利用地基GPS/MET反演内蒙古中部地区大气水汽含量

利用内蒙古中部地区地基GPS/MET水汽监测网（三部双频GPS/MET)资料，用水汽解算原理和GAMIT数据解算程序，分析研究内蒙古中部地区大气水汽含量，结合气象探空和双通道微波辐射计资料进行对比分析。     

地基GPS遥感大气水汽含量及在气象上的应用

简单介绍了地基GPS遥感大气水汽含量的原理以及GPS反演水汽信息的种类，比较了两种GPS数据解算水汽策略，分析了在解算过程中影响GPS水汽精度的因子。最后简述了GPS水汽在气象上应用的进展，并提出了以后需努力的方向。     

西安地基ＧＰＳ水汽解算系统及初步应用

介绍全球定位系统(GPS)地基遥感水汽的基本原理和方法;水汽解算的三类基本资料条件,即GPS原始观测资料、匹配的气象观测资料、GPS水汽解算参数资料;西安地基GPS水汽解算系统技术基础和架构。系统由资料传输转换前处理、水汽解算核心、后处理产品显示三大模块组成。利用GPS水汽反演资料,分析西安2010年降水天气过程,归纳出峰点前置、喇叭口、锥形、大值区相近等特征,可应用于天气分析与预报业务中。     

利用BERNESE 5.0解算地基GPS天顶湿延迟

地基GPS技术已被公认为观测大气水汽的最具潜力手段,而天顶湿延迟（ZWD）是地基GPS解算高精度水汽的关键量。瑞士伯尔尼大学天文研究所开发的BERNESE软件在解算天顶湿延迟方面独树一帜。以香港地基GPS连续运行参考站数据为解算实例,详细介绍了BERNESE软件解算ZWD的基本步骤和相关设置,并对有气象观测文件、数据跨天、跨周和定点解算ZWD情况的特殊设置进行了研究,结果表明BERNESE软件完全胜任ZWD解算工作。     

地基GPS水汽遥测系统远程通讯与控制系统及其初步应用

地基GPS遥感大气水汽技术是20世纪90年代发展起来的一种全新的大气观测手段，建立科学合理的GPS数据实时采集通讯网，实时下载观测数据，可为地基GPS资料应用开发成果的业务化推广提供必要的技术支撑，是地基GPS大气水汽遥感系统可否推广应用的一项关键指标。介绍了采用Modem、依托公共电话网(PSTN)建立起来的远程数据通讯和控制系统。使用该系统可通过电话拨号的方式，对GPS水汽探测网内指定的GPS接收机的参数进行设置，还可以下载该接收机内存储的数据文件。该通讯系统的应用，增强了整个GPS遥感大气水汽探测网的可维护性，为最终实现GPS水汽探测网的业务化运行奠定了一定的理论和实践基础。针对该系统存在的数据下载速度慢，依赖人工操作等缺陷，提出了解决问题的思路。     

云南地基GPS水汽解算方案及精度检验

在分析GAMIT水汽解算方案特点的基础上,利用云南6站地基GPS水汽探测资料,进行了不同解算方案计算结果的分析,并与GPS探空资料的PWV值进行比较,结果显示:不同解算方案对云南地基GPS水汽反演结果有显著的影响;在进行本地化后,GAMIT软件包对云南GPS水汽反演的精度有显著提高;不同季节的云南地基GPS反演水汽值与高精度探空水汽值的数值和变化趋势极为一致,二者的均方根差小于2 mm,说明该解算方案的地基GPS水汽反演结果可用.     

地基GPS水汽监测技术及气象业务化应用系统研究

〖HT5K〗本研究建立了川渝地区地基GPS(global positioning system,全球定位系统)遥感水汽的本地化计算模型,开发出GPS遥感水汽的计算软件包,开展了局域地基GPS观测网遥感大气水汽的试验及业务应用,反演出30 min间隔的高时间分辨率GPS可降水量序列。评估了反演精度,研究了GPS水汽产品在气象业务应用的可行性。研发了可搭建在MICAPS (meteorological information comprehensive analysis and process system)平台上的地基GPS水汽监测业务化应用系统,实现了局域地基GPS观测网数据的实时传输、数据解算、可降水量反演和GPS水汽产品的可视化,并在气象业务部门试运行,在强降水、暴雪等灾害性天气预报中发挥了独特作用。     

GPS水汽探测原理及应用

随着地基GPS技术日益完善以及GPS气象学研究的迅速发展,地基GPS探测技术已经成为一种有效的大气水汽探测手段,可提供高精度、高容量、快速变化的水汽信息。介绍地基GPS遥感大气可降水量的基本原理,分析国内地基GPS水汽探测取得的主要成果及应用现状,展望GPS水汽探测的发展及潜在应用。     

大连地区地基GPS水汽自动处理系统设计

简要概述基于GAMIT开发的大连地区地基GPS水汽自动处理系统的总体结构,设计思路,以及具体实现过程;还对系统反演的水汽资料进行精度检验以及误差分析,并介绍了系统反演水汽的质量控制方法,运行中常见故障的处理方法和日常业务中应用情况.初步应用结果表明:系统可用于解算地基GPS观测数据,获取高时空分辨率的水汽资料,用于天气分析和预报.系统具有解算精度高、运行稳定、自动化程度高等特点,具有很好的推广价值和业务使用价值.     

