大氣化學(xué)、大氣成分觀測與服務(wù)進(jìn)展

大氣化學(xué)、大氣成分觀測與服務(wù)

大氣化學(xué)、大氣成分觀測與服務(wù)進(jìn)展

1. 973項(xiàng)目“中國大氣氣溶膠及其氣候效應(yīng)的研究”主要進(jìn)展

中國氣象科學(xué)研究院主持的國家重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)劃項(xiàng)目“中國大氣氣溶膠及其氣候效應(yīng)的研究”在2010年年底完成，并順利通過了項(xiàng)目驗(yàn)收。取得的主要研究進(jìn)展如下：

通過大規(guī)模網(wǎng)絡(luò)化觀測和加強(qiáng)觀測與實(shí)驗(yàn)，對(duì)中國不同區(qū)域近地面層大氣氣溶膠的化學(xué)組成、物理和光學(xué)特性有了較以往更為全面、系統(tǒng)的認(rèn)識(shí)，通過飛機(jī)觀測初步獲得了對(duì)高污染區(qū)域氣溶膠與云相互作用特征的認(rèn)識(shí)。發(fā)展了系列大氣氣溶膠輻射特性反演的新方法。

在霾形成與發(fā)展的不同階段，通過實(shí)驗(yàn)觀測與分析獲得的二次氣溶膠核化、增長、老化過程中的混合狀況，吸濕增長、非均相化學(xué)反應(yīng)、氣溶膠與云（霧）的聯(lián)系等認(rèn)識(shí)，形成了對(duì)高氣溶膠濃度和復(fù)雜類型情況下區(qū)域性霾形成機(jī)制的認(rèn)識(shí)。建立了氣溶膠及其前體物的排放源清單和源動(dòng)態(tài)處理系統(tǒng)，自主研發(fā)了包括氣溶膠-氣體在線耦合的氣溶膠數(shù)值模擬系統(tǒng)，并研發(fā)出區(qū)域性霾天氣數(shù)值預(yù)報(bào)系統(tǒng)，參與了2008年北京奧運(yùn)會(huì)和2009年國慶60周年氣象保障服務(wù)任務(wù)，提供了PM10、O3和能見度的數(shù)值預(yù)報(bào)，取得良好效果。

實(shí)現(xiàn)了自主發(fā)展的輻射傳輸模式以及氣溶膠模式系統(tǒng)與中國氣象局氣候系統(tǒng)模式的在線耦合。取得了諸如中國多種氣溶膠綜合的“冷卻”效應(yīng)明顯，對(duì)大尺度環(huán)流和氣候的影響與西方學(xué)者前期結(jié)果和ABCs（大氣棕色云）的明顯不同，即使是氣溶膠的增溫效應(yīng)，其中還有受自然過程控制的沙塵氣溶膠的貢獻(xiàn)，北極黑碳?xì)馊苣z與亞洲的排放沒有直接聯(lián)系等有利于國家氣候變化外交的系列研究成果。

項(xiàng)目共發(fā)表論文450篇，其中SCI（SCIE）論文221篇，并向國家報(bào)送10余份決策服務(wù)報(bào)告，其中兩份獲得國家領(lǐng)導(dǎo)人的批示。

我國各主要區(qū)域的氣溶膠化學(xué)組成特征Chemical composition properties of aerosols over main regions of China

CUACE/Aero 氣溶膠模擬系統(tǒng)CUACE/Aero modeling system

2. 酸雨973課題順利完成

我國區(qū)域降水平均pH值對(duì)比Comparison of the distributions of the mean pH value

1992—2009年不同降水酸度等級(jí)覆蓋區(qū)域占我國大陸面積比例的變化Percentage area coverages of different ranges of annual mean precipitation pH in China during 1992—2009

