Distinct aerosol effects on cloud-to-ground lightning in the plateau and basin regions of Sichuan, Southwest China

Abstract. The joint effects of aerosol, thermodynamic, and cloud-related factors on cloud-to-ground lightning in Sichuan were investigated by a comprehensive analysis of ground-based measurements made from 2005 to 2017 in combination with reanalysis data. Data include aerosol optical depth, cloud-to-ground (CG) lightning density, convective available potential energy (CAPE), mid-level relative humidity, lower- to mid-tropospheric vertical wind shear, cloud-base height, total column liquid water (TCLW), and total column ice water (TCIW). Results show that CG lightning density and aerosols are positively correlated in the plateau region and negatively correlated in the basin region. Sulfate aerosols are found to be more strongly associated with lightning than total aerosols, so this study focuses on the role of sulfate aerosols in lightning activity. In the plateau region, the lower aerosol concentration stimulates lightning activity through microphysical effects. Increasing the aerosol loading decreases the cloud droplet size, reducing the cloud droplet collision–coalescence efficiency and inhibiting the warm-rain process. More small cloud droplets are transported above the freezing level to participate in the freezing process, forming more ice particles and releasing more latent heat during the freezing process. Thus, an increase in the aerosol loading increases CAPE, TCLW, and TCIW, stimulating CG lightning in the plateau region. In the basin region, by contrast, the higher concentration of aerosols inhibits lightning activity through the radiative effect. An increase in the aerosol loading reduces the amount of solar radiation reaching the ground, thereby lowering the CAPE. The intensity of convection decreases, resulting in less supercooled water being transported to the freezing level and fewer ice particles forming, thereby increasing the total liquid water content. Thus, an increase in the aerosol loading suppresses the intensity of convective activity and CG lightning in the basin region.

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Distinct aerosol effects on cloud-to-ground lightning in the plateau and basin regions of Sichuan, Southwest China

10.5194/acp-2020-429 ◽

2020 ◽

Author(s):

Pengguo Zhao ◽

Zhanqing Li ◽

Hui Xiao ◽

Fang Wu ◽

Youtong Zheng ◽

...

Keyword(s):

Cloud Droplet ◽

Lightning Activity ◽

Freezing Process ◽

Plateau Region ◽

Freezing Level ◽

Aerosol Loading ◽

Cloud To Ground Lightning ◽

Basin Region ◽

Total Column ◽

Cg Lightning

Abstract. The joint effects of aerosol, thermodynamic, and cloud-related factors on cloud-to-ground lightning in Sichuan were investigated by a comprehensive analysis of ground measurements made from 2005 to 2017 in combination with reanalysis data. Data include aerosol optical depth, cloud-to-ground (CG) lightning density, convective available potential energy (CAPE), mid-level relative humidity, lower- to mid-tropospheric vertical wind shear, cloud-base height, total column liquid water (TCLW), and total column ice water (TCIW). Results show that CG lightning density and aerosols are positively correlated in the plateau region and negatively correlated in the basin region. Sulfate aerosols are found to be more strongly associated with lightning than total aerosols, so this study focuses on the role of sulfate aerosols in lightning activity. In the plateau region, the lower aerosol concentration stimulates lightning activity through microphysical effects. Increasing the aerosol loading reduces the cloud droplet size, reducing the cloud droplet collision-coalescence efficiency and inhibiting the warm-rain process. More small cloud droplets are transported above the freezing level to participate in the freezing process, forming more ice particles and releasing more latent heat during the freezing process. Thus, an increase in aerosol loading increases CAPE, TCLW, and TCIW, stimulating CG lightning in the plateau region. In the basin region, by contrast, the higher concentration of aerosols inhibits lightning activity through the radiative effect. An increase in aerosol loading reduces the amount of solar radiation reaching the ground, thereby lowering CAPE. The intensity of convection decreases, resulting in less supercooled water transported to the freezing level and fewer ice particles forming, thus increasing the total liquid water content. Therefore, an increase in aerosol loading suppresses the intensity of convective activity and CG lightning in the basin region.

