scholarly journals Spatiotemporal Variability of Lightning Flash Distribution over Sri Lanka

2019 ◽  
Vol 82 ◽  
pp. 1-13
Author(s):  
U.G.Dilaj Maduranga ◽  
Mahesh Edirisinghe ◽  
L. Vimukthi Gamage
Keyword(s):  
Sri Lanka ◽  
Monsoon Season ◽  
Tropical Rainfall Measuring Mission ◽  
Spatiotemporal Variability ◽  
Spatial And Temporal Variation ◽  
Lightning Flash ◽  
Northeast Monsoon ◽  
Time Period ◽  
Total Lightning ◽  
Imaging Sensor

The variation of the lightning activities over Sri Lanka and surrounded costal belt (5.750N-10.000N and 79.50E-89.000E) is studied using lightning flash data of Lightning Imaging Sensor (LIS) which was launched in November 1997 for NASA’s Tropical Rainfall Measuring Mission (TRMM). The LIS data for the period of 1998 to 2014 are considered for this study. The spatial and temporal variation of lightning activities is investigated and respective results are presented. The diurnal variation over the studied area presents that maximum and minimum flash count recorded at 1530-1630 Local Time (10-11UTC) and 0530-0630LT (00-01UTC) respectively. Maximum lightning activities over the observed area have occurred after the 1330LT (08UTC) in every year during the considered time period. The seasonal variation of the lightning activities shows that the maximum lightning activities happened in First inter monsoon season (March to April) with 30.90% total lightning flashes and minimum lightning activities recorded in Northeast monsoon season (December to February) with 8.51% of total lightning flashes. Maximum flash density of 14.37fl km-2year-1 was observed at 6.980N/80.160E in First inter monsoon season. These seasonal lighting activities are agree with seasonal convective activities and temperature variation base on propagation of Intra-Tropical Convection Zone over the studied particular area. Mean monthly flash count presents a maximum in the month of April with 29.12% of lightning flashes. Variation pattern of number of lightning activities in month of April shows a tiny increment during the time period of 1998 to 2014. Maximum annual flash density of 28.09fl km-2yr-1 was observed at 6.980N/80.170E. The latitudinal variation of the lightning flash density is depicted that extreme lightning activities have happened at the southern part of the county and results show that there is a noticeable lack of lightning activities over the surrounded costal belt relatively landmass.

scholarly journals Climatology of Lightning Activities over Bandaranaike International Airport in Sri Lanka

2021 ◽  
Vol 16 (6) ◽  
pp. 1027-1038
Author(s):  
Dilaj Maduranga ◽  
Mahesh Edirisinghe
Keyword(s):  
Sri Lanka ◽  
Monsoon Season ◽  
Tropical Rainfall Measuring Mission ◽  
Southwest Monsoon ◽  
Aviation Industry ◽  
Lightning Flash ◽  
Northeast Monsoon ◽  
International Airport ◽  
Environmental Goals ◽  
Imaging Sensor

This study reveals the spatiotemporal distribution of lightning activities over Bandaranaike International Airport, the main international airport of Sri Lanka. Lightning flash data was acquired from the Lightning Imaging Sensor (LIS) on Tropical Rainfall Measuring Mission (TRMM) of NASA to investigate lightning activities from 1998 to 2014 covering an area of 30 km×30 km over the airport. Overhead annual flash density was 8.19 flashes km-2 year-1. The maximum lightning activities (57%) with an overhead flash density of 28.83 flashes km-2 year-1 was recorded in the first inter-monsoon season. The overhead flash density of 5.28 flashes km-2 year-1, 16.36 flashes km-2 year-1 and 7.46 flashes km-2 year-1 were recorded in the southwest monsoon season, second inter-monsoon season, and northeast monsoon season respectively. The month of April accounts for the highest number of lightning activities while maximum lightning flashes (22%) had occurred during 19.00-20.00 Local Time. According to the international climate season, maximum lightning activities over the study area have been recorded from March to May and during this seasonal period, the northern hemisphere is in spring and the southern hemisphere is in autumn. Safety guidelines are proposed to minimize lightning accidents in the airport. It is important to concern the regions with high lightning activity and vulnerable time periods to mitigate lightning accidents and to take adequate safety precautions to ensure the safety of passengers and the working crew to achieve environmental goals of sustainable development in the aviation industry.

