Chapter 3 (2) Photosynthetically Active Radiation(Par) Definition Solar radiation with wave band of 0.4-0.7um, absorbed by plants for their photosynthesis · Amount about 50%o of insolation Unit Photon flux density(umol/ms) 2021/2/22 Assessment of Climate/Change Impacts 28of76Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 28 of 76 • Definition Solar radiation with wave band of 0.4 - 0.7m, absorbed by plants for their photosynthesis • Amount About 50% of insolation • Unit Photon flux density(mol/m2 s) (2) Photosynthetically Active Radiation(PAR)