國家重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)劃(973計(jì)劃)項(xiàng)目“中國酸雨沉降機(jī)制、輸送態(tài)勢及調(diào)控原理”第2課題“典型氣候/生態(tài)區(qū)降水化學(xué)背景特征與演變規(guī)律研究”于2010年順利完成并以優(yōu)秀成績通過結(jié)題驗(yàn)收。該課題主要圍繞歷史資料分析、典型地區(qū)地面觀測及綜合分析和衛(wèi)星數(shù)據(jù)反演與同化3個(gè)方面開展了大量研究工作。通過5年的研究，課題揭示了我國降水酸度和區(qū)域性酸雨時(shí)空演變規(guī)律與成因；取得了我國主要酸雨區(qū)內(nèi)關(guān)鍵背景站點(diǎn)濕沉降的化學(xué)成分以及主要酸、堿性氣體的變化特征、分布規(guī)律及其與氣象條件的關(guān)系；掌握了我國區(qū)域大氣本底地區(qū)的降水化學(xué)成分和酸雨相關(guān)氣體的演變規(guī)律；探索、發(fā)展了適合我國的關(guān)鍵痕量氣體衛(wèi)星遙感資料反演算法和數(shù)據(jù)同化技術(shù)，并將衛(wèi)星遙感資料應(yīng)用于我國區(qū)域性酸雨研究。

通過大量、翔實(shí)的歷史與現(xiàn)狀的觀測資料，課題建立并有效應(yīng)用了酸雨觀測資料的K-pH不等式關(guān)系質(zhì)量控制方法；揭示了1992—2009年我國酸雨區(qū)面積和地理分布的演變趨勢，闡明了全國酸雨面積與強(qiáng)度的3階段發(fā)展特征；發(fā)現(xiàn)了21世紀(jì)我國重酸雨區(qū)向東擴(kuò)展、向北延伸的事實(shí)，回答了關(guān)于我國酸雨的現(xiàn)狀與演變態(tài)勢關(guān)鍵問題；掌握了多年來我國大氣本底地區(qū)降水化學(xué)成分和硫/氮比值的長期變化態(tài)勢；取得了2007—2009年我國典型區(qū)域降水化學(xué)成分、酸雨類型和酸堿性氣體的現(xiàn)狀、空間差異與時(shí)間變化特征；揭示了我國對(duì)流層NO2和SO2東部快速增長、西部微弱下降或維持平穩(wěn)的趨勢；建立并驗(yàn)證了我國SO2、NO2和O3衛(wèi)星數(shù)據(jù)反演技術(shù)方法；課題為總項(xiàng)目提供了關(guān)鍵的基礎(chǔ)數(shù)據(jù)，形成并提交了13個(gè)共享數(shù)據(jù)集。

在我國酸雨時(shí)空演變方面的分析結(jié)果表明：1992—1999年我國酸雨總體呈減緩趨勢；2000—2006年華北、華中、華東及華南地區(qū)酸雨加重；2007—2009年我國酸雨總體趨于緩解，主要表現(xiàn)在重酸雨區(qū)面積的顯著下降；我國酸雨長期演變的結(jié)果導(dǎo)致重酸雨區(qū)與20世紀(jì)90年代相比明顯地向東轉(zhuǎn)移、向北延伸。

3. 北京夏季細(xì)顆粒物的高分辨率的演變特征和變化規(guī)律

大氣氣溶膠是北京主要的大氣污染物，為了更好地了解北京地區(qū)氣溶膠的特征、來源和過程，2006年夏季在北京市區(qū)利用氣溶膠質(zhì)譜儀開展了觀測試驗(yàn)，主要測量亞微米顆粒的化學(xué)組成。整個(gè)觀測期間有機(jī)物、硫酸鹽、硝酸鹽、銨鹽、氯化物的相對(duì)貢獻(xiàn)分別為35%、25%、22%、16%、1.4%。通常NH4NO3具有較高的揮發(fā)性，但是北京夏季仍然有大量硝酸鹽存在，硝酸鹽的百分比也比其他城區(qū)觀測到的高2倍。這可能與北京大氣中存在大量的氨氣有關(guān)，大氣中的氨氣不僅能夠中和硫酸，還能中和硝酸。如果假定硫酸鹽、硝酸鹽、氯等以銨鹽的形式存在，計(jì)算得到銨鹽的濃度與實(shí)際測量的銨鹽濃度吻合很好，說明北京地區(qū)無機(jī)氣溶膠多以銨鹽的形式存在，而且氣溶膠基本呈現(xiàn)中性。

