این سایت در حال حاضر پشتیبانی نمی شود و امکان دارد داده های نشریات بروز نباشند
پژوهش های جغرافیای طبیعی، جلد ۴۶، شماره ۱، صفحات ۵۹-۷۶
عنوان فارسی مطالعۀ الگوی دمای سطوح فیزیکی در شرایط جوی متفاوت
چکیده فارسی مقاله الگوی رفتاری دمای سطوح در طول شبانه‎روز و نیز در شرایط آب‎وهوایی گوناگون در محیط‎های شهری، شاید در زمینۀ مدیریت و برنامه­ریزی شهری کارآمد باشد. در این پژوهش، روند تغییرات دمای اندازه­گیری‎شدۀ چهار پوشش آسفالت، سیمان، خاک و سنگ، در محدودۀ ایستگاه هواشناسی ژئوفیزیک در شرایط جوی گوناگون واکاوی شد. با توجه به ارتباط بین دمای سطح و دمای هوا، مدل رگرسیونی محاسبۀ دمای سطوح با دمای هوا انتخاب و دمای برآوردشده با دمای اندازه­گیری‎شده در ایستگاه، واسنجی شد. نتایج روش­های آماری نشان داد اختلاف دمای کمینه و بیشینۀ سطوح (به جز آب به‎دلیل تأثیر تبخیر) در شرایط آفتابی، حدود 30 درجۀ سلسیوس است؛ در حالیکه اختلاف آنها در شرایط بارانی، ابری و بادی، به‎ترتیب به حدود 6، 10 و 20 درجۀ سلسیوس می‎رسد. همچنین، در شرایط جوی همراه با بارندگی، علاوه‎بر وقوع کمترین دامنۀ دمایی، رفتار دمایی سطوح نسبت به یکدیگر نیز دچار تغییر می‎شود. نتایج مدل رگرسیونی نشان داد که بیشترین همبستگی بین میانگین دمای هوا و میانگین دمای سطوح وجود دارد. براساس ضرایب همبستگی و ضریب کارایی ناش ـ ساتکلیف، رابطۀ رگرسیونی مورد استفاده برای تخمین میانگین دمای سطوح، از کارآیی مناسبی برخوردار است.
کلیدواژه‌های فارسی مقاله الگوی دمای سطوح، پوشش سطحی، شرایط جوی، مدل رگرسیون،
عنوان انگلیسی Study on Physical Surface Temperature Patterns in Different Weather Conditions
چکیده انگلیسی مقاله IntroductionMaterials and surfaces with different thermo-physical properties provide variety of temperaturepatterns and temporal changes. Analyzing thermal behavior of the different land covers is one ofthe significant factors to determine urban microclimates. Urban land covers have usually hightemperature. This can potentially increase the intensity of urban heat island effect and buildingcooling energy consumption and also change energy balance and heat fluxes in these areas.Therefore, regarding to the impact of surface temperature on changes of surrounding aircomponents and formation of Urban Heat Islands (UHI), the main objectives of this study areincluding identification of the circadian pattern of surface temperature in different weatherconditions and providing the best regression model to estimate surface temperature using airtemperature.MethodologyTo determine the surface temperature patterns of different land covers such as Asphalt, Soil,Cement and Stone, three data loggers along with four Platinum Resistance Thermometers(PT100 sensors) were installed in Geophysic Weather Station in University of Tehran.􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯􀀯∗E-mail: Shamsipr@ut.ac.ir Tel: +98 9126024199Physical Geography Research Quarterly, 46 (1), Spring 2014 11Therefore, temperature of these land covers was recorded hourly during the November 2012.Furthermore, meteorological data including air temperature (°C), relative humidity (%),precipitation (MM), and cloudiness (Okta) were gathered from Geophysic Weather Station.Then, circadian temperature pattern of different land covers were selected to be analyzed in sixdays of November with different weather conditions (Sunny, Cloudy, Rainy conditions).Finally, the best regression model for predicting daily mean surface temperature was providedusing air temperature. In addition, two statistical methods such as Nash-Sutcliffe efficiencycoefficient and correlation coefficient were used for determining the efficiency of the regressionmodel in estimating the different land covers surface temperature.Results and DiscussionAccording to the results, it can be concluded that in sunny and cloudy conditions surfacetemperature of all land covers increase with sunrise at 6 A.M. (local time) and this trendcontinue until noon so that, maximum surface temperature occur around 12 P.M. Then, surfacetemperature decreases because of reducing the amount of solar radiation