scholarly journals Analysis of temperature variability and trends over Tripura

MAUSAM ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 149-160
Author(s):  
C. S. TOMAR ◽  
D. SAHA ◽  
S. DAS ◽  
SANJAY SHAW ◽  
SANJAY BIST ◽  
...  
Keyword(s):  
Diurnal Temperature Range ◽  
Winter Season ◽  
Temporal Variations ◽  
Temperature Data ◽  
Maximum Temperature ◽  
Mk Test ◽  
Four Seasons ◽  
Temperature Indices ◽  
Annual Scale ◽  
Increasing Trends

Attempts have been made to study the temporal variations and trends in monthly, seasonal and annual temperature over two stations - Agartala and Kailashahar in Tripura, India for the period 1969 to 2014. Analysis has been carried for four temperature indices, namely - minimum temperature (Tmin), maximum temperature (Tmax), mean temperature (Tmean) and diurnal temperature range (DTR). Non-parametric Mann-Kendall (MK) test was used to detect the trends and the magnitude of the trends were determined with Sen’s estimator of slope. The analysis of the temperature data revealed significant increasing trends in Tmin, Tmax and Tmean variables at both the stations on annual scale, while decreasing trend in DTR was significant over Agartala only. On the seasonal scale, the increasing (decreasing) trends were observed in Tmin, Tmax and Tmean (DTR) temperature indices in all the four seasons - winter, pre-monsoon, monsoon and post-monsoon except non-significant decreasing trend in Tmax in winter season over Agatala. On the monthly scale, significant rising trends in Tmin, Tmax and Tmean were observed in the most of the months and significant decreasing trend in DTR was found only in the months of January and December.  

ANNUAL AND SEASONAL VARIATIONS IN TEMPERATURE EXTREMES AND RAINFALL IN BANGLADESH, 1989–2018

2021 ◽  
pp. 2150004
Author(s):  
LIPON CHANDRA DAS ◽  
ZHIHUA ZHANG
Keyword(s):  
Winter Season ◽  
Temperature Data ◽  
Maximum Temperature ◽  
Average Maximum ◽  
Yearly Average ◽  
Average Rainfall ◽  
Increasing Trend ◽  
Average Maximum Temperature ◽  
Average Minimum Temperature ◽  
Increasing Trends

Based on temperature and rainfall recorded at 34 meteorological stations in Bangladesh during 1989–2018, the trends of yearly average maximum and minimum temperatures have been found to be increasing at the rates of 0.025∘C and 0.018∘C per year. Analysis of seasonal average maximum temperature showed increasing trend for all seasons except the late autumn season. The increasing trend was particularly significant for summer, rainy and autumn seasons. Seasonal average minimum temperature data also showed increasing trends for all seasons. The trend of yearly average rainfall has been found to be decreasing at a rate of 0.014[Formula: see text]mm per year in the same period; especially, for most of the meteorological stations the rainfall demonstrates an increasing trend for rainy season and a decreasing trend in the winter season. It means that in Bangladesh dry periods became drier and wet periods became wetter.

scholarly journals Change in mean and extreme temperature at Yingkou station in Northeast China from 1904 to 2017

2021 ◽  
Vol 164 (3-4) ◽  
Author(s):  
Xiaoying Xue ◽  
Guoyu Ren ◽  
Xiubao Sun ◽  
Panfeng Zhang ◽  
Yuyu Ren ◽  
...  
Keyword(s):  
Northeast China ◽  
Extreme Temperature ◽  
Maximum Temperature ◽  
Data Set ◽  
The Past ◽  
Significant Downward Trend ◽  
Cold Events ◽  
Temperature Indices ◽  
Increasing Trends ◽  
Change In Mean

AbstractThe understanding of centennial trends of extreme temperature has been impeded due to the lack of early-year observations. In this paper, we collect and digitize the daily temperature data set of Northeast China Yingkou meteorological station since 1904. After quality control and homogenization, we analyze the changes of mean and extreme temperature in the past 114 years. The results show that mean temperature (Tmean), maximum temperature (Tmax), and minimum temperature (Tmin) all have increasing trends during 1904–2017. The increase of Tmin is the most obvious with the rate of 0.34 °C/decade. The most significant warming occurs in spring and winter with the rate of Tmean reaching 0.32 °C/decade and 0.31 °C/decade, respectively. Most of the extreme temperature indices as defined using absolute and relative thresholds of Tmax and Tmin also show significant changes, with cold events witnessing a more significant downward trend. The change is similar to that reported for global land and China for the past six decades. It is also found that the extreme highest temperature (1958) and lowest temperature (1920) records all occurred in the first half of the whole period, and the change of extreme temperature indices before 1950 is different from that of the recent decades, in particular for diurnal temperature range (DTR), which shows an opposite trend in the two time periods.

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.

