scholarly journals Characteristics of thunderstorms and squalls over Indira Gandhi International (IGI) airport, New Delhi - Impact on environment especially on summer’s day temperatures and use in forecasting

MAUSAM ◽  
2021 ◽  
Vol 60 (4) ◽  
pp. 461-474
Author(s):  
R. K. JENAMANI ◽  
R. C. VASHISTH ◽  
S. C. BHAN
Keyword(s):  
Wind Speed ◽  
Environmental Changes ◽  
Maximum Wind Speed ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Peak Time ◽  
New Delhi ◽  
Maximum Wind ◽  
Average Maximum

In the present study, commencement timings and duration of thunderstorms (TS) and squalls at IGI airport, Palam, New Delhi have been analysed critically based on most recent eleven years data of 1995-2005 to find their favourable time of occurrences. Then utility of such data base in the aviation warning has been demonstrated. Environmental changes associated with these squalls have also been further analysed to understand their impact. Being recent May 2007 a very cool month over Delhi, the role of TS on controlling the day’s soaring temperature has also been studied from their data.  Results show TS are maximum in June followed by July whereas squalls are maximum in May followed by June. It shows more than 80% of TS in each season are of duration less than 3 hours with remaining are mostly 3 to 6 hours. The peak time period of commencement of both TS and squalls in the day differ with the progress of the months. For pre monsoon months, the most favourable timing of TS and squalls are 1200-1500 UTC while for monsoon, it starts earlier. Around 37% of the total TS during the period were associated with squalls. The average maximum wind speed in squall at IGI airport is about 68 kmph with highest maximum wind speed 139 kmph. On an average the environmental temperature falls by 5.6° C, humidity levels rises by 17.8% and mean sea level pressure rises by 1.6 hPa due to the occurrences of squalls. Study also shows daily maximum temperature rise is highly controlled by TS occurrences and May 2007, being a month of highest TS occurrences at the airport since 1995, became one of the coolest month in May over Delhi. The comparison of TS frequencies shows 12% increase in their annual activities since 1950-1980 with very high unusual increase of 51% in June and 26% in May. Since analysis of data from 1995 shows occurrences of TS are reversely but strongly correlated with summer temperatures and longer period temperature data since 1975 also confirms absence of significant trend in maximum temperature and higher temperature days in peak summer months of May and June till recent as expected due to high pollution, global warming and fast urbanization in the city, so it is the higher number of TS occurrences over the region from time to time which might have been main factor for controlling its significant rise.

scholarly journals Variability of Daily Maximum Wind Speed across China, 1975–2016: An Examination of Likely Causes

2020 ◽  
Vol 33 (7) ◽  
pp. 2793-2816 ◽  
Author(s):  
Gangfeng Zhang ◽  
Cesar Azorin-Molina ◽  
Deliang Chen ◽  
Jose A. Guijarro ◽  
Feng Kong ◽  
...  
Keyword(s):  
Wind Speed ◽  
Large Scale ◽  
Southern Oscillation ◽  
Vertical Wind Shear ◽  
Maximum Wind Speed ◽  
The Arctic ◽  
Risk Governance ◽  
Daily Maximum ◽  
Near Surface ◽  
Maximum Wind

AbstractAssessing change in daily maximum wind speed and its likely causes is crucial for many applications such as wind power generation and wind disaster risk governance. Multidecadal variability of observed near-surface daily maximum wind speed (DMWS) from 778 stations over China is analyzed for 1975–2016. A robust homogenization protocol using the R package Climatol was applied to the DMWS observations. The homogenized dataset displayed a significant (p < 0.05) declining trend of −0.038 m s−1 decade−1 for all China annually, with decreases in winter (−0.355 m s−1 decade−1, p < 0.05) and autumn (−0.108 m s−1 decade−1; p < 0.05) and increases in summer (+0.272 m s−1 decade−1, p < 0.05) along with a weak recovery in spring (+0.032 m s−1 decade−1; p > 0.10); that is, DMWS declined during the cold semester (October–March) and increased during the warm semester (April–September). Correlation analysis of the Arctic Oscillation, the Southern Oscillation, and the west Pacific modes exhibited significant correlation with DMWS variability, unveiling their complementarity in modulating DMWS. Further, we explored potential physical processes relating to the atmospheric circulation changes and their impacts on DMWS and found that 1) overall weakened horizontal airflow [large-scale mean horizontal pressure gradient (from −0.24 to +0.02 hPa decade−1) and geostrophic wind speed (from −0.6 to +0.6 m s−1 decade−1)], 2) widely decreased atmospheric vertical momentum transport [atmospheric stratification thermal instability (from −3 to +1.5 decade−1) and vertical wind shear (from −0.4 to +0.2 m s−1 decade−1)], and 3) decreased extratropical cyclones frequency (from −0.3 to 0 month decade−1) are likely causes of DMWS change.

scholarly journals An Analysis of Daily Maximum Wind Speed in Northwestern Europe Using Generalized Linear Models

