Based on the series of daily mean temperature,maximum temperature and minimum temperature in Xi'an observation station from 1971 to 2013,the interpolation experiments are carried out by using standard series method and multiple linear regression method,calculating the average error,average absolute error,root mean square error and the proportion of samples with the error between the interpolation value and the measured value within 0.5℃.The relative advantages and disadvantages of the two interpolation methods are compared and analyzed The experimental results show that the daily temperature series which obtained by the multiple linear regression method is better than the standard series method,and the characteristics of climate trend are more consistent with the actual observed data series.The t-test,the penalized maximal T test(PMTT)and the penalized maximal F test(PMFT)are used to test the homogeneity of the annual mean temperature series in Xi'an observation station from 1951 to 2020.The test results show that according to the t-test conducted on the historical evolution data of the station,only 2 of 6 times changes caused the discontinuity of the annual mean temperature and annual mean maximum temperature series,which were respectively caused by the increase of observation time and the change the instrument type.There were four discontinuities in the annual mean minimum temperature,which were caused by the relocation of stations,the increase of observation time,the replacement of instruments and the interpolation of missing measurement values.The four discontinuity points found in PMTT and PMFT detection are considered to be reasonable discontinuity points because there is no metadata support,and none of the two methods detected discontinuities caused by interpolation of missing measurement values,which indicates to a certain extent that the temperature series of Xi'an observation station from 1951 to 2020 obtained by the interpolation of missing measurement values with multiple linear regression method is relatively reasonable,and the temperature series have good homogeneity.
新疆东部黑戈壁气候恶劣、人迹罕至，是具有黑色砾石下垫面的生态脆弱区。利用东疆哈密戈壁陆气相互作用站2018年全年观测资料，给出该戈壁地表动力学与热力学粗糙度、比辐射率和地表反照率等陆面过程特征参数，并将这些参数代入Noah模式对该戈壁热通量、地表温度及土壤温湿度进行模拟。结果表明：（1）东疆黑戈壁下垫面动力学粗糙度为1.13×10-3 m，热力学粗糙度为0.32×10-3 m，比辐射率为0.905。（2）地表反照率日变化呈早晚高，中午低的“U”型曲线。12月因地面积雪，反照率最高，年内极大值出现在12月8日，为0.79，年均反照率为0.29。地表反照率关于太阳高度角的参数化方案为：α=0.78-0.47×(1-e^((-h)/1.12))，地表反照率关于5 cm土壤湿度的参数化方案为α=0.28-0.136w_s。（3）将改进后的陆面过程参数带入Noah模式，大大提高了模式在戈壁区域的模拟能力。
采用1961—2020年西北地区364站逐日降水观测数据，从降水量和降水日的角度对比研究了西北地区夏季降水趋势时空变化特征。结果表明：平均而言，西北地区夏季降水量占该地区全年总降水量的50%以上。整体上西北地区降水量呈现显著增多的线性趋势，但并非全区一致性增多。降水量增多（减少）的站数约占区域内总站数的57%（43%），降水日数呈现增多（减少）的站数约占总站数的43%（57%）。两者同时增加的站点主要位于南疆盆地、北疆西部及青海中部和北部等地，两者同时减少的站点主要位于甘肃东南部、宁夏、陕西中部偏东等地，而两者反相变化的站点主要位于新疆北疆地区、青海省西南部边缘地区和陕西南部。近60年西北地区极端降水量和降水日数也呈现出线性增加的趋势。西北地区各个区域降水量和降水日数除年际变化外，还存在年代际变化特征，但不同区域变化位相存在一定差异。
A wide-range low temperature rain and snow occurred in southern China at the end of 2018 and 2021 respectively,which made a severe damage to the life and production.As a result,it is of great significance to compare the formation factors of the two low temperature rain and snow weathers.The results show that:the northerly airflow in front of high pressure ridge lying the west side of the Lake Baikal accumulates at the rear of the downstream transverse trough which makes the Siberian high become stronger.The Rossby wave originating from the North Atlantic has energy dispersion in the blocking high regions,which is conducive to the weakening and collapse of blocking high.The cold air sweeps across China after the transverse trough turns to a meridional trough,resulting in strong cooling of the ground.At this time,the related strong cooling on the east and south sides of the Siberian high is controlled by the cold advection by low-frequency wind.The south branch trough in the low latitude is active,and the warm and wet air northward merges with the cold air from mid-high latitude,causing a wide range of rain,snow and freezing rain in southern China.However,compared with the process in 2018,the process in 2021 has shorter duration,smaller precipitation range and greater cooling amplitude in key regions.The reason is that Rossby wave energy disperses faster and the blocking high weakens more quickly which makes the cold air directly intrude China from mid-high latitude.While the cold air accumulates and transports westward near Lake Baikal,and then becomes weak when it penetrates southward in the 2018 process.
