摘要 Photosynthetically active radiation (PAR) is an important input parameter for estimating plant produc-tivity due to its key role in the growth and development of plants. However, a worldwide routine network for sys-tematic PAR measurements is not yet established, and PAR is often calculated as a constant fraction of total solar radiation (SR). Although the ratio of PAR to SR (PAR/SR) has been reported from many places, few studies have been performed for dry regions. The present study was therefore carried out in an arid region of Mongolia to obtain PAR/SR and examine its dependency on sky clearness (the clearness index), water vapor in the atmosphere and aeolian dust. Continuous measurements of PAR and SR were taken every one second using quantum and pyranometer sensors, respectively, and the readings were averaged and recorded at intervals of 30 minutes for a period of 12 months. The lowest monthly mean daily PAR/SR occurred in April (0.420), while the highest ratio was observed in July (0.459). Mean daily PAR/SR during plant growing season (May−August) was estimated to be 0.442, which could be useful for modeling plant productivity in the study area. The annual mean daily PAR/SR (0.435) was lower than the values reported in many previous studies. This difference could be explained with the regional variation in climate: i.e. drier climatic condition in the study area. PAR/SR was negatively correlated with the clearness index (r= –0.36, P<0.001), but positively with atmospheric water vapor pressure (r=0.47, P<0.001). The average PAR/SR was significantly lower (P=0.02) on the dusty days compared to the non-dust days. Water vapor in the atmosphere was shown to be the strongest factor in the variation of PAR/SR. This is the first study examining PAR/SR under a semi-arid condition in Mongolia.
Abstract: Photosynthetically active radiation (PAR) is an important input parameter for estimating plant produc-tivity due to its key role in the growth and development of plants. However, a worldwide routine network for sys-tematic PAR measurements is not yet established, and PAR is often calculated as a constant fraction of total solar radiation (SR). Although the ratio of PAR to SR (PAR/SR) has been reported from many places, few studies have been performed for dry regions. The present study was therefore carried out in an arid region of Mongolia to obtain PAR/SR and examine its dependency on sky clearness (the clearness index), water vapor in the atmosphere and aeolian dust. Continuous measurements of PAR and SR were taken every one second using quantum and pyranometer sensors, respectively, and the readings were averaged and recorded at intervals of 30 minutes for a period of 12 months. The lowest monthly mean daily PAR/SR occurred in April (0.420), while the highest ratio was observed in July (0.459). Mean daily PAR/SR during plant growing season (May−August) was estimated to be 0.442, which could be useful for modeling plant productivity in the study area. The annual mean daily PAR/SR (0.435) was lower than the values reported in many previous studies. This difference could be explained with the regional variation in climate: i.e. drier climatic condition in the study area. PAR/SR was negatively correlated with the clearness index (r= –0.36, P<0.001), but positively with atmospheric water vapor pressure (r=0.47, P<0.001). The average PAR/SR was significantly lower (P=0.02) on the dusty days compared to the non-dust days. Water vapor in the atmosphere was shown to be the strongest factor in the variation of PAR/SR. This is the first study examining PAR/SR under a semi-arid condition in Mongolia.
Tserenpurev BAT-OYUN, Masato SHINODA, Mitsuru TSUBO. Effects of cloud, atmospheric water vapor, and dust on photosynthetically active radiation and total solar radiation in a Mongolian grassland[J]. 干旱区科学, 2012, 4(4): 349-356.
Tserenpurev BAT-OYUN, Masato SHINODA, Mitsuru TSUBO. Effects of cloud, atmospheric water vapor, and dust on photosynthetically active radiation and total solar radiation in a Mongolian grassland. Journal of Arid Land, 2012, 4(4): 349-356.
