scholarly journals Analysis of rainfall and temperature trends of selected stations over North East India during last century

MAUSAM ◽  
2021 ◽  
Vol 65 (4) ◽  
pp. 497-508
Author(s):  
S.I. LASKAR ◽  
S.D. KOTAL ◽  
S.K.ROY BHOWMIK
Keyword(s):  
Monsoon Season ◽  
Maximum Temperature ◽  
Rainfall Time Series ◽  
North East India ◽  
Post Monsoon ◽  
North East ◽  
The North ◽  
Increasing Trend ◽  
Post Monsoon Season ◽  
Increasing Trends

In this study, the trends of seasonal maximum and minimum temperatures and rainfall time series were investigated for 9 selected stations in the north eastern India with the available data stretching between the years 1913-2012.During the period under study the minimum temperature has increasing trends in almost all the stations of north east India except Cherrapunji where it shows decreasing trend in all the season of the year. In case of maximum temperature Cherrapunji, Guwahati and Imphal show increasing trends during all the seasons. Agartala and Shillong show increasing trend of maximum temperature during monsoon and post monsoon season. Dibrugarh and Pasighat show decreasing trend during pre monsoon season and increasing trend during all other seasons of the year. Gangtok shows decreasing trend of maximum temperature during all the seasons where as Silchar shows no trend in maximum temperature.Out of all the selected nine stations, most of the stations show either decreasing trend or no trend of rainfall except Guwahati which shows significant increasing trend of rainfall during post monsoon season.

scholarly journals Seasonal Nature and Trends of Tropical Cyclone Frequency and Intensity over the North Indian Ocean

2020 ◽  
Vol 15 (3) ◽  
pp. 526-534
Author(s):  
Abhisek Pal ◽  
Soumendu Chatterjee
Keyword(s):  
Time Series ◽  
Tropical Cyclone ◽  
Indian Ocean ◽  
Monsoon Season ◽  
North Indian Ocean ◽  
Post Monsoon ◽  
The North ◽  
Increasing Trend ◽  
Post Monsoon Season ◽  
Cyclone Frequency

Tropical cyclone (TC) genesis over the North Indian Ocean (NIO) region showed significant amount of both spatial and temporal variability.It was observed that the TC genesis was significantly suppressed during the monsoon (June-September) compared to pre-monsoon (March-May) and post-monsoon (October-December) season specifically in terms of severe cyclonic storms (SCS) frequency. The Bay of Bengal (BoB) was characterized by higher TC frequency but lower intensity compared to the Arabian Sea (AS). It was also observed that the TC genesis locations were shifted significantly seasonally.The movement of the TCs also portrayed some significant seasonal differences. The pre-monsoon and post-monsoon season was responsible for generating TCs with higher values of accumulated cyclone energy (ACE) compared to the monsoon. The time series of TC frequency showed a statistically significant decreasing trend whereas the time series of ACE showed astatistically significant increasing trend over the NIO.

Assessment of Extremes in Air Temperature Over North-East and West Coast Regions of India

2012 ◽  
Vol 19 (1) ◽  
Author(s):  
Jamir Tondgimenba ◽  
Uday Shankar De ◽  
Gaddam Krishnakumar
Keyword(s):  
West Coast ◽  
Monsoon Season ◽  
Extreme Weather Events ◽  
Maximum Temperature ◽  
North East ◽  
East Region ◽  
Weather Events ◽  
Increasing Trend ◽  
Post Monsoon Season ◽  
Coast Region

AbstractThe projected effect of climate change is the increase of both the frequency and intensity of extreme weather events. An attempt has been made to study the extremes in temperature over two regions of India i.e. North-East Region (NER) and West Coast Region (WCR). A detailed analysis indicated that in the NER, ten stations indicate increase in annual extreme minimum but significant at four stations. Post-monsoon season is very predominant where five stations show significant increase. In the WCR, all the stations indicate increasing trend in annual extreme maximum temperature significant at nine stations. Majority of the stations indicate significant increasing trend in all the seasons except monsoon season.

scholarly journals Historical and Temporal Trends of Climatic Parameters in North East India

2017 ◽  
Vol 19 (4) ◽  
pp. 547-561 ◽  
Keyword(s):  
Meteorological Data ◽  
Temporal Trends ◽  
Maximum Temperature ◽  
Local Climate ◽  
Water Resources Systems ◽  
North East India ◽  
North East ◽  
Mk Test ◽  
Ne India ◽  
Increasing Trends

