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1.
利用高密度的中国国家级地面气象站逐时降水数据,系统分析和比较了中国大陆地区暖季降水量、降水频次和降水强度的日变化峰值位相的整体特征、空间分布差异及典型区域平均的日变化演变特征。研究指出,中国大陆暖季降水日变化峰值时间主要表现为下午、清晨、夜间3类典型位相,且整体而言降水频次的清晨峰值更凸出,降水强度以下午峰值为主。综合考虑降水量和降水频次的日变化峰值位相,发现中国大陆地区降水日变化峰值位相在空间分布上存在7个典型区域:下午峰值区(东北至华北山区、东南内陆地区)、夜间峰值区(四川盆地西部至云贵高原东部、华北平原西部贴近山地的区域)和清晨峰值区(华北平原东部、秦巴山区至华中西南部)各两个,以及傍晚至夜间峰值位相的青藏高原区。各典型区域内部具有较一致的降水量和频次的日峰值时间位相,而区域边缘或交界处降水量和频次的峰值位相则相反,主要是降水量的下午主峰值时段与降水频次的清晨主峰值时段的错位。从降水量、降水频次和降水强度的日变化的演变特征来看,午后峰值区、夜间峰值区和青藏高原的傍晚至夜间峰值区的多数台站,都存在降水量位相滞后于降水强度而超前于降水频次的特征,这应是降水演变过程中时间演变不对称性和对流云系发展演变的具体表现。 相似文献
2.
利用江苏近10 a（2005-2014年）暖季（5-9月）69站逐时降水资料,详细分析了短时强降水的空间分布、年际变化、季节内演变以及日变化特征。分析结果表明：短时强降水空间分布不均,整体上北部比南部活跃,最活跃区均位于沿淮西部,高强度短时强降水多发生在淮北东部,且空间分布集中。近10 a来江苏短时强降水整体呈减少趋势,主要表现为北部地区减少最为显著。短时强降水季节内分布不均匀,以7月最为活跃,高强度短时强降水在8月最为频繁;其逐候分布显示,梅期短时强降水骤增,于7月第2候达到峰值,盛夏期间高强度短时强降水增多,8月第3候达到峰值。江苏短时强降水的日变化整体呈双峰结构,主峰和次峰分别出现在傍晚17时（北京时间,下同）和清晨07时,高强度短时强降水多发于午后;短时强降水日变化存在季节内演变的阶段性特征和地域性差异,其中梅期和盛夏两个高发阶段均呈单峰结构,但梅期峰值出现在清晨,盛夏阶段峰值则出现在傍晚;由南向北,日变化特征由单峰向双峰、多峰演变,在淮河以南地区日峰值大多出现在午后至傍晚,而淮河以北地区多出现在夜间至清晨。 相似文献
3.
利用江苏近10 a(2005—2014年)暖季(5—9月)69站逐时降水资料,详细分析了短时强降水的空间分布、年际变化、季节内演变以及日变化特征。分析结果表明:短时强降水空间分布不均,整体上北部比南部活跃,最活跃区均位于沿淮西部,高强度短时强降水多发生在淮北东部,且空间分布集中。近10 a来江苏短时强降水整体呈减少趋势,主要表现为北部地区减少最为显著。短时强降水季节内分布不均匀,以7月最为活跃,高强度短时强降水在8月最为频繁;其逐候分布显示,梅期短时强降水骤增,于7月第2候达到峰值,盛夏期间高强度短时强降水增多,8月第3候达到峰值。江苏短时强降水的日变化整体呈双峰结构,主峰和次峰分别出现在傍晚17时(北京时间,下同)和清晨07时,高强度短时强降水多发于午后;短时强降水日变化存在季节内演变的阶段性特征和地域性差异,其中梅期和盛夏两个高发阶段均呈单峰结构,但梅期峰值出现在清晨,盛夏阶段峰值则出现在傍晚;由南向北,日变化特征由单峰向双峰、多峰演变,在淮河以南地区日峰值大多出现在午后至傍晚,而淮河以北地区多出现在夜间至清晨。 相似文献
4.