scholarly journals TRMM LIS Climatology of Thunderstorm Occurrence and Conditional Lightning Flash Rates*

2015 ◽  
Vol 28 (16) ◽  
pp. 6536-6547 ◽  
Author(s):  
Daniel J. Cecil ◽  
Dennis E. Buechler ◽  
Richard J. Blakeslee
Keyword(s):  
East Coast ◽  
Eastern China ◽  
Central Africa ◽  
Tropical Rainfall Measuring Mission ◽  
Lightning Flash ◽  
Conditional Mean ◽  
Flash Rate ◽  
Central United States ◽  
Total Lightning ◽  
Imaging Sensor

Abstract The Lightning Imaging Sensor (LIS) on the Tropical Rainfall Measuring Mission (TRMM) satellite has previously been used to build climatologies of mean lightning flash rate across the global tropics and subtropics. This new work explores climatologies of thunderstorm occurrence as seen by LIS and the conditional mean flash rates when thunderstorms do occur. The region where thunderstorms are seen most often by LIS extends slightly farther east in central Africa than the corresponding region with the highest total mean annual flash rates. Presumably this reflects a difference between more frequent thunderstorm initiation in the east and upscale growth as storms move westward. There are some differences between locations with the greatest total lightning flash counts and those where thunderstorms occur most often. The greatest conditional mean flash rates—considering only those TRMM orbits that do have lightning in a given grid box—are found in subtropical regions. The highest values are in Argentina, with the central United States, Pakistan, eastern China, and the east coast of Australia also having particularly high values.

scholarly journals Lightning Climatology and Human Vulnerability to Lightning Hazards in a School Community: A Case Study in Sri Lanka using LIS Data from TRMM Satellite

2021 ◽  
Vol 4 (3) ◽  
pp. 29-50
Author(s):  
U. G. D. Maduranga ◽  
Mahesh Edirisinghe
Keyword(s):  
Sri Lanka ◽  
Monsoon Season ◽  
Tropical Rainfall Measuring Mission ◽  
After School ◽  
Sri Lankan ◽  
Human Vulnerability ◽  
Outdoor Activities ◽  
Risk Levels ◽  
Imaging Sensor

This study reported lightning climatology and human vulnerability to lightning in a 20 km × 20 km high-density school area in Colombo city in Sri Lanka from 1998 to 2014 using Lightning Imaging Sensor (LIS) flash data of NASA’s Tropical Rainfall Measuring Mission (TRMM). An average annual flash density recorded over the study area was 9.43 flashes km-2 year-1. A maximum of 49% lightning flashes happened during the first inter-monsoon season. There were only 4% lightning flashes that occurred during 06.00-12.00 LT and during 18.00-24.00 LT, it was 67%, whereas 94% of lightning flashes within a day had occurred after 14.00 LT. It is recommended that, without having proper lightning hazard preventive measures, schools in the study area should avoid or minimalize scheduling their outdoor activities in high lightning risk months of April and November. Especially, after-school outdoor activities should be planned with proper safety measures during the aforementioned months as per the diurnal analysis. Moreover, May to September and December to February were the months with the least lightning risk levels. It is recommended to follow the proposed five-level lightning safety guideline which includes, schedule outdoor activities by considering the variation of lightning activities, follow the 30-30 rule whenever required, avoid staying at the most hazardous locations which are vulnerable to lightning accidents, crouching action if required and providing first-aid whenever necessary. Not only for the Sri Lankan context but also the study is crucial and highly applicable for all schools and other institutes especially in other tropical countries.

scholarly journals Preliminary Observations from the China Fengyun-4A Lightning Mapping Imager and Its Optical Radiation Characteristics

2020 ◽  
Vol 12 (16) ◽  
pp. 2622 ◽  
Author(s):  
Wen Hui ◽  
Wenjuan Zhang ◽  
Weitao Lyu ◽  
Pengfei Li
Keyword(s):  
Data Processing ◽  
Optical Radiation ◽  
Monsoon Season ◽  
Tropical Rainfall Measuring Mission ◽  
Radiation Characteristics ◽  
Southeastern China ◽  
Northeastern India ◽  
Satellite Platform ◽  
Variation Characteristics ◽  
Imaging Sensor

