Analysis of a severe precipitation process in Aksu Area under the background of the Central Asian Vortex

Mapping Intimacies ◽

10.5194/egusphere-egu2020-1718 ◽

2020 ◽

Author(s):

Nannan Guo ◽

Yushu Zhou

Keyword(s):

Water Vapor ◽

Large Scale ◽

Heavy Rain ◽

Tianshan Mountains ◽

Precipitation Process ◽

The South ◽

The West ◽

Valley Wind ◽

Central Asian ◽

Convergence Line

<p>Central Asian Vortices (CAVs) are deep cyclonic systems that occur in the Central Asian and are identified at the 500 hPa level. CAVs are significantly associated with many convective events in the Xinjiang province. In order to strengthen the understanding of the mesoscale systems development mechanisms in torrential rain under the influence of CAVs, we analyzes the rainstorm process occurred in the Aksu region that is near the west of Tianshan Mountains, during June 17 to 18, 2013 basing on a variety of data. The results show that the precipitation process occurs under the background of the circulation of the two ridges in a trough over the middle and high latitudes, and the CAV provides favorable large-scale dynamic and water vapor conditions for this rainstorm. The convergence line is the important mesoscale system, which is formed by the superposition of the CAV circulation and the flow stream around the special topography of the west Tianshan Mountains. Due to the difference of thermal properties between the mountain and desert, the slope wind drives convergence line to move and the strong convection developed along the convergence line triggers strong precipitation in the Aksu region. The WRF is able to well simulate not only the location and intensity of the heavy rain but also the evolution of wind field. Preliminary analysis combined with observations and simulation data shows that under the blockage of west Tianshan Mountains, the south wind accumulates and convergences near the valley. As a result, a local convergence line is formed. Meanwhile, with the adjustment of the large-scale circulation situation, especially after the CAV moves to the vicinity of the Aksu area, one part of the westward flow that comes from the south of the vortex turns into northwest wind after crossing the west Tianshan Mountains, and the other part turns into the northeast wind after passing through the Yili Valley, these two flow aggravate the northerly airflow and enhance the intensity of convergence, thereby promote the formation of mesoscale convergence lines and strengthen it. The eastward airflow-induced water vapor accumulates in front of the southern foot of the Tianshan Mountains, and strengthens as the convergence line moves towards southeast with the enhancement of the valley wind at night. Accompanied with the convergence uplift, the accumulation of water vapor at the foot of the mountain promotes the release of unstable energy and brings heavy precipitation to the Aksu region.</p>

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Triggering Mechanism of an Extreme Rainstorm Process near the Tianshan Mountains in Xinjiang, an Arid Region in China, Based on a Numerical Simulation

Advances in Meteorology ◽

10.1155/2020/8828060 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Yong Zeng ◽

Lianmei Yang

Keyword(s):

Water Vapor ◽

Arid Region ◽

Middle Atmosphere ◽

Wrf Model ◽

Heavy Rain ◽

Cloud Water ◽

Tianshan Mountains ◽

Triggering Mechanism ◽

Cold Air ◽

Convergence Line

The current study investigated the triggering mechanism of a record-breaking heavy rain process in the area near the Tianshan Mountains in Xinjiang, an arid region in China, from July 31 to August 1, 2016, based on the simulation using the Weather Research and Forecasting (WRF) model. The results illustrated that the rainstorm system was generated in the middle atmosphere of the western Aksu region near the Tianshan Mountains and gradually evolved into a multicell linear echo during system evolution. The cold air transported from the Tianshan Mountains partly reached the low altitudes during the downhill process, and the warm southwest air from Aksu was lifted, forming oblique updraft airflow. The other part of the cold air converged with the southeastern warm air in the middle atmosphere, and the transportation and convergence of the water vapor related to the southwestern, southeastern, and oblique updraft airflows provided good water vapor conditions for the storm system. Meanwhile, the inclined upward air transported cloud water and ice-phase particles to high altitudes, mixing the two and generating a large amount of supercooled cloud water, which was very beneficial for the development and maintenance of the storm system. These conditions were favorable for power, heat, water vapor, and water condensate particles, which enabled the development and maintenance of the rainstorm system on the convergence line, thus triggering this rare rainstorm process during the movement to the northeast.

