scholarly journals Trends in surface temperature variability over Mumbai

MAUSAM ◽  
2021 ◽  
Vol 64 (2) ◽  
pp. 251-264
Author(s):  
SUSHMA NAIR ◽  
K.S. HOSALIKAR

izs{k.kkRed izek.kksa ls HkweaMy ij lrg rkiekuksa esa m".k izo`fRr dk irk pyrk gSA bl 'kks/k i= esa eqacbZ ds vf/kdre vkSj U;wure rkiekuksa dh izo`fRr;ksa dks Li"V fd;k x;k gSA blesa ,d n’kd ls ysdj izfrnu rd ds fofHkUu dkfyd ekiØeksa ij rkieku izo`fRr;ksa dh tk¡p dh xbZ gSA fo"ke ?kVukvksa ds ?kfVr gksus dh vko`fRr esa izo`fRr;ksa ds fy, ekSle ds leku xq.kksa ds rRoksa dh Hkh tk¡p dh xbZ gSA lkekU;r% eqacbZ esa rkieku dh c<+rh gqbZ izo`fRr ikbZ xbZ gS ftlesa U;wure rkiekuksa dh vis{kk vf/kdre rkieku vf/kd ik;k x;k gS rFkk ;g 95 izfr’kr dh fo’oLrrk Lrj ij lkaf[;dh; :i  ls egRoiw.kZ gSA tk¡p dh varj&okf"kZd vkSj varjk ekSle ekuksa nksuksa ij ekWulwu iwoZ vkSj ekWulwu _rqvksa dh vis{kk 'khr _rq vkSj ekWulwuksRrj _rqvksa esa m".krk lfgr ekSleh fHkUurk Li"V :i  ls vf/kd ns[kh xbZ gSA pje rkieku ds fo’ys"k.k esa ekSleh fHkUurk Hkh Li"Vr% ns[kh xbZ gSA xeZ fnuksa vkSj xeZ jkrksa esa ?kVukvksa dh vko`fRr 'khr_rq vkSj ekWulwuksRrj _rqvksa dh vis{kk ekWulwu iwoZ vkSj ekWulwu _rqvksa esa vf/kd Li"V :i  ls ns[kh xbZ gSA lHkh _rqvksa esa nksuksa LVs’kuksa ij fnu vkSj jkr nksuksa ds le; ds rkiekuksa esa larqfyr m".k izo`fRr ikbZ xbZ gS gk¡ykfd ekWulwuksRrj _rq esa lkarkØqt esa ;g fHkUurk lkaf[;dh; :i ls ux.; ikbZ xbZ gSA Observational evidence points to a warming trend in surface temperatures over the globe. This paper focuses on the trends in Maximum and Minimum temperatures over Mumbai. The temperature trends were investigated at different temporal scales from decadal to daily. The seasonal series were also investigated for trends in frequency of occurrences of extreme events. In general an increasing trend is observed over Mumbai, with the increase in Maximum temperatures more than the Minimum temperatures and statistically significant at 95% confidence level.  A seasonal distinction is evident with the warming more in the Winter and Post Monsoon seasons as compared to the Pre Monsoon and Monsoon seasons at both the inter-annual and intra-seasonal scales of investigation. The seasonal distinction was also evident in the extreme temperature analysis. The frequency of occurrences in the hot days and hot nights were more pronounced in the Pre Monsoon and Monsoon seasons as compared to the Winter and Post Monsoon seasons. Symmetric warming trend was observed for both the daytime and nighttime temperatures at both the stations in all the seasons though the variations at Santacruz are statistically insignificant in the Post-Monsoon season

2020 ◽  
Vol 15 (3) ◽  
pp. 526-534
Author(s):  
Abhisek Pal ◽  
Soumendu Chatterjee

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.


MAUSAM ◽  
2021 ◽  
Vol 65 (4) ◽  
pp. 497-508
Author(s):  
S.I. LASKAR ◽  
S.D. KOTAL ◽  
S.K.ROY BHOWMIK

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.


Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2117
Author(s):  
Su-mi Kim ◽  
Hyun-su Kim

The variations in water quality parameters and trophic status of a multipurpose reservoir in response to changing intensity of monsoon rain was investigated by applying a trophic state index deviation (TSID) analysis and an empirical regression model to the data collected in two periods from 2014 to 2017. The reservoir in general maintained mesotrophic conditions, and Carlson’s trophic state index (TSIc) was affected most by TSITP. Nutrient concentrations, particularly phosphorus, did not show strong correlations with precipitation, particularly in the period with weak monsoon, and a significant increase in total phosphorus (TP) was observed in Spring 2015, indicating the possibility of internal phosphorus loading under decreased depth and stability of water body due to a lack of precipitation. TSIChl was higher than TSISD in most data in period 1 when a negligible increase in precipitation was observed in the monsoon season while a significant fraction in period 2 showed the opposite trend. Phytoplankton growth was not limited by nutrient limitation although nutrient ratios (N/P) of most samples were significantly higher than 20, indicating phosphorus-limited condition. TSID and regression analysis indicated that phytoplankton growth was limited by zooplankton grazing in the Spring, and that cell concentrations and community structure in the monsoon and post-monsoon season were controlled by the changing intensity of the monsoon, as evidenced by the positive and negative relationships between community size and cyanobacterial population with the amount of precipitation in the Summer, respectively. The possibility of contribution from internal loading and an increase in cyanobacterial population associated with weak monsoon, in addition to potential for nutrient enrichment in the post-monsoon season, implies a need for the application of more stringent water quality management in the reservoir that can handle all potential scenarios of eutrophication.


