1 |
adcroft |
1.5 |
C $Header: $ |
2 |
adcroft |
1.1 |
|
3 |
|
|
#include "CPP_OPTIONS.h" |
4 |
|
|
|
5 |
|
|
SUBROUTINE SWFRAC( |
6 |
adcroft |
1.5 |
I imax, fact, z, |
7 |
adcroft |
1.1 |
O swdk ) |
8 |
|
|
C /==========================================================\ |
9 |
|
|
C | SUBROUTINE SWFRAC | |
10 |
|
|
C | Compute fraction of solar short-wave flux penetrating to | |
11 |
|
|
C | specified depth, z, due to exponential decay in | |
12 |
|
|
C | Jerlov water type jwtype. | |
13 |
|
|
C | Reference : Two band solar absorption model of Paulson | |
14 |
|
|
C | and Simpson (1977, JPO, 7, 952-956) | |
15 |
|
|
C | Notes | |
16 |
|
|
C | ===== | |
17 |
|
|
C | Below 200m the solar penetration gets set to zero, | |
18 |
|
|
C | otherwise the limit for the exponent (+/- 5678) needs to | |
19 |
|
|
C | be taken care of. | |
20 |
|
|
C | Written by : Jan Morzel | |
21 |
|
|
C | Date : July 12, 1995 | |
22 |
|
|
C \==========================================================/ |
23 |
|
|
|
24 |
|
|
IMPLICIT NONE |
25 |
|
|
|
26 |
|
|
C === Routine arguments === |
27 |
|
|
|
28 |
|
|
C input arguments |
29 |
adcroft |
1.5 |
C imax number of vertical grid points |
30 |
|
|
C fact scale factor to apply to depth array |
31 |
|
|
C z vertical depth for desired sw fraction |
32 |
|
|
C (fact*z) is negative distance (m) from surface |
33 |
|
|
C jwtype index for jerlov water type |
34 |
|
|
|
35 |
|
|
INTEGER imax |
36 |
|
|
_RS fact |
37 |
|
|
_RS z(imax) |
38 |
adcroft |
1.1 |
|
39 |
|
|
C output arguments |
40 |
adcroft |
1.5 |
C swdk short wave (radiation) fractional decay |
41 |
|
|
_RS swdk(imax) |
42 |
|
|
|
43 |
|
|
C === Local variables === |
44 |
adcroft |
1.1 |
|
45 |
adcroft |
1.5 |
C max number of different water types |
46 |
|
|
integer nwtype |
47 |
|
|
PARAMETER(nwtype = 5) |
48 |
adcroft |
1.4 |
|
49 |
adcroft |
1.1 |
_RS facz |
50 |
adcroft |
1.5 |
_RL rfac(nwtype),a1(nwtype),a2(nwtype) |
51 |
adcroft |
1.1 |
INTEGER i |
52 |
|
|
C |
53 |
|
|
C Jerlov water type : I IA IB II III |
54 |
|
|
C jwtype 1 2 3 4 5 |
55 |
|
|
C |
56 |
|
|
DATA rfac / 0.58 , 0.62 , 0.67 , 0.77 , 0.78 / |
57 |
|
|
DATA a1 / 0.35 , 0.6 , 1.0 , 1.5 , 1.4 / |
58 |
|
|
DATA a2 / 23.0 , 20.0 , 17.0 , 14.0 , 7.9 / |
59 |
adcroft |
1.5 |
INTEGER jwtype |
60 |
adcroft |
1.1 |
C |
61 |
adcroft |
1.5 |
jwtype=1 |
62 |
adcroft |
1.1 |
DO i = 1,imax |
63 |
|
|
facz = fact*z(i) |
64 |
|
|
IF (facz .LT. (-200.)) THEN |
65 |
|
|
swdk(i) = 0. |
66 |
|
|
ELSE |
67 |
|
|
swdk(i) = rfac(jwtype) * exp(facz/a1(jwtype)) |
68 |
|
|
$ + (1.-rfac(jwtype)) * exp(facz/a2(jwtype)) |
69 |
|
|
ENDIF |
70 |
|
|
ENDDO |
71 |
adcroft |
1.4 |
|
72 |
adcroft |
1.1 |
RETURN |
73 |
|
|
END |