Trends In Maximum Temperatures Research Articles

Evaluation of climate change impact on extreme temperature variability in the Blue Nile Basin, Ethiopia

Abstract. Climate change raises important issues concerning hydrological engineering. The impact of climate change on important river basins should be investigated rigorously. Extreme temperature variability has a direct impact on the hydrological cycle, especially the evaporation component. In this paper, spatial and temporal patterns of changes in extreme temperatures were investigated using 10 meteorological stations' data for the period 1950–2018 in the Blue Nile Basin. Long-term trends in the Blue Nile Basin annual and monthly temperatures were investigated. The statistical significance of the trend was calculated by applying the Mann–Kendall (MK) test. The analysis of data was performed using the coefficient of variance and anomaly index. The results showed that the annual maximum and minimum temperatures were increasing significantly with a magnitude of 0.037 and 0.025 ∘C per decade respectively in the period from 1950 to 2018. The result of the Mann–Kendall analysis test revealed a marked increase in the mean maximum and minimum temperature trends over time during the study period (the minimum temperature rate is more evident than the maximum). The long-term anomalies of mean annual minimum temperature revealed the interannual variability while the trend after 1977 was higher than the long-term average, which is proof of the warming trend's existence during the last two decades of the 20th century.

Prophesying the stream flow and perpetrating the performance of Halele-Werabessa reservoirs of Ethiopia using HEC-HMS and HEC-ResSim

Purpose To assess the impacts of climate change on stream flow and evaluation of reservoir performances, reliability, resilience and vulnerability (RRV) indices are contemplated. Precipitation, temperature (Tmax, Tmin), relative humidity and solar radiation are the hydrological and meteorological data which have been used extensively. Climate data like RCP2.6, RCP4.5 and RCP8.5 were evaluated for the base period 1976–2005 and future climate scenario for 2021–2050 and 2051–2080 as per the convenience. Design/methodology/approach The hydrologic engineering center hydrologic modeling system (HEC-HMS) model was used to simulate the current and future inflow volume into the reservoir. The model performance resulted as 0.76 Nash-Sutcliffe efficiency (NSE), 0.78 R2 and −3.17 D and during calibration the results obtained were 0.8 NSE, 0.82 R2 and 2.1 D. The projected climate scenario illustrates an increasing trend for both maximum and minimum temperature though a decreasing trend was documented for precipitation. The average time base reliability of the reservoirs was less than 50% without reservoir condition and greater than 50% for other conditions but volumetric reliability and resilience varies between 50% and 100% for all conditions. The vulnerability result of reservoirs may face shortage of flow ranging from 5.7% to 33.8%. Findings Evaluating reservoir simulation and hydropower generation for different climate scenarios by HEC-ResSim model, the energy generated for upper dam ranges from 349.4 MWhr to 331.2 MWhr and 4045.82 MWhr and 3946.74 MWhr for short and long-term future scenario, respectively. RCP for Tmax and Tmin goes on increasing whereas precipitation and inflow to reservoir decreases owing to increase in evapotranspiration. Under diverse climatic conditions power production goes on varying simultaneously. Originality/value This paper is original and all the references are properly cited.

Seasonal temperature trends on the Spanish mainland: A secular study (1916–2015)

AbstractTrends in seasonal mean values of maximum and minimum temperature are analysed in the Spanish mainland from the new MOTEDAS_century database. This new data set has been developed combining the digitalized archives from the Spanish Meteorological Agency (AEMET) with information retrieved from Annual Books published by the former Meteorological Agency dating back to 1916, and covers the period 1916–2015. In all four seasons, mean seasonal temperature of maximum (Tmax) and minimum (Tmin) increased. The raising occurred in two main pulses separated by a first pause around the middle of the 20th century, but differed among seasons and also between maximum and minimum temperature. Analysis of the percentage of land affected by significant trends in maximum temperature reveals two increasing phases in spring and summer for Tmax, and in spring, summer, and autumn for Tmin. However, winter Tmax only rose during the recent decades, and autumn Tmax in the first decades. Negative significant trends were found in extended areas in spring Tmax, and in spring, autumn, and summer Tmin, confirming the first pause around the 1940's–1960's. Trends of seasonal mean values of Tmax and Tmin are not significant for at least the last 25–35 years of the study period, depending on the season. The areas under significant positive trend are usually more extended for Tmin than Tmax at any season and period. Areas with significant trend expand and contract in time according to two spatial gradients: south‐east to north‐west (east‐west) for Tmax, and west to east for Tmin. We hypothesize a relationship between atmospheric prevalent advection and relief as triggering factors to understand spatial and temporal differences in seasonal temperatures at regional scale during the 20th century in the Iberian Peninsula.

