scholarly journals Spatiotemporal Analysis of Air Temperature Indices, Aridity Conditions and Precipitation in Iran

2021 ◽  
Author(s):  
Amin Sadeqi ◽  
Ercan Kahya
Keyword(s):  
Global Warming ◽  
Air Temperature ◽  
Change Point ◽  
Meteorological Data ◽  
Aridity Index ◽  
Spatiotemporal Analysis ◽  
Warming Trend ◽  
Tropical Regions ◽  
Mountainous Regions ◽  
Temperature Indices

Abstract Global warming has become a major threat to life on the earth, and recognizing its impacts can definitely be useful in controlling and mitigating its adverse effects. In this study, time series variations in air temperature indices (frost days, Tmin, Tmax, Tmean, Tminmin, Tmaxmax, Tsoil-min), De Martonne aridity index (IDM) and total precipitation were investigated using a long-term meteorological data (1960–2019) of 31 synoptic stations throughout Iran. The results indicated that more than 94% of the stations had increasing trend in Tmean, in which about 70% were significant at the 0.05 level. The average increase in Tmin was calculated approximately 1.7 times higher than Tmax and also the increase in Tminmin was about 2.5 times higher than Tmaxmax. Our findings showed that, abrupt changes in Tmin and Tmax mostly observed in the 1990s were upward in 87% of all the stations. Increase in annual Tmean at a rate of 0.3 ºC per decade and reduction of 5 mm per decade in total annual precipitation led to decrease in the IDM aridity index by 0.35 per decade in Iran. The intensity of air temperature increase was higher in tropical regions than in cold regions. Trend analysis in the partial series before and after a change point showed that the trends in Tmean before the change point were negative, but turned to positive afterwards in some stations mostly located in the northwestern cold and mountainous regions of the country. Our results revealed that the climate in Iran, in general, has become warmer and drier in the past 60 years and continuation of the current global warming trend will exacerbate this problem in the future.

scholarly journals Independent Aridity and Drought Pieces of Evidence Based on Meteorological Data and Tree Ring Data in Southeast Banat, Vojvodina, Serbia

Atmosphere ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 586 ◽  
Author(s):  
Milivoj B. Gavrilov ◽  
Wenling An ◽  
Chenxi Xu ◽  
Milica G. Radaković ◽  
Qingzhen Hao ◽  
...  
Keyword(s):  
Tree Ring ◽  
Air Temperature ◽  
Meteorological Data ◽  
Ring Width ◽  
Surface Air Temperature ◽  
Aridity Index ◽  
Precipitation Trend ◽  
Positive Temperature ◽  
Tree Ring Width ◽  
Tree Ring Data

In this study, aridity data and tree ring data were collected in Northern Serbia, in Southeast (SE) Banat, a subregion within Vojvodina, and Vojvodina at large. They were each investigated independently. The De Martonne Aridity Index and the Forestry Aridity Index are derived from examining the relationship between precipitation and surface air temperature data sets sourced from seven meteorological stations in SE Banat, and from 10 meteorological stations located in Vojvodina as a whole. Vojvodina is a large territory and used as the control area, for the period 1949–2017. The Palmer Drought Severity Index was derived for the period 1927–2016, for both SE Banat and the totality of Vojvodina. The results of the Tree Ring Width Index were obtained from samples collected in or around the villages of Vlajkovac and Šušara, both located in SE Banat, for the period 1927–2017. These tree ring records were compared with three previous aridity and drought indices, and the meteorological data on the surface air temperature and the precipitation, with the objective being to evaluate the response of tree growth to climate dynamics in the SE Banat subregion. It was noted that the significant positive temperature trends recorded in both areas were too insufficient to trigger any trends in aridity or the Tree Ring Width Index, as neither displayed any change. Instead, it appears that these climatic parameters only changed in response to the precipitation trend, which remained unchanged during the investigated period, rather than in response to the temperature trend. It appears that the forest vegetation in the investigated areas was not affected significantly by climate change in response to the dominant temperature increase.

scholarly journals The Effect of Climate Change on Variations in Dew Amount in a Paddy Ecosystem of the Sanjiang Plain, China

