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1.
Simulation of global warming effect on outdoor thermal comfort conditions   总被引：3，自引：2，他引：1  
In the coming decades, global warming and increase in temperature, in different regions of the world, may change indoor and outdoor thermal comfort conditions and human health. The aim of this research was to study the effects of global warming on thermal comfort conditions in indoor ambiences in Iran. To study the increase in temperature, model for assessment of greenhouse-gas induced climate change scenario generator compound model has been used together with four scenarios and to estimate thermal comfort conditions, adaptive model of the American Society of Heating, Refrigerating and Air-conditioning Engineers has been used. In this study, Iran was divided into 30 zones, outdoor conditions were obtained using meteorological data of 80 climatological stations and changes in neutral comfort conditions in 2025, 2050, 2075 and 2100 were predicted. In accordance with each scenario, findings from this study showed that temperature in the 30 zones will increase by 2100 to between 3.4 °C and 5.6 °C. In the coming decades and in the 30 studied zones, neutral comfort temperature will increase and be higher and more intense in the central and desert zones of Iran. The low increase in this temperature will be connected to the coastal areas of the Caspian and Oman Sea in southeast Iran. This increase in temperature will be followed by a change in thermal comfort and indoor energy consumption from 8.6 % to 13.1 % in air conditioning systems. As a result, passive methods as thermal inertia are proposed as a possible solution.  相似文献   

2.
The cognition of thermal comfort plays a pivotal role in human life and activities. Recognizing thermal comfort based on climatic parameters is substantially significant. The main objective of the present study is to map thermal comfort using statistics from 43 meteorological stations, from 1970 to 2013. Initially, according to temperature and relative humidity, annual and seasonal thermal comfort conditions were mapped, and later bioclimatic human thermal comfort conditions in line with spatial factors were zoned based on bioclimatic indexes of Temperature Humidity Index (THI), effective temperature (ET) and Relative Strain Index (RSI). Among geostatistical methods, empirical Bayesian kriging (EBK) method with less RSME is more efficient. The annual distribution of temperature changes according to spatial factors of rugged topography and elevation, and latitude affects relative humidity. Thermal comfort in the northern and western half of Iran is higher than the southern and eastern areas of the country. Spatial factors of latitude and altitude reduce bioclimatic uniformity and create small areas with or without thermal comfort conditions. Bioclimatic indicators based on air temperature and relative humidity range of bioclimatic zones show. The results of ET and THI divide the whole country into six zones, from lack of thermal comfort to having thermal comfort conditions. Areas of southern strip as well as central and southeastern parts of the country do not have any human thermal comfort conditions in most of the year.  相似文献   

3.
Distribution of grassland vegetation is highly associated with climatic conditions and varied with climatic change. The tendency of climatic changes on Qinghai Plateau was analyzed, based on the meteorological data from 1961 to 2007 collected from 50 meteorological stations distributed throughout the whole plateau. The vegetation distribution of alpine grassland under past and future climatic change was estimated by using the approach of Comprehensive and Sequential Classification system. Results show that the climate varied greatly before and after 1987. The temperature increased 0.16°C/10a before 1987 and 0.64°C/10a after 1987. The precipitation increased 0.14 mm/10a before 1987 and 3.92 mm/10a after 1987. There were 12 types of grassland vegetation between 1961 and 1987, while there were 11 types of grassland vegetation between 1988 and 2007 on the Plateau. When climatic warming continued with CO2 doubling in the future, the vegetation of alpine grassland will shrink into nine types.  相似文献   

4.
In this study thermal comfort conditions are analyzed to determine possible thermal perceptions during different months in Iran through the Physiologically Equivalent Temperature (PET). The monthly PET values produced using the RayMan Model ranged from ?7.6°C to 46.8°C. Over the winter months the thermal comfort condition (18–23°C) were concentrated in southern coastal areas along the Persian Gulf and Oman Sea. Most of the country experienced comfort conditions during the spring months, in particular in April, while during the summer months of July and August no thermal comfort conditions were observed. In November coastal areas of the Caspian Sea had the same physiological stress level of thermal comfort as April. The map produced showing mean annual PET conditions demonstrated the greatest spatial distribution of comfortable levels in the elevation range from 1000 to 2000 meter a.s.l., with annual temperatures of 12–20°C and annual precipitation of under 200 mm. The statistical relationship between PET conditions and each controlling parameter revealed a significant correlation in areas above 2000 meter, annual temperature over 20°C and annual precipitation of 200–400 mm with a correlation coefficient (R 2) of 0.91, 0.97 and 0.96, respectively.  相似文献   

