Analysis of Mesoscale System of One Typical Rainstorm in the Warm Zone

[Objective] One mesoscale system of rainstorm in the warm zone in Nansha area during June 8 and 9 in 2009 was studied.[Method] By dint of routine meteorological observation data,NCEP reanalysis data,FY-2C TBB,and wind line data,etc.,the circulation situation,physics field,and the activity of convection system of mesoscale of one rainstorm in the warm zone of Nansha during June 8 and 9 in 2009 were expounded so as to explore the causes of such rainstorm.[Result] The rainstorm had distinct convection nature,with large precipitation intensity,uneven distribution,and short timeliness.Most precipitation fell in 5 hours.And the rainstorm in the warm zone was directly related to the activity of meso-convective system and was resulted from moderate β scale convection system(Mβcss).The flux field of the high layer of convection layer had fine absorption effect.Coordinating with the southwest and south field at middle and low 500 and 850 hPa in the middle and lower layer to converge around the Zhujiang Delta,it provided unstable condition and humidity for the rainstorm in Nansha area.The advantageous combination of flux in convective layer,vortex and vertical speed field and the sufficient water supply provided dynamic and water vapor guarantee for the generation of rainstorm in the Nansha area.The vertical speed of <-0.3 m/s reflected the beginning of precipitation and the smaller the vertical speed was,the stronger the precipitation intensity became.[Conclusion] It provided reference for the report of rainstorm of such kind in the future.

CHARACTERISTICS OF CLIMATE WARMING AND IMPACT ON CLIMATE ZONES CHANGE IN GUANGDONG

Based on temperature data in Guangdong in the past 50years, statistical methods are used to analyze the characteristics of temperature in spatial and temporal variation. The results show that land surface temperature warms by 0.16 °C/10a in Guangdong. The range of warming was lower than the average of nationwide and global land surface. Furthermore, the temperature has a larger increase tendency in winter and spring and coastal areas than in summer and autumn and inland areas. Climate zones move towards the north obviously. North tropical zone is expanding, south subtropical zone is reducing and central subtropical zone is relatively stable. Under the global climate warming, characteristics of climate warming in Guangdong were influenced by atmosphere general circulation, sea surface temperature and human activities etc.

Characteristics of Oxides in Argillic Soils of Warm Tem-perate Zone in China

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新疆北部暖区暴雪的中尺度模拟及云微物理特征研究

暖区暴雪罕见且易致灾,对其准确预报既是重点又是难点。本文采用WRF中尺度模式中Lin、Thompson、 WDM6和WSM6四种云微物理方案对2016年11月中旬一次典型新疆北部暖区暴雪过程进行数值模拟,评估模式对暖区暴雪过程的模拟能力,遴选最优参数化方案,分析暴雪过程中水凝物粒子垂直分布及演变特征,探讨导致暴雪过程的相关中尺度系统的发生发展规律。分析结果表明:(1)不同云微物理参数化模拟中,Lin方案效果最佳,较为成功地模拟出降雪量级、落区和趋势。(2)云中各种水凝物粒子活跃于对流层中下层,其中以霰和雪最多,自高层向低层分别分布着冰晶、雪、云水、霰粒子,阿尔泰山迎风坡附近为各水凝物粒子浓度大值中心,强降雪区四种云中水凝物粒子高值中心垂直对齐有利于各粒子间的转化。(3)上游高湿系统沿西路移动,低空偏南急流增强时水汽汇合强烈,阿尔泰山脉西麓迎风坡阻挡利于水汽辐合;低空偏南急流使暴雪区低层增温,不稳定条件增强,垂直次级环流发展,次级反环流的增强促进不稳定能量的释放,加剧垂直运动增长,为大暴雪的发展和维持提供较强的动力抬升条件,对暴雪起增幅作用。