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yingying Xu ◽  
Baixing Yan ◽  
Jie Tang
Keyword(s):  
Global Warming ◽  
Relative Humidity ◽  
Meteorological Data ◽  
Warming Trend ◽  
Sanjiang Plain ◽  
Dew Point ◽  
The Sanjiang Plain ◽  
Growing Seasons ◽  
Paddy Ecosystem ◽  
Dew Amount

Due to global warming, a drying and warming trend has been observed over the last 50 years in the Sanjiang Plain of Heilongjiang Province, China, which could significantly affect the condensation of vapor in paddy ecosystems. Dew is a crucial factor in the water and nutrient cycling of farmland ecosystems, and it exerts an important influence on fertilization and other agricultural activities. In order to reveal the effects of global warming on dew variation in a paddy ecosystem, anin situexperiment was conducted in paddy fields in the Sanjiang Plain during the growing seasons of 2011 to 2013. Dew was collected and measured with a poplar stick. The results of correlation analysis between meteorological factors and dew intensity in the paddy ecosystem indicate that the dew point temperature and relative humidity significantly influenced the dew intensity. Based on synchronous meteorological data, a stepwise linear multivariation regression model was established to predict dew amount. The model successfully interpreted the relationship between simulated and measured dew intensity. The results suggest that a warmer and drier climate would lead to a reduction in dew amount because water cannot condense when relative humidity falls below 71%.

scholarly journals Air temperature in Southern Roztochia

2015 ◽  
pp. 239-245
Author(s):  
Bohdan Mucha ◽  
Iryna Bulavenko ◽  
Oksana Rodych
Keyword(s):  
Air Temperature ◽  
Meteorological Data ◽  
Warming Trend ◽  
Annual Average ◽  
Regional Warming ◽  
Average Temperature ◽  
Air Temperatures ◽  
Average Maximum ◽  
National University

The demonstration and analysis of the monthly and annual average air temperatures in Southern Roztochia for last 46 years are proposed. The meteorological data of the Roztochia landscapegeophysical station (RLGS) of Ivan Franko National University of Lviv have served as the starting material for this publication. The long-term value of the average air temperature in RLGS has been defined. The average temperature warming by 2 °C has occurred from 1970 to 2000 and the amplitude of fluctuations of average temperatures has increased since 2000. The fact of a gradual warming trend in the region Roztochia and the adjacent Small Polissia was confirmed as an attribute of the consequences of global warming and drainage reclamation during the XX century. The graphs for annual average, maximum and minimum air temperatures for last 46 years were concluded for the duration of 5 years at the seasons. The coldest period of research is the years 1969–1989 and the warmest ones are the years since 2000 and especially 2015. The parameters of extreme warming in 2015 were fixed in agriculture and water management. We are warning about the possibility of aridization of the territory as a result of the trend of warming. The ways of preventing of regional warming due to reducing the activity of drainage reclamation systems, conservation of forest and meadow vegetation are suggested. Key words: average air temperature, regional warming, extreme air temperature, Southern Roztochia.

scholarly journals Long-Term Spatial and Temporal Variation of Near Surface Air Temperature in Southwest China During 1969–2018

2021 ◽  
Vol 9 ◽  
Author(s):  
Jia Zhou ◽  
Tao Lu
Keyword(s):  
Air Temperature ◽  
Southwest China ◽  
Surface Air Temperature ◽  
Absolute Error ◽  
Warming Trend ◽  
Vital Role ◽  
Spatial And Temporal Variation ◽  
Related Factors ◽  
Near Surface ◽  
Mountainous Regions