ANÁLISIS DEL REGISTRO DE TEMPERATURA LOCAL EN EL SURESTE DE MÉXICO

Durante los últimos años, el planeta se ha visto envuelto en un proceso de calentamiento global, lo que lleva a la necesidad conocer más sobre variaciones de temperatura. El objetivo de esta investigación fue identificar las tendencias anuales de temperatura máxima (variable 1) y mínima (variable 2) en el sur de México en el periodo de registro de 1960 a 2000. Las estaciones de los estados de Campeche, Quintana Roo, Tabasco y Yucatán presentaron rangos de temperatura similares, mientras que Chiapas presenta variaciones asociadas a la orografía del estado. Los resultados para ambas mostraron una tendencia positiva en la mayoría de las estaciones. Tenían en común que gran parte de éstas, se localizan en zonas urbanizadas o con nula o muy poca vegetación. Esto puede asociarse a la manifestación de islas de calor debido a la urbanización.

Long-term nationwide spatiotemporal changes of freshwater temperature in Japan during 1982–2016

We analyzed freshwater temperature data from 1982 to 2016 throughout Japan to better understand how waters are warming in Japan. We used linear regression to determine the temperature change rate and Mann–Kendall tests to identify significant temporal trends in the annual maximum and mean temperatures. Among 11,240 monitoring sites screened, 159 with fewer missing values were selected for analysis. On the basis of this analysis, we identified and ranked the sites showing significant temporal increasing or decreasing trends for future management. At nearly half (42%) of the analyzed sites, the annual mean freshwater temperature was increasing; thus, in the future, adverse impacts from warm temperatures may increase in those aquatic ecosystems. The temperature change rate of fresh water was higher than that of air, indicating that the observed increases in freshwater temperature were not due to atmospheric warming only. Among individual sites, the annual maximum freshwater temperature change rate ranged from −1.27 to 1.91 °C/decade, and the annual mean rate ranged from −1.13 to 1.28 °C/decade. Few other studies have reported decreasing temperatures for fresh water. We expect our results will improve understanding of how freshwater temperatures are changing at a large scale, enhance understanding of human impacts on the aquatic environment, support effective management of ecosystems experiencing temperature changes, and help to minimize the loss of biodiversity over the next half century.

Assessing the Impacts of Climate Change and Variability on Maize (Zea mays) Yield over Tanzania

This study aimed at understanding the impacts of the seasonal hydroclimatic variables on maize yield and developing of statistical crop model for future maize yield prediction over Tanzania. The food security of the country is basically determined by availability of maize. Unfortunately, agriculture over the country is mainly rain fed hence highly endangered by the detrimental consequences of climate change and variability. Observed climate data was acquired from Tanzania Meteorological Authority (TMA) and Maize yield data from Food and Agriculture Organization (FAO). The study used the Mann-Kendall test and Sen’s slope for trend and magnitude detection in minimum, maximum temperature and rainfall at the 95% confidence level. The results have shown that rainfall is decreasing over the country and especially during the growing season but increasing during short rains season. Characteristics of seasonal climatic variables, cycle during growing period were linked to maize yield, and high (low) yield was reported during anomalous wet (dry) growing seasons. This portrays seasonal dependence of maize production. Statistical crop model was built by aggregating spatial regions that have statistically significant relation with maize yield. Results show that, 58.8% of yield variance is linked to seasonal hydroclimate variability. Rainfall emerged as the dominant predictor variable for maize yield since it accounts for 44.1% of yield variance. The modeled and observed yields exhibit statistically substantial relationship (r = 0.78) hence depicting high credence of the built statistical crop model. Also, the results revealed a decreasing trend in Maize yield with further Lessing trend is projected to proceed in the future. This calls for adaptation and implementation of appropriate regional measures to raise maize production in order to feed the burgeoning human population amidst climate change.

