Detection of possible thunderstorm formation inferred from weather element changes at ground level on a mountain slope

Authors and Affiliation: Vishnu R, Murali Das S, Sampath S and Mohan Kumar G, Centre for Earth Science Studies, Akkulam, Trivandrum, Kerala

Journal: Journal of Lightning Research, II, 12-24, 2010

Abstract: In India, Kerala state is known to have relatively high lightning incidence. The nature of spatial and temporal distribution of past incidents, type of thunderclouds which cause lightning, the topography, proximity to a mountain range 

and sea point to the possibility of the mountain weather aiding in Cb formation. For investigating the role of mountain weather in convective Cb formation a field station consisting of an automatic weather station and a lightning detector was established on the slope of the nearby Western Ghats mountain range. On thunderstorm days the mountain weather data show specific reduction in air temperature with synchronized increase in relative humidity along with a reduction in pressure of the order of 0.5 hPa between 10:00 h and 18:00 h. The variations in data are indicative of a strong updraft. The lightning detector showed thunderstorm activity, aligned with the direction of the mountain range, about an hour after detecting the changes in weather elements. Water vapour for thunderstorm formation seems to come from the nearby sea as indicated by the wind data. Data collected for three years show that existence of strong updrafts seem to be a characteristic of the mountain weather during thunderstorm months. Data from a coastal station located 40 km south west of the mountain station do not indicate updrafts either on the thunderstorm days or otherwise. As updrafts can lead to Cb formation monitoring weather elements as discussed here is useful for detecting thunderstorms at the developing stage itself.

Prevalence of autochthonous Vibrio cholera and role of abiotic environmental factors in their distribution along the Kerala- Karnataka Coast

Authors and Affiliation: V.S. Sudhanandh , S. Amaldev and K.N. Babu, Centre for Earth Science Studies, Akkulam, Trivandrum, Kerala

Journal: Research Journal of Microbiology, 5(11), 2010, 1083-1092

Abstract: Occurrence and distribution of Vibrio cholerae (VC) with respect to different abiotic environmental factors were studied for a period of three year from 2003-2005 and interpreted using Principal component analysis and Pearson correlation. Study reveals the serious dimensions of increase in VC population (2.67% in 2003, 5.33% in 2004 and 92% in 2005 in Mangalore) over the years. Among all stations, Kochi and Mangalore seems to be highly polluted. The PCA extracted four significant main components explains more than 75% of the variance. Of them the most contributing descriptors in the first PC (24.29%) were total nitrogen, silicate, temperature and V.cholerae. On the other hand V. cholerae showed significant positive correlation against temperature (0.01 levels) and also with total nitrogen and silicate (0.05 levels). Component plot showed that variables have tendency to accumulate into three distinct groups. V. cholerae and temperature belongs to one group and nutrients on the other group, which indicate that temperature and nutrients are the major factor governing the distribution of V. cholerae. The result of the study provides insight into the ecology of this aquatic species and is potentially important to the understanding of the epidemiology of cholerae on a global scale.