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Analysis of cloud-to-ground lightning and its relation with surface pollutants over Taipei, Taiwan

Annales Geophysicae ◽

10.5194/angeo-32-1085-2014 ◽

2014 ◽

Vol 32 (9) ◽

pp. 1085-1092 ◽

Cited By ~ 4

Author(s):

S. K. Kar ◽

Y. A. Liou

Keyword(s):

Lower Troposphere ◽

Lightning Activity ◽

Background Concentration ◽

Moderate Resolution ◽

Cloud To Ground Lightning ◽

Resolution Imaging ◽

Moderate Resolution Imaging Spectroradiometer ◽

Two Parameters ◽

Enhanced Surface ◽

Cg Lightning

Abstract. Premonsoon (March–April) cloud-to-ground (CG) lightning activity over Taipei, Taiwan, is analyzed in relation to surface pollutants like particulate matter (PM10), sulfur dioxide (SO2), nitrogen oxides (NOx) and ozone (O3) concentration for a period of 6 years (2005–2010). Other surface parameters like aerosol optical depth and cloud top temperature are also investigated taking data from Moderate Resolution Imaging Spectroradiometer satellite products. Results reveal that SO2 is more strongly associated with CG lightning activity compared to PM10 concentration. Other surface pollutants like NOx and O3 also show strong linear association with CG lightning flashes. Additional investigations have also been performed to extreme lightning events, particularly to a few long-lasting lightning episodes considering the concentrations of NOx and O3 found on days with no lightning activity as representative of the background concentration levels of the said two parameters. Results indicate that the NOx concentration on days with lightning activity is more than 2-fold compared to the non-lightning days while the O3 concentration is increased by 1.5-fold. Such increase in NOx and O3 concentration on days with lightning strongly supports the transport phenomena of NOx and O3 from the upper or middle troposphere to the lower troposphere by downdraft of the thunderstorm during its dissipation stage. Overall, studies suggest that enhanced surface pollution in a near-storm environment is strongly related to the increased lightning activity, which in turn increases the surface NOx level and surface O3 concentration over the area under study.

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Enhancement of Cloud-to-Ground Lightning Activity Caused by the Urban Effect: A Case Study in the Beijing Metropolitan Area

Remote Sensing ◽

10.3390/rs13071228 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1228

Author(s):

Yongping Wang ◽

Gaopeng Lu ◽

Tao Shi ◽

Ming Ma ◽

Baoyou Zhu ◽

...

Keyword(s):

Metropolitan Area ◽

Industrial Area ◽

Lightning Activity ◽

Beijing Area ◽

Factors Affecting ◽

Pollutant Concentrations ◽

Lightning Detection ◽

Cloud To Ground Lightning ◽

Beijing Metropolitan Area ◽

Cg Lightning

To investigate the possible impact of urban development on lightning activity, an eight-year (2010–2017) cloud-to-ground (CG) lightning dataset provided by the National-Wide Lightning Detection Network in China was analyzed to characterize the CG lightning activity in the metropolitan area of Beijing. There is a high CG flash density area over the downtown of Beijing, but different from previous studies, the downwind area of Beijing is not significantly enhanced. Compared with the upwind area, the CG flash density in the downtown area was enhanced by about 50%. Negative CG flashes mainly occurred in the downtown and industrial area, while positive CG flashes were distributed evenly. The percentage of positive CG flashes with Ipeak ≥ 75 kA is more than six times that of the corresponding negative CG flashes in the Beijing area. The enhancement of lightning activity varies with season and time. About 98% of CG flashes occurred from May to September, and the peak of CG diurnal variation is from 1900 to 2100 local time. Based on the analysis of thunderstorm types in Beijing, it is considered that the abnormal lightning activity is mainly responsible for an enhancement of the discharge number in frontal systems rather than the increase of the number of local thunderstorms. In addition, there is a non-linear relationship between pollutant concentrations and CG flash number, which indicates that there are other critical factors affecting the production of lightning.