The Fengyun-4A (FY-4A) Lightning Mapping Imager (LMI) is the first satellite-borne lightning imager developed in China, which can detect lightning over China and its neighboring regions based on a geostationary satellite platform. In this study, the spatial distribution and temporal variation characteristics of lightning activity over China and its neighboring regions were analyzed in detail based on 2018 LMI observations. The observation characteristics of the LMI were revealed through a comparison with the Tropical Rainfall Measuring Mission (TRMM)-Lightning Imaging Sensor (LIS) and World Wide Lightning Location Network (WWLLN) observations. Moreover, the optical radiation characteristics of lightning signals detected by the LMI were examined. Factors that may affect LMI detection were discussed by analyzing the differences in optical radiation characteristics between LMI and LIS flashes. The results are as follows. Spatially, the flash density distribution pattern detected by the LMI was similar to those detected by the LIS and WWLLN. High-flash density regions were mainly concentrated over Southeastern China and Northeastern India. Temporally, LMI flashes exhibited notable seasonal and diurnal variation characteristics. The LMI detected a concentrated lightning outbreak over Northeastern India in the premonsoon season and over Southeastern China in the monsoon season, which was consistent with LIS and WWLLN observations. LMI-observed diurnal peak flash rates occurred in the afternoon over most of the regions. There was a “stepwise” decrease in the LMI-observed optical radiance, footprint size, duration, and number of groups per flash, from the ocean to the coastal regions to the inland regions. LMI flashes exhibited higher optical radiance but lasted for shorter durations than LIS flashes. LMI observations are not only related to instrument performance but are also closely linked to onboard and ground data processing. In future, targeted improvements can be made to the data processing algorithm for the LMI to further enhance its detection capability.

Investigation of Lightning Distribution Using LIS Data from TRMM Satellite

2014 ◽  
Vol 695 ◽  
pp. 836-839
Author(s):  
Norbayah Yusop ◽  
Siti Hawa Zainal ◽  
Nor Azlan Mohd Aris ◽  
S.A.M. Chachuli ◽  
Mawarni Mohamed Yunus
Keyword(s):  
Initial Data ◽  
Lightning Discharge ◽  
Winter Season ◽  
Tropical Rainfall Measuring Mission ◽  
Washington Dc ◽  
Spring Season ◽  
Seasonal Basis ◽  
Earth’S Climate ◽  
Total Lightning ◽  
Imaging Sensor

This paper presents an investigation on lightning distribution using Lightning Imaging Sensor (LIS) data from Tropical Rainfall Measuring Mission (TRMM) satellite. The investigation is carried out on distribution and variability of total lightning occurred in the area of Washington DC (38.54°N, 77.2°W) during January to April 2011. LIS captures emissions that occurred in the atmosphere which emitted by lightning discharge by covering the most between ±35o in latitude. The lightning distributions are characterized based on monthly, daily, hourly and seasonal basis. The maps of global distribution of lightning flashes have been used as initial data. This analysis shows that a total number of 3.5 million flashes were detected during four months observation. The highest number of flashes recorded in April is about 3.4 million flashes compared to the 3,993 flashes in January. In terms of seasonal, this observation show that the spring season during March and April has highest occurrence of lightning which is 53.2% compared to the winter season in January and February which only 46.8%. This study can provides expected variations of the lightning distribution on the diurnal and seasonal basis, thus make it useful in describing the Earth’s climate.

scholarly journals Relationship between Lightning Activity over Peninsular India and Sea Surface Temperature

2010 ◽  
Vol 49 (4) ◽  
pp. 828-835 ◽  
Author(s):  
M. I. R. Tinmaker ◽  
Kaushar Ali ◽  
G. Beig
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Monsoon Season ◽  
Lightning Activity ◽  
Sea Surface ◽  
Lightning Flash ◽  
Northeast Monsoon ◽  
Monsoon Period ◽  
Peninsular India ◽  
Seasonal Time Scale