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Meteorological Drought Changes and Related Circulation Characteristics in Yulin City of the Northern Shaanxi from 1961 to 2015

Atmosphere ◽

10.3390/atmos11111196 ◽

2020 ◽

Vol 11 (11) ◽

pp. 1196

Author(s):

Yixing Yin ◽

Lijuan Zhang ◽

Xiaojun Wang ◽

Wucheng Xu ◽

Wenjun Yu ◽

...

Keyword(s):

Water Vapor ◽

Standardized Precipitation Index ◽

Meteorological Drought ◽

Precipitation Process ◽

Observation Data ◽

The South ◽

Vapor Flux ◽

The North ◽

Northern Shaanxi ◽

Yulin City

This study explored the spatio-temporal patterns of meteorological drought change and the mechanisms of drought occurrence in Yulin City of the northern Shaanxi by using Standardized Precipitation Index (SPI), Empirical Orthogonal Function (EOF) analysis and composite analysis based on the meteorological observation data and NCEP/NCAR reanalysis data from 1961 to 2015. The main findings of the research are as follows: (1) In the annual and seasonal drought series, there is a non-significant trend toward drought in summer, while there are non-significant trends toward wetness for the other series. Overall, the frequency of drought is low in the southeast and high in the west and the north of the study area. (2) EOF1 is characterized by a uniform pattern in the whole region, i.e., there is a feature of consistent drought or flood in Yulin City. EOF2, EOF3 and EOF4 mainly indicate opposite characteristics of the changes of floods and droughts in the eastern/western parts and the southeast/other parts in the study area. (3) In the summer of the typical drought (flood) years, the study area is controlled by the northwest airflow behind the trough (zonal airflow at the bottom of low-pressure trough), and the meridional circulation (zonal circulation) is distributed in the mid-latitudes, which is conducive to the intrusion of cold air into the south (north) of China. The cold and warm air intersection area is to the south (to the north). The water vapor flux is weak (strong) and the water vapor divergence (convergence) prohibits (enhances) the precipitation process in the study area.

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‘Burn it down!’: Materialising intersectional solidarities in the architecture of the South African Embassy during the London Poll Tax Riot, March 1990

Environment and Planning C Politics and Space ◽

10.1177/2399654419857183 ◽

2019 ◽

Vol 38 (2) ◽

pp. 233-250 ◽

Cited By ~ 1

Author(s):

Gavin Brown

Keyword(s):

South Africa ◽

Working Class ◽

South African ◽

Large Scale ◽

The South ◽

The West ◽

England And Wales ◽

Metropolitan Police ◽

Trafalgar Square ◽

Poll Tax

This paper offers a new way of conceptualising how intersectional solidarities are actualised. It recounts and theorises an outbreak of radical internationalism, when working class struggles in Britain and South Africa were unexpectedly linked. It examines how intersectional solidarity was materialised through a process of coming together against the architectural fabric of the South African Embassy and considers the interwoven temporalities that enabled this action to occur. On 31 March 1990, nearly a quarter of a million people demonstrated in London against the Poll Tax that was due to take effect in England and Wales the following day. On the day, the Metropolitan Police lost control of an already enraged crowd and provoked a large scale riot that engulfed the West End of London for several hours. In the midst of the riot, during a short retreat by the police, protesters took the opportunity to attack the South African Embassy in Trafalgar Square – many windows were broken and an attempt was made to set the building alight. Drawing on interviews with former anti-apartheid protesters who were present on that day (and who had concluded a four-year long Non-Stop Picket of the embassy a month earlier), this paper explores and analyses their memories of that unexpected moment when their previously symbolic call to ‘burn it down’ was (almost) materialised. In doing so, it contributes new ways of conceptualising the spatiality and temporality of intersectional solidarity.

