PP Systems CIRAS-2, Руководство оператора

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Addendum
CIRAS-2 Operator's Manual Version 2.04
- 162 -
Addendum
Corrections to Stomatal Resistance Measurements for Differing Transpiration
Rates from Upper and Lower Leaf Surfaces
The assumption is made that the internal diffusion resistance to water vapor and CO
2
are small compared
with the stomatal resistances, so that there are uniform H
2
O and CO
2
concentrations within the leaf.
Where:
(ea) and (el) are the water vapor pressures of the cuvette air and the leaf air spaces respectively
RB is the boundary layer resistance for whole leaf, with RBu = RBl = 2(RB) (m
2
s mol
-1
)
RS is the total leaf resistance
Then for the two leaf surfaces:
N and (1-N) are the fractions of the total evaporation E in mol m
-2
s
-1
from the upper (u) and lower (l) leaf
surfaces
RB
N E
ea el
RSu * 2
*
(1)
and
RB
N E
ea el
RSl * 2
) 1 ( *
(2)
el Leaf =
ea
2RB = RBu
RSu
RSl
2RB = RBl
ea
CInt
el
RSu
RSl
ea
RBu
RBl