硫酸鹽、硝酸鹽、銨鹽、有機(jī)物具有很強(qiáng)的日變化特征。硫酸鹽在下午左右出現(xiàn)峰值，而硝酸鹽和氯離子則在凌晨出現(xiàn)高值，銨鹽則在凌晨和下午均出現(xiàn)峰值。有機(jī)物在下午(12:00—13:00)和晚上(20:00)均有一個(gè)峰值。硫酸鹽、硝酸鹽、銨鹽具有相似的粒徑分布，主要在600 nm左右的積聚模態(tài)出現(xiàn)峰值，這表明硫酸鹽、硝酸鹽和銨鹽很可能是以內(nèi)部混合形式存在的。有機(jī)物的粒徑分布與無機(jī)鹽不同，在比較寬的粒徑范圍(150～600 nm)內(nèi)，濃度都比較高，在粒徑小于200 nm的顆粒物中有機(jī)物占主導(dǎo)，特別在超細(xì)顆粒物 (Dva ＜ 100 nm) 中有機(jī)物占到了總質(zhì)量的70%～90%，而積聚模態(tài)中以硫酸鹽和硝酸鹽為主。

利用正矩陣因子（positive matrix factorization, PMF）法對(duì)有機(jī)物質(zhì)譜進(jìn)行解析，得到了3個(gè)主要因子。根據(jù)各因子的質(zhì)譜特征、以及與無機(jī)組分的相關(guān)性，將它們分別定義為烴類有機(jī)氣溶膠（HOA）、半揮發(fā)性有機(jī)氣溶膠（SV-OOA）以及低揮發(fā)性氧化性有機(jī)氣溶膠（LV-OOA）。北京夏季氣溶膠中氧化性有機(jī)氣溶膠占主導(dǎo)地位，細(xì)顆粒物化學(xué)組成和濃度變化快，受氣象條件影響明顯。

4. 中國上空大氣霾－云的氣候冷卻效應(yīng)

工業(yè)化革命以來大氣中CO2等溫室氣體濃度的不斷增加，被認(rèn)為是近百年來氣候變暖的主要原因?；蜕镔|(zhì)的燃燒，也同時(shí)向大氣中排放大量的煙塵，大氣中的黑碳?xì)馊苣z也具有增溫效應(yīng)。近年來，中國等發(fā)展中國家的黑碳污染及其氣候增溫效應(yīng)問題，越來越受到歐美等發(fā)達(dá)國家的關(guān)注。有觀點(diǎn)認(rèn)為，應(yīng)該將黑碳列入國際有關(guān)減排方案中，因?yàn)檫@既可以減少溫室效應(yīng)，又可以抑制大氣污染。在國家自然科學(xué)基金重點(diǎn)項(xiàng)目“華北地區(qū)大氣污染對(duì)氣溶膠和云微物理特征的影響”的資助下，中國氣象科學(xué)研究院和中國環(huán)境科學(xué)研究院的科學(xué)家于2006年春季，在華北典型污染地區(qū)首次開展了包括飛機(jī)航測在內(nèi)的大氣痕量氣體、氣溶膠和云微物理的野外綜合觀測試驗(yàn)。觀測到華北典型污染地區(qū)非降水層狀云中混有高濃度的氣態(tài)污染物和氣溶膠粒子，與較輕污染的大氣相比，云滴本身的數(shù)濃度很高、尺度很小。數(shù)據(jù)分析表明，大氣化學(xué)過程對(duì)于大氣霾-云的形成和發(fā)展起著非常關(guān)鍵的作用，污染的酸性物質(zhì)在沙塵表面的凝結(jié)，是華北污染地區(qū)春季云凝結(jié)核的主要來源。研究還發(fā)現(xiàn)，華北地區(qū)霾粒子的增加導(dǎo)致云滴譜型變窄，這會(huì)使氣溶膠的間接氣候冷卻效應(yīng)增加，這一結(jié)果與國外已有的研究結(jié)論完全相反。有關(guān)的研究結(jié)果，已于2010年9月18日發(fā)表在美國地球物理協(xié)會(huì)主辦的Journal of Geophysical Research-Atmospheres上。污染導(dǎo)致的大氣霾-云會(huì)在不同程度上抵消溫室氣體增加引起的增溫效應(yīng)，這一研究結(jié)果使得大氣污染與氣候變化問題變得更錯(cuò)綜復(fù)雜。