GPS地基遥感大气水汽总量分析

概述了利用地基GPS接收机遥感大气水汽总量的一般方案,分析了各种因素导致的误差以及相应的消除或降低办法,总结了由湿项延迟计算水汽总量的方法。介绍了GPS/STORM试验和两种解算方案。最后提出试验研究方案和在我国进行业务应用要解决的问题。     

CHARACTERISTICS AND TRENDS OF CLIMATIC EXTREMES IN CHINA DURING 1959–2014

The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics.     

Revisiting the Concentration Observations and Source Apportionment of Atmospheric Ammonia

正While China’s Air Pollution Prevention and Control Action Plan on particulate matter since 2013 has reduced sulfate significantly, aerosol ammonium nitrate remains high in East China. As the high nitrate abundances are strongly linked with ammonia, reducing ammonia emissions is becoming increasingly important to improve the air quality of China. Although satellite data provide evidence of substantial increases in atmospheric ammonia concentrations over major agricultural regions, long-term surface observation of ammonia concentrations are sparse. In addition, there is still no consensus on     

VARIABILITY OF INTER-ANNUAL RELATIONSHIP BETWEEN INDIAN OCEAN DIPOLE AND HUAXI REGION’S AUTUMN PRECIPITATION

The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region.     

Information for Authors

正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography.     

Connections between the Eurasian teleconnection and concurrent variation of upper-level jets over East Asia

The variation of the East Asian jet stream(EAJS) associated with the Eurasian(EU) teleconnection pattern is investigated using 60-yr NCEP–NCAR daily reanalysis data over the period 1951–2010. The EAJS consists of three components: the polar front jet(PFJ); the plateau subtropical jet(PSJ); and the ocean subtropical jet(OSJ). Of these three jets over East Asia,the EU pattern exhibits a significant influence on the PFJ and OSJ. There is a simultaneous negative correlation between the EU pattern and the PFJ. A significant positive correlation is found between the EU pattern and the OSJ when the EU pattern leads the OSJ by about 5 days. There is no obvious correlation between the EU pattern and the PSJ. The positive EU phase is accompanied by a weakened and poleward-shifted PFJ, which coincides with an intensified OSJ. A possible mechanism for the variation of the EAJS during different EU phases is explored via analyzing the effects of 10-day high-and low-frequency eddy forcing. The zonal wind tendency due to high-frequency eddy forcing contributes to the simultaneous negative correlation between the EU pattern and the PFJ, as well as the northward/southward shift of the PFJ. High- and low-frequency eddy forcing are both responsible for the positive correlation between the EU pattern and the OSJ, but only high-frequency eddy forcing contributes to the lagged variation of the OSJ relative to the EU pattern. The negative correlation between the EU pattern and winter temperature and precipitation anomalies in China is maintained only when the PFJ and OSJ are out of phase with each other. Thus, the EAJS plays an important role in transmitting the EU signal to winter temperature and precipitation anomalies in China.     

THE INFLUENCES OF SSTA OVER KUROSHIO AND ITS EXTENSION ON RAINFALL IN NORTHEAST CHINA UNDER THE BACKGROUND OF TWO DIFFERENT EL NIO CASES

By using the gauged rainfall in 160 stations within mainland China and the NCEP/NCAR reanalysis data, the impacts of anomalous SST in Kuroshio and its extension on precipitation in Northeast China were investigated. The results show that a difference in the meridional circulation such as the East Asia/Pacific teleconnection pattern(EAP)may be responsible for the difference in rainfall between 1998 and 2010. In comparison with 1998, the anomalous meridional circulation pattern in 2010 shifted northeastward, and then the western subtropical high, the mid-latitudinal trough and the northeastern Asia blocking high also shifted northeastward, causing intensified convergence of the cold and warm air masses at the southern region and thus more rainfall in the southwestern region and less in the northwestern region. In 1998, the anomalous cyclone, one component of the meridional pattern, located at the Songhuajiang-Nengjiang River basin, resulted in more rainfall in the majority of the area. The results of observation and the model show that the difference in SSTA in Kuroshio and its extension under the background of different El Ni觡o events is the key point:(1) The anomalous warmth moved westward from the mid-Pacific to the east of the Philippine Sea during the central event, which led the heat resources shifting to the northeast in 2010; subsequently, a shift occurred to the north of the anomalous ascent and decent, followed by a warm SSTA in the region of Kuroshio's extension in 2010 and Kuroshio in 1998.(2) The warm SSTA in the Kuroshio extension causing the Rossby wave activity flux strengthened in 2010, and then the westerly jet shifted northward and extended eastward. A warm SSTA in Kuroshio and cold SSTA in its extension in 1998 caused the westerly jet to shift southward and weaken. As a result,the anomalous anticyclone and cyclone shifted northward in 2010, and the blocking high also shifted northward.     

