scholarly journals Unusual weather over northwest & west India during November, 2010

MAUSAM ◽  
2021 ◽  
Vol 64 (4) ◽  
pp. 699-710
Author(s):  
BP YADAV ◽  
NARESH KUMAR ◽  
MEDHA KHOLE

lkekU;r% uoEcj dk eghuk /kwi ds fnuksa o fcuk ckfj'k  okyk eghuk dgykrk gS vkSj uoEcj eghus ds chrus ds lkFk-lkFk mRrj if'peh Hkkjr ds eSnkuh Hkkxksa esa lqcg dh gYdh BaMd fy, ekSle lqgkouk jgrk gS fdUrq uoEcj 2010 ds nkSjku mRrj if'peh vkSj if'pe Hkkjr esa o"kkZ dh ckSNkjksa ds lkFk yEcs le; rd yxkrkj ckny Nk, jgs ftlds dkj.k ekSle vlkekU; jgkA bl vlkekU; ekSle ds fy, mRrjnk;h HkkSfrd izfØ;kvksa dk irk yxkus ds fy, bl 'kks/k i= esa bl ekg esa cuh flukfIVd fLFkfr;ksa dk foLr`r fo'ys"k.k fd;k x;k gSA bl v/;;u ls ;g irk pyk gS fd vjc lkxj esa xgu fuEu vonkc iz.kkyh dh mifLFkfr vkSj fupys Lrjksa esa if'peh gokvksa esa e/; {kksHkeaMyh; nzksf.k;ksa ds lkFk&lkFk iwohZ gokvksa esa mPp vk;keh nzksf.k;ksa dh ijLij fØ;kvksa ds dkj.k uoEcj ekg esa ekSle vlkekU; jgkA  Generally, November is the dry month with sunny days and pleasant weather for plains of northwest & west India with a bit of early morning chill as the month progresses. But during November, 2010, there was unusual weather in the form of prolonged and persistent cloudy conditions with wet spell over northwest & west India. To find out the physical processes leading to this unusual weather, detailed analysis of synoptic conditions during the month has been carried out in this paper. This study reveals that the unusual weather that occurred in association with presence of an intense low pressure system in the Arabian Sea and interaction of high-amplitude troughs in easterlies in the lower levels with mid-tropospheric troughs in the westerlies.

2021 ◽  
Author(s):  
Oliver Sjögren ◽  
Carlos Xisto ◽  
Tomas Grönstedt

Abstract The aim of this study is to explore the possibility of matching a cycle performance model to public data on a state-of-the-art commercial aircraft engine (GEnx-1B). The study is focused on obtaining valuable information on figure of merits for the technology level of the low-pressure system and associated uncertainties. It is therefore directed more specifically towards the fan and low-pressure turbine efficiencies, the Mach number at the fan-face, the distribution of power between the core and the bypass stream as well as the fan pressure ratio. Available cycle performance data have been extracted from the engine emission databank provided by the International Civil Aviation Organization (ICAO), type certificate datasheets from the European Union Aviation Safety Agency (EASA) and the Federal Aviation Administration (FAA), as well as publicly available data from engine manufacturer. Uncertainties in the available source data are estimated and randomly sampled to generate inputs for a model matching procedure. The results show that fuel performance can be estimated with some degree of confidence. However, the study also indicates that a high degree of uncertainty is expected in the prediction of key low-pressure system performance metrics, when relying solely on publicly available data. This outcome highlights the importance of statistic-based methods as a support tool for the inverse design procedures. It also provides a better understanding on the limitations of conventional thermodynamic matching procedures, and the need to complement with methods that take into account conceptual design, cost and fuel burn.


1978 ◽  
Vol 73 (2) ◽  
pp. 220-229 ◽  
Author(s):  
K. Kirsch ◽  
A. Ameln ◽  
H. J. Wicke

2016 ◽  
Author(s):  
Hyun Cheol Kim ◽  
Soontae Kim ◽  
Seok-Woo Son ◽  
Pius Lee ◽  
Chun-Sil Jin ◽  
...  

Abstract. We demonstrate that daily pollutant transport patterns in East Asia are visible from satellite images when inspected with corresponding synoptic weather analyses. Transport pathways of air pollutants in East Asia are investigated using satellite observations, surface weather charts, and chemical-transport model simulations. It is found that during cool season (fall to spring), pollutant transports in East Asia are largely determined by synoptic weather patterns associated with high pressure system over southern China, which is extended from the Siberia High, and low pressure system over Manchuria, which is initiated by Altai-Sayan cyclogenesis. Based on the relative location and strength of these weather systems, three types of synoptic weather patterns that may contribute to pollutants transport in East Asia, especially in China and Korea, are identified: i.e., (1) a strengthening of the Siberian High and its southeastward propagation; (2) a high-pressure system over southern China followed by a frontal passage associated with a northern low-pressure system; and (3) a stagnant high-pressure system over southern China. For all three patterns, the high-pressure system in southern China is essential for the development of regional air pollution, while frontal activities associated with low-pressure system provide a forcing mechanism to transport those pollutants eastward or southeastward. Observed and simulated surface PM distributions show good agreement in both aerosol optical depth and NO2 column density further implying that anthropogenic emissions also contribute to regional events of high surface PM concentrations. It is argued that the quasi-periodic migration of synoptic weather systems in East Asia works as an efficient pump of pollutants; i.e., regional air pollutions developed under high-pressure systems are transported downstream by low-pressure systems.


2021 ◽  
pp. 407-416
Author(s):  
A. R. P. Warnasooriya ◽  
K. H. M. S. Premalal ◽  
A. W. S. J. Kumara ◽  
Chathuska G. Premachandra

Author(s):  
Kenzo Kumagai ◽  
Sooyoul Kim ◽  
Daiki Tsujio ◽  
Mase Hajime ◽  
Takahito Tsuji

Typhoon-induced storm surge can cause catastrophic consequences in low-lying city areas on coasts. From the historical observations, it is found that Winter Low Pressure System (WLPS) has impacts similar to a typhoon in terms of surge and wave generation. For instance, from 16th to 17th in December 2014, a winter low pressure system of 951 hPa occurred in Hokkaido, Japan, generated a surge of 1.75 m high and flooded many low-lying regions on the Kushiro coast. This was the record-break surge level due to WLPS in Japan, since the WLPS-induced surge of 0.9 m was recorded in 1994.


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