scholarly journals Diurnal evolution and distribution of warm-season convective storms in different prevailing wind regimes over contiguous North China

2014 ◽  
Vol 119 (6) ◽  
pp. 2742-2763 ◽  
Author(s):  
Mingxuan Chen ◽  
Yingchun Wang ◽  
Feng Gao ◽  
Xian Xiao
Keyword(s):  
North China ◽  
Warm Season ◽  
Prevailing Wind ◽  
Convective Storms ◽  
Wind Regimes

A seven-year climatology of the initiation, decay and morphology of severe convective storms during the warm season over North China

2021 ◽  
Author(s):  
Ruoyun Ma ◽  
Jianhua Sun ◽  
Xinlin Yang
Keyword(s):  
Nonlinear Systems ◽  
Short Duration ◽  
Heavy Rainfall ◽  
North China ◽  
Doppler Radar ◽  
Warm Season ◽  
High Wind ◽  
Convective Storms ◽  
Reflectivity Data ◽  
Convective Weather

AbstractThe present work established a 7-year climatology of the initiation, decay, and morphology of severe convective storms (SCSs) during the warm seasons (May–September) of 2011–2018 (except 2014) over North China. This was achieved by using severe weather reports, precipitation observations, and composite Doppler radar reflectivity data. A total of 371 SCSs were identified. SCSs primarily initiated around noon with the highest frequency over the high terrain of Mount Taihang, and they mostly decayed over the plains at night. The storm morphologies were classified into three types of cellular storms (individual cells, clusters of cells, and broken lines), six types of linear systems (convective lines with no stratiform, with trailing stratiform, leading stratiform, parallel stratiform, embedded lines, and bow echoes), and nonlinear systems. Three types of severe convective weather, namely, short-duration heavy rainfall, hail, and thunderstorm high winds associated with these morphologies were investigated. Nonlinear systems were the most frequent morphology, followed by clusters of cells. Convective lines with trailing stratiform were the most frequent linear morphology. A total of 1,429 morphology samples from the 371 SCSs were found to be responsible for 15,966 severe convective weather reports. Linear (nonlinear) systems produced the most short-duration heavy rainfall (hail and thunderstorm high wind) reports. Bow echos were most efficient in producing both short-duration heavy rainfall and thunderstorm high wind reports whereas broken lines had the highest efficiency for hail production. The results in the present study are helpful for local forecasters to better anticipate the storm types and associated hazardous weather.

scholarly journals Relationships between Updraft Characteristics and Cloud-to-Ground Lightning Activity in Warm-Season Convective Storms in the Kanto Region, Japan

SOLA ◽  
2015 ◽  
Vol 11 (0) ◽  
pp. 177-180 ◽  
Author(s):  
Namiko Sakurai ◽  
Shingo Shimizu ◽  
Yukari Shusse ◽  
Shin-ichi Suzuki ◽  
Takeshi Maesaka ◽  
...  
Keyword(s):  
Warm Season ◽  
Lightning Activity ◽  
Convective Storms ◽  
Cloud To Ground Lightning ◽  
Kanto Region

Diurnal Variations of Warm-Season Precipitation over Northern China

2010 ◽  
Vol 138 (4) ◽  
pp. 1017-1025 ◽  
Author(s):  
Huizhong He ◽  
Fuqing Zhang
Keyword(s):  
High Resolution ◽  
North China ◽  
Warm Season ◽  
Northern China ◽  
Early Morning ◽  
Diurnal Variations ◽  
Broad Area ◽  
Mountain Ranges ◽  
Low Level ◽  
Nocturnal Jet

Abstract This study examines the diurnal variations of the warm-season precipitation over northern China using the high-resolution precipitation products obtained from the Climate Prediction Center’s morphing technique (CMORPH) during May–August of 2003–09. The areas of focus are the Yanshan–Taihangshan Mountain ranges along the east peripheries of the Loess and Inner Mongolian Plateaus and the adjacent North China Plains. It is found that the averaged peak in local precipitation begins early in the afternoon near the top of the mountain ranges and propagates downslope and southeastward at a speed of ∼13 m s−1. The peak reaches the central North China Plains around midnight and the early morning hours resulting in a broad area of nocturnal precipitation maxima over the plains. The diurnal precipitation peak (minimum) is closely collocated with the upward (downward) branch of a mountain–plains solenoid (MPS) circulation. Both the MPS and a low-level southwesterly nocturnal jet are likely to be jointly responsible for the nighttime precipitation maxima over the plains.

