scholarly journals Analysis of Temperature and Precipitation Trends Observed at Some Selected Districts of Punjab, Pakistan

2020 ◽  
Vol 10 (4) ◽  
pp. 51-58
Author(s):  
Safdar Ali Shirazi ◽  
Anum Liaqut ◽  
Khadija Shakrullah
Keyword(s):  
Daily Basis ◽  
Total Rainfall ◽  
Temperature And Precipitation ◽  
Increasing Trend ◽  
Annual Total ◽  
Precipitation Indices ◽  
Weather Stations ◽  
Warm Spell ◽  
Extreme Daily Temperature ◽  
Yearly Data

Present study examines the trends of extreme daily temperature and rainfall indices in some selectedmeteorological stations/districts of the Punjab. Due to paucity of data only six weather stations were selected from thewhole Punjab, having data of 33 years for temperature and precipitation on daily basis. A set of 14 indices(recommended by climate ET) were used to calculate the trends over a period of 32 years (1985–2017) by usingRClimDex (1.0) software package. These results showed that the number of tropical nights (TR20) and warm nights(TN90p) has been increasing in selected weather stations/districts and number for cool nights (TN10p) has been falling.Other temperature related indices trends such as, summer days, warms days, warm spell duration indicator (WSDI) andcool spell duration (CSDI) shows a mix pattern. The precipitation indices like SDII, RX1day, R10mm and PRCPTOTshowed an increasing trend in some selected stations. Most of the trends were not significant at level of 0.05 % whilemaximum day temperature increase has been observed at five out of six selected stations. Similarly, an average increasein precipitation in the vicinity of 3 mm per decade has been noted. The annual total rainfall and number of heavyrainfall days has also increased by 18 mm and 8.4 mm respectively during each decade. The analysis identified andhighlighted a slight change which was not temporally and spatially rational. However, there is need to more andadequate yearly data of different weather stations across the Punjab to identify the ongoing apparent and impeccablechanges in climate of the Punjab province.

scholarly journals Analysis of Temperature and Precipitation Trends Observed at Some Selected Districts of Punjab, Pakistan

2020 ◽  
Vol 10 (4) ◽  
pp. 51-58
Author(s):  
Safdar Ali Shirazi ◽  
Anum Liaqut ◽  
Khadija Shakrullah
Keyword(s):  
Daily Basis ◽  
Total Rainfall ◽  
Temperature And Precipitation ◽  
Increasing Trend ◽  
Annual Total ◽  
Precipitation Indices ◽  
Weather Stations ◽  
Warm Spell ◽  
Extreme Daily Temperature ◽  
Yearly Data

Present study examines the trends of extreme daily temperature and rainfall indices in some selectedmeteorological stations/districts of the Punjab. Due to paucity of data only six weather stations were selected from thewhole Punjab, having data of 33 years for temperature and precipitation on daily basis. A set of 14 indices(recommended by climate ET) were used to calculate the trends over a period of 32 years (1985–2017) by usingRClimDex (1.0) software package. These results showed that the number of tropical nights (TR20) and warm nights(TN90p) has been increasing in selected weather stations/districts and number for cool nights (TN10p) has been falling.Other temperature related indices trends such as, summer days, warms days, warm spell duration indicator (WSDI) andcool spell duration (CSDI) shows a mix pattern. The precipitation indices like SDII, RX1day, R10mm and PRCPTOTshowed an increasing trend in some selected stations. Most of the trends were not significant at level of 0.05 % whilemaximum day temperature increase has been observed at five out of six selected stations. Similarly, an average increasein precipitation in the vicinity of 3 mm per decade has been noted. The annual total rainfall and number of heavyrainfall days has also increased by 18 mm and 8.4 mm respectively during each decade. The analysis identified andhighlighted a slight change which was not temporally and spatially rational. However, there is need to more andadequate yearly data of different weather stations across the Punjab to identify the ongoing apparent and impeccablechanges in climate of the Punjab province.

scholarly journals Historical Spatial and Temporal Climate Trends in Southern Ontario, Canada

