Relationships between Rainy Days,Mean Daily Intensity and Seasonal Rainfall in Normal,Flood and Drought Years over India

here are limitations in using the seasonal rainfall total in studies of Monsoon rainfall climatology. A correlation analysis of the individual station seasonal rainfall with all India seasonal mean rainfall has been made. After taking the significance test (strictly up to 5% level) the stations which are significantly correlated have been considered in this study in normal, flood and drought years respectively. Analysis of seasonal rainfall data of 50 stations spread over a period of 41 years suggests that a linear relationship fits better than the logarithmic relationship when seasonal rainfall versus number of rainy days is studied. The linear relationship is also found to be better in the case of seasonal rainfall versus mean daily intensity.

Temporal Variability of Extreme Precipitation in Jiangxi during 1961-2018

Using 58 years (1961 to 2018) of daily rainfall data, this study focuses on determining trends in the annual and seasonal precipitation extremes of Jiangxi, China, by choosing four extreme precipitation indices, including strong precipitation amount (SPA), mean precipitation intensity (MPI), strong precipitation days (SPD), and strong precipitation frequency (SPF). The monotonic trends are tested by using the Mann-Kendall test for the trends and Sen’s method for the magnitude of the trends. The effective sample size (ESS) method was used to eliminate the influence of serial correlation in the Mann-Kendall test. The results indicated that station Zixi had the strongest extreme precipitation, while Wanzai had the weakest. The trends for each index showed an obvious regional feature over Jiangxi. Increasing trends in annual extreme precipitation indices were found at almost all stations, and the annual variability of the extreme precipitation indices was pronounced, especially for the mean precipitation intensity and the strong precipitation frequency;the majority of these positive trends were shown by the statistical tests. In spring, four indices exhibited significant increasing trends in Northeast and Southwest Jiangxi;however, in summer, only MPI had a remarkable positive trend across almost all of Jiangxi. For the other indices, few stations had remarkable trends. In autumn, MPI and SPF showed remarkable increasing trends in most regions of Jiangxi, while SPA and SPD showed increasing trends at only 6 stations and 3 stations, respectively, which were scattered in the northern and middle parts. In winter, the stations with remarkable upward trends in SPA and SPD were mainly located in the middle of the region, whereas the significant patterns of MPI and SPF were located in the south and middle of the region.

The statistical fluctuation of a single-mode laser system driven by coloured pump noise with signal modulation and the quantum noise with cross-correlation between its real and imaginary parts

Using the linear approximation method, this paper studies the statistical property of a single-mode laser driven by both coloured pump noise with signal modulation and the quantum noise with cross-correlation between its real and imaginary parts, and calculates the steady-state mean normalized intensity fluctuation and intensity correlation time. It analyses the influences of the modulation signal, the net gain coefficient, the noise and its correlation form on the statistical fluctuation of the laser system respectively. It is found that the coloured pump noise modulated by the signal has a great suppressing action on the statistical fluctuation of the laser system; the pump noise self-correlation time and the specific frequency of modulation signal have the result that the statistical fluctuation tends to zero. Furthermore, the ＇colour＇ correlation of pump noise has much influences on the statistical fluctuation of the laser system. Increasing the intensity of pump noise will augment the statistical fluctuation of the laser system, but the intensity of quantum noise and the coefficient of cross-correlation between its real and imaginary parts have less influence on the statistical fluctuation of the laser system. Therefore, from the conclusions of this paper the statistical property can be known and a theoretical basis for steady operation and output of the laser system can be provided.

A preliminary survey on parasitic occurrence in indigenous climbing perch,Anabas testudineus(Bloch,1972)from West Bengal state of India

Objective:To describe the parasitic infestations of Anabas testudineus(A.testudineus)collected from three different fish producing districts of West Bengal state in India.Methods:A total number of 75 specimens of A.testudineus were collected from different floodplain areas of West Bengal,India.These specimens were examined for parasites using established techniques after measuring basic morphometric parameters.Results:A total 165 individual of 20 parasites(13 ectoparasites and 7 endoparasites)belonging to 7 phyla were recorded from 64 infected A.testudineus.Among the observed parasites,8 were protozoan including 3 ciliates;2 monogenic trematodes,2 strigeidid trematodes,1 nematode,3 crustaceans,3 myxozoans and 1 echinorhynchus acanthocephalan parasites.The quantitative abundance of parasites were highest in gill(37%)followed by body outer layer(35%)and intestine(28%).District wise quantitative count of parasites in different investigated organ from A.testudineus revealed that North 24 Parganas is highly infected followed by West Midnapore and East Midnapore.The highest prevalence(%)and mean abundance of parasitic occurrence was observed in North 24 Parganas followed by West Midnapore and East Midnapore.The highest mean intensity was found at West Midnapore followed by North 24 Parganas and East Midnapore.Conclusions:Especially West Bengal state of India,inland culture and capture fishery mainly rural based and operated by poor farmers.Developing right kind of interventions and management practice can prevent adverse impact of diseases and assist poor farmers for sustainable production.