SWCWARMS及ECMWF模式对四川盆地暖区型和斜压锋生型暴雨预报检验分析

利用2014~2016年5~10月四川盆地所有观测站资料及SWCWARMS模式、ECMWF模式同时段20时起报的24h累积降水资料,基于邻域法FSS、ETS评分指数检验了两模式对于高能暖区型暴雨及斜压锋生型暴雨预报的预报性能。主要结论为:(1)两种类型暴雨过程平均误差均是SWCWARMS模式较ECMWF模式大,且误差值为正,表明模式以湿偏差为主;(2)高能暖区型暴雨FSS评分各降水量级各空间尺度均是SWCWARMS模式高于ECMWF模式;斜压锋生型暴雨50mm以下量级降水在36km以下空间尺度ECMWF模式FSS评分高于SWCWARMS模式,54km以上空间尺度SWCWARMS模式评分较高,大暴雨量级降水各尺度下均是SWCWARMS模式评分较高;(3)高能暖区型暴雨ETS评分暴雨、大暴雨量级SWCWARMS模式评分较高,中雨、大雨ECMWF模式预报更优;斜压锋生型暴雨ETS评分,中雨、大雨及暴雨量级降水预报ECMWF优于SWCWARMS,大暴雨量级SWCWARMS模式预报更优。

华北一次层状云系暖区水汽和液态水分布特征

基于机载微波辐射计、地基微波辐射计和Ka波段云雷达3种遥感资料,结合FY-4A气象卫星、气象观测站、天气雷达及再分析资料,研究2021年5月15日一次华北降水性层状云系暖区的水汽和液态水分布特征。结果表明:水汽和液态水的水平分布不均,飞机平飞时机载微波辐射计探测的积分水汽含量和液态水路径起伏变化,最大值分别为4.00 cm和1.87 mm,随着暖区云顶高度和云层厚度降低,二者分别降至0.89 cm和0.13 mm。随着降水发生发展,地基微波辐射计探测的积分水汽含量和液态水路径均出现跃增,峰值分别为8.62 cm和3.85 mm,水汽变化滞后于液态水,垂直方向上液态水含量的累积区厚度、最大值及所在高度均随降水先增后减,液态水的时空演变对暖区降水及增雨作业时机和部位的判识有重要指示意义。云雷达探测的液态水含量也出现跃增,在1 km高度以下反射率因子较大、粒子下落速度及离散程度较大时段,液态水丰富,对应降水量较大,粒子碰并是暖区降水的主要机制。

海洋沉积证据在低纬过程气候变化中的应用及展望

在国内外研究的基础上,对印太暖池区的沃克环流和厄尔尼诺-南方涛动(ENSO)、热带辐合带(ITCZ)等低纬过程的空间分布和随时间的变化规律及其研究方法进行初步归纳,并指出研究中存在的问题。本文论述了厄尔尼诺-南方涛动变率在全新世早期及中世纪气候异常期(1 000~700 a BP)的晚期逐渐增强,介绍了热带辐合带在BA暖期(B?llingAller?d Warm Period)和前北方期(pre-Boreal,10.3~9.5 ka BP)的北移,以及在新仙女木事件(Younger Dryas Event,12.5~11.5 ka BP)和北大西洋冷期(距今7.5~5 ka BP)期间的南移。对低纬过程长时间尺度轨道周期的探讨表明,末次冰盛期赤道东太平洋出现了较偏南的热带辐合带锋面系统,甚至在1.65 Ma冰期,热带辐合带也有快速南移的证据。海洋沉积的粒度、黏土矿物、陆源粉尘、元素和同位素、有孔虫分析等研究方法在推测厄尔尼诺-南方涛动和热带辐合带位移中有很好的应用,建议以陆源生态系统对气候的响应为切入点、以孢粉为手段来探讨陆源植被、气候、火灾和海-陆大气环流等低纬过程的变化特征,进而反演沃克环流(或厄尔尼诺-南方涛动)演化和热带辐合带位移的影响。

Carbon,nitrogen and phosphorus stoichiometry in Pinus tabulaeformis forest ecosystems in warm temperate Shanxi Province,north China