Healthline ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 100-107
Author(s):  
Arti Agrawal ◽  
Vikas Kumar ◽  
Sanjeev Kumar ◽  
Neha K Mani

Introduction: Dengue virus infection is a major public health issue prevalent in tropical and sub-tropical countries all over the world mostly in urban and semi-urban areas. WHO estimates about 50-100 million dengue infections worldwide every year. The present study is aimed to assess the prevalence and seasonal distribution of dengue disease during three consecutive years from 2016-2018 at a tertiary care centre of North India. Method: This is an observational retrospective study conducted on total 6,481 clinical suspected cases referred from indoor and outdoor departments of Medicine and Pediatrics of one of the medical colleges of Agra during the period from 1st January 2016 to 31st December 2018. Results: The maximum positivity was recorded in the year 2016 (16.66%), followed by 2017 (14.07%) and 2018(13.56%).Our study shows male preponderance with maximum cases in the year 2018 was recorded in the month of October (22.75%) whereas the lowest in the month of May (1.96%). Most of the cases were in the age group 0-30 years with a male preponderance. The outbreak occurred during the months of August to November indicating vector transmission in the monsoon and post-monsoon season. Conclusion: From the analysis, this study reflects that the numbers of dengue cases in 2016 were maximum and outnumbered the dengue cases among three consecutive years from 2016 to 2018. The peak in dengue positivity was observed during September to October. As this disease affects the population in the monsoon and post monsoon months therefore continuous monitoring of dengue infection is important during the post-monsoon season.


2021 ◽  
Vol 13 (3) ◽  
pp. 17963-17971
Author(s):  
A. Vivek Chandran ◽  
Subin K. Jose ◽  
Sujith V. Gopalan

A year-long study was conducted at the Kole Wetlands, a Ramsar site in central Kerala to document the diversity of dragonflies and damselflies and understand their seasonality.  Checklist survey method was used to sample adult odonates in 30 randomly chosen locations.  A total of 44 species (30 dragonflies and 14 damselflies) belonging to 33 genera and eight families were recorded in the study area.  Species richness showed a peak in the post-monsoon season and a dip in the summer.  The observations support the value of the Kole Wetlands in providing valuable resources for Odonata.


1979 ◽  
Vol 15 (2) ◽  
pp. 161-168 ◽  
Author(s):  
P. J. Gregory ◽  
G. R. Squire

SUMMARYIrrigated and unirrigated crops of pearl millet were grown in Hyderabad, India, during the post-monsoon season of 1977. Irrigation increased both the dry weight of roots and the number of root axes, but because the additional axes were thick and unbranched the total length of roots was unaffected. However, irrigation did cause more of the root length to be in the top 20 cm of soil. Yield of the irrigated crop was higher than that of the dry crop, mainly because more tillers survived to produce grain. Grain growth of the dry crop occurred when the net growth of the crop was zero, probably because of movement of assimilate from stems to panicles. Possible strategies for improving yields are examined in the light of the growth data.


2018 ◽  
Vol 18 (9) ◽  
pp. 6441-6460 ◽  
Author(s):  
Hewen Niu ◽  
Shichang Kang ◽  
Hailong Wang ◽  
Rudong Zhang ◽  
Xixi Lu ◽  
...  

Abstract. Deposition and accumulation of light-absorbing carbonaceous aerosol on glacier surfaces can alter the energy balance of glaciers. In this study, 2 years (December 2014 to December 2016) of continuous observations of carbonaceous aerosols in the glacierized region of the Mt. Yulong and Ganhaizi (GHZ) basin are analyzed. The average elemental carbon (EC) and organic carbon (OC) concentrations were 1.51±0.93 and 2.57±1.32 µg m−3, respectively. Although the annual mean OC ∕ EC ratio was 2.45±1.96, monthly mean EC concentrations during the post-monsoon season were even higher than OC in the high altitudes (approximately 5000 ma.s.l.) of Mt. Yulong. Strong photochemical reactions and local tourism activities were likely the main factors inducing high OC ∕ EC ratios in the Mt. Yulong region during the monsoon season. The mean mass absorption efficiency (MAE) of EC, measured for the first time in Mt. Yulong, at 632 nm with a thermal-optical carbon analyzer using the filter-based method, was 6.82±0.73 m2 g−1, comparable with the results from other studies. Strong seasonal and spatial variations of EC MAE were largely related to the OC abundance. Source attribution analysis using a global aerosol–climate model, equipped with a black carbon (BC) source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 %) to annual mean near-surface BC in the Mt. Yulong area. There is also a strong seasonal variation in the regional source apportionment. South Asia has the largest contribution to near-surface BC during the pre-monsoon season, while East Asia dominates the monsoon season and post-monsoon season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.


2016 ◽  
Vol 4 (2) ◽  
pp. 15
Author(s):  
Deshpande A.V. ◽  
Patil S.N.

The study was conducted to evaluate the groundwater quality along the Kopargaon taluka. Thirty six ground water samples were collected from different sources in pre monsoon and post monsoon season, during the year 2013. The descriptive statistical analysis was carried out besides Pearson correlation. Correlation analysis revealed that very strong correlation exists between HCO3and Na(0.961), HCO3and Mg++ (0.935), HCO3and EC (0.927). Where highly negative correlation is observed between Na and pH (-0.537) during pre-monsoon season. During post monsoon season highly positive correlation is observed between Cl- and Ca++ (0.973), Ca and EC (0.967), Cl- and EC (0.966), SO4 and EC (0.948). Where, highly negative correlation is observed between Ca and pH (-0.533).


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