LESSONS OF EASTER ISLAND
March 17th, 2016
Excel® Column A holds user inputs for Bird clear sky model in rows 6 to 29. Note the cell references rely on the exact structure of rows and columns shown. User values are entered in shaded cells. Bold text are labels for values to be entered in cell below label.
TABLE A.1
Bird Clear Sky Input Parameters
Row Number Column A, Label, Value, or Function 1 2
3 4 5 
N/A 
6 
USER 
7 
INPUTS 
8 
Latitude 
9 
User Value (+N, – S) 
10 
Longitude 
11 
User Value (+E, – W) 
12 
Time Zone 
13 
User Value (W, +E) 
14 
Station Pressure mB 
15 
User Value 
16 
Ozone atmcm 
17 
User Value (0.00.35) 
18 
Water Vapor H2O atmcm 
19 
User Value (0.06.0) 
20 
Aerosol Optical Depth (AOD) @ 500 nm 
21 
User Value (0.00.4) 
22 
AOD @ 380 nm 
23 
User value (~1.5 x AOD @ 500 nm) 
24 
Taua (total AOD) 
25 
= 0.2758*$A$23+0.35*$A$21 
26 
Asymmetry Factor Ba 
27 
0.85 
28 
Ground Albedo (0.0 to 1.0) 
29 
0.2 
TABLE A.2
Values and Functions to Be Entered in Row 3, from Columns B to V
Column Row 1 
Row 2 
Rows 38762 

B 
DOY 
1 to 365 

C 
HR 
0 to 23 

D 
Solar Position 
ETR 
= 1367*(1.00011+0.034221*COS(6.28318*(B31)/365) +0.00128*SIN(6.28318*(B31)/365)+0.000719 *COS(2*(6.28318*(B31)/365))+0.000077 *SIN(2*(6.28318*(B31)/365))) 
E 
Dangle 
= 6.283185*(B31)/365 

F 
DEC 
= (0.0069180.399912*COS(E3)+0.070257*SIN(E3) 0.006758*COS(2*E3)+0.000907*SIN(2*E3) 0.002697*COS(3*E3)+0.00148*SIN(3*E3)) *(180/3.14159) 

G 
EQT 
= (0.000075+0.001868*COS(E3)0.032077*SIN(E3) 0.014615*COS(2*E3)0.040849*SIN(2*E3))*(229.18) 

H 
Hour Angle 
= 15*((C30.5)$A$1312)+$A$11+G3/4 

I 
Zenith Angle 
= ACOS(COS(F3/(180/3.14159))*COS($A$9/(180/3.14159)) *COS(H3/(180/3.14159))+SIN(F3/(180/3.14159)) *SIN($A$9/(180/3.14159)))*(180/3.14159) 

J 
Air Mass 
= IF(I3<89,1/(COS(I3/(180/3.14159)) +0.15/(93.885I3)A1.25),0) 

K 
Transmittances 
T Rayleigh 
= IF(J3>0,EXP(0.0903*($A$15/1013)A0.84 *(1+$A$15/1013($A$15/1013)A1.01)),0) 
L 
T Ozone 
= IF(J3>0,10.1611*($A$17*J3)*(1+139.48*($A$17*J3))a 0.30340.002715*($A$17*J3)/(1+0.044*($A$17*J3) +0.0003*($A$17*J3)A2),0) 

M 
T Gases 
= IF(J3>0,EXP(0.0127*(J3*$A$15/1013)A0.26),0) 

N 
T Water 
= IF(J3>0,12.4959*J3*$A$19/((1+79.034*$A$19*J3) A0.6828+6.385*$A$19*J3),0) 

O 
T Aerosol 
= IF(J3>0,EXP(($A$25A0.873) *(1+$A$25$A$25A0.7088)*J3A0.918),0) 

P 
TAA 
= IF(J3>0,10.1*(1J3+J3A1.06)*(1O3),0) 

Q 
Intermediate Results 
Rs 
= IF(J3>0,0.0685+(1$A$27)*(1O3/P3),0) 
R 
Id 
= IF(J3>0,0.9662*D3*O3*N3*M3*L3*K3,0) 

S 
IdnH 
= IF(I3<90,R3*COS(I3/(180/3.14159)),0) 

T 
Ias 
= IF(J3>0,D3*COS(I3/(180/3.14159))*0.79*L3*M3*N3*P3 *(0.5*(1K3)+$A$27*(1(O3/P3))/(1J3+(J3)A1.02)),0) 

U 
GH 
= IF(J3>0,(S3+T3)/(1$A$29*Q3),0) 

V 
Decimal 
Time 
= B3+(C30.5)/24 
W 
MODEL RESULT (W/M2) 
Direct Beam 
= R3 
X 
Direct Hz 
= S3 

Y 
Global Hz 
= U3 

Z 
Diffuse Hz 
= Y3X3 

Note: 
Text in columns 2 and 3 
are simply labels to be entered into designated cell row/column location. 

Column 3 contains functions with references to row 3 cell contents, to be copied to the rows following. 
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