scholarly journals Statistical Characteristics and Circulation Situation of Shear Line in Autumn Tibet Plateau

2017 ◽  
Vol 06 (03) ◽  
pp. 215-223
Author(s):  
林君 韩
Keyword(s):  
Statistical Characteristics ◽  
Tibet Plateau ◽  
Shear Line

Impact of the Qinghai-Tibet Plateau Weather System on the Rainstorm on the North Slope of Kunlun Mountain

2020 ◽  
Author(s):  
Zhang junlan
Keyword(s):  
High Pressure ◽  
Water Vapor ◽  
Tarim Basin ◽  
Bay Of Bengal ◽  
Tibet Plateau ◽  
Weather System ◽  
Shear Line ◽  
The North ◽  
Qinghai Tibet Plateau ◽  
Southern Xinjiang

<p>Based on the encryption automatic station data, the conventional ground and high altitude observation data, the FY2 static satellite data, and the initial field data of the ECMWF fine grid forecast model (spatial resolution 0.125 °× 0.125 °) in Tarim Basin in the southern Xinjiang, the rare rainstorm process occurred on the north slope of Kunlun Mountains from 24-26 June 2019 is analyzed. Aiming at the circulation situation, the weather system and the configuration of the high and low altitude systems, the plateau weather systems such as the Qinghai-Tibet high pressure, the plateau low vortex and shear line, and the jet stream south of the plateau were analyzed. Their important effects of the formation of Rainstorm on the northern slope of Kunlun Mountain is concluded as follows:</p><p>(1) The development and maintenance of the Qinghai-Tibet Plateau weather system are generated during favorable weather-scale dynamic and thermal processes, which are mainly manifested in the following three aspects: First of all, the South Asian High pressure changed from a double type to Qinghai-Tibet high pressure at 100hPa. At 200 to 300hPa, the southwestern jet stream lifted northward from the plateau and strengthened in the Tarim Basin in the southern Xinjiang. Suction effect can promote the ascending movement over the rainstorm area; Secondly, the low value system of the shear line nearly in the north-south direction between the Qinghai-Tibet high, the plateau vortex, the shear line and the Indian low is stable in 500hPa. The southerly flow prevails in the periphery of the West Pacific subtropical high, which runs through the Qinghai-Tibet Plateau and the South Xinjiang basin from the Bay of Bengal. The positive vorticity advection and warm advection on the southerly flow over the Qinghai-Tibet Plateau are conducive to the large-scale uplift movement over the rainstorm area and the western part of South Xinjiang, forming water vapor channel from south to north. While warm air transporting to the north, the North-South cold and warm air convergence is enhanced. Thirdly, the coupling between strong high-level divergence and middle-level convergence during heavy rains can result in enhanced mid-level water vapor convergence and vertical water vapor transport.</p><p> (2) Weather systems below 600hPa have positive feedback on the maintenance and development of plateau weather systems. Easterly airflow was in the Tarim Basin in the southern Xinjiang between 600hPa and 700Pa，and the airflow at 600hPa was stronger than 700hPa. The easterly airflow carried part of the cold air into the Tarim Basin in the southern Xinjiang. A cold pad was formed in the lower layer below 600hPa in the southern Xinjiang basin, which facilitated the transfer of warm and humid air northward by the 500hPa middle-south wind and the 500 to 200hPa ascent movement development and maintain, while exacerbating the vertical cold and warm exchanges.</p><p> (3) Water vapor mainly comes from the Bay of Bengal, the Caspian Sea and the Aral Sea, but the water vapor contribution from the Bay of Bengal is even greater.</p>

scholarly journals Application of Ground-Based Microwave Radiometer in Retrieving Meteorological Characteristics of Tibet Plateau

2021 ◽  
Vol 13 (13) ◽  
pp. 2527
Author(s):  
Jiahua Wei ◽  
Yang Shi ◽  
Yan Ren ◽  
Qiong Li ◽  
Zhen Qiao ◽  
...  
Keyword(s):  
Asian Summer Monsoon ◽  
Microwave Radiometer ◽  
Convective Available Potential Energy ◽  
Precipitable Water ◽  
Atmospheric Temperature ◽  
Precipitation Forecast ◽  
Statistical Characteristics ◽  
Tibet Plateau ◽  
Special Focus ◽  
Sky Conditions

The characteristics of plateau precipitation and atmosphere, once accurately and comprehensively understood, can be used to inform sound air–water resource development practices. In this study, atmospheric exploration of the Tibet Plateau (TP) was conducted using ground-based microwave radiometer (MWR) data collected during the East Asian summer monsoon. Atmospheric temperature, pressure, humidity, and other variables were gathered under clear-sky, cloudy-sky, and rainy-sky conditions. Statistical characteristics of the air parcel height and stability/convection indices such as convective available potential energy (CAPE) and convective inhibition (CIN) were investigated, with a special focus on the rainy-sky condition. Two retrieval applications for characterizing precipitation, namely short-term precipitation forecast and quantitative precipitation estimation were presented. Results showed that CAPE values in the Darlag region reached extremes around 18:00–20:00 (UTC+8) for cloudy-sky and rainy-sky conditions with corresponding peaks of about 1046.56 J/kg and 703.02 J/kg, respectively. When stratiform or convective–mixed precipitation occurs, the precipitable water vapor (PWV) and CAPE values were generally greater than 1.7 cm and 1000 J/kg, respectively. CAPE values are likely to decrease before the occurrence of precipitation due to the release of the latent heat in the atmosphere.

Influence of Yield Strength Variability over Cross-Section to Steel Beam Load-Carrying Capacity

2005 ◽  
Vol 10 (2) ◽  
pp. 151-160 ◽  
Author(s):  
J. Kala ◽  
Z. Kala
Keyword(s):  
Yield Strength ◽  
Cross Section ◽  
Carrying Capacity ◽  
Bending Moment ◽  
Statistical Characteristics ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Strength Variability ◽  
Hot Rolled ◽  
Hot Rolled Steel

Authors of article analysed influence of variability of yield strength over cross-section of hot rolled steel member to its load-carrying capacity. In calculation models, the yield strength is usually taken as constant. But yield strength of a steel hot-rolled beam is generally a random quantity. Not only the whole beam but also its parts have slightly different material characteristics. According to the results of more accurate measurements, the statistical characteristics of the material taken from various cross-section points (e.g. from a web and a flange) are, however, more or less different. This variation is described by one dimensional random field. The load-carrying capacity of the beam IPE300 under bending moment at its ends with the lateral buckling influence included is analysed, nondimensional slenderness according to EC3 is λ¯ = 0.6. For this relatively low slender beam the influence of the yield strength on the load-carrying capacity is large. Also the influence of all the other imperfections as accurately as possible, the load-carrying capacity was determined by geometrically and materially nonlinear solution of very accurate FEM model by the ANSYS programme.

Spatial Statistical Characteristics of Soil

2003 ◽  
Vol 59 (3-4) ◽  
pp. 10
Author(s):  
Ye. V. Tarnavsky ◽  
G. P. Kulemin
Keyword(s):  
Statistical Characteristics
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