Abstract This paper presents a study of spatiotemporal variation of lightning activity over Peninsular India (8°–22°N, 72°–88°E) by using monthly satellite-based lightning flash grid (1° × 1°) data for a period of 10 yr (1998–2007). The data are examined in terms of spatial, annual, and seasonal distribution of the lightning activity. It is found that lightning activity is higher over south Peninsular India and eastern India. On a seasonal time scale, the lightning activity shows two maxima—first in the month of May and then in the month of September. The lightning activity in the monsoon period is noticed to be considerable because of the occurrence of the low-level jet and increase in the monsoon break period. During the postmonsoon, the activity is mainly due to the presence of the convective nature of the disturbed weather during the northeast monsoon season over most parts of the east coast of south Peninsular India. The relationship between lightning activity over Peninsular India and sea surface temperature in the bordering seas (Arabian Sea and Bay of Bengal) is also examined. The results disclose a significant link between them.

scholarly journals Blue whales off the Southern coast of Sri Lanka during the Southwest Monsoon Season

2020 ◽  
Vol 21 (1) ◽  
pp. 1-7
Author(s):  
Grace Russell ◽  
Marcus Bridge ◽  
Maja Nimak-Wood
Keyword(s):  
Sri Lanka ◽  
Monsoon Season ◽  
Weather Conditions ◽  
Southwest Monsoon ◽  
Lower Latitude ◽  
Northeast Monsoon ◽  
Southern Coast ◽  
Northern India ◽  
Blue Whales ◽  
Southwest Monsoon Season

Observations of 37 individual blue whales (Balaenoptera musculus) were recorded off the southern coast of Sri Lanka during the Southwest Monsoon Season (SWM). Sightings were made during a scientific geophysical survey campaign conducted in July and August 2017. Whilst blue whales are regularly recorded on the continental slope of southern Sri Lanka during the Northeast Monsoon Season (NEM) (December - March) and during the two inter-monsoonal periods (March - April and September - October), limited data is available for the SWM (May - September) mostly due to unfavourable weather conditions and very little survey effort. In the northern hemisphere blue whales undertake seasonal migrations from higher latitude feeding grounds to lower latitude breeding and wintering areas. However it has been suggested that a population of blue whales in the Northern India Ocean (NIO) remains in lower latitudes year round taking advantage of the rich upwelling areas off Somalia, southwest Arabia and western Sri Lanka. Data from this study nevertheless support a theory that a certain number of individuals remain off the southern coast off Sri Lanka during the SWM, suggesting that the productivity in this region is sufficient to support their year-round presence. This study therefore fills a knowledge gap regarding the presence and movement of blue whales in the NIO highlighting the importance of data obtained from platforms of opportunity.

scholarly journals An analytical study of easterly waves over southern peninsular India during the northeast monsoon 2010

MAUSAM ◽  
2021 ◽  
Vol 65 (4) ◽  
pp. 591-602
Author(s):  
B. GEETHA ◽  
S. BALACHANDRAN
Keyword(s):  
Monsoon Season ◽  
Wave Radiation ◽  
Northeast Monsoon ◽  
Peninsular India ◽  
Upper Troposphere ◽  
Easterly Waves ◽  
Easterly Wave ◽  
Time Period ◽  
Meridional Winds ◽  
The Waves

Easterly wave characteristics over southern peninsular India during the northeast monsoon season of 2010 are examined by means of synergetic analysis involving synoptic, statistical and numerical methods. NCEP        6-hourly reanalysis datasets of zonal and meridional winds, vertical velocity, temperature and net long wave radiation at 2.5° × 2.5° grid resolution for the period 20th October to 31st  December, 2010 form the main database for the analysis.  During this period, 3 easterly waves could be identified to have passed over this region and the time period of these waves are determined to be 4.2 days (4.5 days) by statistical methods (synoptic methods). The speed of movement, wavelength and amplitude of the waves are determined to be 7.28 ms-1, 2800 km and 6.7 ms-1 respectively. While rising motion is observed at most of the tropospheric levels over and behind the trough, subsidence occurs ahead of the trough. Divergence is noted over and behind the trough at upper troposphere while convergence occurs in the lower to mid-troposphere. Concomitantly warming is noted ahead of the trough while colder anomalies are noted in the lower levels over and behind the trough. 

scholarly journals Spatio-temporal Variability of Lightning Climatology and Its Association With Thunderstorm Indices Over India