Alados I, Foyo-Moreno I, Alados-Arboledas L. 1996. Photosyn¬th¬etically active radiation: measurements and modeling. Agricul¬tural and Forest Meteorology, 78: 121–131.Allen R G, Pereira L S, Raes D, et al. 1998. Crop Evapotran¬spiration—Guidelines for Computing Crop Water Requirements. Rome, Italy: FAO Irrigation and Drainage Paper, 56: 161–169.Al-Shooshan A A. 1997. Estimation of photosynthetically active radi¬ation under an arid climate. Journal of Agricultural Engineering Research, 66: 9–13.Badarinath K V S, Kharol S K, Kaskaoutis D G, et al. 2007. Case study of a dust storm over Hyderabad area, India: its impact on solar radiation using satellite data and ground measurements. Science of the Total Environment, 384: 316–332.Britton C M, Dodd J D. 1976. Relationships of photosynthetically active radiation and shortwave irradiance. Agricultural Meteorology, 17: 1–7.Falkowski P G, Barber R T, Smetacek V. 1998. Biogeochemical con¬trols and feedbacks on ocean primary production. Science, 281: 200–206. Finch D A, Bailey W G, McArthur L J B, et al. 2004. Photosynth¬etically active radiation regimes in a southern African savanna environment. Agricultural and Forest Meteorology, 122: 229–238.Frouin R, Pinker R T. 1995. Estimating photosynthetically active radiation (PAR) at the earth’s surface from satellite observations. Remote Sensing of Environment, 51: 98–107.Gonzalez J A, Calbo J. 2002. Modelled and measured ratio of PAR to global radiation under cloudless skies. Agricultural and Forest Meteorology, 110: 319–325.Gueymard C. 1989. A two-band model for the calculation of clear sky solar irradiance, illuminance, and photosynthetically active radiat¬ion at the earth’s surface. Solar Energy, 43: 253–265.Hansen V. 1984. Spectral distribution of solar radiation on clear days: a comparison between measurements and model estimates. Journal of Climate and Applied Meteorology, 23: 772–780.Howell T A, Meek D W, Hatfield J L. 1983. Relationship of photo¬synthetically active radiation to shortwave radiation in the San Joa¬quin valley. Agricultural Meteorology, 28: 157–175.Hu B, Wang Y S, Liu G R. 2007. Measurements and estimations of photos¬ynthetically active radiation in Beijing. Atmospheric Research, 85: 361–371. Intergovernmental Panel on Climate Change. 2007. Climate change 2007: the physical science basis. In: Solomon S, Qin D, Manning M, et al. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. New York: Cambridge University Press. Jacovides C P, Karalis J D. 1996. Broad band turbidity parameters and spectral band resolution of solar radiation for the period 1954–1991, in Athens, Greece. International Journal of Climatology, 16: 107–119.Jacovides C P, Tymvios F S, Asimakopoulos D N, et al. 2003. Global photosynthetically active radiation and its relationship with global solar radiation in the Eastern Mediterranean basin. Theoretical and Applied Climatology, 74: 227–233.Jacovides C P, Tmvios F S, Papaioannou G, et al. 2004. Ratio of PAR to broadband solar radiation measured in Cyprus. Agricultural and Forest Meteorology, 121: 135–140. Jacovides C P, Kaltsounides N A, Asimakopoulos D N, et al. 2005. Spectral aerosol optical depth and Angstrom parameters in the polluted Athens atmosphere. Theoretical and Applied Climatology, 81: 161–167. Jugder D, Chung Y S, Batbold A. 2004. Cyclogenesis over the territory of Mongolia during 1999−2002. Journal of the Korean Meteoro¬logical Society, 40(3): 293−303.Kaufman Y J, Tanre D, Boucher O. 2002. A satellite view of aerosols in the climate system. Nature, 419: 215–223.Li R, Zhao L, Ding Y J, et al. 2010. Monthly ratios of PAR to global solar radiation measured at northern Tibetan Plateau, China. Solar Energy, 84: 964–973. Liao H, Seinfeld J H. 1998. Radiative forcing by mineral dust aerosols: sensitivity to key variables. Journal of Geophysical Research, 103: 31637–31645.Maher B A, Prospero J M, Mackie