2002 ◽  
Vol 15 (15) ◽  
pp. 2073-2088 ◽  
Author(s):  
Zhongwei Yan ◽  
Steven Bate ◽  
Richard E. Chandler ◽  
Valerie Isham ◽  
Howard Wheater
Keyword(s):  
Wind Speed ◽  
Generalized Linear Models ◽  
Linear Models ◽  
Maximum Wind Speed ◽  
Daily Maximum ◽  
Maximum Wind

scholarly journals SPATIO-TEMPORAL DISTRIBUTION OF WIND SPEED AND DAILY MAXIMUM WIND SPEED IN MOROCCO FOR THE PERIOD 2020-2050

2018 ◽  
pp. 68-71
Author(s):  
V. Khokhlov ◽  
Y. El Hadri
Keyword(s):  
Wind Speed ◽  
Climate Models ◽  
Regional Climate ◽  
Atlantic Coast ◽  
Surface Wind ◽  
Regional Climate Models ◽  
Maximum Wind Speed ◽  
Daily Maximum ◽  
Near Surface ◽  
Maximum Wind

The Moroccan energy system is highly dependent on external energy markets. Therefore, the current renewable energy strategy is focused on deployment of large-scale renewable technologies projects. Morocco has abundant wind resources. Estimations made by development organizations in Morocco quantify that the economic and technical potential of wind energy in Morocco amount to 26 GW. The aim of this study is to determine the possible quantitative indicators of wind speed, the daily maximum wind speed and their space-time distribution in the period 2020-2050 on the territory of Morocco. In study used data from regional climate modelling with a high spatial resolution of the project CORDEX. Simulations of regional climate models provide opportunities for a better understanding of atmospheric processes in the region and their possible future change. In the study use of regional climate models simulations for the RCP 4.5 scenario for the Africa region, presented in a rectangular coordinate system with a spatial resolution of ≈ 44 km. As a result of the regional climate models calculation, the mean monthly Near-Surface Wind Speed, and Daily Maximum Near-Surface Wind Speed values for the period 2020-2050 for the territory of Morocco were obtained. Regional climate models simulations showed that in Morocco will be dominated by gentle and moderate winds. The smallest values of the average wind speed are predicted in Fez − Meknes and Beni-Mellal − Henifra regions and will be about 3 m/s, the highest values can reach 9 m/s on the Atlantic coast to the south of Dakhla village. An analysis showed that in the future a character of annual course, in general, will have two types: in central mountain regions of Atlas, in the northeastern part of country and on the Mediterranean coast maximum wind speed will be register in winter; summer seasonal maximum of wind speed will be typical on the flat areas of the Atlantic coast, in the southern part of the country and on areas located behind the ridges of the Atlas mountains on the border with Algeria. The most favorable for the development of wind energy will be areas located on the shore of the Mediterranean Sea and the Atlantic Ocean and in the southern part of Morocco.

scholarly journals Walking is regulated by environmental temperature

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuichi P. Obuchi ◽  
Hisashi Kawai ◽  
Juan C. Garbalosa ◽  
Kazumasa Nishida ◽  
Kenji Murakawa
Keyword(s):  
Environmental Temperature ◽  
Private Insurance ◽  
Movement Speed ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Curvilinear Relationship ◽  
Daily Maximum ◽  
Insurance Company ◽  
Average Maximum ◽  
Average Maximum Temperature

AbstractThe mechanisms that regulate human walking are not fully understood, although there has been substantial research. In our study, we hypothesized that, although walking can be volitionally modified, it is also involuntary and controlled by evolutionary factors, such as the relationship between temperature and movement speed in poikilotherms. This study aimed to determine the effects of environmental temperature on speed, step length, and cadence during unrestrained walking over long periods. Customers of a private insurance company were asked to use a background smartphone GPS application that measured walking parameters. Participants were 1065 app users (298 men and 767 women) aged 14–86 years. Observed walking speed and cadence were higher in winter (average maximum temperature: 10.2 °C) than in summer (average maximum temperature: 29.8 °C) (p < 0.001). The walking parameters were closely related to environmental temperature, with cadence most strongly correlated with daily maximum temperature (r = − 0.812, p < 0.001) and indicating a curvilinear relationship. A decrease in environmental temperature was found to increase cadence when the temperature was below 30 °C. The findings suggest that walking may be regulated by environmental temperature and potentially by the autonomic nervous system’s response to environmental temperature.

scholarly journals Impacts of Some Climatic Variables on the Seasonal Productivity of Aman Rice at Dhaka Region, Central Part of Bangladesh

2016 ◽  
Vol 8 (2) ◽  
pp. 7-10
Author(s):  
SMSA Tuhin ◽  
MA Farukh ◽  
BS Nahar ◽  
MA Baten
Keyword(s):  
Crop Production ◽  
Climatic Variability ◽  
Climatic Variables ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Climatic Data ◽  
Average Maximum ◽  
Average Maximum Temperature ◽  
Daily Sunshine