2022 ◽  
Author(s):  
Unashish Mondal ◽  
Subrat Kumar Panda ◽  
Someshwar Das ◽  
Devesh Sharma
Keyword(s):  
Tropical Rainfall Measuring Mission ◽  
Eastern Region ◽  
Lightning Flash ◽  
Time Duration ◽  
Jammu And Kashmir ◽  
Flash Rate ◽  
North Eastern ◽  
Very High Spatial Resolution ◽  
Spatio Temporal ◽  
Imaging Sensor

Abstract Lightning is an electrical discharge - a'spark' or 'flash' as charged regions in the atmosphere instantly balance themselves through this discharge. It is a beautiful and deadly naturally occurring phenomenon. In June 2020, more than a hundred people died in the state Bihar of India only in three days’ span due to lightning events. In this work, Lightning Imaging Sensor (LIS) information from the Tropical Rainfall Measuring Mission (TRMM) satellite with a very high spatial resolution of 0.1 X 0.1 degree has been utilized to create the climatology of India for 16 years from 1998 to 2013. Diurnal, monthly, and seasonal variations in the occurrence of lightning flash rate density have also been analyzed. TRMM satellite low-resolution monthly time series (LRMTS) with 2.5-degree resolution datasets have been used for lightning trend analysis. The diurnal lightning event mainly occurs in the afternoon/evening (1400-1900 Hrs) time duration around 0.001 flashes/km2/hr. The highest lightning occurred in May (0.04 flashes/km2/day) and the least in December (0.005 flashes/km2/day). The distribution of lightning flash counts by season over India landmass is mainly in pre-monsoon (MAM) ranges from 0.248 – 0.491 flashes/km2/day, and monsoon (JJA) ranges from 0.284 – 0.451 flashes/km2/day and decreases afterward. Spatially, the distribution of lightning flashes mainly at North-Eastern region along with Bangladesh, Bihar, Jharkhand, Orissa, and Jammu & Kashmir region. The CAPE and K Index have positively correlated with the flash rate density seasonally but CAPE is more significantly correlated. This study also focused on finding of lightning hotspots region of India district wise and Rajouri district in Jammu and Kashmir got the highest lightning with 121 flashes/km2/yr.

scholarly journals Where Are the Lightning Hotspots on Earth?

2016 ◽  
Vol 97 (11) ◽  
pp. 2051-2068 ◽  
Author(s):  
Rachel I. Albrecht ◽  
Steven J. Goodman ◽  
Dennis E. Buechler ◽  
Richard J. Blakeslee ◽  
Hugh J. Christian
Keyword(s):  
Tropical Rainfall Measuring Mission ◽  
Low Earth Orbit ◽  
Congo Basin ◽  
Sea Breezes ◽  
Mountain Ranges ◽  
Flash Rate ◽  
Temporal Smoothing ◽  
Total Lightning ◽  
Lake Waters ◽  
Imaging Sensor

Abstract Previous total lightning climatology studies using Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS) observations were reported at coarse resolution (0.5°) and employed significant spatial and temporal smoothing to account for sampling limitations of TRMM’s tropical to subtropical low-Earth-orbit coverage. The analysis reported here uses a 16-yr reprocessed dataset to create a very high-resolution (0.1°) climatology with no further spatial averaging. This analysis reveals that Earth’s principal lightning hotspot occurs over Lake Maracaibo in Venezuela, while the highest flash rate density hotspot previously found at the lower 0.5°-resolution sampling was found in the Congo basin in Africa. Lake Maracaibo’s pattern of convergent windflow (mountain–valley, lake, and sea breezes) occurs over the warm lake waters nearly year-round and contributes to nocturnal thunderstorm development 297 days per year on average. These thunderstorms are very localized, and their persistent development anchored in one location accounts for the high flash rate density. Several other inland lakes with similar conditions, that is, deep nocturnal convection driven by locally forced convergent flow over a warm lake surface, are also revealed. Africa is the continent with the most lightning hotspots, followed by Asia, South America, North America, and Australia. A climatological map of the local hour of maximum flash rate density reveals that most oceanic total lightning maxima are related to nocturnal thunderstorms, while continental lightning tends to occur during the afternoon. Most of the principal continental maxima are located near major mountain ranges, revealing the importance of local topography in thunderstorm development.

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