5. 對(duì)流層上層和平流層下層水汽濃度垂直廓線的直接探測

“夏季青藏高原對(duì)流層－平流層臭氧和水汽垂直分布觀測研究”，是中國氣象科學(xué)研究院科學(xué)家首次利用低溫露點(diǎn)儀（Cryogenic Frost Hygrometer）在云南騰沖地區(qū)系統(tǒng)地開展的對(duì)流層－平流層25 km高度的水汽垂直分布的絕對(duì)濃度的觀測研究，這對(duì)增強(qiáng)了解青藏高原東南部地區(qū)水汽輸送及該地區(qū)對(duì)流層上層－平流層下層大氣動(dòng)力、熱力學(xué)上的精細(xì)結(jié)構(gòu)特點(diǎn)均有著重要的意義。

6. 南極中山站大氣化學(xué)成分觀測

在第27次中國南極科學(xué)考察隊(duì)的支持下，中國氣象科學(xué)研究院科學(xué)家利用中國氣象局Brewer光譜儀傳遞標(biāo)準(zhǔn)（Brewer#197），對(duì)在中山站地區(qū)執(zhí)行了18年連續(xù)觀測的單光柵型Brewer#074光譜儀進(jìn)行獨(dú)立地校準(zhǔn)，檢驗(yàn)了中山站地區(qū)歷史臭氧總量觀測數(shù)據(jù)的質(zhì)量。新布置的精確度更高的雙光柵Brewer#193光譜儀也得到了修復(fù)和標(biāo)定，并將用于長期的觀測。對(duì)中山站地區(qū)近地面的在線溫室氣體（CO2，CH4）觀測儀器進(jìn)行了有效標(biāo)定。

2010年8月8—30日低溫露點(diǎn)儀12次觀測云南騰沖地區(qū)上對(duì)流層－下平流層水汽濃度的垂直分布Vertical distributions of water vapor concentrations in UT-LS altitude observed by using cryogenic frost hygrometer at Tengchong ,Yunnan province from August 8th to 30th ,2010.

標(biāo)準(zhǔn)儀器（Brewer#197）對(duì)南極中山站臭氧總量觀測的儀器（#193）和執(zhí)行長達(dá)18年連續(xù)觀測的儀器（#074）的 比對(duì)標(biāo)定觀測結(jié)果The quality of Brewer#074 total ozone data is evaluated by calibration of the traveling standard Brewer#197 and the inter-comparison with Brewer #193 at Zhongshan, Antarctica in 2010-2011

7. MeteoInfo - 氣象數(shù)據(jù)圖形信息系統(tǒng)軟件

MeteoInfo軟件示例Sample plots of MeteoInfo software

自主開發(fā)了交互式氣象數(shù)據(jù)圖形信息系統(tǒng)軟件MeteoInfo，可以用于多數(shù)據(jù)源氣象及空間數(shù)據(jù)的顯示、分析。軟件包含一些從底層開發(fā)的GIS功能。軟件可以在Windows系統(tǒng)下運(yùn)行，也可以在Mono的支持下在類Unix系統(tǒng)下運(yùn)行。MeteoInfo具備腳本程序編寫自動(dòng)運(yùn)行及數(shù)據(jù)分析能力。MeteoInfo類庫可用于氣象業(yè)務(wù)軟件的開發(fā)，大氣成分多個(gè)業(yè)務(wù)軟件就是在此類庫基礎(chǔ)上開發(fā)的。