利用2017、2019年7月塔克拉玛干沙漠腹地GPS探空观测数据和地面观测资料，对比分析了沙漠腹地夏季晴天和沙尘暴天气大气边界层结构变化特征。结果表明：晴天和沙尘暴天气大气边界层结构显著不同，两者的位温、风速和比湿垂直分布规律差异较大。晴天大气边界层各气象要素垂直分布较为均一，形成深厚的对流边界层，高度可达5000m，夜间稳定边界层一般在500m左右。沙尘暴天气边界层内各气象要素垂直分布变化较大，白天对流边界层在1500m左右，而夜间稳定边界层在1000m左右。在陆面过程中，晴天净辐射强烈，地表增温迅速，近地层感热通量能量充足，为对流运动和湍流运动提供了热力条件，是形成深厚的对流边界层主要因素。而沙尘暴天气因云和沙尘颗粒的影响，阻挡了到达地表的辐射轻度，减弱了外部的热力条件，同时大尺度天气系统冷平流提供了充足的动力条件，迫使低空2000m高度范围的温度减小，风速增大，并携带大量的水汽，导致气象要素垂直分布特征改变，并最终形成了沙尘暴天气独特的大气边界层结构特征。
利用新疆昌吉佃坝绿洲区陆气相互作用观测站2020年3—11月的地表辐射观测数据和同期的天气现象观测记录数据，定量分析昌吉绿洲区不同时间尺度和不同天气条件下的地表辐射变化特征。结果表明：（1）辐射分量日均值和日峰值时间有季节性差异，特殊天气现象对辐射通量有影响。(2) 地表辐射月曝辐量随季节变化显著。(3) 地表反照率月平均日变化季节性明显，晴天时地表反照率呈平滑的“U形”曲线，非晴天时曲线变化皆不规则、不平滑。(4)不同天气下辐射分量有独特日变化特征，轻雾、雨天、大风、扬沙、多云天等典型天气会给辐射分量带来不同程度的衰减，雨天、大风和多云天气衰减最为明显。
统计宿迁市2017—2021年秋冬季PM2.5数据以及同期常规气象观测资料，基于PM2.5日变化特征，根据15:00—23:00的浓度变化将其分为快速积累、慢速积累、消散三大过程，从积累速率的角度分析了宿迁市PM2.5的积累特征，并将其应用于重污染天气过程下的环流形势与积累速率相关性的探讨。结果表明，发生快速积累过程的平均积累速率为7.14 〖μg∙m〗^(-3) 〖∙h〗^(-1)；慢速积累过程平均积累速率为3.27 〖μg∙m〗^(-3) 〖∙h〗^(-1)；发生消散过程的PM2.5平均消散速率为5.42 〖μg∙m〗^(-3) 〖∙h〗^(-1)。PM2.5慢速积累过程中气温高，风速大，湿度小，逆温强度弱，快速积累则与之相反。慢速积累过程的PM2.5潜在源区主要位于苏北地区及北部的山东、河北地区，快速积累过程的PM2.5主要潜在源区则位于西部的安徽、湖北地区。快速积累过程以高空槽后配地面高压前部型为主，慢速积累过程以纬向环流配合地面均压场为主。
检验梅雨期降水的预报效果，对于提升梅雨期降水预报能力、减少梅雨期降水带来 的人员伤亡和经济财产损失有着重要的意义。文章对安徽省 2021 年梅雨期（6 月 10 日—7 月 10 日）六个客观模式和一个主观订正预报产品进行了检验分析，其中包含了三个区域模式数值预报 （中国气象局中尺度天气数值预报系统（简称 CMA-MESO）、中国气象局上海数值预报模式系统 （简称 CMA-SH9）、安徽 WRF）、三个全球模式数值预报（中国气象局全球同化预报系统（简称 CMA-GFS）、欧洲中期天气预报中心确定性预报模式（简称 ECMWF）、美国国家环境预报中心全 球预报系统（简称 NCEP-GFS））和安徽智能网格主观订正预报的降水产品，进行了检验分析，结 果表明：传统检验中安徽智能网格和区域模式对晴雨准确率的预报效果优于全球模式，又以 CMA-MESO 最优；在暴雨及以上量级的强降水预报中，传统检验表明安徽智能网格预报的得分 最高（23.83），ECMWF 模式则是客观模式预报中效果最好的（20.12），CMA-SH9 次之（19.34）；通 过对除安徽智能网格以外的各个客观数值模式进行的 MODE 空间检验可知，不同数值模式间暴 雨预报误差原因不尽相同，ECMWF 与各区域数值模式主要是由雨区位置的预报偏差，尤其是纬 度偏差导致的，NCEP-GFS 全球模式对降水强度和雨区面积的预报偏弱偏小比较明显，CMA-GFS 在强降水方面的预报可参考性较差；各个主客观预报暴雨及以上量级预报，整体表现出较明显的 日变化特征，在午夜前后、上午时段 TS 评分较高，而午后到傍晚评分较低，这个现象或许是梅雨 期的午后降水多以地表太阳加热引起的短历时热对流降水为主造成的。