2017 ◽  
Vol 56 (10) ◽  
pp. 2767-2787 ◽  
Author(s):  
Hussein Wazneh ◽  
M. Altaf Arain ◽  
Paulin Coulibaly
Keyword(s):  
Climate Models ◽  
Global Climate ◽  
Global Climate Models ◽  
Climate Indices ◽  
Total Precipitation ◽  
Southern Ontario ◽  
Temperature And Precipitation ◽  
Annual Total ◽  
Precipitation Indices ◽  
Temperature Indices

AbstractSpatial and temporal trends in historical temperature and precipitation extreme events were evaluated for southern Ontario, Canada. A number of climate indices were computed using observed and regional and global climate datasets for the area of study over the 1951–2013 period. A decrease in the frequency of cold temperature extremes and an increase in the frequency of warm temperature extremes was observed in the region. Overall, the numbers of extremely cold days decreased and hot nights increased. Nighttime warming was greater than daytime warming. The annual total precipitation and the frequency of extreme precipitation also increased. Spatially, for the precipitation indices, no significant trends were observed for annual total precipitation and extremely wet days in the southwest and the central part of Ontario. For temperature indices, cool days and warm night have significant trends in more than 90% of the study area. In general, the spatial variability of precipitation indices is much higher than that of temperature indices. In terms of comparisons between observed and simulated data, results showed large differences for both temperature and precipitation indices. For this region, the regional climate model was able to reproduce historical observed trends in climate indices very well as compared with global climate models. The statistical bias-correction method generally improved the ability of the global climate models to accurately simulate observed trends in climate indices.

Assessment of changes in air temperature and precipitation in Transbaikalia

2021 ◽  
Vol 2 ◽  
pp. 138-146
Author(s):  
V.K. Smakhtin ◽  
Keyword(s):  
Air Temperature ◽  
High Water ◽  
Total Precipitation ◽  
Significance Level ◽  
Temperature And Precipitation ◽  
Annual Total Precipitation ◽  
Lena Basin ◽  
Annual Total ◽  
Weather Stations

Assessment of changes in air temperature and precipitation in Transbaikalia/ Smakhtin V.K. // Hydrometeorological Research and Forecasting, 2021, no. 2 (380), pp. 138-146. The paper analyzes long-term fluctuations in average air temperature and annual total precipitation in Transbaikalia. Between 1951 and 2020, air temperature increased by 2.3 °C according to 40 weather stations. Warming is mainly manifested in the air temperature rise in February, March and April. From 1955 to 2017, the decrease in annual total precipitation was 56 mm in the Amur basin and 39 mm in the Yenisei basin. The trends are reliable at the 5% significance level. In the Lena basin, annual total precipitation during the mentioned period increased by 7 mm, the trend is not reliable at the 5% significance level. The high-water phase has been observed since 2017. Taking into account that two previous high-water phases lasted 16‒17 years, it may be supposed that a risk of precipitation above the normal will be kept in the next 13–14 years. Keywords: climate change, air temperature, precipitation, phases of water content, trendsRef. 81.

scholarly journals A Comparison of Trends in Extreme Rainfall Using 20-Year Data in Three Major Cities in Oman

2016 ◽  
Vol 13 (2) ◽  
pp. 137 ◽  
Author(s):  
L.N. Gunawardhan ◽  
G.A. Al-Rawas
Keyword(s):  
Daily Precipitation ◽  
Extreme Rainfall ◽  
Climate Indices ◽  
Annual Maximum ◽  
Sultanate Of Oman ◽  
Precipitation Regime ◽  
Total Rainfall ◽  
Increasing Trend ◽  
Annual Total ◽  
Precipitation Records

 Many regions in the world have recently experienced more frequent and intensive disasters such as flash floods and persistent droughts. The Sultanate of Oman is no exception to this. We analyzed twodecade long daily precipitation records in three major cities, namely, Sohar, Muscat and Salalah, mainly focusing on extremes. A set of climate indices defined in the RClimDex software package was used. Moreover, annual maximum 1-day precipitations in three study areas were analyzed using the Generalized Extreme Value (GEV) distribution function.  Results showed significant changes in the precipitation regime in recent years. The annual total precipitation in Sohar and Salalah decreased, while that in Muscat shows statistically week increasing trend. However, all indices analyzed indicate enhanced extreme precipitation toward 2010 in Muscat and Salalah. As a result, the contribution from extreme events to the annual total rainfall steadily increases in both study areas. A clear conclusion could not be made based on selected indices for Sohar due to consistent drier years occurred from 1999 to 2005. Frequency analysis indicates that the annual the maximum 1-day rainfall estimated in Sohar and Muscat for 5 and 10 year return periods are approximately same (70 mm/day and 108 mm/day, respectively) but about two-fold greater than that in Salalah (29 mm/day and 60 mm/day, respectively). 