Trend Analysis of the Variations of Ambient Temperature Using Mann-Kendall Test and Sen’s Estimate in Calabar, Southern Nigeria

Studies have been made to understand the fluctuations of temperature in regions around the world because of an ever changing variation due mostly to man’s anthropogenic activities. This study is focused on analysing the temperature variations in Calabar, Southern Nigeria for 20 years (1998 – 2018) using the Mann-Kendall trend test and Sen’s slope estimator. Results from the Mann-Kendall test shows that the annual trends of the maximum and average ambient temperature are both increasing after showing positive Kendall Z-values (1.04 and 0.10 respectively). The minimum ambient temperature annual trend was observed to be decreasing after having a negative Kendall Z-value (-0.32); the estimations from Sen’s slope agreed with these results. The p-values were calculated to be 0.745, 0.299, and 0.922 for the minimum, maximum, and average ambient temperature trend respectively; these values were all found to be less than all significant levels used 0.1% (0.001), 1% (0.01), 5% (0.05), and 10% (0.1). This shows that the trends were not increasing or decreasing significantly, hence there is “no significant trend”. This may be due to the almost unchanging weather condition in the region arising from its closeness to the Atlantic Ocean.

Characteristics of meteorological variables and their implications on evaporation in Roorkee (India)

Estimation of evaporation from meteorological variables and analysis of its properties are very important in the planning of cropping pattern and in the studies of climate change. This study presents the estimation of evaporation, its trends and variation with meteorological variables for the observatory located in Roorkee (India) using the data from 1987 to 2018. The observed pan evaporation was compared with the estimated pan evaporation. The anomalies, trend and shifts in the meteorological variables were correlated with observed pan evaporation. The conclusions from this analysis are (1) decreasing trend for maximum temperature and wind speed was observed for the period from 1987 to 2018, (2) pan evaporation observed during the post-monsoon season indicated a decreasing trend (3) fast urbanization of Roorkee after the creation of Uttarakhand state in the year 2000 enhanced the anthropogenic activities which was evidenced by the shifts in the data of relative humidity and temperature.

Statistical Forecast of Daily Maximum Air Temperature in Arid Areas at Summertime

Based on historical observations of summers for the period from 2004 to 2018 with a focus on daily maximum and minimum air temperatures and wind speed recorded at 0600 GMT, a non-linear regression hypothesis is developed for forecasting daily maximum air temperature (Tmax) in arid areas such as Baghdad International airport station, which has a hot climate with no cloud cover or rain. Observations with dust storm events were excluded, thus this hypothesis could be used to predict daily Tmax on any day during summers characterized by fair weather. Using mean annual daily temperature range, daily minimum temperature, and the trend of maximum temperature with wind speed, Tmax was forecasted and then compared to those recorded by meteorological instruments. To improve the accuracy of the hypothesis, daily forecast errors, bias, and mean absolute error were analyzed to detect their characteristics through calculating relative frequencies of occurrence. At the end of this analysis, a value of (-0.45ºC) was added to the hypothesis as a bias term.

Trends of Climate Change in Some Selected Districts of Western Nepal

Climate change is a global threat that has particularly strong impacts on countries whose economies are highly dependent on agriculture and still developing--like Nepal. The main objective of this study is to assess the trend of climate change in Gandaki Province, Nepal. This study is based on secondary data. It utilizes the data from the Department of Hydrology and Meteorology between 1970- 2018 based on eight districts with 10 different stations ranging from 110m. to 2680m. in Gandaki Province. Mann-Kendall test and Sen’s slope is used to find the trend. The analyses reveal that trend of maximum temperature is increasing and significant. The maximum temperature trend is 0.08°C/year in monsoon and post-monsoon which is greater than the global rate. The minimum temperature trend is positive and significant and is highest in the monsoon season (0.04°C/year). The trend of the average rainfall sum is insignificant and is positive only in pre-monsoon and negative in other seasons, which indicates erratic rainfall that causes floods and droughts.

Long-Term Trend Analysis in Annual and Seasonal Precipitation, Maximum and Minimum Temperatures in the Southwest United States

The objective of this study is to perform trend analysis in the historic data sets of annual and crop season [May–September] precipitation and daily maximum and minimum temperatures across the southwest United States. Eighteen ground-based weather stations were considered across the southwest United States for a total period from 1902 to 2017. The non-parametric Mann–Kendall test method was used for the significance of the trend analysis and the Sen’s slope estimator was used to derive the long-term average rates of change in the parameters. The results showed a decreasing trend in annual precipitation at 44.4% of the stations with the Sen’s slopes varying from −1.35 to −0.02 mm/year while the other stations showed an increasing trend. Crop season total precipitation showed non-significant variation at most of the stations except two stations in Arizona. Seventy-five percent of the stations showed increasing trend in annual maximum temperature at the rates that varied from 0.6 to 3.1 °C per century. Air cooling varied from 0.2 to 1.0 °C per century with dominant warming phenomenon at the regional scale of the southwest United States. Average annual minimum temperature had increased at 69% of the stations at the rates that varied from 0.1 to 8 °C over the last century, while the annual temperature amplitude showed a decreasing trend at 63% of stations. Crop season maximum temperature had significant increasing trend at 68.8% of the stations at the rates varying from 0.7 to 3.5 °C per century, while the season minimum temperature had increased at 75% of the stations.