5.
In this research, the frequency of dust storms was prepared at 87 synoptic stations for the period of 1987–2013. These data were classified by means of Fuzzy c-means clustering algorithm. Satellite images of MODIS and brightness temperature index were also used for detection and tracking dust storm of 30 Jun 4 July 2008. The results indicated that Iran is classified in five clusters by the dust-storm-frequencies from which, cluster 5 is reclassified in three clusters because of its wide range. The maximum number of days with dust storms was observed in cluster 1 that includes only Zabol station with the frequency of 790 days with the duration 1987–2013. The minimum number of days with dust storms was observed in cluster 5-3 that includes the stations located in portions of North, Northwest, Northeast Iran and the higher elevations of the Zagros in western Iran. A case study about a severe dust storm in Iran using satellite images indicate that brightness temperature index (BTI) is a desired index for detection and monitoring of dust storms. The source of the investigated dust storms is Iraq and South of the Arabian Peninsula that had influenced the western half of Iran in several days. The frequency of dust storms increased markedly in the west, southwest of Iran and Persian Gulf around as main receptors from emerging dusty areas but it increased slightly in the eastern half of Iran.  相似文献   

6.
Variations of the Effective Temperature Index (ET) in Kenya   总被引：2，自引：0，他引：2  
Using the Effective Temperature Index (ET) as a measure of climatic comfort conditions in Kenya, this study analyses its spatial, seasonal and diurnal variations. This index is computed using data collected from 57 weather stations spread throughout the country. Isarithmic mapping technique and the conditioning square method are used in this analysis. The results indicate that there exists in Kenya marked spatial, seasonal and diurnal variations of climatic comfort conditions. A classification of the country using this index and the Terjung (1968) system of climatic classification yields six climatic comfort zones. This type of physio-climatic studies has significant implications for Kenya in aspects such as building, clothing, recreation and sporting. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

7.
In this study, the regional variations of climate extremes and its possible impact on rice yield in Jiangsu province, southeast China were investigated. A total of 18 climate extremes indices (CEI) of rice-growing period (May–October) based on the daily climate records and rice yield data at 52 stations during 1961–2012 were calculated and analyzed. The main findings were as follows: (1) due to the remarked regional differences of climate extremes, Jiangsu could be divided into six climatic subregions: westernmost, northwest, north, southwest, south, and southeast corner; (2) trends of 18 indices in the six subregions using Mann–Kendall test indicated that Jiangsu was dominated by an obvious wetting and warming tendency, especially in the southern area; (3) correlation analysis between rice yield and CEI using first-difference and climate-induced yield method showed that the negative influences of precipitation extremes were more notable compared to temperature extremes; (4) P95 [precipitation due to very wet days (> 95th percentile)] should be selected as a key meteorological disasters indicator affecting rice yield in the northwest, north, southwest, and south Jiangsu; (5) the increase of P95 since 1990s was detected in most of Jiangsu, which would bring huge risks to rice growing.  相似文献   

8.
新疆40a来气温、降水和沙尘天气变化   总被引：67，自引：10，他引：57  
何清  杨青  李红军 《冰川冻土》2003,25(4):423-427
根据1961-2001年新疆代表北疆的8个气象站、天山山区的8个气象站、南疆的8个气象站的实测资料, 分析了40 a来新疆气温、降水、沙尘暴、扬沙、浮尘年代际变化特征.结果显示: 40 a来新疆气温呈明显上升趋势, 后10 a(1991-2000年)比前30 a平均气温升高, 北疆偏高0.8℃, 南疆和天山山区均偏高0.℃; 降水变化的总趋势是增湿明显, 后10 a与前30 a相比降水增加, 南疆偏多20.4%, 北疆偏多11.3%, 天山山区偏多9.8%; 南疆与北疆各类沙尘天气年际变化趋势基本相似, 80年代以来呈减少趋势; 南疆沙尘暴、扬沙、浮尘总日数之和与同期的温度、降水在春季有相对较好的线性相关关系.  相似文献   