Although carbon(C), nitrogen(N), and phosphorous(P) stoichiometric ratios are considered good indicators of nutrient excess/limitation and thus of ecosystem health, few reports have discussed the trends and the reciprocal effects of C:N:P stoichiometry in plant–litter–soil systems. The present study analyzed C:N:P ratios in four age groups of Chinese pine, Pinus tabulaeformis Carr., forests in Shanxi Province, China: plantation young forests(AY,<20 year-old); plantation middle-aged forests(AM, 21–30 year-old); natural young forests(NY,<30 year-old); and natural middle-aged forests(NM,31–50 year-old). The average C:N:P ratios calculated for tree, shrub, and herbaceous leaves, litter, and soil(0–100 cm) were generally higher in NY followed by NM,AM, and AY. C:N and C:P ratios were higher in litter than in leaves and soils, and reached higher values in the litter and leaves of young forests than in middle-aged forests;however, C:N and C:P ratios were higher in soils of middle-aged forests than in young forests. N:P ratios were higher in leaves than in litter and soils regardless of stand age; the consistent N:P<14 values found in all forests indicated N limitations. With plant leaves, C:P ratios were highest in trees, followed by herbs and shrubs, indicating a higher efficiency in tree leaf formation. C:N ratios decreased with increasing soil depth, whereas there was no trend for C:P and N:P ratios. C:N:P stoichiometry of forest foliage did not exhibit a consistent variation according to stand age. Research on the relationships between N:P, and P, N nutrient limits and the characteristics of vegetation nutrient adaptation need to be continued.

Discussion on position of China’s north-south transitional zone by comparative analysis of mountain altitudinal belts

The Qinling Mountains has always been regarded as an essential dividing line between the warm temperate zone and the subtropical zone in eastern China and plays a vital role in the geoecological pattern of China.However,there is controversy about the specific location of this geographical boundary in the academic community.As a product of the combined effects of zonal and non-zonal factors,the mountain altitudinal belts(MABs)can reflect both the horizontal zonality and the vertical zonality of vegetation distribution.Using the MAB information,we can not only profoundly understand the complex mountain system of QinlingDaba Mountains but can also judge its nature as a geographical boundary more scientifically.Therefore,based on the comparative analysis of basal belt,dominant belt characteristics and belt structure characteristics of the MABs in Qinling-Daba Mountains,subtropical and temperate mountains,this paper analyzed the MAB differences and similarities among Qinling-Daba Mountains,subtropical and temperate typical mountains,to reveal the vegetation distribution characteristics in the north-south transitional zone.The results show that:(1)The MABs of the southern part of QinlingDaba Mountains(southern slope of the Daba Mountains)are the same or similar to those of the Subtropical Mountains,and the MABs of the northern part of Qinling-Daba Mountains(northern slope of the Qinling Mountains)are similar to those of the temperate mountains.While it shows obvious transitional characteristics in the vast area between the northern slope of the Daba Mountains and the southern slope of the Qinling Mountains:the basal belts gradually transit from the evergreen broadleaved forest belt(basal belt in subtropical mountains)to the evergreen and deciduous broad-leaved mixed forest belt,and the dominant belts also transit from the evergreen broad-leaved forest belt to the evergreen and deciduous broad-leaved mixed forest belt or the deciduous broad-leaved forest belt.(2)The transitional zone between the subtropical zone and the warm temperate zone is located between the northern slope of the Daba Mountains and the southern slope of the Qinling Mountains.The southern boundary of the transitional zone is along the northern slope of Shennongjia Mountain-the northern slope of Micang Mountain-Baishuijiang Nature Reserve,and the northern boundary is along the southern slope of Funiu Mountain-the southern slope of Taibai Mountain-Lianhua Mountain.Additionally,in the transitional zone,the average temperature in January is between-5°C and 1°C,the annual average temperature is between 10°C and 13°C except Hanzhong Basin and Hanshui Valley,and the accumulated temperature above 10°C ranges from 2000°C to 4000°C,the annual rainfall is about 800-1000 mm.The results provide a scientific basis for revealing the characteristics of China’s north-south transitional zone and scientific division of the boundary between the subtropical zone and warm temperate zone in China.