Occurrence of extreme temperature events – A Probable risk on natural rubber cultivation

2015 ◽  
Vol 43 (3) ◽  
Author(s):  
K.K. Jayasooryan ◽  
P.R. Satheesh ◽  
R. Krishnakumar ◽  
James Jacob
Keyword(s):  
Climate Change ◽  
Ecological Impact ◽  
Extreme Temperature ◽  
Temporal Variations ◽  
Maximum Temperature ◽  
Extreme Temperature Events ◽  
The Past ◽  
Hot Days ◽  
Expert Team ◽  
Increasing Trends

<span style="line-height: 107%; font-family: 'Times New Roman','serif'; font-size: 12pt; mso-bidi-language: HI; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-ansi-language: EN-GB; mso-fareast-language: EN-US;" lang="EN-GB">Climate change and occurrence of extreme temperature events were studied in Kottayam, a major rubber growing district in Kerala. Occurrence of extreme temperature events can affect the livelihood of rubber growers apart from the ecological impact. The present study was conducted by analysing the occurrence of extreme temperature events in the past 40 years (1970-2010) using the RClimDex package developed by the Expert Team on Climate Change Detection Monitoring and Indices (ETCCDMI), Canada. Temporal variations in trends of occurrence of extreme temperature events were tested with Mann-Kendall trend analysis. The 5-year diurnal temperature range (DTR, difference between monthly mean maximum and minimum temperatures) increased from 7.8 (during 1970-1974) to 9.2 0C (during 2006-2010). The monthly mean maximum temperature increased by 0.035 0C per year. Frequency of occurrence of hot days increased at a rate of 0.56 per cent per year and the highest temperature recorded in a month showed an increase of 0.038 0C per year. As observed, the increasing trends in the occurrence of extreme temperature events may eventually lead to the warming up of the region in future. The study indicates that the projected warming tendency in the traditional rubber growing regions of India may affect the rubber cultivation adversely.</span>

Temporal variations of reference evapotranspiration in Heihe River basin of China

2012 ◽  
Vol 44 (5) ◽  
pp. 904-916 ◽  
Author(s):  
Zhanling Li ◽  
Zhanjie Li ◽  
Zongxue Xu ◽  
Xun Zhou
Keyword(s):  
River Basin ◽  
Influence Factor ◽  
Reference Evapotranspiration ◽  
Temporal Variations ◽  
Heihe River Basin ◽  
Maximum Temperature ◽  
Heihe River ◽  
Agricultural Crop ◽  
Different Seasons ◽  
Increasing Trends

Temporal variations in reference evapotranspiration (ETo) have profound implications for hydrological processes as well as for agricultural crop performance. The main aim of this study was to analyze the annual, seasonal trends in ETo in the Heihe River basin. The likely causative meteorological variables for such temporal changes in ETo were also identified. Results showed that, on a seasonal and annual scale, ETo for the upper reach showed increasing trends from 1960 to 2010; both increasing and decreasing trends were observed for the middle and lower reaches. In spring, wind speed (WS) and relative humidity (RH) were the most likely causative variables for changes of ETo for the whole basin; in summer and autumn, maximum temperature (Tmax) and RH contributed more to the trends in ETo for the upper reach, and WS contributed more for the middle and lower reaches; in winter, Tmax, WS and RH contributed more in different locations and in different seasons. From the spatial perspective, WS, RH and Tmax contributed more to the changes of ETo in the upper reach; WS was the main likely influence factor in the middle reach, and WS and RH were the probable main factors in the lower reach.

scholarly journals Analytical Determination of the Brake Temperature Mode During Repetitive Short-Term Braking

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1912
Author(s):  
Aleksander Yevtushenko ◽  
Katarzyna Topczewska ◽  
Michal Kuciej
Keyword(s):  
Friction Pair ◽  
Thermal Sensitivity ◽  
Finite Difference Methods ◽  
Temporal Variations ◽  
Frictional Heat ◽  
Maximum Temperature ◽  
Analytical Determination ◽  
Flash Temperature ◽  
Short Term ◽  
The One

An algorithm to determine the maximum temperature of brake systems during repetitive short-term (RST) braking mode has been proposed. For this purpose, the intermittent mode of braking was given in the form of a few cyclic stages consisting of subsequent braking and acceleration processes. Based on the Chichinadze’s hypothesis of temperature summation, the evolutions of the maximum temperature during each cycle were calculated as the sum of the mean temperature on the nominal contact surface of the friction pair elements and temperature attained on the real contact areas (flash temperature). In order to find the first component, the analytical solution to the one-dimensional thermal problem of friction for two semi-spaces taking into account frictional heat generation was adapted. To find the flash temperature, the solution to the problem for the semi-infinite rod sliding with variable velocity against a smooth surface was used. In both solutions, the temperature-dependent coefficient of friction and thermal sensitivity of materials were taken into account. Numerical calculations were carried out for disc and drum brake systems. The obtained temporal variations of sliding velocity, friction power and temperature were investigated on each stage of braking. It was found that the obtained results agree well with the corresponding data established by finite element and finite-difference methods.