9.
The Effective Temperature (ET), which considers the aggregate effects of temperature, relative humidity and wind speed to describe the human thermal sensitivity, was employed to investigate the change of thermal conditions over Yunnan Province in China during the period of 1961-2014. The observation data used in the study is the high resolution gridded daily scale dataset CN05.1. The results show that over the northern part of the Province with high elevation mountains, colder temperature, lower relative humidity and stronger wind speed prevail, which leads to the lower ET values there. Opposite conditions are found over the low elevation areas in the south. An overall warming and decrease of both relative humidity and wind speed are observed in the latest decades in the whole Province, resulting in the general increase of ET over the region. Analysis based on the different assessment scales of ET shows that, more cold/extreme cold days and cool days exist in the north, while the cool days and comfortable days are mainly distributed in the south. General decrease of cold/extreme cold days is found over the region. An increase of the cool days in the north and decrease of it in the south, significant increase of the comfortable days, and increase of warm and hot/extreme hot days over portions in the south are reported. More climatic favorable days are found in all of the four seasons. Within the climate change context, the significant reduction of cold/extreme cold days and increase of climatic favorable days indicate that the climate in Yunnan Province so far tends to be more favorable for the human beings.  相似文献   

10.
The current and future wind energy potentials for two square areas (SA) in the region of Freiburg were assessed and analyzed, with the aim of mitigating climate change by increasing the use of wind energy. For future conditions the regional climate models REMO and CLM were taken into account for the IPCC Emission Scenarios (SRES) A1B and B1. One aim was to provide information of the applicability of data from regional climate models in terms of wind energy. As a reference dataset, the wind energy potentials of the two measurement stations of the German Weather Service (DWD) (1961–1990) in Freiburg (SA I) and on the Feldberg (SA II) were assessed. Calculations were carried out by the Wind Analysis and Application Program (WAsP). Results were in terms of visual analysis displayed with maps. While the annual electricity performances of the reference data in SA I and SA II reach up to 7.2 GWh and 10.1 GWh respectively, the calculations for REMO and CLM show an underestimation of the real conditions for every period and Emission Scenario. Hence the applicability of the models in consideration seems to be limited. Nevertheless, with regard to different socio-economic developments (SRES A1B and B1), the results provide an overview of the wind energy potentials’ development in the different periods.  相似文献   

11.
Direct information about climate change from meteorological surface air temperature records are available in India only since 1901 A.D. Meteorological surface air temperature (SAT) data for the period 1901–2006 from 49 sites in peninsular India have been combined with the geothermal data from 146 sites to extract a baseline (or pre-observational mean, POM) surface temperature prior to the existence of the observational record in the region. Periodicities of 5, 11 and 22 years in the SAT time series have little influence on the combined analysis to infer long-term climate change. The best estimate of the long-term average temperature for the 19th Century is 0.7 °C lower than the 1961–1990 mean temperature. Considering the additional warming of 0.38°C relative to the 1961–1990 mean over a 10-year window centred on the year 2000, the hybrid POM-SAT method suggests that the total surface warming in peninsular India from mid-1800s to early- 2000s is about 1.1 °C. The study provides new evidence for significant warming prior to the establishment of widespread meteorological stations in peninsular India.  相似文献   

12.
杨成松  程国栋 《冰川冻土》2011,33(3):461-468
对1961-2100年IPCC气候模拟与预测结果进行降尺度处理,得到铁路沿线空间分辨率为1km、时间分辨率为1h的大气边界条件.对铁路和公路沿线钻孔资料在垂直和水平两个方向进行空间差值处理,得到水平1 km、垂直0.1m分辨率的沿线地下含水（冰）量的二维分布,作为初始条件.考虑气候模型预测误差和空间格网内地形的变化,以...  相似文献   

13.
About the observed and future changes in temperature extremes over India   总被引：1，自引：0，他引：1  
An attempt is made in the present study to analyse observed and model simulated temperature extremes over Indian region. Daily maximum and minimum temperature data at 121 well-distributed stations for the period 1970–2003 have been used to study the observed changes in objectively defined values of temperature extremes. In addition, an assessment of future scenarios of temperature extremes associated with increase in the concentration of atmospheric greenhouse gases is done using simulations of a state-of-the-art regional climate modelling system known as PRECIS (Providing Regional Climate for Impact Studies) performed to generate the climate for the present (1961–1990) and future projections for the period 2071–2100. Observational analysis done with 121 stations suggests the widespread warming through increase in intensity and frequency of hot events and also with decrease in frequency of cold events. More than 75% stations show decreasing trend in number of cold events and about 70% stations show increasing trend in hot events. Percentage of stations towards the warming through intensity indices of highest maximum temperature, lowest minimum temperature is 78 and 71% stations, respectively. Remaining stations show opposite trends, however, most of them are statistically insignificant. Observational analysis for India as a whole also shows similar results. Composite anomalies for monthly temperature extremes over two equal parts of the data period show increase (decrease) in the frequency of hot (cold) events for all months. In general, PRECIS simulations under both A2 and B2 scenarios indicate increase (decrease) in hot (cold) extremes towards the end of twenty-first century. Both show similar patterns, but the B2 scenario shows slightly lower magnitudes of the projected changes. Temperatures are likely to increase in entire calendar year, but the changes in winter season are expected to be prominent. Diurnal temperature range is expected to decrease in winter (JF) and pre-monsoon (MAM) months.  相似文献   