Near surface air temperature (NSAT) is one of the most important climatic parameters and its variability plays a vital role in natural processes associated with climate. Based on an improved ANUSPLIN (short for Australian National University Spline) model which considers more terrain-related factors, this study analyzed the trends, anomalies, change points, and variations of NSAT in Southwest China from 1969 to 2018. The results revealed that the improved approach performed the best in terms of Mean Absolute Error (MAE), Root Mean Square Error (RMSE) and R-squared (R2) comparing to the conventional ANUSPLIN and co-kriging methods. It has great potential for future meteorological and climatological research, especially in mountainous regions with diverse topography. In addition, Southwest China experienced an overall warming trend of 0.21°C/decade for annual mean NSAT in the period 1969–2018. The warming rate was much higher than mainland China and global averages, and statistically significant warming began in the late 1990s. Moreover, consistent warming and significant elevation-dependent warming (EDW) were observed in most parts of Southwest China, and the hiatus or slowdown phenomenon after the 1997/1998 EL Niño event was not observed as expected. Furthermore, the remarkable increase in winter and minimum NSATs contributed more to the whole warming than summer and maximum NSATs. These findings imply that Southwest China responds to global warming more sensitively than generally recognized, and climate change in mountainous regions like Southwest China should be of particular concern.

scholarly journals An analysis of present and future seasonal Northern Hemisphere land snow cover simulated by CMIP5 coupled climate models

2013 ◽  
Vol 7 (1) ◽  
pp. 67-80 ◽  
Author(s):  
C. Brutel-Vuilmet ◽  
M. Ménégoz ◽  
G. Krinner
Keyword(s):  
Global Warming ◽  
Snow Cover ◽  
Northern Hemisphere ◽  
Air Temperature ◽  
Large Scale ◽  
Climate Models ◽  
Surface Air Temperature ◽  
Warming Trend ◽  
Climate Forcing ◽  
Snow Cover Extent

Abstract. The 20th century seasonal Northern Hemisphere (NH) land snow cover as simulated by available CMIP5 model output is compared to observations. On average, the models reproduce the observed snow cover extent very well, but the significant trend towards a reduced spring snow cover extent over the 1979–2005 period is underestimated (observed: (−3.4 ± 1.1)% per decade; simulated: (−1.0 ± 0.3)% per decade). We show that this is linked to the simulated Northern Hemisphere extratropical spring land warming trend over the same period, which is also underestimated, although the models, on average, correctly capture the observed global warming trend. There is a good linear correlation between the extent of hemispheric seasonal spring snow cover and boreal large-scale spring surface air temperature in the models, supported by available observations. This relationship also persists in the future and is independent of the particular anthropogenic climate forcing scenario. Similarly, the simulated linear relationship between the hemispheric seasonal spring snow cover extent and global mean annual mean surface air temperature is stable in time. However, the slope of this relationship is underestimated at present (observed: (−11.8 ± 2.7)% °C−1; simulated: (−5.1 ± 3.0)% °C−1) because the trend towards lower snow cover extent is underestimated, while the recent global warming trend is correctly represented.

scholarly journals The effect of air temperature on hospital admission of adults with community acquired pneumonia in Baotou, China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wenfang Guo ◽  
Letai Yi ◽  
Peng Wang ◽  
Baojun Wang ◽  
Minhui Li
Keyword(s):  
Hospital Admission ◽  
Air Temperature ◽  
Meteorological Data ◽  
Community Acquired Pneumonia ◽  
Adult Patients ◽  
Distributed Lag ◽  
Specific Effects ◽  
Lower Temperature Range ◽  
Lower Temperature ◽  
Inner Mongolia Autonomous Region

AbstractThe relationship between air temperature and the hospital admission of adult patients with community-acquired pneumonia (CAP) was analyzed. The hospitalization data pertaining to adult CAP patients (age ≥ 18 years) in two tertiary comprehensive hospitals in Baotou, Inner Mongolia Autonomous Region, China from 2014 to 2018 and meteorological data there in the corresponding period were collected. The exposure–response relationship between the daily average temperature and the hospital admission of adult CAP patients was quantified by using a distributed lag non-linear model. A total of 4466 cases of adult patients with CAP were admitted. After eliminating some confounding factors such as relative humidity, wind speed, air pressure, long-term trend, and seasonal trend, a lower temperature was found to be associated with a higher risk of adult CAP. Compared to 21 °C, lower temperature range of 4 to –12 °C was associated with a greater number of CAP hospitalizations among those aged ≥ 65 years, and the highest relative risk (RR) was 2.80 (95% CI 1.15–6.80) at a temperature of − 10 °C. For those < 65 years, lower temperature was not related to CAP hospitalizations. Cumulative lag RRs of low temperature with CAP hospitalizations indicate that the risk associated with colder temperatures appeared at a lag of 0–7 days. For those ≥ 65 years, the cumulative RR of CAP hospitalizations over lagging days 0–5 was 1.89 (95% CI 1.01–3. 56). In brief, the lower temperature had age-specific effects on CAP hospitalizations in Baotou, China, especially among those aged ≥ 65 years.