利用1991-2014年新疆16个国家基准气象站逐时降水资料,分析了新疆夏季不同区域降水日变化基本特征,揭示出新疆夏季降水日变化呈现显著的南、北疆区域差异,有别于我国中东部的一些新事实。结果显示:北疆降水量日变化呈现准单峰型特征,峰值主要发生在傍晚前后（16:00-20:00,地方时,下同）;南疆降水量日变化呈现三峰特征,峰值分别出现在傍晚（17:00-18:00）、午夜后（00:00-01:00）和上午（10:00）。新疆夏季降水事件以6 h以内的短历时性质为主（平均为85%,比例明显高于我国中东部）,而持续12 h以上的较长历时降水事件偶有发生;在天山东麓以外的新疆绝大部分地区,6 h以内短历时降水事件对总降水量的贡献率达54%,高于我国中东部地区。新疆西部和北疆北部降水量日变化主峰的贡献者是2~3 h短持续性降水为主的事件;而天山中-东部降水量日变化峰值则是来自于12 h内各不同持续时间降水事件的大致均等贡献。 相似文献
5.
边界层方案对中国中东部地区降水日变化的影响 总被引：2，自引：0，他引：2
以华中区域中尺度业务模式WRF3D为平台,使用MYJ、ACM2边界层方案完成了2012年7月的批量敏感试验,并与高时空分辨率实况降水数据作对比,重点关注不同边界层方案对中国中东部地区降水日变化的影响。结果表明,两种方案下的降水预报均对我国中东部地区清晨和午后并存的降水双峰值有所表现,且两者对清晨降水峰值的预报差异不大,但预报的午后降水峰值差异明显,尤其表现在峰值幅度上,位相上也略有差异。总体而言,ACM2方案下的降水日变化特征更接近实况。进一步对高分辨率模式输出的诊断表明,午后降水峰值主要由隐式降水决定。在此基础上,从模式中隐、显式降水产生机制的角度考察了不同边界层方案下降水日变化差异的可能原因。 相似文献
6.
利用CMA-SH9模式逐小时降水预报数据和地面自动站-CMORPH卫星融合降水数据,开展该模式对2020年暖季（5~9月）川渝地区降水日变化的预报效果评估。结果表明:CMA-SH9模式可以再现小时平均降水量在四川盆地偏小、盆地周边陡峭地形处偏大的空间分布特征;显著的预报正偏差分布于青藏高原东坡至四川盆地西南部一带和四川盆地以东地区,偏差来自降水频率和降水强度的共同贡献;预报负偏差分布于四川盆地,主要来自模式对降水强度的低估;降水日变化峰值时间自西向东呈午夜到上午的滞后,模式预报的降水日变化峰值时间超前于观测;模式能够较好地把握青藏高原东坡至四川盆地西南部一带和四川盆地的单峰型日变化位相,以及盆地以东地区的双峰型日变化位相,但预报的降水量值和观测存在一定偏差。 相似文献
7.
利用海东区域自动气象站2007—2016年逐小时降水数据,分析比较河湟流域~*5—9月份降水量、降水频次和降水强度的日变化峰值位相的整体特征、空间分布差异和典型区域平均的日变化演变特征。得出,河湟流域降水日变化峰值时间主要是傍晚到夜间和清晨双峰型位相和午夜单峰型位相,就整体而言,降水强度的下午峰值特征更加突出,降水频次以午夜峰值为主。综合考虑降水量和降水强度降水频次的日变化峰值位相发,发现河湟流域降水日变化峰值位相在空间分布上存在南北差异,北部双峰型位相和南部单峰型位相特征;从降水量、频次、强度的日变化演变特征来看,北部地区双峰型位相特征,降水量以傍晚至夜间峰值为主清晨峰值为次,降水量位相与降水频次位同步相滞后于降水强度位相;南部地区是单峰型位相特征,降水量峰值出现在午夜,低谷出现在中午,降水量位相与降水频次位相同步滞后于降水强度位相,这应是降水演变过程中时间演变不对称性和高原对流云系发展演变的具体表现。 相似文献
8.
利用秦岭地区1961—2015年暖季(4—10月)国家级地面气象站观测的逐时降水资料,从降水逐候变化与降水日变化的角度,比较了秦岭南北两侧暖季降水的演变特征,研究表明:在逐候演变上,秦岭南北两侧均为夏秋双峰型降水,但北侧降水主峰值出现在秋季,秦岭南侧降水主峰值出现在夏季.在降水日变化上,夏秋两季中南侧降水量、降水频次和降水强度均以清晨峰值为主,仅在降水频次上夏季出现了午后的次峰值;而北侧降水量日变化夏秋变化较大,且主要由降水强度贡献,夏季降水强度在午后较强,而秋季清晨降水强度更大.对于不同持续时间的降水事件,南北两个区域在夏秋均表现为持续9h以上(3h以下)的降水为清晨(午后)降水峰值,其差别主要存在于持续时间为4～8h的降水事件中. 相似文献
9.