Object-Oriented Composite Analysis of Warm-Sector Rainfall in North China

2020 ◽  
Vol 148 (7) ◽  
pp. 2719-2735
Author(s):  
Jiaolan Fu ◽  
Fuqing Zhang ◽  
Timothy D. Hewson
Keyword(s):  
North China ◽  
Asian Summer Monsoon ◽  
Warm Season ◽  
Object Oriented ◽  
Northern China ◽  
Early Morning ◽  
The Other ◽  
Maximum Rainfall ◽  
Warm Sector ◽  
Upper Level

Abstract Warm-sector rainfall (WSR) occurs, by definition, in a warm-air region that is isolated from any forcing related to synoptic frontal boundaries at the surface. This study explores the use of an object-oriented technique to objectively and automatically identify various WSR events over North China from June to September in 2012–17. A total of 768 substantive events are identified over the 6 years. They have a mean maximum rainfall accumulation of 35 mm h−1. Most such events occur over the plains, with two-frequency maxima: one to the south of the Yanshan Mountain Ranges, and the other near the junction of Henan, Shandong, and Jiangsu provinces. WSR-related rainstorms can form in all warm-season months but are most commonly observed between mid-July and mid-August (40% of all events occurred then). Geographically, the region at greatest risk moves gradually northward from mid-June to mid-August, consistent with the progression of the East Asian summer monsoon. There are two diurnal peaks in WSR activity, one from late afternoon to early evening and the other from late evening to early morning. Three classes of upper-level synoptic pattern seem to be conducive to WSR: (i) a “Mongolia front pattern,” (ii) a “northern China front pattern,” and (iii) a “southern front pattern.” All of these patterns are accompanied by warm and moist southwesterly flow at low levels. Prior to WSR events, there is usually an upper-level trough. According to other studies, such a feature is not usually seen for WSR events in South China.

scholarly journals A 5-yr Climatology of Severe Convective Wind Events over China

2017 ◽  
Vol 32 (4) ◽  
pp. 1289-1299 ◽  
Author(s):  
Xinlin Yang ◽  
Jianhua Sun ◽  
Yongguang Zheng
Keyword(s):  
High Frequency ◽  
North China ◽  
Eastern China ◽  
Warm Season ◽  
Guangdong Province ◽  
Bimodal Distribution ◽  
Western China ◽  
Seasonal And Diurnal Variations ◽  
Report Data ◽  
Wind Events

Abstract A method using cloud-to-ground lightning was developed to retrieve severe convective wind (SCW) events from significant weather report data over China during the period 2010–14. The results showed that SCW events were a feature of local weather activity, and their distribution showed clear seasonal and diurnal variations. The SCW events mainly occurred over eastern China during the midafternoon in the warm season and rarely occurred over western China. The highest frequency of SCW events was recorded in north China and Guangdong Province. There was also a high frequency of SCW events in the middle and lower reaches of the Yangtze River. The most frequent occurrence of SCW events was in Guangdong Province in spring, while a high frequency of SCW events was observed in both north China and Guangdong Province during the summer months. The peak month for SCW events was July over the whole of China and June in north China. The pattern in Guangdong Province had a bimodal distribution, with the peak months being May and August. The majority of SCW events occurred between 1200 and 2000 local time.

scholarly journals Decoupling of water and air temperature in winter causes warm season bias of lacustrine brGDGTs temperature estimates