暖温带山地天然次生林演替序列根系呼吸速率对林地增温的响应

【目的】通过增温对比试验观测天然次生林演替序列森林内不同层次植物根系呼吸速率生长季的变化,揭示森林演替和模拟增温及其交互作用对根系呼吸速率的影响,为森林更新过程中土壤碳循环对气候变暖响应机制的研究提供数据支持。【方法】以关帝山4种天然次生林(杨桦林、油松林、华北落叶松林和白杄林)为对象,采用野外定点对比试验,以林下地面搭建温室模拟林地增温和用去根试验结合差减法区分根系呼吸组分。于2016—2019年利用Li-6400便携式分析仪观测根系呼吸速率。【结果】增温提高了4种林型细根生物量和根系总呼吸(土壤自养呼吸)的生长季碳通量;增温显著提高了灌木层和草本层根系呼吸速率,提高幅度分别为8.37%~15.26%和10.88%~14.00%,降低了根系呼吸速率的温度敏感性(Q_(10))。但增温没有改变根系呼吸的生长季单极值变化特征。各林分细根生物量和根系呼吸速率均随演替进程而降低,而根系呼吸速率Q_(10)的值则升高。【结论】灌木和草本层根系呼吸速率对增温和演替及其交互作用的响应程度显著,而乔木层根系呼吸速率对增温和增温与演替的交互作用响应程度不显著。随林地温度升高,森林根系呼吸速率升高而温度敏感性却降低,说明森林根系呼吸速率对温度升高的响应较为复杂。

港口客运站建筑能耗分析及节能潜力研究

本文针对我国寒冷地区、夏热冬暖地区的港口客运站展开实地调研测试;基于调研数据,利用eQUEST建立了建筑模型;设计正交试验,分析了不同影响因子的显著性水平,并进行了建筑节能潜力研究。结果表明:对于寒冷地区的港口客运站,冬季采用市政热水地板辐射供暖、昼光照明采用三阶断续型控制时建筑总节能率分别为3.09%和10.35%;对于夏热冬暖地区的港口客运站,夏季室内设计温度采用热中性温度、昼光照明采用三阶断续型控制时建筑总节能率分别为5.18%和7.58%。

气候变暖对新疆棉花种植气候适宜性分区的影响

基于新疆102个气象站1961—2020年历史气候资料,使用统计学方法以及ArcGIS的空间插值技术,在对近60年影响新疆棉花种植的主要气候因子,≥10℃积温、无霜冻期和7月平均气温时空变化分析的基础上,结合新疆棉花种植气候适宜性区划指标,就不同品种熟性棉花适宜种植分区的变化进行研究。结果表明:1961—2020年新疆≥10℃积温、无霜冻期和7月平均气温呈显著增多或上升趋势,并且上述要素均于1997年发生突变。受其影响,1997年后较之前,新疆不同品种熟性棉花适宜种植区的海拔上限均不同程度的抬升,其中,准噶尔盆地和吐鲁番、哈密盆地棉区海拔上限抬升150~200 m,塔里木盆地棉区抬升50~100 m;气候变暖使新疆宜棉区扩大,不宜棉区缩小,且部分棉区适宜种植的棉花品种向生育期较长、产量较高的品种转变,这对促进新疆棉花的发展十分有利。

2017-2018年河南宝天曼天然栎林碳水通量观测数据集

基于微气象学理论的涡度相关通量观测技术,直接测定了亚热带暖温带过渡区天然栎林生态系统尺度的生产力、能量分配和水分利用等功能和过程,为研究森林生态系统碳水循环过程机理提供了重要的数据基础。本研究选取位于河南宝天曼森林生态站的天然栎林作为研究对象,使用涡度相关系统和环境梯度系统进行长期定位观测,并对2017年1月至2018年12月的监测数据进行了整理、质量控制和分析。本数据集包括空气温湿度、土壤温湿度、风速、风向、光合有效辐射、向上/向下的短波辐射、向上/向下的长波辐射、净辐射、显热通量、潜热通量和碳通量等观测指标,形成了半小时、日尺度、月尺度和年尺度的数据产品,以期为研究亚热带-暖温带过渡区典型森林生态系统对气候变化的响应和适应及其机制提供数据基础。