<p>PARTITION OF SEASON BASED ON MULTIELEMENTS AND THE DECADAL CHANGE OF SEASON DURATION IN CHINA</p>

<p>Using the multielements similarity measurement method and 1950–C2017 NCEP/NCAR gridded daily reanalysis datasets, we analyzed season duration in China during 1950–C2016, and we defined the element with maximum absolute sensitivity as the key impact element at each point using the sensitivity analysis method. The decadal change of season duration and its key impact element before and after 1980 were studied. The results indicated obvious meridional and zonal differences in the distribution of season duration for the 67-year average, and that the key impact element has the same distribution characteristics as season duration. In addition, complementary relationships were found between the durations of spring and summer, autumn and winter, and the cold and warm seasons. Of those, the complementary relationship between the durations of spring and summer was strongest and the regions of complementarity were numerous. The complementary regions of autumn and winter durations were found mainly in western China. In the cold and warm seasons, the complementary regions were widespread and the complementary relationship was generally weak. Comparison of the periods before and after 1980 revealed an east–Cwest difference in the interdecadal variation of season duration. Interdecadal variation in spring and summer was found concentrated in northern and western regions, while that in autumn and winter was concentrated in the western region. Areas of significant interdecadal variation of the key elements were found concentrated in northern and western regions, corresponding well with the areas of significant interdecadal variation of season duration.</p>     

Land-use and sustainability under intersecting global change and domestic policy scenarios: Trajectories for Australia to 2050

Understanding potential future influence of environmental, economic, and social drivers on land-use and sustainability is critical for guiding strategic decisions that can help nations adapt to change, anticipate opportunities, and cope with surprises. Using the Land-Use Trade-Offs (LUTO) model, we undertook a comprehensive, detailed, integrated, and quantitative scenario analysis of land-use and sustainability for Australia’s agricultural land from 2013–2050, under interacting global change and domestic policies, and considering key uncertainties. We assessed land use competition between multiple land-uses and assessed the sustainability of economic returns and ecosystem services at high spatial (1.1 km grid cells) and temporal (annual) resolution. We found substantial potential for land-use transition from agriculture to carbon plantings, environmental plantings, and biofuels cropping under certain scenarios, with impacts on the sustainability of economic returns and ecosystem services including food/fibre production, emissions abatement, water resource use, biodiversity services, and energy production. However, the type, magnitude, timing, and location of land-use responses and their impacts were highly dependent on scenario parameter assumptions including global outlook and emissions abatement effort, domestic land-use policy settings, land-use change adoption behaviour, productivity growth, and capacity constraints. With strong global abatement incentives complemented by biodiversity-focussed domestic land-use policy, land-use responses can substantially increase and diversify economic returns to land and produce a much wider range of ecosystem services such as emissions abatement, biodiversity, and energy, without major impacts on agricultural production. However, better governance is needed for managing potentially significant water resource impacts. The results have wide-ranging implications for land-use and sustainability policy and governance at global and domestic scales and can inform strategic thinking and decision-making about land-use and sustainability in Australia. A comprehensive and freely available 26 GB data pack (http://doi.org/10.4225/08/5604A2E8A00CC) provides a unique resource for further research. As similarly nuanced transformational change is also possible elsewhere, our template for comprehensive, integrated, quantitative, and high resolution scenario analysis can support other nations in strategic thinking and decision-making to prepare for an uncertain future.     

碳交易政策的经济影响:以广东省为例

通过构建广东省两区域动态模型,对广东省碳交易及其他政策措施进行定量评估,分析实施可调控总量的碳交易政策机制对广东省及参与交易部门的经济影响。研究结果表明,按照减排情景到2015年广东完成19.5%的碳强度下降目标,相比基准情景,GDP将减少0.7%;按照强减排情景到2015年将完成20.5%的碳强度下降目标,相比基准情景GDP将减少0.9%;如果在强减排情景的基础上实施碳交易政策,GDP相对基准情景减少0.8%,到2015年实施碳交易政策可减少GDP损失约90亿元,说明广东建立碳排放权交易机制能够发挥支持经济发展和节能减碳双赢的作用。     

气候变化对中国东部季风区水资源脆弱性的影响评价

将耦合暴露度、灾害风险、敏感性与抗压性的脆弱性评估模型应用于中国东部季风区水资源脆弱性评价,从水资源供需平衡角度分析了气候变化对东部季风区水资源脆弱性的影响。结果表明,2000年气候条件下,我国东部季风区接近90%的区域水资源处于中度脆弱及以上状态。其中水资源中度和高度脆弱区域约占全区的75%,极端脆弱区域接近15%。中国北方海河、黄河、淮河和辽河流域的水资源脆弱性最高。未来气候变化影响将加剧水资源脆弱性的风险,不同RCP排放情景下2030年代我国东部季风区水资源中度脆弱及以上区域面积有明显的扩大,极端脆弱区域将达到20%~25%。由于未来需水的进一步增加,中国北方水资源脆弱性的格局并未发生根本变化,而南方东南诸河等区域将面临可能发生的水危机。