An agro-climatic study was conducted at Dhaka region of Bangladesh using 43 years (1970-2012) of climatic data (daily maximum temperature, seasonal total rainfall, daily average humidity, and daily sunshine hour) to observe the climatic variability and their impacts on the productivity of Aman rice. The average maximum temperature increased by 0.04°C in Aman season in Dhaka region. The average sunshine hours decreased by 0.05 in the season. The average humidity decreased by 0.14% in the season. The average seasonal rainfall increased slightly by 0.09 mm in the season. The Aman rice production increased by 0.03 t ha-1 in the region. The production year 2003 shows highest productivity due to less climatic devastation impact on the seasonal productivity of the rice. The climatic variables impact ( Savg > Havg > Tmax ) implies the seasonal productivity of Aman rice was mostly and inversely correlated with average sunshine (Savg) hour. However, most of the time the production showed increasing trend except some devastating natural calamities in the year of 1988 and 1998 which affected crop production seriously.J. Environ. Sci. & Natural Resources, 8(2): 7-10 2015

scholarly journals Some climatological aspects of thunderstorms and squalls over Guwahati Airport

MAUSAM ◽  
2021 ◽  
Vol 57 (2) ◽  
pp. 231-240
Author(s):  
GAJENDRA KUMAR ◽  
M. MOHAPATRA
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Frequency Distribution ◽  
Environmental Temperature ◽  
Environmental Changes ◽  
Monsoon Season ◽  
Early Morning ◽  
Maximum Wind ◽  
The Past ◽  
Average Maximum

Lkkj & xqokgkVh gokbZ vM~Ms ij vk, paMokr ls tqM+s okf"kZd vkSj ekfld ckjEckjrk dk forj.k] xtZ ds lkFk vk, rwQkuksa  vkSj paMokrksa ds vkjEHk gksus dk le; vkSj mudh vof/k rFkk i;kZoj.kh; ifjorZuksa dk fo’ys"k.k fd;k x;k gSA rwQku vkSj paMokr lcls T;knk ebZ ds eghusa esa vkrs gSa vkSj mlds ckn viSzy ds eghus esa vkrs gSaA rwQkuksa vkSj paMokrksa dh vko`fr;k¡ lcls T;knk ebZ ds eghusa esa gksrh gSa vkSj mlds ckn vizSy ds eghus esa gksrh gSaA vf/kdk¡’k rwQku ekulwu _rq ls iwoZ vkSj ekulwu _rq ds nkSjku vkrs gSa rFkk paMokr Qjojh ls ebZ ds eghuksa ds nkSjku vkrs gSaA ekulwu _rq ls iwoZ vkus okys vf/kdk¡’k rwQku e/; jkf= ls ysdj rM+ds lqcg ds le; esa vkrs gSa tcfd ekulwu _rq ds nkSjku vkus okys rwQku 0600&1200 ;w- Vh- lh- ds chp vk;k djrs gSa  vf/kdk¡’k rwQkuksa dh vof/k rhu ?kaVksa ls Hkh de dh gksrh gSA vf/kdk¡’k paMokrksa dh vof/k pkj feuVksa ls Hkh de dh gksrh gS] fn’kk mÙkj if’pe vkSj ;s 0900&2100 ;w- Vh- lh- ds le; vkrs gSaA xqokgkVh gokbZ vM~Ms ij paMokr ds vkus ls i;kZoj.kh; rkieku vkSlru 2-2° lsa- rd fxj tkrk gS] lkisf{kd vknzZrk 8-5 izfr’kr rd c<+ tkrh gS vkSj nkc 1-6 gSDVkikLdy rd c<+ tkrk gSA xqokgkVh gokbZ vM~Ms ij paMokr ds vkus ls vf/kdre iou xfr vkSlru yxHkx 39 ukWV~l gksrh gSA fiNys v/;;uksa ls rqyuk djus ij ;g irk pyrk gS fd fiNys dqN o"kksZa esa rQkuksa vkSj paMokrksa ds y{k.kksa esa fo’ks"k ifjorZu ugha vk;k gSA  The annual and monthly frequency distribution, time of commencement and duration of thunderstorms & squalls and environmental changes associated with occurrence of squall at Guwahati Airport have been analyzed. The frequencies of thunderstorms and squalls are maximum in the month of May followed by April. Most of the thunderstorms occur during premonsoon and monsoon season and squalls occur during Feb-May. Most of the premonsoon thunderstorms commence during midnight to early morning while the thunderstorms during monsoon season have preference to commence between 0600-1200 UTC. Majority of thunderstorms is of the duration of less than three hours. Majority of squalls have the duration of less than four minutes, direction as northwesterly and occur during 0900-2100 UTC. On the average, environmental temperature falls by 2.2° C, the relative humidity rises by 8.5%, and the pressure increases by 1.6 hPa due to squall over Guwahati Airport. The average maximum wind speed associated with a squall over Guwahati Airport is about 39 knots. Comparison with the past studies indicates that characteristics of thunderstorms and squalls have not changed significantly over the years.

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