D, et al. 2010. Global connections between aeolian dust, climate and ocean biogeochemistry at the present day and at the last glacial maximum. Earth Science Reviews, 99: 61–97.McCree K J. 1966. A solarimeter for measuring photosynthetically active radiation. Agricultural Meteorology, 3: 353–366.McCree K J. 1972. Test of current definitions of photosynthetic active radiation against leaf photosynthesis data. Agricultural Meteorology, 10: 443–453.Mikami M. 2007. Japan-China collaborative investigation on aeolian dust experiment on climate impact (ADEC). Tenki, 54: 142–150.Miskolczi F, Aro T O, Iziomon M, et al. 1997. Surface radiative fluxes in sub-sahel Africa. Journal of Applied Meteorology, 36: 521–530.Monteith J L. 1973. Principles of Environmental Physics. London: Edward Arnold, 23–38.Monteith J L, Unsworth M. 1990. Principles of Environmental Physics, 2nd ed. London: Edward Arnold, 291.Moon P. 1940. Proposed standard solar-radiation curves for engineer¬ing use. Journal of the Franklin Institute, 230: 583–618.Natsagdorj L, Jugder D, Chung Y S. 2003. Analysis of dust storms observed in Mongolia during 1937–1999. Atmospheric Environ¬ment, 37: 1401–1411. Papaioannou G, Papanikolaou N, Retalis D. 1993. Relationships of photosynthetically active radiation and shortwave irradiance. Theoretical and Applied Climatology, 48: 23–27.Papaioannou G, Nikolidakis G, Asimakopoulos D, et al. 1996. Photo¬synthetically active radiation in Athens. Agricultural and Forest Meteorology, 81: 287–298.Pinker R T, Laszlo I. 1992. Global distribution of photosynthetically active radiation as observed from satellites. Journal of Climate, 5: 56–65.Rao C R. 1984. Photosynthetically active components of global solar radiation: measurements and model computations. Theoretical and Applied Climatology, 34: 353–364.Rodskjer N. 1983. Spectral daily insolation at Uppsala, Sweden. Theoretical and Applied Climatology, 33: 89–98.Ross J, Sulev M. 2000. Sources of errors in measurements of PAR. Agricultural and Forest Meteorology, 100: 103–125.Shinoda M, Ito S, Nachinshonhor G U, et al. 2007. Phenology of Mongolian grasslands and moisture conditions. Journal of the Meteorological Society of Japan, 85: 359–367.Shinoda M, Nachinshonhor G U, Nemoto M. 2010. Impact of drought on vegetation dynamics of the Mongolian steppe: a field experiment. Journal of Arid Environments, 74: 63–69.Szeicz G. 1974. Solar radiation for plant growth. Journal of Applied Ecology, 11: 617–636.Tsubo M, Walker S. 2005. Relationships between photosynthetically active radiation and clearness index at Bloemfontein, South Africa. Theoretical and Applied Climatology, 80: 17–25.Tugjsuren N, Takamura T. 2001. Investigation for photosynthetically active radiation regime in the Mongolian Grain Farm Region. Journal of Agricultural Meteorology, 57(4): 201–207.Udo S O, Aro T O. 1999. Global PAR related to global solar radiation for central Nigeria. Agricultural and Forest Meteorology, 97: 21–31.UNEP. 1992. World Atlas of Desertification. London: Edward Arnold.Waggoner A P, Weiss R E, Ahlquist N C, et al. 1981. Optical characteristics of atmospheric aerosols. Atmospheric Environment, 15: 1891–1909.Wang Q, Tenhunen J, Schmidt M, et al. 2005. Diffuse PAR irradiance under clear skies in complex alpine terrain. Agricultural and Forest Meteorology, 128: 1–15.Wang Q, Kakubari Y, Kubota M, et al. 2007. Variation of PAR to global solar radiation ratio along altitude gradient in Naeba Mountain. Theoretical and Applied Climatology, 87: 239–253. Zhang X Z, Zhang Y G, Zhou Y H. 2000. Measuring and modeling photosynthetically active radiation in Tibet Plateau during April–October. Agricultural and Forest Meteorology, 102: 207–212.Zhu X D, He H L, Liu M, et al. 2010. Spatio-temporal variation of photosynthetically active radiation in China in recent 50 years. Journal of Geographical Sciences, 20(6): 803–817.
2012, Vol. 4 
