کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10694175 | 1020014 | 2015 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Observation and estimation of photosynthetically active radiation in Lhasa (Tibetan Plateau)
ترجمه فارسی عنوان
مشاهده و برآورد تابش فعال فتوسنتزی در لهاسا (پلاتو تبت)
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علوم فضا و نجوم
چکیده انگلیسی
In this study, we measured photosynthetically active radiation (PAR) and global solar radiation (G) in Lhasa, located on the Tibetan Plateau, from 2006 to 2012 to examine the PAR and PAR/G (PAR fraction) seasonal characteristics. The maximum and minimum values of both PAR and the PAR fraction occurred in summer and winter, respectively. Moreover, the PAR and PAR fraction annual averages were 38.64 mol mâ2 dâ1 and 1.84 mol M Jâ1, respectively. An efficient all-weather model used for estimating PAR under various sky conditions was developed based on the relationships among PAR, the cosine of the solar zenith angle and the clearness index in Lhasa. The model also produced acceptable estimations of PAR with high accuracy at the Donghu and Sanjiang weather stations. A PAR dataset was reconstructed from G using the newly developed model for the period 1961-2012. The modelled annual mean daily PAR was approximately 37.62 mol mâ2 dâ1. A significant decreasing trend (â0.61 mol mâ2 per decade) over the last 50 years was observed on the Tibetan Plateau; this decrease was largest in autumn (â1.024 mol mâ2 per decade), and relatively small decreases were observed in summer. The results also revealed that PAR began increasing at 0.164 mol mâ2 per year from 1991 to 2012, which was inconsistent with the variations of G. The proposed all-weather PAR model could be useful for ecological modelling and agricultural processes in the Tibetan Plateau region of China.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Advances in Space Research - Volume 55, Issue 6, 15 March 2015, Pages 1604-1612
Journal: Advances in Space Research - Volume 55, Issue 6, 15 March 2015, Pages 1604-1612
نویسندگان
Simao Peng, Qingyun Du, Aiwen Lin, Bo Hu, Ke Xiao, Yuliang Xi,