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The Climatological Analysis of Typhoon Tracks, Steering Flow, and the Pacific Subtropical High in the Vicinity of Taiwan and the Western North Pacific

Atmosphere ◽

10.3390/atmos11050543 ◽

2020 ◽

Vol 11 (5) ◽

pp. 543

Author(s):

Chih-wen Hung ◽

Ming-Fu Shih ◽

Te-Yuan Lin

Keyword(s):

Tropical Cyclones ◽

Large Scale ◽

Subtropical High ◽

Boreal Summer ◽

The South ◽

The West ◽

Steering Flow ◽

The Pacific ◽

Typhoon Season ◽

Typhoon Tracks

Taiwan frequently suffers from typhoon hits in the boreal summer and fall. The location of Taiwan makes it vulnerable to the pathways of typhoons mainly determined by the position of the Pacific subtropical high. In order to clarify the linkage between typhoon invasion and associated large-scale environments from a climatological perspective, this study counts the historical typhoon invasion days for each month in the typhoon season to establish analyzed cases and then categorizes them with statistical thresholds. Besides, the categorized cases with less typhoon invasion are further sorted to distinguish different movements of tropical cyclones. Therefore, corresponding composites are applied for each category. The results reveal that when the subtropical high retreats eastward, the accompanying steering flow guides typhoons to make an early recurvature toward Japan and South Korea. While the subtropical high further extends its property to the west covering Taiwan, the steering flow on the south transfers typhoons moving westward to the South China Sea. However, when the subtropical high lies in areas between the above two scenarios, the steering flow along the periphery of the subtropical high continuously sends typhoons toward Taiwan and the vicinity, which greatly increases the threat to the island.

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Evaluation of the ability of the Chinese stalagmite δ<sup>18</sup>O to record the variation in atmospheric circulation during the second half of the 20th century

Climate of the Past ◽

10.5194/cp-10-975-2014 ◽

2014 ◽

Vol 10 (3) ◽

pp. 975-985 ◽

Cited By ~ 7

Author(s):

S. Nan ◽

M. Tan ◽

P. Zhao

Keyword(s):

Water Vapor ◽

South China Sea ◽

South China ◽

Bay Of Bengal ◽

North Pacific ◽

Western North Pacific ◽

Large Scale ◽

The South China Sea ◽

The South ◽

China Sea

Abstract. The Chinese stalagmite δ18O (δ18Ocs) has provoked debate worldwide over the past few years due to its lack of quantitative calibration, leading us to questions of whether δ18Ocs records a local or large-scale signal and whether δ18Ocs records the signal of a single remote water vapor source or multiple water vapor sources. In this study, we observe all of the δ18Ocs trends within the instrumental period to verify whether they possess a common trend, which could be used as a basis to determine whether the trends reflect the large-scale signal together or whether each trend reflects the local signal. The results show that most of the δ18Ocs experienced a linear increase from 1960 to 1994, which may indicate that the δ18Ocs could record a trend occurring in large-scale atmosphere circulations. We then quantitatively describe the proportion of water vapor transport (WVT) from different source regions. Using the NCEP/NCAR (National Centers for Environmental Protection/National Center for Atmospheric Research) reanalysis data from 1960 to 1994, the ratios of the intensities of three WVTs from the Bay of Bengal, the South China Sea, and the western North Pacific during the summer are calculated. We define RSCS/BOB as the ratio of the WVT intensities from the South China Sea to those from the Bay of Bengal, RWNP/BOB as the ratio of the WVT intensities from the western North Pacific to those from the Bay of Bengal, and RWNP/SCS as the ratio of the WVT intensities from the western North Pacific to those from the South China Sea. The significant decadal increase occurs in the time series of RWNP/BOB and RWNP/SCS, most likely resulting from the strengthening of the WVT from the western North Pacific in the late 1970s due to the western Pacific subtropical high that extended westward. Further analysis indicates that when the equatorial central and eastern Pacific is in the El Niño phase, the sea surface temperature (SST) in the tropical Indian Ocean, the Bay of Bengal, and the South China Sea is high, and the SST at the middle latitudes in the North Pacific is low, then the RWNP/BOB and RWNP/SCS values tend to be high. After the late 1970s, the equatorial central and eastern Pacific have often been in the El Niño phase. Therefore, we confirm that the δ18Ocs primarily records the variation in atmospheric circulation during the second half of the 20th century.