Accessing temporal trend of different meteorological parameters is essential for understanding the local climate changing pattern of a region. Quantitative estimates of the effect of climate change helps in understanding, planning, and management of water resources systems. In this study, monthly meteorological data were collected from 30 stations of north-east (NE) India for 1971–2010 and non-parametric Mann-Kendall (MK) test and Sen slope were employed for detection and quantification of significant temporal trends, respectively. An ESRI ArcGIS toolbar “ArcTrends” was used for the above mentioned tasks. The results obtained for rainfall were of mixed nature and both increasing and decreasing significant trends were found for different stations in different months. Most of the negative trends were found in the months of July–August (monsoon), whereas, more stations showed positive trends in April–May (pre-monsoon), and October–November (post-monsoon), indicating inter-seasonal shifting of rainfall without much change in the annual total. Number of rainy days was found to have positive trends in March–May (pre-monsoon) and negative trends in September–December. Except some positive trends during June–December in Manipur and Meghalaya, there were no significant trends in maximum temperature. In some stations, minimum temperature was found to have significant increasing trends throughout the year indicating a general rising trend in NE India. Some major towns like Guwahati, Imphal, Agartala and Kailashshahar showed significant positive trends in mean temperature, mostly during June–December. Mean relative humidity was, in general, found to be significantly increasing, especially during February–March. In some stations, wind speed was found to have significant negative trends throughout the year, with Agartala being the most affected.

In vitro Fertilisation Capacity of Frozen Crossbred Bull Semen Cryopreserved During Different Seasons in Kerala

2021 ◽  
Author(s):  
M.M. Revathy ◽  
R.S. Abhilash ◽  
C. Jayakumar ◽  
P.K. Magnus ◽  
K. Raji ◽  
...  
Keyword(s):  
Rainy Season ◽  
Monsoon Season ◽  
Summer Season ◽  
Maximum Temperature ◽  
In Vitro Fertilisation ◽  
Post Monsoon ◽  
Bull Semen ◽  
Post Monsoon Season ◽  
Different Seasons

Background: Assessment of semen quality of bulls in frozen semen stations is of paramount importance as they are used for inseminating large number of cattle. The present study was conducted to assess the in vitro fertilisation capacity of crossbred bull semen cryopreserved during different seasons in Kerala as reports of such an evaluation are scarce.Methods: Semen samples from six crossbred bulls of same exotic inheritance, cryopreserved during rainy, post monsoon and summer seasons were procured from KLDB, Dhoni. The collected samples were evaluated for their in vitro fertilisation potential.Result: Hot dry summer season in Kerala adversely affects the fertilisation capacity of spermatozoa. Rainy season was observed to be the most favourable season for good quality semen production and post monsoon season was intermediate between summer and rainy season. It can be concluded from the present investigation that semen cryopreserved during summer season have lower fertilisation and cleavage rate than rainy and post monsoon season. This might be due to the harmful effect of significantly higher average maximum temperature and lower relative humidity occurred in the area during summer season on spermatogenesis.

scholarly journals Recent trends in climate of Bangalore

MAUSAM ◽  
2022 ◽  
Vol 53 (4) ◽  
pp. 425-438
Author(s):  
M. MOHAPATRA
Keyword(s):  
Relative Humidity ◽  
Monsoon Season ◽  
Winter Season ◽  
Maximum Temperature ◽  
Average Temperature ◽  
Bangalore City ◽  
Post Monsoon ◽  
Diurnal Range ◽  
Rate Of Increase ◽  
Post Monsoon Season

The linear trends in the monthly, seasonal and annual mean maximum temperature, minimum temperature, average temperature, diurnal range of temperature, rainfall, relative humidities at 0830 & 1730 hr IST of Bangalore city and airport have been analysed based on the data for the period from 1960-95. The variation in surface wind over Bangalore during above period has also been studied to find out impact of urbanisation on weather parameters. It is found that Bangalore city is becoming warmer in terms of mean maximum & mean minimum temperatures. Rate of increase is significantly higher over Bangalore city (central observatory) than that over airport during winter months. Similarly the rising trend of average temperature of Bangalore city is higher than of Bangalore airport during October to April being significantly so during winter season. Also the diurnal range of temperature of Bangalore is becoming larger in winter months with the rising trend being higher over Bangalore city than over airport. Even though rainfall does not show any significant trend, the rising trend during monsoon & falling trend during post monsoon season over Bangalore city are higher than that of Bangalore airport. Also though both Bangalore city & airport show maximum rising trend in mean relative humidity at 0830 hr IST during winter, the rate of rise is less over Bangalore city. Similarly though the relative humidity at 1730 hr IST shows decreasing trend during all the seasons, the rate of decrease is less over Bangalore city for all seasons except post monsoon season. The mean maximum, minimum and average temperatures and relative humidities show cyclic variation of their monthly trend coefficients during the year.

scholarly journals Seasonal Trend Analysis in Rainfall and Temperature for Udaipur District of Rajasthan