and finally at sunset,the surfaces lose their heat, obtained during the day, as long wave radiation. It is important tonote that in cloudy conditions, the amount of energy absorption during the day and it losesduring the night is less than sunny conditions because of cloud cover existence in the sky andthe effect of the cloud's albedo. Therefore, in these weather conditions surface temperaturepattern has sinusoidal mode but temperature range (difference between maximum and minimumtemperature) on cloudy conditions is less than sunny conditions due to cloud cover so thatstudying relationship between surface temperature and cloudiness depicted that there is inverserelationship between them and temperature reduces when cloudiness increase. It was alsoillustrated that there is no specific hourly trend in surface temperature in rainy conditions andthere are many variations in surface temperature. Totally, on sunny and cloudy conditions thehighest temperature is related to Asphalt, Cement, soil and Stone, in order. While on rainyconditions Asphalt has the lowest temperature between the studied land covers because of waterflow over the surface. Thus, it can also be concluded that permeability of the surfaces is one ofthe most significant physical properties in the surface temperature behavior. Land covers whichare impermeable (such as Asphalt, Cement and Stone) in rainy conditions show lowertemperature because of the water impact. In addition, reconstructed surface temperature datadisplay that there is a significant correlation between observed and estimated temperature usingdaily mean air temperature, so that correlation coefficient between these two parameters variesfrom 0.98 to 0.97 and is significant at 0.01% level. Moreover, result of Nash-Sutcliffe efficiencycoefficient varies from 0.8232 to 0.9205 which shows proper efficiency of the regression model.ConclusionThe main objective of this study is analyzing surface temperature of different land covers duringthe day/night and different weather conditions and also providing a regression model forestimating the surface temperature in these land covers. Generally, this can be concluded thatdifferent land covers surface temperature is completely a function of their thermal properties in12 Physical Geography Research Quarterly, 46 (1), Spring 2014calm and sunny weather conditions. Some surfaces such as Asphalt and cement which have lessthermal conductivity and high absorbency show the highest surface temperature during the day.While, on rainy conditions both air and surface temperature have many variation because ofcloudiness and precipitation. In such conditions some physical properties like permeability ofthe surfaces play significant role in thermal behavior of land covers. Finally, according to thecorrelation and Nash-Sutcliffe coefficients it is concluded that regression coefficients betweendaily mean air temperature and surface temperature have proper efficiency for calculating dailymean surface temperature.
کلیدواژه‌های انگلیسی مقاله
نویسندگان مقاله علی اکبر شمسی پور | ali akbar
استادیار دانشکدۀ جغرافیا، دانشگاه تهران
سازمان اصلی تایید شده: دانشگاه تهران (Tehran university)

قاسم عزیزی |
دانشیار دانشکدۀ جغرافیا، دانشگاه تهران
سازمان اصلی تایید شده: دانشگاه تهران (Tehran university)

مصطفی کریمی احمدآباد | karimi ahmadabad
استادیار دانشکدۀ جغرافیا، دانشگاه تهران
سازمان اصلی تایید شده: دانشگاه تهران (Tehran university)

معصومه مقبل |
دانشجوی دکتری اقلیم شناسی، دانشکدۀ جغرافیا، دانشگاه تهران
سازمان اصلی تایید شده: دانشگاه تهران (Tehran university)

نشانی اینترنتی http://jphgr.ut.ac.ir/article_50619_f2affe2bb400b3a54adea538c48329d5.pdf
فایل مقاله اشکال در دسترسی به فایل - ./files/site1/rds_journals/1375/article-1375-274838.pdf
کد مقاله (doi)
زبان مقاله منتشر شده fa
موضوعات مقاله منتشر شده
نوع مقاله منتشر شده
برگشت به: صفحه اول پایگاه   |   نسخه مرتبط   |   نشریه مرتبط   |   فهرست نشریات