Characteristics of diurnal variations of warm-season precipitation over Xinjiang Province in China 
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下载免费PDF全文 降水日变化受大气热力,动力过程以及复杂地形影响,演变特征复杂且区域差异显著.本文采用中国气象局发布的中国地面与CMORPH融合逐小时降水产品(2008-2019年),分析了新疆省暖季降水日变化特征.研究结果表明:(1)新疆大部分地区降水主峰值发生在清晨;(2)持续时间超过三小时的降水事件是新疆地区主要降水事件,贡献了南... 相似文献
10.
江苏南部汛期降水日变化特征分析 总被引：2，自引：1，他引：1
利用江苏南部20个气象观测站2008—2012年汛期(5—10月)逐小时降水资料,应用降水频率来分析了江苏南部地区降水日变化基本特征和区域差异。研究表明:降水日变化特征地域性差异较强,西部站、东部站和东北沿海站都存在一定的特征差异。东部站降水量的最大值主要出现在下午和傍晚;西部站降水量主峰值出现在下午,并且在清晨和夜间还有两个次峰值;东北沿海站呈现出午前、午后的双峰值形式。2008—2011年降水量下午高值区有先减弱后增强并提前的趋势,而上午的高值区有总体减弱并推迟的特征。2011年后有明显减弱的趋势。江苏南部总体来说,短时强降水(大于20和25 mm/h)在16—19时出现主峰值,07—09时也有相对较小的次峰值。 相似文献
11.
This paper summarizes the recent progress in studies of the diurnal variation of precipitation over con- tiguous China. The main results are as follows. （1） The rainfall diurnal variation over contiguous China presents distinct regional features. In summer, precipitation peaks in the late afternoon over the south- ern inland China and northeastern China, while it peaks around midnight over southwestern China. In the upper and middle reaches of Yangtze River valley, precipitation occurs mostly in the early morning. Summer precipitation over the central eastern China （most regions of the Tibetan Plateau） has two diurnal peaks, i.e., one in the early morning （midnight） and the other in the late afternoon. （2） The rainfall diurnal variation experiences obvious seasonal and sub-seasonal evolutions. In cold seasons, the regional contrast of rainfall diurnal peaks decreases, with an early morning maximum over most of the southern China. Over the central eastern China, diurnal monsoon rainfall shows sub-seasonal variations with the movement of summer monsoon systems. The rainfall peak mainly occurs in the early morning （late afternoon） during the active （break） monsoon period. （3） Cloud properties and occurrence time of rainfall diurnal peaks are different for long- and short-duration rainfall events. Long-duration rainfall events are dominated by strat- iform precipitation, with the maximum surface rain rate and the highest profile occurring in the late night to early morning, while short-duration rainfall events are more related to convective precipitation, with the maximum surface rain rate and the highest profile occurring between the late afternoon and early night. （4） The rainfall diurnal variation is influenced by multi-scale mountain-valley and land-sea breezes as well as large-scale atmospheric circulation, and involves complicated formation and evolution of cloud and rainfall systems. The diurnal cycle of winds in the lower troposphere also contributes to the regional differences 相似文献
12.
近30 a江苏夏季降水日变化的气候学特征 总被引：2，自引：1，他引：1
基于1980—2013年江苏省61站小时降水资料,分析了江苏省夏季降水日变化的特点及小时极端降水、不同级别雨日的日变化特征。结果表明,江苏省夏季降水日变化具有显著的双峰分布特征,然而江苏省北部和南部降水的主峰时段并不一致。从降水频次、累积降水量来看,江苏省北部降水以清晨至早上时段为主峰、午后至傍晚时段为次峰,南部降水与之相反。长持续性降水占夏季降水的2/3左右,且江苏北部占比多于南部,均为清晨至早上的单峰分布;短持续性降水占夏季降水的1/3,在江苏北部呈现出以午后至傍晚为主峰,清晨至早上为次峰的双峰分布,而在江苏南部呈现出以午后至傍晚的单峰分布特点。小时极端降水,阈值分布南低北高,虽然频次较少,但占夏季降水的40%左右。小时极端降水日变化的双峰分布和夏季总体降水分布类似,但主峰大都出现在午后至傍晚。不同级别雨日的日变化分布各有不同,但全省各区无显著差异。累积降水量贡献主要来自于暴雨和大雨。暴雨无论是从降水频次、累积降水量还是降水强度都呈现清晨至早上的单峰分布。 相似文献
13.