scholarly journals Observed Trends in Indices of Daily Temperature Extremes in South America 1960–2000

2005 ◽  
Vol 18 (23) ◽  
pp. 5011-5023 ◽  
Author(s):  
L. A. Vincent ◽  
T. C. Peterson ◽  
V. R. Barros ◽  
M. B. Marino ◽  
M. Rusticucci ◽  
...  
Keyword(s):  
Climate Change ◽  
South America ◽  
Climate Extremes ◽  
Daily Temperature ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Temperature Extremes ◽  
Increasing Trends

Abstract A workshop on enhancing climate change indices in South America was held in Maceió, Brazil, in August 2004. Scientists from eight southern countries brought daily climatological data from their region for a meticulous assessment of data quality and homogeneity, and for the preparation of climate change indices that can be used for analyses of changes in climate extremes. This study presents an examination of the trends over 1960–2000 in the indices of daily temperature extremes. The results indicate no consistent changes in the indices based on daily maximum temperature while significant trends were found in the indices based on daily minimum temperature. Significant increasing trends in the percentage of warm nights and decreasing trends in the percentage of cold nights were observed at many stations. It seems that this warming is mostly due to more warm nights and fewer cold nights during the summer (December–February) and fall (March–May). The stations with significant trends appear to be located closer to the west and east coasts of South America.

scholarly journals Impact of abiotic factors on build-up of citrus psylla, Diaphorina citri Kuwayama population in Punjab, India

2014 ◽  
Vol 6 (2) ◽  
pp. 371-376 ◽  
Author(s):  
Hijam S. Devi ◽  
D. R. Sharma
Keyword(s):  
Relative Humidity ◽  
Disease Transmission ◽  
Minimum Temperature ◽  
Abiotic Factors ◽  
Winter Season ◽  
Seasonal Abundance ◽  
Maximum Temperature ◽  
Weak Links ◽  
Diaphorina Citri ◽  
Citrus Psylla

Seasonal abundance of citrus psylla (Diaphorina citri) Kuwayama was studied on Kinnow mandarin under Punjab conditions during 2012 and 2013. Population of D. citri was present throughout the year but only adults found surviving during December and February. There was no nymphal population when maximum temperature was > 39°C or < 7°C. Two population peaks of nymphs wer e observed, first in April-May and second in August- September. Thereafter, there was abrupt decline in nymphal population during June and July during both the years when the weather conditions i.e. maximum, minimum temperature (°C), relative humidity (%), rainfall (m m) and sunshine (hrs) ranged from 24.4-44, 22.4-31.8, 25.5-100, 0-108.0 and 0-13.5, respectively. Highest peaks of adult were found during May followed by June. With the decrease in temperature from the end of September, the population of D. citri started to decrease and reached its lowest during winter season. Correlation analysis for both the years indicated that maximum and minimum temperature, sunshine and rainfall were positively correlated with nymphal, adult and mixed population but the effect of rainfall on adult population was non-significant, while relative humidity was negatively correlated. The study is useful to find out the weak links of psyllid populations in relation to abiotic factors and that could be exploited to curb its infestation and disease transmission.

scholarly journals IMPACTS OF SNOWMELT AND CLIMATE CHANGE ON HIMALAYAN RIVERS: THE CASE OF DATA-SCARCE DUDHKOSHI RIVER IN EASTERN NEPAL

2021 ◽  
Vol 5 (12) ◽  
Author(s):  
Sudeep Pokhrel ◽  
Saraswati Thapa
Keyword(s):  
Maximum Temperature ◽  
Climate Projections ◽  
Snow Melt ◽  
Snow Hydrology ◽  
Statistical Downscaling Model ◽  
Snowmelt Runoff ◽  
Annual Average ◽  
Temperature And Precipitation ◽  
Increasing Trends ◽  
Runoff Model

Water from snow-melt is crucial to provide ecosystem services in downstream of the Himalayas. To study the fate of snow hydrology, an integrated modeling system has been developed coupling Statistical Downscaling Model (SDSM) outputs with Snowmelt Runoff Model (SRM) in the Dudhkoshi Basin, Nepal. The SRM model is well-calibrated in 2011 and validated in 2012 and 2014 using MODIS satellite data. The annual average observed and simulated discharges for the calibration year are 177.89 m3 /s and 181.47 m3 /s respectively. To assess future climate projections for the periods 2020s, 2050s, and 2080s, the SDSM model is used for downscaling precipitation, maximum temperature, and minimum temperature from the Canadian GCM model (CanESM2) under three different scenarios RCP2.6, RCP4.5 and RCP8.5. All considered scenarios are significant in predicting increasing trends of maximumminimum temperature and precipitation and the storehouse of freshwater in the mountains is expected to deplete rapidly if global warming continues.

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