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The Cloud-to-Ground Lightning Parameterization Development with the Canadian Local Climate Model

10.20944/preprints201611.0085.v1 ◽

2016 ◽

Author(s):

Abderrazak Arif

Keyword(s):

Climate Model ◽

Numerical Models ◽

Warm Season ◽

Precipitable Water ◽

Absolute Error ◽

Lightning Activity ◽

Static State ◽

Local Climate ◽

Freezing Level ◽

Cg Lightning

We use the third version of the Canadian Local Climate Model  as a diagnostic tool to study the climatology of observed CG lightning activity at Maniwaki (latitude: 46,23°N; Longitude: 75,58°W). We examine the dependence between the hourly lightning activity and the related atmospheric variables during the warm season of sixteen years (between 1984 and 2004). The goal of this research is: a) to evaluate the atmospheric static state evolution and its moisture contents for conditions having generated lightning occurrence, b) to develop a CG lightning parameterization, and c) to verify this CG lightning parameterization on other Canadian areas. The freezing level altitude and the precipitable water content are used to estimate the static air instability and its moisture content respectively. These two parameters are served to develop the CG lightning parameterization. A comparison between the observations and simulations CG lightning occurrence and frequency at Maniwaki showed a mean absolute error rate of 27% and 55% respectively. We apply this parameterization at four Canadian regions, distributed from west to east. The simulated CG lightning results are comparable to observed CG lightning at Maniwaki and tested regions. The application of the CG lightning parameterization to the daily data enabled us to find the monthly results. This application represents a preliminary stage for validation this parameterization in regional numerical models in Canada during the historic period.

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Characteristics of cloud-to-ground lightning activity over Seoul, South Korea in relation to an urban effect

Annales Geophysicae ◽

10.5194/angeo-25-2113-2007 ◽

2007 ◽

Vol 25 (10) ◽

pp. 2113-2118 ◽

Cited By ~ 18

Author(s):

S. K. Kar ◽

Y.-A. Liou ◽

K.-J. Ha

Keyword(s):

South Korea ◽

Correlation Coefficients ◽

Lightning Activity ◽

Lightning Flash ◽

Urban Effect ◽

Percentage Decrease ◽

Lightning Detection ◽

Cloud To Ground Lightning ◽

The City ◽

Cg Lightning

Abstract. Cloud-to-ground (CG) lightning flash data collected by the lightning detection network installed at the Korean Meteorological Administration (KMA) have been used to study the urban effect on lightning activity over and around Seoul, the largest metropolitan city of South Korea, for the period of 1989–1999. Negative and positive flash density and the percentage of positive flashes have been calculated. Calculation reveals that an enhancement of approximately 60% and 42% are observed, respectively, for negative and positive flash density over and downwind of the city. The percentage decrease of positive flashes occurs over and downwind of Seoul and the amount of decrease is nearly 20% compared to upwind values. The results are in good agreement with those obtained by Steiger et al. (2002) and Westcott (1995). CG lightning activities have also been considered in relation to annual averages of PM10 (particulate matter with an aerodynamic diameter smaller than 10 μm) and sulphur dioxide (SO2) concentrations. Interesting results are found, indicating that the higher concentration of SO2 contributes to the enhancement of CG lightning flashes. On the other hand, the contribution from PM10 concentration has not appeared in this study to be as significant as SO2 in the enhancement of CG lightning flashes. Correlation coefficients of 0.33 and 0.64 are found between the change in CG lightning flashes and the PM10 and SO2, respectively, for upwind to downwind areas, suggesting a significant influence of the increased concentration of SO2 on the enhancement of CG flashes.

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Diurnal Variations in the Characteristics of Cloud-to-Ground Lightning Activity in the Great Lakes Region of the United States

The Professional Geographer ◽

10.1111/0033-0124.00171 ◽

1999 ◽

Vol 51 (3) ◽

pp. 349-366 ◽

Cited By ~ 2

Author(s):

Claudia K. Walters ◽

Julie A. Winkler

Keyword(s):

United States ◽

Great Lakes ◽

The United States ◽

Diurnal Variations ◽

Lightning Activity ◽

Great Lakes Region ◽

Cloud To Ground Lightning

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Cloud-to-ground lightning in Portugal: patterns and dynamical forcing

Natural Hazards and Earth System Science ◽

10.5194/nhess-12-639-2012 ◽

2012 ◽

Vol 12 (3) ◽

pp. 639-649 ◽

Cited By ~ 18

Author(s):

J. A. Santos ◽

M. A. Reis ◽

J. Sousa ◽

S. M. Leite ◽

S. Correia ◽

...