14.
Climate extreme and its linkage to regional drought over Idaho, USA   总被引：2，自引：0，他引：2  
To investigate consequences of climate extreme and variability on agriculture and regional water resource, twenty-seven climatic indices of temperature and precipitation over Idaho, USA, were computed. Precipitation, mean temperature and maximum temperature, self-calibrated Palmer Drought Index and Standardized Precipitation Index for 1-, 3-, 6- and 12-month time scales were used to identify spatial and temporal distribution of climatic extreme and variability as well as drought frequency and magnitude. Seven oceanic indices were also used to detect teleconnections between climatic indices and regional droughts. The analyses were conducted for 56 meteorological stations, during 1962?C2008, characterized by a long-term and high-quality data set. The result indicates that decreasing trends and increasing trends are identified for precipitation and temperature, respectively. Consequently, it appears that frost and ice days dwindle as growing season (May?CAugust) length, tropical nights and summer days increase. Given current climate conditions, the results also imply that these trends will continue in the future possibly driven by uncertain climate variability. We anticipate that these indices explained by teleconnections will improve drought-forecasting capability in this region.  相似文献   

15.
Thermal comfort evaluation in Tehran metro using Relative Warmth Index   总被引：2，自引：2，他引：0  
Underground railway systems, can generate heat from their operations to raise the temperatures of carriages and the station substantially. This may lead to passenger discomfort and complain especially in warm weather conditions that prevail in Tehran if underground environment is not cooled. Transportation air conditioning Committee of American Society of Heating, Refrigerating and air-conditioning Engineers proposed the Relative Warmth Index for thermal comfort design and investigation in subway environment. In this research, thermal comfort at Tehran metro stations and carriages of lines 1 and 2 has been studied using this index. The measurements were taken during two periods of September 2006 and July 2007 at different zones of stations. For this purpose, temperature, relative humidity and air velocity were measured at different times. The status of the air-conditioning systems together with passenger traffic was also recorded. A total number of 231 measurements including 114 and 117 measurements were carried out in September 2006 and in July 2007 respectively. The measurements in September 2006 did not exceed the thermal limit. However, it did exceed in July 2007. In comparison, with thermal comfort level of metros all over the world, Tehran Metro stands in an acceptable condition, while the maximum capacity of air-conditioning systems was not used, if so the thermal comfort condition would be better.  相似文献   

16.
The present research evaluated the relation between the normalized difference vegetation index (NDVI) changes and the climate change during 2000–2014 in Qazvin Plain, Iran. Daily precipitation and mean temperature values during 2015–2040 and 2040–2065 were predicted using the statistical downscaling model (SDSM), and these values were compared with the values of the base period (2000–2014). The MODIS images (MOD13A2) were used for NDVI monitoring. In order to investigate the effects of climate changes on vegetation, the relationship between the NDVI and climatic parameters was assessed in monthly, seasonal, and annual time periods. According to the obtained results under the B2 scenario, the mean annual precipitation at Qazvin Station during 2015–2040 and 2040–2065 was 6.7 mm (9.3%) and 8.2 mm (11.36%) lower than the values in the base period, respectively. Moreover, the mean annual temperature in the mentioned periods was 0.7 and 0.92 °C higher than that in the base period, respectively. Analysis of the correlations between the NDVI and climatic parameters in different periods showed that there is a significant correlation between the seasonal temperature and NDVI (P < 0.01). Moreover, the NDVI will increase 0.009 and 0.011 during 2015–2040 and 2040–2065, respectively.  相似文献   