MeteoInfo支持多種氣象數(shù)據(jù)格式：GrADS二進(jìn)制、NetCDF、GRIB1、GRIB2、METAR、ARL、AWX、MICAPS (第1、3、4、7、11、13類) 數(shù)據(jù)、HYSPLIT模式輸出的數(shù)據(jù)、站點(diǎn)文本文件格式數(shù)據(jù)、ISH數(shù)據(jù)格式、ESRI ASCII Grid、Surfer ASCII Grid。

MeteoInfo通過網(wǎng)絡(luò)免費(fèi)共享，已在國內(nèi)外有了一定的用戶基礎(chǔ)，下載地址： http://www.esnips. com/web/MeteoInfo；http://www.06climate.com/view/1098.html。

8. 霧霾數(shù)值預(yù)報(bào)系統(tǒng)

建立了帶有氣溶膠數(shù)值同化的霧霾數(shù)值預(yù)報(bào)系統(tǒng)（CUACE），實(shí)現(xiàn)了對(duì)中國地區(qū)的霧霾數(shù)值預(yù)報(bào)。CUACE可模擬大氣中多種氣溶膠組分：黑碳、有機(jī)碳、沙塵、海鹽、硫酸鹽、硝酸鹽、銨鹽；氣溶膠的譜分布采用先進(jìn)的分檔處理，而非其他氣溶膠模式所采用的固定模態(tài)分布，實(shí)現(xiàn)了不同檔之間物質(zhì)交換；CUACE/Aero實(shí)現(xiàn)了與氣態(tài)化學(xué)、氣溶膠熱力學(xué)平衡模式之間的完全耦合。氣溶膠生成轉(zhuǎn)化各個(gè)過程更加合理、完善。2010年CUACE評(píng)估顯示氣溶膠組分和氣體成分與觀測基本一致，相關(guān)水平較高。CUACE對(duì)華北地區(qū)夏季高溫高濕的靜穩(wěn)型污染起始、發(fā)展和結(jié)束的模擬和觀測基本一致，總的相關(guān)系數(shù)較高。

將CUACE在線耦合到中尺度模式MM5/GRAPES中，利用實(shí)時(shí)衛(wèi)星反演的AOD資料，建立了氣溶膠數(shù)值同化系統(tǒng)，為霧霾模式系統(tǒng)提供了分檔的不同氣溶膠組分更為準(zhǔn)確的初值，建立了配有自主開發(fā)的可動(dòng)態(tài)更新的高時(shí)空分布各種氣溶膠及其前體物的排放源清單、帶有氣溶膠數(shù)值同化的霧霾數(shù)值預(yù)報(bào)系統(tǒng)。該系統(tǒng)參加了2010年的亞運(yùn)會(huì)期間霾的預(yù)報(bào)服務(wù)，實(shí)時(shí)提供了廣州及廣東省的O3、PM10、能見度等預(yù)報(bào)產(chǎn)品。

Atmospheric Chemistry, Atmosphere Composition Monitoring and Services

Achievements in Atmospheric Chemistry, Atmosphere Composition Monitoring and Services

1. Aerosols over China and their climate effect

The national key project of basic research “Aerosols over China and their climate effect”hosted by Chinese Academy of Meteorological Sciences was completed at the end of 2010, and passed the acceptance check successfully. The main progress of the project is described as follows.