Diurnal variations of precipitation over the South China Sea 总被引：1，自引：0，他引：1
In this study, the diurnal variations of precipitation and related mechanisms over the South China Sea (SCS) are studied using the TRMM and other auxiliary atmospheric data. We have found that: (1) the amplitude and peak time of the diurnal precipitation over SCS exhibit remarkable regional features and seasonal variations. Diurnal variations are robust all the year around over the southern SCS especially over the Kalimantan Island and its offshore area. Over the middle to northern SCS, however, diurnal variations are noticeable only in the summer and autumn; (2) over the northern SCS precipitation peaks in early morning, while over the southern SCS it has two diurnal peaks: one in the early morning and another in the late afternoon; (3) the diurnal variations of precipitation over the SCS are related to the activity of the SCS summer monsoon and the ENSO events. The late afternoon precipitation increases remarkably after the onset of the SCS summer monsoon over the northern SCS. The early-morning rainfall peak is much more significant during La Nina years than during El Nino years; (4) the land–sea breeze is responsible for the diurnal cycle over the Kalimantan Island and its offshore area while the “static radiation–convection” mechanisms may result in the early-morning rainfall peak over the SCS. 相似文献
14.
华北地区夏季降水日变化的时空分布特征 总被引：5，自引：2，他引：3
利用2008~2014年间全国自动站观测降水和CMORPH[CPC（Climate Prediction Center）morphing technique]卫星反演降水资料融合而成的0.1°×0.1°小时降水产品揭示了华北夏季降水的日变化特征,发现华北多数地区夏季降水量和降水频率日变化呈现出明显的双峰特征且存在明显的区域性差异。在太行山以西地区,降水量和降水频率的日峰值出现在傍晚18:00左右（北京时）,规律性最强;而在太行山以东的平原和沿海地区,日峰值一般出现在上午。研究不同持续时间降水对总降水的贡献发现短时降水对傍晚的降水日峰值贡献较大,而长时降水则对凌晨的峰值影响更大。分析不同强度降水对总降水量的贡献结果表明,0.1~10 mm h-1强度降水较其它强度降水对夏季华北地区总降水量贡献更大,随着降水强度的增加降水量日变化的峰值个数增加。 相似文献
15.
Diurnal phase of late-night against late-afternoon of stratiform and convective precipitation in summer southern contiguous China 总被引：7，自引：0，他引：7
Using the tropical rainfall measuring mission (TRMM) Precipitation Radar (PR) observations combined with the surface rain
gauge data during 1998–2006, the robust diurnal features of summer stratiform and convective precipitation over the southern
contiguous China are revealed by exploring the diurnal variations of rain rate and precipitation profile. The precipitation
over the southern contiguous China exhibits two distinguishing diurnal phases: late-night (2200–0600 LST) and late-afternoon
(1400–2200 LST), dependent on the location, precipitation type and duration time. Generally, the maximum rain rate and the
highest profile of stratiform precipitation occur in the late-afternoon (late-night) over the southeastern (southwestern)
China, while most of the stratiform short-duration rain rate tends to present late-afternoon peaks over the southern China.
For convective precipitation, the maximum rain rate and the highest profile occur in the late-afternoon over most of the southern
contiguous China, while the convective long-duration rain rate exhibits late-night peaks over the southwestern China. Without
regional dependence, the convective precipitation exhibits much larger amplitude of diurnal variations in both near surface
rain rate and vertical extension compared with stratiform precipitation and the convective rain top rises most rapidly between
noon and afternoon. However, there are two distinctive sub-regions. The diurnal phases of precipitation there are very weakly
dependent on precipitation type and duration time. Over the eastern periphery of the Tibetan Plateau, the maximum rain rate
and the highest profile of either convective or stratiform precipitation occur in the late-night. Over the southeastern coastal
regions, both the near surface rain rate and rain top of convective and stratiform precipitation peak in the late-afternoon. 相似文献
16.
Changes in the Diurnal Cycles of Precipitation over Eastern China in the Past 40 Years 总被引：2，自引：0，他引：2
This study analyzed the interdecadal changes in the diurnal variability of summer(June-August) precipitation over eastern China during the period 1966-2005 using hourly station rain gauge data.The results revealed that rainfall diurnal variations experienced significant interdecadal changes.Over the area to the south of the Yangtze River,as well as the area between the Yangtze and Yellow Rivers,the percentages of morning rainfall(0000-1200 LST) to total rainfall in terms of amount,frequency and intensity,all exhibited increasing interdecadal trends.On the contrary,over North China,decreasing trends were found.As a result,diurnal rainfall peaks also presented pronounced interdecadal variations.Over the area between the Yangtze and Yellow Rivers,there were 16 out of 46 stations with afternoon(1200-0000 LST) frequency peaks in the first 20 years of the 40-year period of study,while only eight remained in the latter 20 years.In North China,seven stations experienced the opposite changes,which accounted for about 21% of the total number of stations.The possible causes for the interdecadal changes in diurnal features were discussed.As the rainfall in the active monsoon period presents morning diurnal peaks,with afternoon peaks in the break period,the decrease(increase) of rainfall in the active monsoon period over North China(the area south of the Yangtze River and the area between the Yangtze and Yellow Rivers) may contribute to interdecadal changes in diurnal rainfall variability. 相似文献
17.