17.
This article concerns the analysis of the heavy precipitation, which allows investigating the effect of the blocking system on the unusual precipitation and temperature occurrence in Iran. The days of January 2008 have been the coldest days during the history of recorded data in Iran. Variation of precipitation during January 2008 compared with long-term data (30 years) shows the maximum positive anomaly in the stations located in southeast of Iran. However, the precipitation in consecutive days, 14–15 and 15–16 of January, produce a more important proportion of the heavy precipitation in this region. In order to study the role of the blocking system related to heavy precipitation in January 2008, the position and movement of the atmospheric systems including cyclones, anticyclones, fronts, and wind fields have been analyzed by the use of synoptic maps by the environment to circulation approach. Consequently, the weather maps indicated that the blocking system over the north of the Caspian Sea has caused the relatively deep low trough on January 5, 7, 14, 15, and 16, 2008, while the thermal and moisture gradients in the warm section of air masses have produced heavy precipitation. As a result, wind field of low levels (850 hPa) provided remarkable moisture fed by the Arabian Sea, Oman Sea, and Persian Gulf in the study area. Furthermore, the speed of wavelength and the position of the blocking system associated with the heavy precipitation can be clearly identified.  相似文献   

18.
Particulate matter concentration and assessment of its movement pattern is crucial in air pollution studies. However, no study has been conducted to determine the PM10 concentration using atmospheric correction of thermal band by temperature of nearest dark pixels group (TNDPG) of this band. For that purpose, 16 Landsat Enhanced Thematic Mapper plus ETM+ images for Sanandaj and Tehran in Iran were utilized to determine the amount of PM10 concentration in the air. Thermal infrared (band 6) of all images was also used to determine the ground station temperature (GST b6) and temperature of nearest dark pixels group. Based on atmospheric correction of images using temperature retrieval from Landsat ETM+, three empirical models were established. Non-linear correlation coefficient with polynomial equation was used to analyze the correlations between particulate matter concentration and the ground station temperature for the three models. Similar analyses were also undertaken for three stations in Klang Valley, Malaysia, using 11 Landsat ETM+ images to show the effectiveness of the model in different region. The data analysis indicated a good correlation coefficient R = 0.89 and R = 0.91 between the trend of the result of temperature of nearest dark pixels group b6 ? (GST b6 ? GST) model and the trend of PM10 concentration in Iran and Malaysia, respectively. This study reveals the applicability of the thermal band of Landsat TM and ETM+ to determine the PM10 concentration over large areas.  相似文献   

19.
Future changes of seasonal minimum and maximum temperature over Northern Italy are assessed for the periods 2021–2050 and 2070–2099 against 1961–1990. A statistical downscaling technique, applied to the ENSEMBLES-Stream1 and CIRCE global simulations (A1B scenario), is used to reach this objective. The statistical scheme consists of a multivariate regression based on Canonical Correlation Analysis. The set-up of the statistical scheme is done using large-scale fields (predictors) derived from ERA40 reanalysis and seasonal mean minimum and maximum temperature (predictands) derived from observational data at around 75 stations, distributed over Northern Italy, over the period 1960–2002. A similar technique is also applied to the number of frost days and ice days at a reduced number of stations in order to construct projections on change of the selected extreme temperature indices for the two future periods. The evaluation of future projections for these extreme indices is relevant due to its impacts on transports, health, and agriculture. The downscaling scheme constructed using observed data is then applied to large-scale fields simulated by global models (A1B scenario), in order to construct scenarios on future change of seasonal temperature, mean and extreme indices, at local scale. The significance of changes is tested from the statistical point of view. The results show that significant increases could be expected to occur under scenario conditions in both minimum and maximum temperature, associated with a decrease in the number of frost and ice days in both periods and more intense to the end of the century.  相似文献   

20.
It is important to predict how groundwater levels in an aquifer will respond to various climate change scenarios to effectively plan for how groundwater resources will be used in the future. Due to the overuse of groundwater resources and the multi-year drought in the Kerdi-Shirazi plain in Iran, some land subsidence and a drop in groundwater levels has taken place, and without active management, further degradation of the groundwater resource is possible under predicted future climate change scenarios in the country. To determine the potential impacts of climate change on groundwater levels in the region, the groundwater model GMS was coupled with the atmospheric circulation model HADCM3 using scenarios A1B, A2 and B1 for the period 2016–2030. The results of the climate modelling suggest that the Kerdi-Shirazi plain will experience an increase in minimum temperature and maximum temperature of, respectively, between 0.03 and 0.47, and 0.32–0.45 °C for this time period. The results of the groundwater modelling suggest that water levels on the Kerdi-Shirazi plain will continue to decline over the forecast period with decreases of 34.51, 36.57 and 33.58 m being predicted, respectively, for climate scenarios A1B, A2 and B1. Consequently, groundwater resources in the Kerdi-Shirazi plain will urgently need active management to minimize the effects of ongoing water level decline and to prevent saltwater intrusion and desertification in the region.  相似文献   

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