Spatio-temporal variation and trends of long-term meteorological variables in Nigeria

Natural environmental disasters in the developing countries of West Africa are at alarming rate which necessitate the investigation of long-term trend of rainfall and temperature. Current variation, trends of temperature, and rainfall across Nigeria were investigated using parametric and non-parametric statistical tools. Meteorological data obtained from the Nigeria Meteorological Agency in Lagos, Nigeria, from 1970 to 2010 were used for this analysis. Seasonal and annual trends of maximum temperature, minimum temperature, and rainfall were carried out using Mann-Kendall and Sen’s slope methods. Long-term linear regression of these meteorological variables was analyzed across eighteen locations in the country. Spatial distribution of seasonal trends of these variables was also estimated for the four seasons in Nigeria. The result of the linear regression on temperatures and rainfall showed increasing trends in most of the locations across the country. Similarly, Mann-Kendall and Sen’s slope analysis showed a significant increasing trend in most areas across the country. Consequently, recent phenomena of environmental hazard such as an outbreak of airborne diseases and flooding leading to the collapse of buildings and various environmental disasters can be linked to the observed result.

Statistical Downscaling and Hydrological Modeling-Based Runoff Simulation in Trans-Boundary Mangla Watershed Pakistan

The economy of Pakistan relies on the agricultural sector which mainly depends on the irrigation water generating from the upper Indus river basin. Mangla watershed is a trans-boundary basin which shares borders of India and Pakistan, it comprises five major sub-basins, i.e., Jhelum, Poonch, Kanshi, Neelum and Kunhar. The runoff production of this basin is largely controlled by snowmelt in combination with the winter precipitation in the upper part of the basin and summer monsoon. The present study focusses on the application of a statistical downscaling method to generate future climatic scenarios of climatic trends (temperature and precipitation) in Mangla watershed. Statistical Downscaling Model (SDSM) was applied to downscale the Hadley Centre Coupled Model, version 3, Global Climate Model (HadCM3-GCM) predictions of the A2 and B2 emission scenarios. The surface water analyst tool (SWAT) hydrological model was used for the future projected streamflows based on developing climate change scenarios by SDSM. The results revealed an increasing trend of annual maximum temperature (A2) at the rates of 0.4, 0.7 and 1.2 °C for the periods of 2020s, 2050s and 2080s, respectively. However, a consistent decreasing trend of temperature was observed at the high-altitude region. Similarly, the annual minimum temperature exhibited an increasing pattern at the rates of 0.3, 0.5 and 0.9 °C for the periods of 2020s, 2050s and 2080s, respectively. Furthermore, similar increases were observed for annual precipitation at the rates of 6%, 10%, and 19% during 2020, 2050 and 2080, respectively, for the whole watershed. Significant increasing precipitation trends in the future (2080) were observed in Kunhar, Neelum, Poonch and Kanshi sub-basins at the rates of 16%, 11%, 13% and 59%, respectively. Consequently, increased annual streamflow in the future at the rate of 15% was observed attributing to an increased temperature for snow melting in Mangla watershed. The similar increasing streamflow trend is consistent with the seasonal trends in terms of winter (16%), spring (19%) and summer (20%); however, autumn exhibited decreasing trend for all periods.

Simulating the Impact of Climate Change on Maize Productivity in Trans-gangetic Plains using Info Crop Model

Background: Climate change is a nonpareil threat to the food security of hundred millions of people who depends on agriculture for their livelihood. A change in climate affects agricultural production as climate and agriculture are intensely interrelated global processes. Global warming is one of such changes which is projected to have significant impacts on environment affecting agriculture. Agriculture is the mainstay economy in trans-gangetic plains of India and maize is the third most important crop after wheat and rice. Heat stress in maize cause several changes viz. morphological, anatomical and physiological and biochemical changes. Methods: In this study during 2014-2018, impact of climate change on maize yield in future scenarios was simulated using the InfoCrop model. Average maize yield from 2001-15 was collected for Punjab, Haryana and Delhi to calibrate and validate the model. Future climatic data set from 2020 to 2050 was used in the study to analyse the trends in climatic parameters.Result: Analysis of future data revealed increasing trends in maximum temperature and minimum temperature. Rainfall would likely follow the erratic behaviour in Punjab, Haryana and Delhi. Increase in temperature was predicted to have negative impact on maize yield under future climatic scenario.