2020 ◽  
Author(s):  
Jiantao Cao ◽  
Zhiguo Rao ◽  
Fuxi Shi ◽  
Guodong Jia
Keyword(s):  
Air Temperature ◽  
Lake Water ◽  
North China ◽  
Physical Phenomenon ◽  
Warm Season ◽  
High Latitudes ◽  
Study Region ◽  
Suspended Particulate ◽  
Local Mean ◽  
The Mean

Abstract. It has been frequently found that lacustrine brGDGTs-derived temperatures are warm season biased relative to measured annual mean air temperature (AT) in the mid to high latitudes, the mechanism of which, however, is not very clear. Here, we investigated the brGDGTs from catchment soils, and suspended particulate matter (SPM) and surface sediments in the Gonghai Lake in north China to explore this question. Our results showed that the brGDGTs distribution in sediments resembled that in the SPM but differed from the surrounding soils, suggesting a substantial aquatic origin of the brGDGTs in the lake. Therefore, established lake-specific calibrations were applied to estimate local mean annual AT. As usual, the estimates were significantly higher than the measured mean annual AT. However, they were similar to, and thus actually reflected, the mean annual lake water temperature (LWT). Interestingly, the mean annual LWT is close to the measured mean warm season AT, hence suggesting that the apparent warm season bias of lacustrine brGDGTs-derived temperatures could be caused by the discrepancy between AT and LWT. In our study region, ice forms at the lake surface during winter, leading to isolation of the underlying lake water from air and hence higher LWT than AT, while LWT follows AT during warm seasons when ice disappears. Therefore, we believe what lacustrine brGDGTs actually reflected is the mean annual LWT, which is higher than the mean annual AT in our study location. Since the decoupling between LWT and AT in winter due to ice formation is a universal physical phenomenon in the mid to high latitudes, we propose this phenomenon could be also the reason for the widely observed warm season bias of brGDGTs-derived temperatures in other lakes, especially the shallow lakes.

scholarly journals Banner clouds observed at Mount Zugspitze

2012 ◽  
Vol 12 (8) ◽  
pp. 3611-3625 ◽  
Author(s):  
V. Wirth ◽  
M. Kristen ◽  
M. Leschner ◽  
J. Reuder ◽  
J. H. Schween
Keyword(s):  
Warm Season ◽  
Time Lapse ◽  
Leeward Side ◽  
Bavarian Alps ◽  
Large Eddy ◽  
Key Factor ◽  
Wind Regimes ◽  
Moisture Conditions ◽  
Lifting Condensation Level ◽  
Daily Time

Abstract. Systematic observations of banner clouds at Mount Zugspitze in the Bavarian Alps are presented and discussed. One set of observations draws on daily time lapse movies, which were taken over several years at this mountain. Identifying banner clouds with the help of these movies and using simultaneous observations of standard variables at the summit of the mountain provides climatological information regarding the banner clouds. In addition, a week-long measurement campaign with an entire suite of instruments was carried through yielding a comprehensive set of data for two specific banner cloud events. The duration of banner cloud events has a long-tailed distribution with a mean of about 40 min. The probability of occurrence has both a distinct diurnal and a distinct seasonal cycle, with a maximum in the afternoon and in the warm season, respectively. These cycles appear to correspond closely to analogous cycles of relative humidity, which maximize in the late afternoon and during the warm season. In addition, the dependence of banner cloud occurrence on wind speed is weak. Both results suggest that moisture conditions are a key factor for banner cloud occurrence. The distribution of wind direction during banner cloud events slightly deviates from climatology, suggesting an influence from the specific Zugspitz orography. The two banner cloud events during the campaign have a number of common features: the windward and the leeward side are characterized by different wind regimes, however, with mean upward flow on both sides; the leeward air is both moister and warmer than the windward air; the background atmosphere has an inversion just above the summit of Mt. Zugspitze; the lifting condensation level increases with altitude. The results are discussed, and it is argued that they are consistent with previous Large Eddy Simulations using idealized orography.

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