TY - JOUR
T1 - Enhancement of cloud-to-ground lightning activity over Taipei, Taiwan in relation to urbanization
AU - Kar, S. K.
AU - Liou, Y. A.
N1 - Funding Information:
We are thankful to Tai-Power Company of Taiwan for providing us the lightning data. Thanks are also given to the National Science Council (NSC) of Taiwan for the financial support through grant No. NSC 102-2221-E-008-034 and NSC 102-2111-M-008-027 and Center for Space and Remote Sensing Research (CSRSR) for its technological support. The second author is thankful to National Science Council (NSC), Taiwan for supporting his visit through grant No. NSC 102-2111-M-008-027 . We are also extremely grateful to the anonymous reviewers for their valuable critical comments which helped us a lot to improve the manuscript.
PY - 2014/10/1
Y1 - 2014/10/1
N2 - Collecting the cloud-to-ground (CG) lightning flash data from Tai-Power Company of Taiwan, a long term study has been performed to investigate the enhancement of lightning activity in and around Taipei City, the largest metropolitan city of Taiwan, in relation to urbanization, for the period of 2005-2010. Results reveal that negative flash density is enhanced by approximately 64% while the positive flash density is enhanced by 48%, over and downwind of the city compared with other neighboring areas. On the other hand a decrease of nearly 24% in the percentage of positive flashes occurs over and downwind of Taipei compared to upwind values. We have also investigated the effect of urbanization on peak current of both polarities but no significant effect is noticed. Possible influence of urban particulate matter on the enhancement of CG lightning activity has been analyzed utilizing the annual averages of PM10 (particulate matter with aerodynamic diameter smaller than 10μm) and SO2 (sulfur dioxide) concentrations data. Interesting results are found, indicating the higher concentrations of PM10 and SO2 contributes to the CG lightning enhancement. Both the concentrations exhibit a positive linear correlation with the percent change in CG flashes from the upwind to the urban area and from the upwind to the downwind area. However, the correlation coefficient for PM10 concentrations is comparatively much lower than SO2 concentrations. Positive correlations of 0.55 and 0.68 are found for the PM10 and SO2 concentrations, respectively, when compared separately with the percent change in CG flashes from the upwind to the downwind area, indicating the influence of aerosols on urban CG lightning enhancement. Hourly variation of lightning flashes show that the urban effects on CG lightning is prominent in the afternoon and early evening hours. The results obtained from the present analysis corroborate the results reported in the literature by other researchers.
AB - Collecting the cloud-to-ground (CG) lightning flash data from Tai-Power Company of Taiwan, a long term study has been performed to investigate the enhancement of lightning activity in and around Taipei City, the largest metropolitan city of Taiwan, in relation to urbanization, for the period of 2005-2010. Results reveal that negative flash density is enhanced by approximately 64% while the positive flash density is enhanced by 48%, over and downwind of the city compared with other neighboring areas. On the other hand a decrease of nearly 24% in the percentage of positive flashes occurs over and downwind of Taipei compared to upwind values. We have also investigated the effect of urbanization on peak current of both polarities but no significant effect is noticed. Possible influence of urban particulate matter on the enhancement of CG lightning activity has been analyzed utilizing the annual averages of PM10 (particulate matter with aerodynamic diameter smaller than 10μm) and SO2 (sulfur dioxide) concentrations data. Interesting results are found, indicating the higher concentrations of PM10 and SO2 contributes to the CG lightning enhancement. Both the concentrations exhibit a positive linear correlation with the percent change in CG flashes from the upwind to the urban area and from the upwind to the downwind area. However, the correlation coefficient for PM10 concentrations is comparatively much lower than SO2 concentrations. Positive correlations of 0.55 and 0.68 are found for the PM10 and SO2 concentrations, respectively, when compared separately with the percent change in CG flashes from the upwind to the downwind area, indicating the influence of aerosols on urban CG lightning enhancement. Hourly variation of lightning flashes show that the urban effects on CG lightning is prominent in the afternoon and early evening hours. The results obtained from the present analysis corroborate the results reported in the literature by other researchers.
KW - Lightning
KW - Urban area
UR - http://www.scopus.com/inward/record.url?scp=84901837874&partnerID=8YFLogxK
U2 - 10.1016/j.atmosres.2014.05.017
DO - 10.1016/j.atmosres.2014.05.017
M3 - 期刊論文
AN - SCOPUS:84901837874
SN - 0169-8095
VL - 147-148
SP - 111
EP - 120
JO - Atmospheric Research
JF - Atmospheric Research
ER -