A much more comprehensive and systematic understanding to the chemical, physical and optical properties of surface aerosols over different areas of China based on the large-scale network observation, enhanced observation and many experiments. Primarily achieving the interaction between aerosol and cloud at highly polluted regions through airplane observation research. Several new retrieving methods of aerosol radiation properties were developed.

The properties during the formation, growing and aging process of aerosol, nucleation, mixing status, hygroscopicity, heterogeneous reaction and the relationship between aerosol and cloud/fog, were obtained by experimental observation and analysis, and the forming mechanism of haze at the regions with high aerosol concentration and complex components was understood. An aerosol modeling system with online coupled gas-aerosol module was developed independently, including an emission inventory of aerosols and pregases and a dynamic emission processing system. Also a regional haze weather numerical forecasting system was developed and well applied in the meteorological services of Beijing Olympic Games and 60th annual National-Day.

The self-development radiation transfer model, aerosol model and CMA climate model were coupled online. And a series of options in relation with China climate diplomacy were fulf lled, such as the signif cant cooling effect of China aerosols, the new understanding of the aerosol impact on large-scale circulation andclimate, un-negligible nature dust contribution to aerosol heating effect, no direct relationship between black carbon aerosol of north pole region and emission of Asia.

450 papers were published supported by the project, including 221 SCI/SCIE papers. More than 10 reports were submitted to the related authorities of China, and two of them were instructed by the national leaders.

2. Study of the chemical characteristics and their evolution of precipitation over typical climate and ecological regions

The subproject “Study of the chemical characteristics and their evolution of precipitation over typical climate and ecological regions”, one of the subprojects of the Acid Rain Project supported by the National Basic Research Program (“973”Program) of China, was completed and passed the f nal appraisal with excellence. In this subproject, a series of studies were done in analysis of historic acid rain data, in observations and analysis of precipitation chemistry and main acidic/alkaline gases in typical regions, in retrieval and assimilation of satellite data, etc. Investigations in the subproject result in a number of outcomes, e.g., revealing the spatio-temporal variations and their causes of the regional acid rain in China, analyzing the spatio-temporal variations of major ions in wet deposition and main acidic/alkaline gases over typical regions and their relationships to meteorological conditions, obtaining the long-term changes in precipitation chemistry and acidic gases at background sites in China, exploring and developing retrieval and assimilation methods for satellite measurements of trace gases under China’s atmospheric and surface conditions, applying satellite measurements to the research of acid rain in China.

Based on the historic and present-day observational data, the inequality relationship K-pH was developed and applied to the QA/QC of acid rain observations, the evolution of precipitation acidity in different regions of China during 1992—2009 was obtained; the evolution of acid rain areas and intensity was found to experience a three-stage development; the severe acid rain area shifted from southwest China eastward and extended northward; the sulfate-to-nitrate ratio in the precipitation over background regions in China showed a signif cant decrease. Except answering the questions about the current status and evolution of acid rain in China, the subproject also made intensive measurements during 2007—2009 and collected valuable data that show current situations and spatio-temporal variability of precipitation chemistry and acidic/alkaline gases in different regions. The satellite measurements of SO2, NO2and O3over China were retrieved and validated. It was found that tropospheric NO2and SO2had been increased over eastern China and were stable or slightly decreased over western China. The subproject has produced and submitted 13 datasets containing many key data.

Some key f ndings have been obtained within this subproject about the spatio-temporal changes of acid rain in China. It was found that acid rain in China showed a general weakening during 1992—1999 and a rapid worsening during 2000-2006, particularly in North China, Central China, East China, and South China, and stablization with reduced severe acid areas during 2007—2009. Such long-term evolution resulted in a clear shift of the center of severe acid from southwestern China to Central and East China.