scholarly journals Increase of Extreme Drought over Ethiopia under Climate Warming

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Asaminew Teshome ◽  
Jie Zhang
Keyword(s):  
Heavy Precipitation ◽  
Extreme Drought ◽  
Precipitation Extremes ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum ◽  
Temperature Extremes ◽  
Temperature And Precipitation ◽  
Increasing Trend ◽  
Annual Total

Recurrent extreme drought and flood in Ethiopia lead to more economic loss. This study examines change and trends of 21 climate extremes of temperature and precipitation over Ethiopia by using indices from the World Meteorological Organization (WMO) Expert Team on Climate Change Detection and Indices (ETCCDI). The analysis was based on the records of observed meteorological data and the future projected from the CMIP5 model under RCP 4.5 and RCP 8.5 scenarios. The results of the seasonal standardized rainfall anomaly and EOF analysis show a decreasing rainfall in JJAS season and significant variability in the FMAM season. The first mode of EOF in FMAM shows that 49.6% was mostly negative with a high amount of variability. The observed precipitation extreme of annual total precipitation (PRCPTOT), consecutive wet days (CWD), and the number of heavy precipitation days (R10) show a decreasing trend, and consecutive dry days (CDD) shows an increasing trend. Additionally, temperature extremes like tropical nights (TR20) and daily maximum and minimum temperatures show a significantly increasing trend. The projected precipitation extremes of CWD, PRCPTOT, very wet day annual total (R95p), and the number of heavy precipitation days (R10) show a decreasing trend. CDD shows longer periods of dryness and a substantial increase which is conducive to the increase of drought. The projected temperature extremes of the warm spell duration indicator (WSDI), daily maximum temperature (TXx) and daily minimum temperature (TNx), summer days (SU25), and tropical nights (TR20) show an increasing trend, while the diurnal temperature range shows a decreasing trend. The projected changes in temperature and precipitation extremes are likely to have significant negative impacts on various socioeconomic activities over Ethiopia. These results highlight the need for planning and developing effective adaptation strategies for disaster prevention.

scholarly journals Trends In Seasonal Precipitation And Temperature – A Review In Doti And Surkhet Districts Of Nepal

2013 ◽  
Vol 2 (1) ◽  
pp. 269-279
Author(s):  
Govinda Bhandari
Keyword(s):  
Meteorological Data ◽  
Growing Season ◽  
Seasonal Rainfall ◽  
Annual Rainfall ◽  
Total Rainfall ◽  
Growing Period ◽  
Mean Temperature ◽  
Increasing Trend ◽  
Annual Total ◽  
Precipitation And Temperature

Rainfall and temperature are the crucial factors for affecting the yield of cereals. The annual mean temperature in Surkhet and Doti district is 21.47°C and 22.84°C respectively. The annual total rainfall in Doti and Surkhet district is 1145 mm and 1609 mm respectively. The average seasonal rainfall in (July-November) in Doti and Surkhet is 670.7 mm and 1109 mm. The average seasonal rainfall in (November-March) in Doti and Surkhet is 168 mm and 135 mm. The average seasonal rainfall in (March-June) in Doti and Surkhet is 352 mm and 389 mm. The average seasonal mean temperature in (July-November) in Doti and Surkhet is 25.76°C and 23.7°C. The average seasonal mean temperature in (November-March) in Doti and Surkhet is 16.67°C and 15.48°C. The average seasonal mean temperature in (March-June) in Doti and Surkhet is 25.5°C and 24.69°C. The analysis of meteorological data indicated that the temperature of both districts is on a rising trend. It has been observed no any trend in total seasonal rainfall during wheat and barley growing season (November-March) in Surkhet. Also, the seasonal total rainfall during maize growing period (March-June) has not shown any trend in Doti. Besides, decreasing trend of annual rainfall has been observed in Doti whereas increasing trend of annual rainfall is observed in Surkhet. The temperature in 1985 in Doti and Surkhet has increased and the rainfall in the same year and same districts has decreased that has negatively affected the yield of all the major cereals except wheat. International Journal of Environment, Volume-2, Issue-1, Sep-Nov 2013, Pages 269-279 DOI: http://dx.doi.org/10.3126/ije.v2i1.9227

scholarly journals Reconstruction of the annual balance of Vadret da Morteratsch, Switzerland, since 1865