基于2007-2021年CALIPSO和MODIS主、被动卫星遥感探测数据，对塔克拉玛干沙漠和撒哈拉沙漠的气溶胶光学特性时空分布特征进行探究及对比分析。结果表明：（1）两大沙漠的沙漠沙尘气溶胶对总气溶胶的贡献率最大，气溶胶类型季节变化的相对单一性反映了塔克拉马干沙漠和撒哈拉沙漠地区存在沙漠沙尘排放对总气溶胶成分的显著影响;（2）塔克拉玛干沙漠AOD的峰值出现在春季（春季>夏季>秋季>冬季），而撒哈拉沙漠AOD的峰值出现在夏季（夏季>春季>秋季>冬季）;（3）撒哈拉沙漠总气溶胶抬升高度与塔克拉玛干沙漠相近，但近地面层消光系数明显小于塔克拉玛干沙漠；塔克拉玛干沙漠的消光系数平均值在所有季节中均是大于撒哈拉沙漠，故塔克拉玛干沙漠的沙尘气溶胶AOD比撒哈拉沙漠的大；相比沙漠沙尘气溶胶，塔克拉玛干沙漠和撒哈拉沙漠都无明显的污染沙尘和抬升烟活动。上述研究结果揭示了两大沙漠源区沙尘气溶胶光学特性的观测事实与利用大气气溶胶时空变化特征反映区域气候变化的可能性。
陆面水热通量的准确模拟可为气候模式提供高质量的下边界条件，对气候模拟和预测具有重要意义。本研究基于干旱区张掖国家气候观象台2021年1月—2022年6月和大满灌区绿洲农田站2020年1—12月的观测数据，评估Noah-MP模式对干旱区荒漠和农田两种下垫面的水热通量的模拟性能。结果表明：Noah-MP模式模拟的干旱区荒漠下垫面辐射与观测值的相关系数均大于0.98，泰勒评分大于0.93。感热的泰勒评分0.809大于潜热的0.504，对辐射及湍流通量的变化特征、峰谷值与观测值总体一致，模拟效果较好。模拟的5 cm土壤湿度对降水过程有明显的响应，表现出明显的冷暖季差异，但其模拟性能仍有待改进。Noah-MP模式模拟的干旱区农田下垫面辐射通量及各层土壤温度的相关系数均大于0.98，泰勒评分大于0.58，模拟效果较理想。但模拟的潜热通量及各层土壤湿度较观测值偏低，尤其在生长季模拟性能并不理想。总体而言，Noah-MP模式对干旱区荒漠下垫面水热通量的模拟性能优于农田下垫面，优化和发展模式水文过程的参数化方案，在模式中考虑人为作用，是提高干旱区陆面过程模式模拟能力的重要方向。
Based on the disaster records during 2008-2020 in Qinghai province,the disaster index is used to study the spatial and temporal distribution characteristics of flood disasters,and high-risk areas are identified.Additionally,a flood disaster prediction model is constructed by machine learning algorithms utilizing the multi-source fusion CLDAS precipitation data from 2017 to 2020,and the disaster-causing rainfall threshold of high-risk area is calculated.The findings indicate that:(1)The highest number of flood disasters,sum to 98,occurred in 2018,while the lowest number,sum to 16,occurred in 2014.The most devastating floods occur in July and August.Based on the annual mean number of disasters in Qinghai,Hainan-eastern Haixi prefecture is the high-risk area of flood disasters,and based on the annual average disaster index,Haidong-Xining is another high-risk area.(2)The 1,2,and 24 h rain intensity of CLDAS data are significant parameters for disasters prediction using a variety of machine learning techniques.The precipitation threshold of Hainan and the eastern part of Haixi prefecture is that the maximum rain intensity of 1 h or 2 h reaches 6.8 mm,or that of 24 h reaches 11.1 mm,while the threshold of Haidong-Xining and nearby areas is that the maximum rain intensity of 1 h or 2 h reaches 13 mm,or that of 24 h reaches 18.2 mm.