Impact of Climate Change on Rice Production and Local Adaptation Practices Adopted by Farmers in Surkhet, Nepal

A total of 120 sample households were randomly selected from two municipalities of Surkhet for this study. The primary data were collected by survey questionnaire, direct observation, FGD whereas secondary data of rainfall temperature and rice productivity were collected from different sources. Majority of farmers perceived increase in temperature, decrease in rainfall frequency, decrease in rainfall duration and increase in flooding hazard during rainy season. Trends analysis of temperature and rainfall data over 35 years (1980-2015) showed, increasing trends of maximum temperature (0.06oC/year) and minimum temperature (0.03oC/year) which were in the line with the farmer's perception. Trend analysis revealed that total annual precipitation was decreasing by 3.77 mm/year while monsoon rainfall was increasing by 0.051 mm/year. About 20% respondents had clear knowledge on climate change. The major source of information was media (43.43%) and self-experiences (36.3%). The major climate change adaptation practices adopted by farmers were use of drought resistant varieties, flood resistant varieties, use of electric water pump, and use of local irrigation channel. The study showed that only 39.17% of the respondents know about crop insurance policy and only 6.66% of the total respondents done crop insurance on different crop. The regression analysis showed that rainfall and average maximum temperature has positive effect on yield and production. The study showed that farmers were positive to adapt climate change adaptation strategies. So, government and policy makers should focus on climate resilient adaptation strategies formulation for rice cultivation through intensive research and extension package.
 Int. J. Soc. Sc. Manage. Vol. 7, Issue-4: 202-213

Recent changes in temperature extremes across the north-eastern region of Italy and their relationship with large-scale circulation

The present study is an analysis of recent changes (1981-2016) in air temperature across the north-eastern region of Italy (NERI), located in a transition zone influenced by the Mediterranean and continental climatological regimes. Annual and seasonal trends in mean maximum and minimum temperatures as well as in selected extreme indices are investigated using high-quality and homogenised daily data deriving from a distributed network of 50 weather stations. The results reveal an overall widespread warming, particularly intense in spring and summer, with significant positive trends in mean and daytime (maximum-related) temperature extremes, especially at lower altitudes. No substantial elevation dependency is observed for trends in minimum-related temperature indices, which are generally characterised by lower spatial variability. Comparable positive and negative trends are identified in the frequency and duration of warm- and cold-related extremes indices. Finally, the influence on temperature extremes of dominant large-scale circulation modes in southern Europe (North Atlantic Oscillation [NAO] and East-Atlantic [EA] pattern) is examined. The results indicate that especially NAO-induced changes can explain observed temperature trends over the NERI, while the impact of the EA pattern is slightly weaker.

Temperature and Rainfall Trends in North Eastern Ethiopia

North-Eastern Ethiopia is one of the sensitive regions to climate variation particularly to temperature and rainfall changes. Rainfall and temperature are one of the most determinant climate patterns for the study area because more than 80% of the area’s agriculture is reliant on rain-fed. The main aim of this study was to investigate trends in temperature and rainfall in the annual, seasonal and monthly time scale at Kombolcha and Dessie Meteorological stations. The daily rainfall and temperature data were collected from National Meteorological Agency of Ethiopia. The Mann-Kendall test and Sen’s slope estimator were used to assess rainfall and temperature trends. The Mann- Kendall test revealed that a non-significant decreasing rainfall trend was observed during February to March and September at Kombolcha and during January to March and September at Dessie stations. The rainfall trends showed decreasing in belg while increasing in both kiremt and bega season at both stations. However; the detected trends are non-significant. Both maximum and minimum temperature revealed that statistically significant decreasing trends in annual and seasonal time scale at Dessie station while at Kombolcha station a significant increasing trend of maximum temperature was observed at both annual and seasonal time scale. On the other hand a non-significant warming trend of minimum temperature was observed during annual and kiremt time scale but a non-significant decreasing trend was experienced during bega and belg season at Kombolcha station. Increase in temperature and decrease in amount of rainfall may have a negative impact on crop production and soil water balance. Therefore, this study could have an important role in identifying possible present and future production strategies.