Hydro-meteorological data preparation for ecosystem hydrological modelling in the riparian forest of Hidegvíz Valley experimental catchment

2021 ◽  
Author(s):  
Csenge Nevezi ◽  
Tamás Bazsó ◽  
Zoltán Gribovszki ◽  
Előd Szőke ◽  
Péter Kalicz
Keyword(s):  
Air Temperature ◽  
Meteorological Parameters ◽  
Extreme Event ◽  
Riparian Forest ◽  
Meteorological Data ◽  
Rain Gauge ◽  
Hydrological Modelling ◽  
Data Preparation ◽  
Air Humidity ◽  
Groundwater Levels

&lt;p&gt;In the Hidegv&amp;#237;z Valley experimental catchment in Hungary the meteorological data have been collected since the 1990s and used for various purposes including hydrological studies. Current research began in 2018&amp;#8211;19, that aimed to reveal the connections between the hydrological and botanical characteristics in riparian forests and a wet meadow. Changes that occurred in both ecosystems in the groundwater levels, soil moisture and vegetation, showed that the local meteorological events influence these factors. Therefore we decided to analyse longer periods in which meteorological extremes&lt;br&gt;strongly influenced hydrological conditions and so status of ecosystems. Further measurements and their analysis were also required because more accuracy and detail were needed for future water balance modelling.&lt;/p&gt;&lt;p&gt;The measured data between 2017&amp;#8211;2020 were chosen as a starting database. For the first analysis we selected three meteorological parameters, i. e. the precipitation, the air temperature, and the air humidity. These parameters were measured by automated instruments, except for the precipitation. We found that the automated tipping-bucket rain gauge needs validation by a manual measurement (Hellmann-type rain gauge), because the data that collected by the automated device will be invalid if the rain intensity is too high.&lt;/p&gt;&lt;p&gt;In 2017 and 2018, the annual precipitation was distributed evenly, but in the following two years we observed some extremes. In 2019 and&lt;br&gt;2020, the spring was especially dry, the lowest monthly sum was 1.2 mm in 2020 April. 2019 April was similar (19.5 mm), but after the drought&lt;br&gt;period intense rainfall events arrived in May, resulted a monthly total of 214.1 mm. Air temperature and air humidity has not been showed such extremes as the precipitation.&lt;/p&gt;&lt;p&gt;This study showed that detailed analysis of meteorological parameters is crucial for hydrological modelling data preparation because errors and extreme event can cause serious problems during modelling process and, also in case of evaluation of model results.&lt;/p&gt;&lt;p&gt;The research has been supported by the Ministry of Agriculture in Hungary.&lt;/p&gt;

Global warming and forest fires in Canada

1993 ◽  
Vol 69 (3) ◽  
pp. 290-293 ◽  
Author(s):  
Brian J. Stocks
Keyword(s):  
Global Warming ◽  
Forest Fire ◽  
Forest Fires ◽  
Fire Management ◽  
Warming Trend ◽  
Research Activities ◽  
Forest Fire Management ◽  
The Future ◽  
Innovative Thinking ◽  
The Impact

The looming possibility of global warming raises legitimate concerns for the future of the forest resource in Canada. While evidence of a global warming trend is not conclusive at this time, governments would be wise to anticipate, and begin planning for, such an eventuality. The forest fire business is likely to be affected both early and dramatically by any trend toward warmer and drier conditions in Canada, and fire managers should be aware that the future will likely require new and innovative thinking in forest fire management. This paper summarizes research activities currently underway to assess the impact of global warming on forest fires, and speculates on future fire management problems and strategies.

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