rT”

163
Io Ig Ip

TOP OF MIXING LAYER

wihL
L

Zz

=@

H

TAVit
a

a?
|

L

2 La

MA

T = PYRHELIOMETER AT TOP OF BUILDING
IM//La M=PYRHELIOMETER HALF WAY UP BUILDING
B
B= PYRHELIOMETER AT BOTTOM OF BUILDING

Fic. 132.—Three pyrheliometers at one wave band and one zenith distance to provide mixing depth information where pollutant concentration is distributed linearly with height.

Ip = Iy exp {a — : {cos 6)(L + 1.)

(27)

Iu = Iy exp (2 — ; (cos 6) (« + zy

(28)

Ir

k

2

In =5 (cos O)(2L-La + La) = P

(29)

In FE = 5 (eos 6) (11. +% = @Q

(30)

(cos 8)(2E-L, + 13) = P

(31)

5 (0s 0)(4L-Le + L2) = 4.

(32)

Solving Equations (31) and (32) for k we have
__ 4P — 8Q
~ eos 6 L2 *

(33)

4Q — P

.

4 In I7/Iy — InT,/TIz
“4 In Ir/ls

or

As previously, we shall assume that the wave bands
At and 2 are 400-450 and 550-600 nanometers. The
same notation as aboveis used.
I ef{h1)

= LoQa) exp {- a— pO) Lv cos |

Tr{h2) = Ig(A2) exp (- a— Ps) L’ cos |

(38)

(39)

= [o(\1) exp {= a— ew (L + La)’ cos |

(40)

4inI7/Iy

k(d2)

= I)(\2) exp \- a—

(35)

From Equations (38) and (39)

2

(L + L,)° cos a.

(41)

—_ 8 In Ir/luy

Tp(da) Lo(r2)\ kOe) — FOn)
2
In Ge Oe) =
5
(cos BL.

—

InTy/Tp

o 9 Fin Le/Ts — 8Ir/Tue
H=z+ax-a+ta

Two Pairs of Pyrheliometers at Two Levels and Two
Wave Bands

(34)

But L = zsecéand LZ, = asec 6
_

All of the quantities are measurable.

Tp(r2)

L = leap 3G
L=L

(37)

Ta(h1)

Andsolving for Z we have

_

_ a3inIs/Ig — 41lnIr/ly

i= 4 In Ip/Ig — 2nIe/Tu

4|n Ie/ly — In Iy/Tp
4 ln Lo/LT»

—_ 8 In Ir/Iu

(36)

(42)

Irom Equations (40) and (41)

TQM) Loe) — kO2) — On) cos@(L + L,).

Ta(h2) Lo)

2

Dividing Equation (42) by Equation (43) we have

(43)

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