气候变化对全球生态环境、人类活动有着重大影响。10~30 d 时效的延伸期预报，作为无缝隙预报预测体系中至关重要的一环，连接着天气预报和短期气候预测。受不断加剧的气候变化的影响，延伸期预报将面临更为重大的挑战。为此，本文从概述国内外延伸期预报现状入手，分析了全球气候变化对极端天气气候事件分布特征、关键环流系统可预报性等方面的影响，发现气候变化将导致延伸期预报难度加大、需求更加旺盛，同时也更加突显延伸期预报在防灾减灾方面的作用。进一步展望延伸期预报将面临的新挑战以及未来业务发展的新动向，提出了适应气候变化的应对措施和建议，如大力发展数值预报模式、深入开展延伸期预报机理研究、大力发展动力—统计相结合的预报方法以及尝试多学科交叉协作等。
为提高对短时局地强降水系统演变的认识，探索短时强降水天气特征及成因，利用FY-4A气象卫星及天气雷达遥感产品，并借助地面及探空资料，对2019年7月27日冀南平原一次局地大暴雨过程进行中尺度时空演化特征分析。结果表明，本次过程是在副热带高压外围，受高空槽以及低层切变线影响生成的局地强降水天气。降水系统内的对流组织主要经历了“新生发展-合并加强-降水维持-移出消散”的演化过程。本次冀南平原地区大暴雨的成因主要包括：两个初期发展的对流系统的合并加强，前期外围对流活动提供了充沛的水汽环境，强对流系统形成了低层旋转、中层强辐合的中尺度垂直环流结构，各层辐合中心空间位置基本一致，有利于水汽供应并维持云中液滴的高效碰并增长。研究结果对冀南平原短时强对流天气的临近预报预警提供了科学依据。
A complete set of quality control schemes is proposed for the selected data of 103 wind measurement towers.Based on the reanalysis data such as JRA-55 and CRA-40,the data quality of the wind measurement tower data and the effect of the quality control scheme are tested and evaluated.The results show that:(1)the missing rate,suspicious rate and error rate of most wind measurement towers are low,and only a few wind measurement towers have higher statistical value at some certain observation heights;(2)For both temperature and U-wind,the OMB results of wind measurement tower data and JRA-55 reanalysis background field data are closer to 0,which indicates that compared with CRA-40 reanalysis data,JRA-55 reanalysis data has certain advantages in the simulation of near-surface meteorological elements;(3)The test and evaluation results of the quality control effect of the observation data of the wind measurement tower show that the deviation of temperature and UV wind after quality control is closer to 0 value which is compared with the reanalysis data,and the standard deviation is reduced.In contrast,the UV wind deviation and standard deviation are reduced more after data quality control,and its application effect is better than the temperature element.
Conventional meteorological statistics methods were used to figure out the annual temperature,sunshine hours,precipitation and precipitation days at Jinhua Meteorological Observatory from 1968 to 2020,and to analyze the characteristics of climate change in Jinhua region and the sensitive areas for extreme climate.The results showed that:(1)Under different climate states,the average temperature and precipitation in Jinhua showed increasing trends,and were the most obvious in states Ⅲ and Ⅳ,while sunshine hours and precipitation days showed decreasing trends,and the most obvious in states Ⅱ and Ⅳ;however,with the changes of the Ⅱ-Ⅳ state,the increase of average temperature,the decreases of sunshine hours and the number of precipitation days all weakened,and the increase of precipitation first increased and then decreased.(2)The average temperature in Jinhua was high in Lanxi and was low in Pujiang,and the sunshine hours were more in Yiwu but less in Yongkang and Lanxi.The precipitation was more in Wuyi and Pujiang but less in Dongyang and Yiwu,the precipitation days were more in the south but less in the north.With the change of climate state,the above four elements showed a significant trend of increasing,decreasing,increasing,and decreasing,respectively.(3)Due to the change of climate state,the average temperature level in Jinhua area moved from low to high,the level of sunshine hours moved from high to low,the precipitation level moved back and forth from 4 to 3,and there was insignificant change in the level of precipitation days.(4)With the change of climate state,the whole Jinhua area except Lanxi was sensitive areas for extreme temperature.Lanxi and Yiwu were sensitive areas for extreme sunshine hours,and there were basically no sensitive areas for extreme precipitation and precipitation days.