2009 ◽  
Vol 50 (50) ◽  
pp. 126-134 ◽  
Author(s):  
Johanna Nemec ◽  
Philippe Huybrechts ◽  
Oleg Rybak ◽  
Johannes Oerlemans
Keyword(s):  
Meteorological Data ◽  
Balance Model ◽  
Surface Energy Fluxes ◽  
Temperature And Precipitation ◽  
Continuous Mass ◽  
Weather Stations ◽  
Precipitation Records ◽  
High Elevations ◽  
Annual Balance ◽  
Almost Continuous

AbstractWe have reconstructed the annual balance of Vadret da Morteratsch, Engadine, Switzerland, with a two-dimensional energy-balance model for the period 1865–2005. The model takes into account a parameterization of the surface energy fluxes, an albedo that decreases exponentially with snow depth as well as the shading effect of the surrounding mountains. The model was first calibrated with a 5 year record of annual balance measurements made at 20 different sites on the glacier between 2001 and 2006 using meteorological data from surrounding weather stations as input. To force the model for the period starting in 1865, we employed monthly temperature and precipitation records from nearby valley stations. The model reproduces the observed annual balance reasonably well, except for the lower part during the warmest years. Most crucial to the results is the altitudinal precipitation gradient, but this factor is hard to quantify from the limited precipitation data at high elevations. The simulation shows an almost continuous mass loss since 1865, with short interruptions around 1920, 1935 and 1980. A trend towards a more negative annual balance can be observed since the beginning of the 1980s. The simulated cumulative mass balance for the entire period 1865–2005 was found to be –46mw.e.

scholarly journals Effects of climatic factors on the net primary productivity in the source region of Yangtze River, China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhe Yuan ◽  
Yongqiang Wang ◽  
Jijun Xu ◽  
Zhiguang Wu
Keyword(s):  
Climate Change ◽  
Primary Productivity ◽  
Yangtze River ◽  
Net Primary Productivity ◽  
Climatic Factors ◽  
Source Region ◽  
Primary Reason ◽  
Vegetation Types ◽  
Temperature And Precipitation ◽  
Increasing Trend

AbstractThe ecosystem of the Source Region of Yangtze River (SRYR) is highly susceptible to climate change. In this study, the spatial–temporal variation of NPP from 2000 to 2014 was analyzed, using outputs of Carnegie–Ames–Stanford Approach model. Then the correlation characteristics of NPP and climatic factors were evaluated. The results indicate that: (1) The average NPP in the SRYR is 100.0 gC/m2 from 2000 to 2014, and it shows an increasing trend from northwest to southeast. The responses of NPP to altitude varied among the regions with the altitude below 3500 m, between 3500 to 4500 m and above 4500 m, which could be attributed to the altitude associated variations of climatic factors and vegetation types; (2) The total NPP of SRYR increased by 0.18 TgC per year in the context of the warmer and wetter climate during 2000–2014. The NPP was significantly and positively correlated with annual temperature and precipitation at interannual time scales. Temperature in February, March, May and September make greater contribution to NPP than that in other months. And precipitation in July played a more crucial role in influencing NPP than that in other months; (3) Climatic factors caused the NPP to increase in most of the SRYR. Impacts of human activities were concentrated mainly in downstream region and is the primary reason for declines in NPP.