Keyword(s):

Large Scale ◽

Bimodal Distribution ◽

Lightning Activity ◽

Atmospheric Conditions ◽

Remote Forcing ◽

Cloud To Ground Lightning ◽

Using Data ◽

Number Of Discharges ◽

Low Pressures ◽

Large Scale Atmospheric Circulation

Abstract. An analysis of the cloud-to-ground discharges (CGD) over Portugal is carried out using data collected by a network of sensors maintained by the Portuguese Meteorological Institute for 2003–2009 (7 yr). Only cloud-to-ground flashes are considered and negative polarity CGD are largely dominant. The total number of discharges reveals a considerable interannual variability and a large irregularity in their distribution throughout the year. However, it is shown that a large number of discharges occur in the May–September period (71%), with a bimodal distribution that peaks in May and September, with most of the lightning activity recorded in the afternoon (from 16:00 to 18:00 UTC). In spring and autumn the lightning activity tends to be scattered throughout the country, whereas in summer it tends to be more concentrated over northeastern Portugal. Winter generally presents low lightning activity. Furthermore, two significant couplings between the monthly number of days with discharges and the large-scale atmospheric circulation are isolated: a regional forcing, predominantly in summer, and a remote forcing. In fact, the identification of daily lightning regimes revealed three important atmospheric conditions for triggering lightning activity: regional cut-off lows, cold troughs induced by remote low pressure systems and summertime regional low pressures at low-tropospheric levels combined with a mid-tropospheric cold trough.

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The European lightning location system EUCLID – Part 2: Observations

Natural Hazards and Earth System Science ◽

10.5194/nhess-16-607-2016 ◽

2016 ◽

Vol 16 (2) ◽

pp. 607-616 ◽

Cited By ~ 42

Author(s):

Dieter Roel Poelman ◽

Wolfgang Schulz ◽

Gerhard Diendorfer ◽

Marina Bernardi

Keyword(s):

Diurnal Cycle ◽

Lightning Activity ◽

European Continent ◽

Peak Current ◽

Location System ◽

European Cooperation ◽

Lightning Detection ◽

Lightning Location System ◽

Cg Lightning

Abstract. Cloud-to-ground (CG) lightning data from the European Cooperation for Lightning Detection (EUCLID) network over the period 2006–2014 are explored. Mean CG flash densities vary over the European continent, with the highest density of about 6 km−2 yr−1 found at the intersection of the borders between Austria, Italy and Slovenia. The majority of lightning activity takes place between May and September, accounting for 85 % of the total observed CG activity. Furthermore, the thunderstorm season reaches its highest activity in July, while the diurnal cycle peaks around 15:00 UTC. A difference between CG flashes over land and sea becomes apparent when looking at the peak current estimates. It is found that flashes with higher peak currents occur in greater proportion over sea than over land.

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Detecting Multiple Ground Contacts in Cloud-to-Ground Lightning Flashes

Journal of Atmospheric and Oceanic Technology ◽

10.1175/2009jtecha1278.1 ◽

2009 ◽

Vol 26 (11) ◽

pp. 2392-2402 ◽

Cited By ~ 25

Author(s):

Christina A. Stall ◽

Kenneth L. Cummins ◽

E. Philip Krider ◽

John A. Cramer

Keyword(s):

Standard Deviation ◽

Rise Time ◽

Random Errors ◽

Peak Current ◽

Video Recordings ◽

Lightning Detection ◽

Cloud To Ground Lightning ◽

The U.S ◽

Good Agreement ◽

Cg Lightning

Abstract Video recordings of cloud-to-ground (CG) lightning flashes have been analyzed in conjunction with correlated stroke reports from the U.S. National Lightning Detection Network (NLDN) to determine whether the NLDN is capable of identifying the different ground contacts in CG flashes. For 39 negative CG flashes that were recorded on video near Tucson, Arizona, the NLDN-based horizontal distances between the first stroke and the 62 subsequent strokes remaining in a preexisting channel had a mean and standard deviation of 0.9 ± 0.8 km and a median of 0.7 km. The horizontal distances between the first stroke and the 59 new ground contacts (NGCs) had a mean and standard deviation of 2.3 ± 1.7 km and a median of 2.1 km. These results are in good agreement with prior measurements of the random errors in NLDN positions in southern Arizona as well as video- and thunder-based measurements of the distances between all ground contacts in Florida. In cases where the distances between ground contacts are small and obscured by random errors in the NLDN locations, measurements of the stroke rise time, estimated peak current, and stroke order can be utilized to enhance the ability of the NLDN to identify strokes that produce new ground terminations.

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