2019 ◽  
Vol 14 (2) ◽  
pp. 312-319
Author(s):  
Vaibhav Deoli ◽  
Saroj Rana
Keyword(s):  
Minimum Temperature ◽  
Monsoon Season ◽  
Winter Season ◽  
Daily Rainfall ◽  
Temperature Trend ◽  
Maximum Temperature ◽  
Rainfall Trend ◽  
Post Monsoon ◽  
Increasing Trend ◽  
Level Of Significance

The present study is mainly focused on to detection of changing trend in rainfall and temperature for Udaipur district situated in the Rajasthan state of India. The district situated in the western part of India which obtained less rainfall as compared with the average rainfall of India. In the present article, the approach has been tried to analysis to detect rainfall trend, maximum temperature trend and minimum temperature trend for the area. For this daily rainfall data of 39 years (1975 to 2013) add seasonally and the temperature has been calculated by averaging of daily temperature for a period of 39 years. For determining the trend the year has been shared out into four seasons like the winter season, pre-monsoon season, monsoon season and post-monsoon season. To obtained magnitude of trend San’s slope estimator test has been used and for significance in trend Mann-Kendall statistics test has been applied. The results obtained for the study show significantly decreasing rainfall trend for the season winter and season post-monsoon whereas pre-monsoon and monsoon show increasing rainfall trend. The maximum temperature of pre-monsoon and monsoon months shows a significantly increasing trend whereas, in minimum temperature, winter season and pre-monsoon season shows an increasing trend which is significant at 10% level of significance and post-monsoon shows a decreasing trend which is also significant at 10% level of significance.

scholarly journals Modulation of cyclonic disturbances over the north Indian Ocean by Madden - Julian oscillation

MAUSAM ◽  
2021 ◽  
Vol 62 (3) ◽  
pp. 375-390
Author(s):  
M. MOHAPATRA ◽  
S. ADHIKARY
Keyword(s):  
Indian Ocean ◽  
Bay Of Bengal ◽  
Monsoon Season ◽  
Phase 1 ◽  
North Indian Ocean ◽  
Maritime Continent ◽  
Phase 3 ◽  
Post Monsoon ◽  
The North ◽  
Post Monsoon Season

The relationship of genesis and intensity of cyclonic disturbances (CDs) over the north Indian Ocean with the Madden – Julian Oscillation (MJO) has been examined using 33 years (1975 - 2007) data of MJO index and best track of (CDs) developed by India Meteorological Department (IMD). The MJO index based on outgoing long wave radiation (OLR) and zonal wind in upper (200 hPa) and lower (850 hPa) troposphere (Wheeler and Hendon, 2004) has been used for this purpose. The MJO strongly modulates the genesis and intensity of CDs over the north Indian Ocean. However there are other factors contributing to cyclogenesis over the north Indian Ocean, as about 60% of cyclogenesis during monsoon and post-monsoon seasons are not significantly related with MJO. While the probability of cyclogenesis during monsoon season is higher with MJO in phase 4 and 5 (Maritime Continent), that during post-monsoon season is higher with MJO in phase 3 and 4 (east Indian Ocean and adjoining Maritime Continent). It indicates that while possibility of genesis during monsoon season is significantly suppressed with active MJO at phase 1, 7 and 8 (Africa, western Hemisphere and adjoining Pacific Ocean), there is no significant relationship between genesis and active MJO at phase 1, 7 and 8 during post-monsoon season. The anomalous cyclonic circulation at lower levels over central and north Bay of Bengal in association with MJO at phase 4 and 5 favours enhanced probability of cyclogenesis over the Bay of Bengal during monsoon season. The anomalous easterlies in association with MJO at phase 1 and development of anomalous ridge over south India in association with MJO at phase 7 and 8 which are weak monsoon features lead to suppressed cyclogenesis over north Indian Ocean during this season. The anomalous north-south trough in easterlies embedded with cyclonic circulation over the south west/west central Bay of Bengal in association with southerly surge over the region during active MJO in phase 3 and 4 most favourably influences the convection and enhances the probability of cyclogenesis over the north Indian Ocean during post-monsoon season. The genesis of CDs is more sensitive to phase than the amplitude while the intensification of CDs is more dependent on the amplitude of MJO. Comparing monsoon and post-monsoon seasons, the modulation of genesis, intensification and duration of CDs by the MJO is more during the monsoon season than the post-monsoon season.

scholarly journals District-wise trend analysis of rainfall pattern in last century (1901-2000) over Gangetic region in West Bengal, India

