weihe River Plain,respectively.The mean organic matter(OM) concentration decreased by 70%,44%,48% and 31%,respectively,and the mean concentration of NH_4~+ decreased by 68%,1.6%,38% and 25%,respectively.The mean elemental carbon(EC) concentration decreased by 84% and 20% in BTH and SC,respectively,and it increased by 61% and 11% in the PRD and Fenhe and Weihe River Plain,respectively.The mean concentration of mineral and unresolved chemical components(MI) dropped by 70%,24% and 13% in BTH,the PRD and the Fenhe and Weihe River Plain,respectively.The change in the PM_(2.5) chemical composition is consistent with the decrease of the PM_(2.5)mass concentration.(3) In 2015,the mean OM concentration contributions to fine particles and coarse particles were 13-46%and 46-57%,respectively,and the mean MI concentration contributions to fine particles and coarse and particles were 31-60%and 39-73%,respectively;these values are lower than the 2013 values from the key regions,which is the most important factor behind the decrease of the particulate matter mass concentration.From 2013 to 2015,among the chemical components of different particle size fractions,the peak value of the coarse particle size fraction decreased significantly,and the fine particle size fractions of SO_4~(2-),NO_3~-,and NH_4~+ decreased with the decrease of the particulate matter mass concentration in different particle size fractions.The fine-particle size peaks of SO_4~(2-),NO_3~-and NH_4~+ shifted from 0.65-1.1μm to the finer size range of0.43-0.65 μm during the same time frame.  相似文献   

Ensemble hindcasts of ENSO events over the past 120 years using a large number of ensembles   总被引：1，自引：0，他引：1  

郑飞  朱江  王慧 《大气科学进展》2009,26(2):359-372

Based on an intermediate coupled model (ICM), a probabilistic ensemble prediction system (EPS) has been developed. The ensemble Kalman filter (EnKF) data assimilation approach is used for generating the initial ensemble conditions, and a linear, first-order Markov-Chain SST anomaly error model is embedded into the EPS to provide model-error perturbations. In this study, we perform ENSO retrospective forecasts over the 120 year period 1886–2005 using the EPS with 100 ensemble members and with initial conditi...  相似文献   

Anthropogenic Direct Radiative Forcing of Tropospheric Ozone and Aerosols from 1850 to 2000 Estimated with IPCC AR5 Emissions Inventories          下载免费PDF全文

CHANG Wen-Yuan  LIAO Hong 《大气和海洋科学快报》2009,2(4):201-207

This study estimates direct radiative forcing by tropospheric ozone and all aerosols between the years 1850 and 2000, using the new IPCC AR5 （the Intergovernmental Panel on Climate Change Fifth Assessment Report） emissions inventories and a fully coupled chemistry-aerosol general circulation model. As compared to the previous Global Emissions Inventory Activity （GEIA） data, that have been commonly used for forcing estimates since 1990, the IPCC AR5 emissions inventories report lower anthropogenic emissions of organic carbon and black carbon aerosols and higher sulfur and NOx emissions. The simulated global and annual mean burdens of sulfate, nitrate, black carbon （BC）, primary organic aerosol （POA）, secondary organic aerosol （SOA）, and ozone were 0.79, 0.35, 0.05, 0.49, 0.34, and 269 Tg, respectively, in the year 1850, and 1.90, 0.90, 0.11, 0.71, 0.32, and 377 Tg, respectively, in the year 2000. The estimated annual mean top of the atmosphere （TOA） direct radiative forcing of all anthropogenic aerosols based on the AR5 emissions inventories is -0.60 W m^-2 on a global mean basis from 1850 to 2000. However, this is -2.40 W m-2 when forcing values are averaged over eastern China （18-45°N and 95-125°E）. The value for tropospheric ozone is 0.17 W m^-1 on a global mean basis and 0.24 W m^-2 over eastern China. Forcing values indicate that the climatic effect of aerosols over eastern China is much more significant than the globally averaged effect.  相似文献   

大同颗粒物化学成分及其对北京影响          下载免费PDF全文

ZHANG Ren-Jian  ZHANG Mei-Gen  ZHU Ling-Yun  HU Liang-Wen 《大气和海洋科学快报》2009,2(6):345-349

Atmospheric particle samples were collected at an urban site of Datong, Shanxi Province, during December 2004 and their element concentrations at different sizes were analyzed by particle-induced X-ray emission （PIXE）. Analysis of the observation data showed that particle pollution was heavy in winter at Datong and that concentrations of most elements were high in the coarse range. Factor analysis （FA） results indicated that the soil and dust, coal combustion dust, and industry dust are main sources for atmospheric particles in winter at Datong. The enrichment factors of element concentrations showed that particle pollution at Datong impacts the down-wind region--Beijing--in the dust season.  相似文献   

亚印太交汇区的海洋再分析系统   总被引：1，自引：0，他引：1       下载免费PDF全文

YAN Chang-Xiang  ZHU Jiang  XIE Ji-Ping 《大气和海洋科学快报》2010,3(2):81-86

An ocean reanalysis system for the joining area of Asia and Indian-Pacific Ocean (AIPO) has been developed and is currently delivering reanalysis data sets for study on the air-sea interaction over AIPO and its climate variation over China in the inter-annual time scale.This system consists of a nested ocean model forced by atmospheric reanalysis,an ensemble-based multivariate ocean data assimilation system and various ocean observations.The following report describes the main components of the data assimilation system in detail.The system adopts an ensemble optimal interpolation scheme that uses a seasonal update from a free running model to estimate the background error covariance matrix.In view of the systematic biases in some observation systems,some treatments were performed on the observations before the assimilation.A coarse resolution reanalysis dataset from the system is preliminarily evaluated to demonstrate the performance of the system for the period 1992 to 2006 by comparing this dataset with other observations or reanalysis data.  相似文献