夏热冬暖地区下沉广场对地下综合交通枢纽通风性能的影响

对夏热冬暖地区有下沉广场的地下综合交通枢纽冬夏两季空调运行工况进行了CFD模拟,得到了冬夏季典型工况各层主要截面的风速场和下沉广场设置所导致的进出风情况,并基于准静风区、换气次数等概念对其进行了分析。结果显示:夏季工况下沉广场进出风呈现“一进三出”的特点,冬季工况呈现“两进两出”的特点;由于玻璃幕墙的设置,在玻璃幕墙内形成了明显的空气流道;室外风向变化与下沉广场设置情况、开口面积、内部结构共同作用影响建筑通风性能,并且室外气流更容易通过开口方向与风向相同、开口面积较大、内部无大量隔断墙等结构的下沉广场进入室内。

2022年2月张家口地区大雪过程分析

应用MICAPS常规气象资料、区域站加密降水资料、NCEP再分析资料,采用天气学分析和动力诊断的方法,对2022年2月13日张家口地区出现的1次降雪天气过程进行综合分析。结果表明:(1)此次降雪过程主要分为2个阶段,第一阶段是暖区内偏南暖湿气流影响下产生的降雪,第二阶段是受冷锋系统过境影产生的降雪。(2)此次降雪过程暖区降雪相对持续时间较长,锋区过境降雪持续时间短,总降雪量最大值偏南。

1991-2020年内蒙古兴安盟热量资源变化特征及区划

利用内蒙古兴安盟8个国家气象观测站1991—2020年的日平均气温数据,对兴安盟30年间10℃活动积温变化特征进行了分析,同时,结合周边呼伦贝尔市、通辽市、吉林省10个气象观测站同时间段日平均气温数据,构建了兴安盟10℃活动积温、稳定通过10℃初终日及持续日数的精细化推算模型,最后,结合兴安盟地理信息数据绘制了热量资源精细化区划图。结果表明:1991-2020年兴安盟10℃平均活动积温气候倾向率为103.64 (℃·d)/10 a,呈显著增加趋势,其变化大致可以分为4个特征明显的阶段。与上一代际相比,1991-2020年各站点10℃活动积温平均值均有所增加,≥2800℃·d区域所占面积约增加5553 km^(2),其他等级10℃积温区域面积均不同程度减少,各等级区域边界均向西北移动。

河套灌区垄膜沟灌模式对春玉米田水热运移及籽粒产量的影响

河套灌区降水稀少、昼夜温差大,早春温度偏低影响春玉米生长,为改善灌区春玉米水热环境,以不同覆膜与灌溉组合为研究对象,探究适宜的保墒增温和提质增效的覆膜灌溉耕作模式,为河套灌区水热资源的高效利用提供理论指导与技术支撑。试验布设4个处理:畦灌+不覆膜(CK)、畦灌+透明地膜覆盖(QB)、沟灌+透明地膜垄体覆盖(GB)、沟灌+黑色地膜垄体覆盖(GH),以探究不同覆膜灌溉方式下春玉米田土壤含水率和土壤温度变化规律、春玉米产量及水热资源利用效率。结果表明:垄膜沟灌可提高表层土壤含水率和根区储水量。播后61d,GH、GB和QB处理根区土壤储水量分别较CK增加36.01%、36.61%和21.37%,且垄膜沟灌显著高于覆膜畦灌。播后133 d,GH根区土壤储水量较CK和QB增加19.02%和17.40%。垄膜沟灌有效提高日均土壤温度,GB生育期日均土壤温度较QB和CK平均增加1.01℃和1.59℃,GH较QB和CK平均增加0.86℃和1.44℃。垄膜沟灌土壤有效积温显著高于畦灌处理,其中GB较QB和CK提高7.78%和16.70%;GH较QB提高6.26%,较CK提升14.46%。春玉米产量呈现出与百粒重结果相同的显著性差异,其中QB较CK提升16.19%,GB较QB提升13.64%,较CK提升32.04%。GB处理下水分利用效率(WUE)和土壤有效积温生产效率(TUE)较QB提升25.79%和5.41%,较CK提升45.69%和13.66%。GB可有效提升根区土壤储水量及温度,改善春玉米水热资源利用效率,提高籽粒产量。综上,建议在内蒙古河套灌区推行沟灌+透明地膜垄体覆盖技术,以提高春玉米产量及水热资源利用效率。