2015 ◽  
Vol 7 (2) ◽  
pp. 750-757 ◽  
Author(s):  
S. Pal ◽  
D. Mazumdar ◽  
P. K. Chakraborty
Keyword(s):  
West Bengal ◽  
Time Series Data ◽  
Monsoon Season ◽  
Statistical Significance ◽  
Kendall Test ◽  
Annual Rainfall ◽  
Series Data ◽  
Rainfall Time Series ◽  
Increasing Trend ◽  
Post Monsoon Season

The aim of the present study was to estimate long-term trend in the amount of rainfall for Gangetic West Bengal (GWB) meteorological sub-division of India and each of the 13 districts under GWB separately. Monthly rainfall time series data of 100 years (1901-2000) were analyzed to measure monotonous trend of rainfall employing Sen’s slope estimator. Statistical significance of the trend was determined using non-parametric Mann-Kendall test. An important result derived from the analysis was that the GWB sub-division and South 24 Parganas (S24P) district showed significant increasing trend (mm/year) of annual rainfall measuring 2.025 and 4.99 respectively. An inclining trend of monsoon precipitation, which was significant, found in four districts viz. Bankura, North 24 Parganas (N24P), S24P and West Midnapore along with GWB itself. A major finding of the study revealed that six districts and GWB had significant increasing trend in September rainfall with a maximum value of 1.324 mm/year in S24P district. Contribution of rainfall in October and post-monsoon season as well increased considerably in Kolkata and S24P districts while in December, similar trend was observed for Birbhum and Howrah districts. Murshidabad, S24P and East Midnapore districts experienced significant rising trend of precipitation in July, August and November respectively. On the contrary, Burdwan and Nadia districts, in the month of May and pre-monsoon season, had considerable declining trend of rainfall. Significant decreasing trend (mm/year) of precipitation, a concern for Nadia district, with magnitude of 0.127 and 0.293, was observed in the months of March and April respectively.

scholarly journals Cyclonic storms and Depressions over the north Indian Ocean during 2019*

MAUSAM ◽  
2021 ◽  
Vol 71 (3) ◽  
pp. 357-376
Author(s):  
Kashyapi A ◽  
Shripad V K ◽  
Natu J C
Keyword(s):  
Arabian Sea ◽  
Monsoon Season ◽  
North Indian Ocean ◽  
Cyclonic Storm ◽  
Post Monsoon ◽  
The North ◽  
Post Monsoon Season ◽  
Severe Cyclonic Storm ◽  
Cyclonic Storms ◽  
Indian Seas

During 2019, in all 12 intense low pressure systems formed over the Indian Seas. These include; one Super cyclonic storm (KYARR), one extremely severe cyclonic storm (FANI), 4 very Severe Cyclonic Storms (VAYU, HIKAA, MAHA & BULBUL), 2 Cyclonic Storms (PABUK & PAWAN), 3 Deep Depressions and  1 Depression. Out of these 12 systems, 4 systems formed over the Bay of Bengal and 8 over the Arabian Sea. Arabian Sea remained exceptionally active in terms of cyclogenesis this year, especially in the post monsoon season. The season-wise distribution had been one cyclonic storm in winter, one in pre-monsoon season,  2 depressions and 2 very severe cyclonic storms during the monsoon season and 4 cyclonic storms and 3 depressions in Post monsoon season.

scholarly journals Trend analysis of annual and seasonal rainfall to climate variability in North-East region of India

2014 ◽  
Vol 6 (2) ◽  
pp. 480-483 ◽  
Author(s):  
G. T. Patle ◽  
A. Libang
Keyword(s):  
Climate Change ◽  
Trend Analysis ◽  
Monsoon Season ◽  
Kendall Test ◽  
Seasonal Rainfall ◽  
Arunachal Pradesh ◽  
Post Monsoon ◽  
North East ◽  
East Region ◽  
Post Monsoon Season

Global warming, climate change and its consequences are major threat for the global agriculture. The agriculture in the North-East region of India is supposed to more in danger due to its topographic features. Agriculture in the state of Arunachal Pradesh is dependent on rainfall and variability in rainfall due to climate change is expected to threaten the food production in future. This study examines the impact of climate change on rainfall using the trend analysis technique for the four districts of Arunachal Pradesh. For this purpose temporal trends in annual and seasonal rainfall were detected using nonparametric Mann-Kendall test at 5% significance level. The daily time series rainfall data for the period 1971-2007 were analyzed statistically for each district separately. The results of Mann Kendall test showed decreasing trend in annual mean rainfall in east Siang, upper Siang and lowers Dibang valley and no trend in the west Siang district over the period of 1971-2007. In case of east Siang, upper Siang and lower Dibang valley districts, decreasing trend of rainfall was observed in the post monsoon season with slope magnitude of 3.01 mm/yr, 3.32 mm/yr and 3.95 mm/yr respectively. Decreasing pattern of rainfall in post monsoon season may affect the vegetable and fruit production in the winter season.

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