Evaluation of CORDEX- South Asia regional climate models for heat wave simulations over India

The episodes of heat wave events have strengthened in recent decades causing great concern for human health, agriculture and natural ecosystem. In the present study, Regional Climate Models (RCMs) namely, CCAM and RegCM, from Coordinated Regional Climate Downscaling Experiments (CORDEX) for South Asia (SA) are evaluated for simulating heat waves (March–June) for a long-term period (1971 to 2005) over India in comparison with observations from India Meteorological Department (IMD). The statistical analysis (correlation, RMSE, MAE, ECDF) results reveal differences in RCMs in simulating spatial pattern and trends of maximum temperature before bias correction. Variance scaling bias correction is found to remove bias and improve model simulations in capturing temperature variability. An increase in correlation in daily observations from 0.24 to 0.70 and reduction in RMSE from 8.08 °C to 2.02 °C and MAE from 3.87 °C to 2.43 °C after bias correction is observed between model and observation.LMDZ4 and GFDL-ESM2M are found to perform best in simulating interannual variability of seasonal mean maximum temperature with an underestimation of −7.74% and −15.41% which improved significantly to around −1.51% and − 0.78%, respectively after bias correction over India. LMDZ4 and GFDL-ESM2M are also best-performing models in significantly reproducing the heat wave frequency and spatial variability in closer proximity with observations over India amongst all models after bias correction. Over NW and western regions, the LMDZ4 and GFDL-ESM2M ensemble models successfully capture the increasing trend of 0.2 events/year and 0.4 events/year accordance to IMD and IITM criteria, respectively. However, the ACCESS1.0, CNRM-CM5 and CCSM4 ensemble experiments overestimated heat waves by ±40 events in most sub-divisions in India. Over the central Indian regions, the ACCESS 1.0 and CNRM-CM5 model output show a negative trend of −0.2 events/year and large spatial variability possibly due to model associated uncertainties. Overall the results show an improvement in capturing maximum temperature and heat waves across the regions of Indian sub-continent in the bias-corrected downscaled CORDEX-SA ensemble RCMs than without bias-corrected output. The study suggests a way forward to assess RCMs performance and uncertainty in extreme weather analysis in future projections.

The Effect of Climate Change on the Health of Aged People in Ibadan, Nigeria

Susceptibility to ill health among aged people had been linked with climate change impacts in rapidly urbanising cities. Therefore, this study evaluates to the vulnerability of aged people to the health impacts of climate change in Ibadan, Nigeria. Data on clinically diagnosed climate related diseases (CRDs) (2000 – 2014) among aged people (>50 years) and temperature and rainfall parameters (1970 – 2007) in Ibadan were obtained and projected to year 2050. Also, the relationship between the climatic parameters and incidence of the five most prevalent CRDs were analysed using multiple regression. The increasing trend of mean maximum temperature (r = 0.47) and rainfall (r = 0.15) is associated with incidences of hypertension (34.4%), respiratory diseases (21.2%) and diarrhoea (14.3%) among aged people (> 60 years), mostly male folk (67.2%). The linear composite of disease communalities extracted 84.0% variance of the data set with the following component scores: skin disease (0.98), hypertension (0.96), respiratory disease (0.92), diarrhoea (0.89) and malaria (0.45). Further, CRDs (R2 = 27%, p = 0.012) in Ibadan among aged people could be significantly attributed to influences of climatic parameters. The study suggests building aged peoples’ resilience to emanating impacts through health and nutritional improvement programs, and re-introduction of neighbourhood parks and gardens.

Spatial Trends of Maximum and Minimum Temperatures in Different Climate Zones of Pakistan by Exploiting Ground-based and Space-borne Observations

Temperature is a key indicator of a changing climate. A trivial change in temperature can result in significant changes in weather patterns with severe repercussions on ecology and socio-economic conditions of an area. This study aims to assess the changing trends in maximum and minimum temperatures in five climatic zones of Pakistan, and compare ground-based with satellite data from AIRS over these climatic zones of Pakistan. Mann Kendall test has been used to signify the temperature trends in all zones and seasons while Sen's slope value has been used to measure the magnitude of the trends for the time period 1978 to 2016. Ground observations have been compared with AIRS satellite observations for ascending and descending air temperatures by employing correlation and mean bias error. The results show that AIRS product (AIRSX3STM) underestimates Tmax and Tmin in all zones of Pakistan with the underestimation being most prominent in zone A. The trend analysis for maximum and minimum temperatures shows an increase in temperatures for all climate zones. Overall, Pakistan's maximum temperature increased by 0.026°C/year with the maximum increase of 0.05°C/year during pre-monsoon, and the minimum temperature increased by 0.027°C/year.