Diurnal variations of circulation and precipitation in the vicinity of the Tibetan Plateau in early summer 总被引：2，自引：2，他引：0
A regional climate model (RCM) has been applied to simulate the diurnal variations of the Asian summer monsoon during the
early summer period. The ERA40 reanalysis data and the TRMM precipitation data are used to evaluate the performance of the
model. The 5-year simulations show that the RCM could simulate well the diurnal cycle of the monsoon circulation over the
region. A strong diurnal variation of circulation over the Tibetan Plateau (TP) can be observed at the 500-hPa level, with
strong convergence and upward motion in the late afternoon. The diurnal variation of the 500-hPa relative vorticity over the
TP associated with the corresponding diurnal variation of convergence may lead to the formation of a prominent plateau-scale
cyclonic circulation over the TP during the evening to midnight period. The simulated diurnal variation of precipitation over
land is generally better than that over the ocean, particularly over the regions close to the TP such as the Bangladesh region
in the southern flank of the TP, where the well-known nocturnal maximum in precipitation is well captured by the RCM. However,
the late-afternoon maximum in precipitation over the Southeast Asia region is not well simulated by the RCM. The model results
suggest that the diurnal variation of precipitation over the southern flank of the TP is associated with the strong diurnal
variation in the circulation over the TP. 相似文献
18.
利用华南地区248个国家级地面气象站逐小时降水数据和14个探空站数据,分析了2003—2016年4—6月华南前汛期降水日变化特征。据南海夏季风爆发时间,将降水分为爆发前后两个时段。华南地区主要存在两条大雨带,一个位于云贵高原至南岭山脉以南,另一个位于广东沿海地区。偏北雨带集中发生在后半夜至清晨时段,偏南雨带集中发生在中午至下午时段。南海夏季风爆发前后,降水量不存在明显相关性,相关系数较大时次位于中午至下午时段。前后期年降水标准差在0.5附近,变化幅度明显时段主要集中于凌晨至清晨。午后出现3 h多年降水量变化幅度最大值,最小时段为中午12时。降水量、降水频率和降水强度的经向分布特征明显且相似:降水量和降水频率在112 °E附近出现日变化转折,以西多出现不稳定夜雨,以东白天降水波动较大。在南海夏季风爆发前,降水特征主要表现为西部高频、南部高强,在清晨更多作用于对暴雨系统的增长;季风爆发后则表现为西北-东南南的高频率高强度降水形态,在傍晚更多作用于增加降水发生频率。 相似文献
19.
The mountain-plains solenoid(MPS) and boundary-layer inertial oscillation(BLO) are two typical regional forcings at the diurnal time scale. Their relative role in regulating the diurnal variations of summer rainfall over North China and their change under different monsoon conditions are studied using a 19-yr archive of satellite rainfall and reanalysis data. It is shown that both a strong MPS and BLO can increase nocturnal rainfall in the North China plains but exhibit evident regional differences. The MPS-induced nocturnal rainfall is relatively confined to the plains adjacent to mountains from late night to morning, due to the upward branch of the nighttime MPS. In contrast, the BLO-induced nocturnal rainfall strengthens from early evening and is more extensive in early morning over the open plains further east. The contrasting effect in the evening is related to the convergent(divergent) easterly anomaly in the plains under the BLO(MPS). The BLO also induces the relatively strong enhancement of moisture convergence and high humidity by the southerly anomaly at late night. On strong monsoon days, the nocturnal rainfall amount associated with the MPS and BLO increases considerably in the plains.Both regional forcings become effective in regulating the rainfall diurnal cycle with enhanced moisture convergence under monsoon conditions. Their induced diurnal amplitudes of moisture convergence can be comparable to the daily mean by monsoon flow. The regional forcings thus couple with monsoon flow to strengthen rainfall in the plains, particularly from late night to morning. The results highlight that a combination of regional and large-scale forcings can strongly regulate the warm-season climate. 相似文献