全球变暖背景下气候内部变率导致热带辐合带移动的不确定性

基于两套模式的大集合试验结果,评估了气候内部自然变率对热带辐合带(ITCZ,Intertropical convergence zone)未来南北移动的影响。研究发现,模式间ITCZ的移动差异源自中高纬度的外强迫模拟差异,而气候内部变率主要通过热带过程调控ITCZ的位置变化。在通用地球系统模式大集合(Community Earth System Model Large Ensemble,CESM-LE)试验中,厄尔尼诺-南方涛动(El Nino-Southern Oscillation,ENSO)振幅变化的自然变率会通过中等和极端厄尔尼诺降水的非线性信号调制ITCZ的移动幅度,而在MPI-GE(the Max Planck Institute Great Ensemble)试验中,ITCZ的位置变化主要与大西洋海温梯度信号异常有关,相较而言ENSO振幅对ITCZ的影响很有限。总体而言,全球变暖背景下由于内部自然变率引起的ITCZ南北移动不确定性幅度能解释未来预估模式间的差异约为20%,但对ITCZ移动的模拟不确定性有贡献。

新疆北部暖区强降雪中尺度环境与落区分析

利用常规气象观测资料、ECMWF、T639(1°×1°)再分析资料和FY-2C卫星云图资料,对2003—2013年11月至次年3月新疆北部出现26次12 h暖区强降雪天气过程的中尺度环境场特征和降雪落区进行了分析。结果表明:强降雪产生在极涡型和短波低槽型两种环流形势下,强降雪区位于低槽前部,低空急流出口区前侧辐合区和高空急流入口区右侧辐散区以及700 hPa和850 hPa辐合线和暖切变线东部、北部及干线东南部,地面辐合线附近减压升温的重叠区域内。强降雪区上空,对流层整层为>80%高湿区;500 hPa以下具有不稳定层结、风垂直切变大、斜压性强;700hPa辐合线和850 hPa暖切变线及干线、地面干线及辐合线易触发不稳定能量的释放,从而为暴雪的产生提供水汽、热力和动力条件。暖区强降雪主要发生在中尺度冷云团开始缓慢减弱东移的前部及云顶亮温TBB梯度最大区域的前部。通过上述分析总结出暖区强降雪落区三维空间配置模型。

新疆北部冬季暖区大降雪过程中尺度云团特征分析

利用1997-2006年深秋到冬季新疆阿勒泰地区出现的17次暖区大降雪天气过程的卫星云图资料、常规观测资料和地面降雪量资料,并选取其中3次典型的暖区大降雪过程,对暖区大降雪天气过程的中尺度云团演变特征进行了详细分析,进一步揭示暖区大降雪天气的成因。结果表明:500 hPa极涡是造成新疆北部阿勒泰地区暖区大降雪过程的天气尺度影响系统,极涡中心南部或东南部分裂出的中尺度短波是造成暖区大降雪天气的直接影响系统;TBB≤-60℃的中-β和中-α尺度系统云团是造成暖区大降雪天气的主要系统。暖区大降雪的TBB≤-60℃的中-β和中-α尺度系统云团是在绕极涡移动的高空锋区短波槽前和暖平流输送区形成,并位于极涡中心南部或东南部的低层到高层强锋区中,在随着天气尺度云系移动的同时,绕极涡中心逆时针旋转,移速缓慢或稳定少动,移动中逐渐加强或合并,其多表现为椭圆形或圆形,暖区大降雪发生在TBB≤-60℃的中-β和中-α尺度云团边缘TBB等值线梯度最大处。中-β和中-α尺度云团面积越大、生命史越长,造成的暖区大降雪范围就越大、强度也越强;TBB≤-60℃的中-β和中-α尺度云团在阿勒泰地区上空维持数小时可造成阿勒泰地区暖区大降雪天气。