3. Highly time- and size-resolved characterization of submicron aerosol particles in Beijing using an aerodyne aerosol mass spectrometer

Atmospheric aerosols are a major pollutant in Beijing –a megacity in China. To achieve a better understanding of the characteristics, sources and processes of aerosols in Beijing, an Aerodyne Aerosol Mass Spectrometer (AMS) was deployed at an urban site in July 2006 to obtain size-resolved chemical composition of non-refractory submicron particles (NR-PM1) at 5 min resolution. During this study, NR-PM1 was on average composed of 25% sulfate, 22% nitrate, 16% ammonium, 1.4% chloride and 35% of organic aerosol (OA) species. The presence of substantial amounts of particulate nitrate in summer is interesting since NH4NO3is relatively volatile and tends to dissociate and remain in the gas phase under high temperature. The average fraction of nitrate in NR-PM1 in Beijing is approximately 2 times higher than the average value observed in anumber of urban locations during summer. A possible reason for the detection of large quantities of particulate nitrate in July is that there was plenty of NH3gas in the air to neutralize H2SO4and HNO3, which is consistent with the observation that the measured particles appear to be bulk neutralized.

The NR-PM1 chemical species show signif cantly different diurnal patterns with respect to each other during this study. Sulfate had a pronounced diurnal prof le that peaks in the late afternoon, which could be driven by enhanced photochemical production and condensation of gaseous H2SO4, while the observed diurnal prof le of chloride and nitrate that peak in the early morning. It is interesting to note that the average mass concentrations of organics shows two peaks, one in the early afternoon (12:00– 13:00) and one in the evening (19:00–20:00). This is unlike the situations often seen in other urban locations, e.g., Pittsburgh, New York City and Mexico City. The average size distributions of sulfate, nitrate and ammonium were very similar and were characterized by a prominent accumulation mode peaking at Dva m/z 600 nm. The average size distribution of OA was signif cantly broader due to the presence of an ultraf ne mode.

Multivariation analysis of the AMS organic spectra with Positive Matrix Factorization (PMF) identif ed a hydrocarbon like OA (HOA) and two oxygenated OA (OOA) components. The HOA component is likely to correspond to primary OA material associated with combustion-related emissions. The two OOA components, which possibly corresponded to more oxidized (LV-OOA ) and less oxidized (SV-OOA) secondary OA materials, to account for 45% and 16 %, respectively, of the observed OA mass. LV-OOA correlated well with sulfate while SV-OOA correlated well with nitrate. The particle loading, composition and size distributions observed during this campaign were highly variable, which was affected by meteorology.

4. Climate cooling effect of atmospheric haze-clouds over China

Increasing CO2in the atmosphere since the pre-industrial revolution is thought to be the main cause of climate warming over the past 100 years. Fossil fuel usage and biomass mass burning emit a large amount of soot into the atmosphere, which can also have a warming effect. Recently, black carbon pollution and its climate effect in China and other developing countries have been paid more attention to in the developed world such as Europe and America. There have been some arguments suggesting that black carbon should be listed as a substance in the emission control scenarios for the benef ts of both slowing down the climate warming and inhibiting the air pollution. A f eld measurement campaign was performed in spring 2006 as part of the project - Inf uence of Pollution on Aerosols and Cloud Microphysics in North China by the scientists from the Chinese Academy of Meteorological Sciences and the Chinese Research Academy of Environmental Sciences. The campaign included the f rst aircraft measurements of atmospheric trace gases, aerosols and clouds over the region that is strongly affected by both natural desert dust and pollution smog. They observed very high concentrations of gaseous air pollutants and haze particles, partly together with non-precipitating stratiform clouds. The clouds were characterized by numerous droplets, much smaller than in a less polluted atmosphere. Their data reveal a central role of atmospheric chemistry in the formation and persistence of the haze-clouds and that the highly eff cient coating of dust particles by pollution acids provides the predominant source of cloud condensation nuclei. Contrary to previous analyses, they f nd that the haze particles inf uence the spectral shape of the cloud droplet size distribution to such a degree that the indirect climate cooling effect of aerosols on clouds is increased. The results were published in the Journal of Geophysical Research- Atmospheres by the American Geophysical Union on 18 September 2010 (Ma, J. et al., 2010, doi:10.1029/2009JD013065). The pollution-induced haze-clouds can partially offset the climate warming effect of increasing green-house gases, and this increases the complexity of air pollution and causes climate change issues.