棉铃虫Helicoverpa armigera 属鳞翅目夜蛾科，是一种世界性的重大害虫，在世界各地均有分布。因其具有远距离迁飞，繁殖力强等特点，条件适宜时常大面积暴发成灾，给农业生产带来较大损失。摸清棉铃虫生活习性、种群变化规律是棉铃虫防治的前提条件。由于棉铃虫是变温昆虫，气候条件对其生长发育、成灾机制等产生极大影响。因此，本文系统综述了气候变暖对棉铃虫影响的研究进展，包括棉铃虫生长发育、体色变化、繁殖、滞育、飞行、越冬、与作物的互作关系等方面，并对未来研究重点进行了展望。以期对棉铃虫的综合治理提供理论依据。
新疆是我国积雪资源最丰富的区域之一，也是雪灾多发区之一，预测最大积雪深度，可以为雪灾的预警与防范提供参考和依据。本研究基于建立的雪灾灾损指数，确定了新疆特重雪灾区域；进一步聚焦特重雪灾区的8个县（市），包括阿勒泰市、福海县、青河县、塔城市、托里县、沙湾市、尼勒克县和伊宁县，分别建立县域RBF网络模型，预测2021—2050年年最大积雪深度，结果表明：该模型可用于新疆特重雪灾区最大积雪深度预测，但预测精度仍有待提升；塔城市、尼勒克县将于2025—2029年连续出现最大积雪深度偏高事件，2039年青河县将出现最大积雪深度的极大值，因此应关注可能发生雪灾的年份与县(市)，积极做好雪灾的防御工作。
使用常规观测资料及 ERA5（0.25毅伊0.25毅）再分析资料，对 2009 号台风“美莎克”进行 分析。结果表明：此次过程，副热带高压异常强大，位置偏北，并与北侧阻高合并形成高压坝阻挡； “美莎克”沿副高外围北上与中纬度低涡及冷空气相互作用，变性后斜压性明显加大，低涡增强； “美莎克”携带大量水汽，同时中低空急流将海上水汽持续向黑龙江输送，并在黑龙江强烈辐合， 形成强的水汽辐合区和水汽辐合带；高低空急流耦合构成强的垂直环流，对应非常强的垂直上升 速度；副热带高压向西北伸展，高空引导气流和热成风方向转为西北—东南向，促使“美莎克”登 陆后向西北移动，穿过黑龙江，是黑龙江出现大暴雨的主要原因。分析台风中心涡度、散度、垂直 速度、位温、湿位涡等物理量的三维结构变化，可以很好地认识台风在北上登陆中的变性过程以 及降水出现非对称结构的原因。
以云和地球辐射能量系统（CERES）数据集为准，量化了中国地球系统模式对地表入射短波辐射和大气逆辐射时空变化的模拟性能，明确了多模式间模拟结果存在不确定性的区域。结果表明：中国模式均能模拟出北半球地表入射短波辐射和大气逆辐射夏高冬低的季节变化特征。陆地上，中国模式对两个辐射分量月均值的模拟结果与CERES相当，在海洋上低于CERES结果。中国模式能模拟出地表入射短波辐射下降、大气逆辐射上升的年际变化趋势。对于2001—2014年均值，中国模式模拟的地表入射短波辐射在海洋和陆地上较CERES分别偏低3.3 W m-2和3.0 W m-2，模拟的大气逆辐射在海洋上与CERES结果相当，在陆地上较CERES低1.3 W m-2。除南北纬30o附近之外，中国模式在其他纬度均低估地表入射短波辐射，以热带和北极最明显。模式对大气逆辐射的模拟偏差呈纬向波动特征，模拟误差大值出现在高大山脉处。中国模式模拟地表入射短波辐射不确定性极大的区域分布在热带雨林和南极洲沿海，模拟大气逆辐射不确定性极大的区域分布在格林兰岛、青藏高原、安第斯山脉和南极洲沿海。
Based on the data of 90 typhoons affecting East China from 2001 to 2020,annual and monthly distribution and landing characteristics of typhoons were analyzed by using statistical method,and occurrence probability of two main disaster-causing factors(wind and rain)were calculated by information diffusion.Then risk assessment of typhoon disaster-causing factors was carried out.The results showed that:the typhoon types were mainly strong typhoon and typhoon,annual average number affecting East China was 4.5,mainly concentrated in July-September,especially in August,landing Taiwan was the most frequent,followed by Fujian and Zhejiang provinces;The probability of the maximum wind speed in 30-40 m/s was high,and probability of maximum rainfall in 200-400 mm was high.Fujian,Zhejiang and Jiangxi provinces had highest risk levels of typhoon disaster-causing factors,serious typhoon impacting areas.Shandong and Anhui provinces had medium risk levels of typhoon disaster-causing factors,moderate typhoon impacting areas.Jiangsu and Shanghai had the lowest risk levels of typhoons disaster-causing factors,light typhoon impacting areas.