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Mental health in Uzbekistan

International Psychiatry ◽

10.1192/s1749367600006160 ◽

2011 ◽

Vol 8 (1) ◽

pp. 10-11

Author(s):

Dina Gazizova ◽

Abdulla Mazgutov ◽

Grigoriy Kharabara ◽

Elena Tsoyi

Keyword(s):

Mental Health ◽

Soviet Union ◽

Asian Country ◽

Russian Empire ◽

The South ◽

The West ◽

The North ◽

The Soviet Union ◽

Central Asian ◽

The Russian Empire

Uzbekistan is a landlocked central Asian country with an area of 447 400 km2. It borders Kazakhstan in the north, Kyrgyzstan and Tajikistan in the east, Turkmenistan in the west and Afghanistan in the south. Uzbekistan has 14 regions (provinces). In 1991 it emerged as a sovereign country after more than a century of Russian rule — first as part of the Russian empire and then as a component of the Soviet Union.

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Characteristic Analysis of Abnormal-Weakening Summer Precipitation in Tianjin under the Influence of Bohai Sea High

E3S Web of Conferences ◽

10.1051/e3sconf/201911803015 ◽

2019 ◽

Vol 118 ◽

pp. 03015

Author(s):

Changyi Xu ◽

Yan Wang

Keyword(s):

Water Vapor ◽

Large Scale ◽

Bohai Sea ◽

Summer Precipitation ◽

Heavy Rain ◽

The Yellow Sea ◽

Type Ii ◽

Characteristic Analysis ◽

China Sea ◽

Daily Precipitation Data

To investigate the characteristics of Bohai High, the daily precipitation data of Beijng-Tianjin region during June to September from 2006 to 2015, national basic automatic weather stations data of 5 minute, NCEP/NCAR 1°×1° reanalysis data as well as CINRAD/SA data of Tianjin, from the definition of and the distribution characteristics of precipitation in Beijng-Tianjin region, the concept of regional precipitation reduction in summer in the context of Bohai High was given. This was done by classifying large-scale synoptic circulation and synthetic diagnosis method. The results show that: (1) Bohai High has the most significant effect of abnormal weaken precipitation in the eastern of Tianjin, while has a relatively mild effect in the northern of Tianjin. (2) According to the characteristics of large-scale circulation situation, the synoptic processes over heavy rain are classified into three patterns: upper-level trough pattern (I), cold vortex pattern (II) and the interaction between subtropical high and western trough (III). Except that water vapor come from the Bohai Sea and the Yellow Sea for Type II, for the other two patterns the water vapor were related to remote supplies from the South China Sea and the East China Sea. The Bohai High of Type Iand III were thick warm negative vorticity system whereas the Type II was a shallow negative vorticity system. (3) The abnormally weakened of Bohai High were related to their depths and duration, the deeper and the longer duration of Bohai High, the stronger weakening effect on the precipitation in Tianjin.

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X.—The Plan of the Church and Monastery of St. Augustine, Bristol

Archaeologia ◽

10.1017/s0261340900011644 ◽

1912 ◽

Vol 63 ◽

pp. 231-250

Author(s):

Roland W. Paul

Keyword(s):

Large Scale ◽

The South ◽

The West ◽

West Side ◽

South Side ◽

Ordnance Survey ◽

The Church

Many plans exist of what is now the Cathedral at Bristol, but there are to my knowledge none to a sufficiently large scale to be of much practical use, and in those that do exist, with two exceptions, the buildings south of the church, that surround the cloister court, are either only roughly outlined or are omitted altogether. The two exceptions are (1) the Ordnance Survey map of 1884, which shows buildings now destroyed, and (2) a plan (without scale) which accompanies a paper by the late Mr. E. W. Godwin, F.S.A., published in the Archaeological Journal for 1863. This is little more than a block plan, but it is the only attempt hitherto made to identify the various monastic buildings. Since this latter plan was made a road has been taken through near the gatehouse, involving the destruction of the buildings that stood on the west side of College Green at that point, and since 1884 another road has been made on the south side across the site of some of the then existing monastic buildings. The precinct is now therefore considerably reduced in area; originally it appears to have included College Green, while the monastic land extended south to the rivers Frome and Avon. The plan (pi. XXXIV) includes all the monastic buildings now remaining, and shows the position and extent as far as possible of those destroyed. Some old plans, the property of the Dean and Chapter, have quite recently been placed at my disposal, which have enabled me to add the buildings west of the church and adjoining the gate-house.

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