Signals of Climate Change and Spatio-temporal Analysis of Climate Extremes in the Homogeneous Climatic Zones of Pakistan During 1962-2019

2021 ◽  
Author(s):  
Firdos Khan ◽  
Shaukat Ali ◽  
Christoph Mayer ◽  
Hamd Ullah ◽  
Sher Muhammad
Keyword(s):  
Climate Change ◽  
Climate Extremes ◽  
Heavy Precipitation ◽  
Temporal Analysis ◽  
Significance Level ◽  
Temperature And Precipitation ◽  
Increasing Trend ◽  
North Pakistan ◽  
Spatio Temporal ◽  
Increasing Temperature

Abstract This study investigates contemporary climate change and spatio-temporal analysis of climate extremes in Pakistan (divided into five homogenous climate zones) using observed data, categorized between 1962–1990 and 1991–2019. The results show that on the average, the changes in temperature and precipitation are significant at 5 % significance level throughout Pakistan in most of the seasons. The spatio-temporal trend analysis of consecutive dry days (CDD) shows an increasing trend during 1991–2019 except in zone 4 indicating throughout decreasing trend. PRCPTOT (annual total wet-day precipitation), R10 (number of heavy precipitation days), R20 (number of very heavy precipitation days) and R25mm (extremely heavy precipitation days) are significantly decreasing (increasing) during 1962–1990 (1991–2019) in North Pakistan. Summer days (SU25) increased across the country, except in zone 4 with a decrease. TX10p (Cool days) decreased across the country except an increase in zone 1 and zone 2 during 1962–1990. TX90p (Warm days) has an increasing trend during 1991–2019 except zone 5 and decreasing trend during 1962–1990 except zone 2 and 5. The Mann-Kendal test indicates increasing precipitation (DJF) and decreasing maximum and minimum temperature (JJA) in the Karakoram region during 1962–1990. The decadal analysis suggests decreasing precipitation during 1991–2019 and increasing temperature (maximum and minimum) during 2010–2019 which is in line with the recently confirmed slight mass loss of glaciers against Karakoram Anomaly.

scholarly journals Individual Rainfall Change Based on Observed Hourly Precipitation Records on the Chinese Loess Plateau from 1983 to 2012

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2268
Author(s):  
Wenbin Ding ◽  
Fei Wang ◽  
Kai Jin ◽  
Jianqiao Han ◽  
Qiang Yu ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Heavy Rainfall ◽  
Rainfall Intensity ◽  
Rainfall Amount ◽  
The Loess Plateau ◽  
Total Rainfall ◽  
Rainfall Events ◽  
Rainfall Duration ◽  
Rainfall Frequency ◽  
Annual Total

The magnitude and spatiotemporal distribution of precipitation are the main drivers of hydrologic and agricultural processes in soil moisture, runoff generation, soil erosion, vegetation growth and agriculture activities on the Loess Plateau (LP). This study detects the spatiotemporal variations of individual rainfall events during a rainy season (RS) from May to September based on the hourly precipitation data measured at 87 stations on the LP from 1983 to 2012. The incidence and contribution rates were calculated for all classes of rainfall duration and intensity to identify the dominant contribution to the rainfall amount and frequency variations. The trend rates of regional mean annual total rainfall amount (ATR) and annual mean rainfall intensity (ARI) were 0.43 mm/year and 0.002 mm/h/year in the RS for 1983–2012, respectively. However, the regional mean annual total rainfall frequency (ARF) and rainfall events (ATE) were −0.27 h/year and −0.11 times/year, respectively. In terms of spatial patterns, an increase in ATR appeared in most areas except for the southwest, while the ARI increased throughout the study region, with particularly higher values in the northwest and southeast. Areas of decreasing ARF occurred mainly in the northwest and central south of the LP, while ATE was found in most areas except for the northeast. Short-duration (≤6 h) and light rainfall events occurred mostly on the LP, accounting for 69.89% and 72.48% of total rainfall events, respectively. Long-duration (≥7 h) and moderate rainfall events contributed to the total rainfall amount by 70.64% and 66.73% of the total rainfall amount, respectively. Rainfall frequency contributed the most to the variations of rainfall amount for light and moderate rainfall events, while rainfall intensity played an important role in heavy rainfall and rainstorms. The variation in rainfall frequency for moderate rainfall, heavy rainfall, and rainstorms is mainly affected by rainfall duration, while rainfall event was identified as a critical factor for light rainfall. The characteristics in rainfall variations on the Loess Plateau revealed in this study can provide useful information for sustainable water resources management and plans.

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