5. Direct measurements of vertical distributions of water vapor concentration at UT-LS altitudes

The National Natural Science Foundation of China routine project“Measurements of vertical distributions of summer water vapor and ozone over the Tibetan Plateau in the troposphere to stratosphere”was implemented. It was the f rst time for CAMS scientists to measure the absolute water vapor concentrationfrom troposphere up to 25 km in the lower stratosphere by using the cryogenic frost hygrometer. These observations are expected to improve the understanding of the transport of water vapor, and the f ne structures in thermal and dynamics at the UT-LS altitudes in the south-eastern Tibetan Plateau.

6. Observations of atmospheric chemicals at China Zhongshan, Antarctica

With the support of the 27th China Antarctic Exploration, the CAMS scientists independently calibrated the single Brewer #074 ozone spectrophotometer, which has been deployed at China Antarctic Zhongshan Station for almost 18 years, by using the CMA traveling standard ,Brewer#197 . This calibration has effectively evaluated the data quality of the historical total ozone at the site. At same time, the newly deployed double Brewer#193 which has higher accuracy and precision, was also repaired and calibrated for its long –term observations in the future. The effective calibration works were also done for the on-line measurements of surface –level green house gases (CO2,CH4).

7. MeteoInfo – meteorological data information system

MeteoInfo software was developed independently to visualize and analyse meteorological and spatial data. It includes some GIS functions developed from ground level. MeteoInfo may be run in Windows with .NetFramework 3.5, or in UNIX like systems with Mono, an open source implementation of the NET Framework. MeteoInfo can also be run automatically using MeteoInfo scripting with the IronPython language. The main functions are packed in the MeteoInfo class library, which could be used to conveniently develop the software.

Many meteorological data formats are supported by MeteoInfo, including: GrADS binary data, NetCDF grid data, GRIB edition 1 and 2 data, ARL packed meteorological data, HYSPLIT model output data, METAR data, NOAA ISH data , Lon/Lat Station ASCII data, MICAPS 1, 3, 4, 7, 11 and 13 format data , ESRI ASCII Grid data , Surfer ASCII Grid data.

8. CUACE, a chemical weather forecasting system together with data assimilation serving for haze forecast

CUACE is a unified chemistry module that can be easily coupled onto different types of weather and climate models at various temporal and spatial scales. It comprises a chemistry module for gases, gas to particles, SOA and aerosols. It also has an interface to pass the atmospheric fields including wind, temperature and humidity etc. and model configurations into the chemistry module and the chemical fields back into the host model for diffusion, advection and direct and indirect feedback. The gas part in CUACE has 21 photochemical reactions by which 66 gas species for O3, NOX, SO2, NH3, CO, CO2and VOCs can be simulated. The aerosol part in CUACE is a size-segregated multi-component module for seven types of aerosols such as dust, sea salt, BC/OC, sulfate, nitrate and ammonium. It also contains major aerosol processes in the atmosphere such as the generation, hygroscopic growth, coagulation, nucleation, condensation, dry depositions, scavenging and aerosol activations. The aerosol thermodynamic model ISORROPIA has been introduced to calculate the composition and phase state of an ammonia-sulfate-nitrate-chloride-sodium-water inorganic aerosol in thermodynamic equilibrium with gas phase precursors.

It has been coupled with the mesoscale model MM5/GRAPES. And with the AOD from FY-3A and surface visibility data, a data assimilation system has also been established to improve the initial conditions for aerosol components. The coupled system in MM5 has been issuing real time products of PM10, visibility and ozone in 3 hrs intervals for 72 hrs forecast length for Asia Games in Guangzhou in 2010.

CUACE has been chosen for the WMO/GURME project: NRT Application to Air Quality Forecasts.