breed [shortphotons shortphoton]
breed [peakphotons peakphoton]
breed [longphotons longphoton]
breed [molecules molecule]
globals [escaped-short escaped-peak escaped-long MAXHEAT]
molecules-own [heat]
patches-own [pheat]
to setup
ca
set MAXHEAT 10
create-molecules nummolecules
[
set shape "square"
set color 21
setxy random-xcor random-ycor
set heading random 360
]
create-shortphotons 10
[
set shape "dot"
set color 95
setxy min-pxcor random-pycor
set heading 90
]
create-peakphotons 10
[
set shape "dot"
set color 65
setxy min-pxcor random-pycor
set heading 90
]
create-longphotons 10
[
set shape "dot"
set color 15
setxy min-pxcor random-pycor
set heading 90
]
end
to go-once
ask turtles
[
forward 1
if breed = shortphotons
[
if xcor = max-pxcor
[
set escaped-short escaped-short + 1
die
]
]
if breed = peakphotons
[
if xcor = max-pxcor
[
set escaped-peak escaped-peak + 1
die
]
]
if breed = longphotons
[
if xcor = max-pxcor
[
set escaped-long escaped-long + 1
die
]
]
]
ask molecules
[
right random 360
if any? shortphotons-here
[
if random 100 < shortprob
[
set heat heat + 1.2
if heat > MAXHEAT
[
set heat MAXHEAT
]
set color 22 + (heat / MAXHEAT) * 7
ask one-of shortphotons-here
[
die
]
]
]
if any? peakphotons-here
[
if random 100 < peakprob
[
set heat heat + 1.0
if heat > MAXHEAT
[
set heat MAXHEAT
]
set color 22 + (heat / MAXHEAT) * 7
ask one-of peakphotons-here
[
die
]
]
]
if any? longphotons-here
[
if random 100 < longprob
[
set heat heat + 0.8
if heat > MAXHEAT
[
set heat MAXHEAT
]
set color 22 + (heat / MAXHEAT) * 7
ask one-of longphotons-here
[
die
]
]
]
]
create-shortphotons 10
[
set shape "dot"
set color 95
setxy min-pxcor random-pycor
set heading 90
]
create-peakphotons 10
[
set shape "dot"
set color 65
setxy min-pxcor random-pycor
set heading 90
]
create-longphotons 10
[
set shape "dot"
set color 15
setxy min-pxcor random-pycor
set heading 90
]
end
@#$#@#$#@
GRAPHICS-WINDOW
34
22
1081
281
70
15
7.355
1
10
1
1
1
0
0
1
1
-70
70
-15
15
0
0
1
ticks
CC-WINDOW
5
458
1090
553
Command Center
0
SLIDER
38
295
210
328
nummolecules
nummolecules
0
1000
401
1
1
NIL
HORIZONTAL
SLIDER
708
296
880
329
shortprob
shortprob
0
100
25
1
1
NIL
HORIZONTAL
SLIDER
709
344
881
377
peakprob
peakprob
0
100
100
1
1
NIL
HORIZONTAL
SLIDER
710
395
882
428
longprob
longprob
0
100
25
1
1
NIL
HORIZONTAL
BUTTON
133
340
237
373
go 20 times
repeat 20 [go-once]
NIL
1
T
OBSERVER
NIL
NIL
NIL
NIL
BUTTON
245
341
377
374
go continuously
go-once
T
1
T
OBSERVER
NIL
NIL
NIL
NIL
BUTTON
37
338
107
371
set up
setup
NIL
1
T
OBSERVER
NIL
NIL
NIL
NIL
MONITOR
910
288
1080
333
short-wavelenth photons
escaped-short
0
1
11
MONITOR
907
339
1080
384
peak-wavelength photons
escaped-peak
0
1
11
MONITOR
908
389
1080
434
long-wavelength photons
escaped-long
0
1
11
TEXTBOX
522
400
731
444
LONG WAVELENGTH
18
15.0
1
TEXTBOX
527
350
713
394
PEAK WAVELENGTH
18
65.0
1
TEXTBOX
511
301
721
345
SHORT WAVELENGTH
18
95.0
1
@#$#@#$#@
WHAT IS IT?
-----------
Greenhouse gases (GHGs) absorb radiation, but they don't absorb all wavelengths equally well. The atmosphere is more transparent to some wavelengths than to others, and while at some concentrations GHGs might block some wavelengths entirely from leaving the atmosphere, other wavelengths might be transmitted to space. Because GHGs generally absorb radiation of some wavelengths with moderate or low efficiency, a greater GHG concentration can reduce the atmosphere's overall transmissivity even if the atmosphere is already saturated for absorption at other wavelengths. Moreover, high GHG concentrations can change the spatial distribution of radiation absorption, concentrating absorption events and therefore heat in the lower atmosphere.
HOW IT WORKS
------------
This model represents just two things: GHG molecules, and photons. In this model, all molecules are the same, and photons have one of three wavelengths. Molecules move around at random. Photons move from left to right at constant velocity. When a molecule and a photon occupy the same place in the model, the photon is absorbed according to a wavelength-specific absorption-probability set by the user. If the photon is absorbed, it disappears and the corresponding molecule increases its heat content (and its color on the screen becomes lighter). If the photon is not absorbed, it continues rightward as if nothing had happened.
HOW TO USE IT
-------------
First, set the absorption-probabilities for wach of the three wavelengths. Set the probability for the peak wavelength to be greater than the other two probabilities. Second, set the number of GHG molecules. Finally, let the model go continuously until the first photons have had a chance to traverse the entire length of the space.
THINGS TO NOTICE
----------------
How good is the atmosphere at transmitting photons of a particular wavelength? Does it block that wavelength entirely, or does it allow some photons to reach the right-hand edge? Also, how is the heat distributed spatially? Are the warmer, lighter-colored molecules clustered at one end of the atmosphere, or are they spread throughout? If they are clumped, do they eventually spread out -- and how long does that take?
THINGS TO TRY
-------------
- Some people have argued that since the earth's atmosphere already absorbs all longwave radiation at CO2's peak absorption wavelength, increases in atmospheric CO2 can have no effect on climate. Try increasing the number of GHG molecules in the atmosphere. Is the overall transmissivity of the atmosphere affected? What about the spatial distribution of heat?
-
If you were to create a larger climate model, you might want to know something about the relationship between GHG concentration and overall atmospheric transmissivity. Choose some molecule-number and run the model long enough to give some photons the chance to reach the right-hand edge. Then use the "go 20 times" function and see how many photons exit the atmosphere in twenty or forty time-steps. Repeat this several times, enough to get an average. Get averages for several molecule-numbers, eough to graph out a curve of transmissivity vs molecule-number.
EXTENDING THE MODEL
-------------------
***
NETLOGO FEATURES
----------------
***
RELATED MODELS
--------------
***
CREDITS AND REFERENCES
----------------------
***
@#$#@#$#@
default
true
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airplane
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arrow
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box
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Polygon -7500403 true true 150 285 285 225 285 75 150 135
Polygon -7500403 true true 150 135 15 75 150 15 285 75
Polygon -7500403 true true 15 75 15 225 150 285 150 135
Line -16777216 false 150 285 150 135
Line -16777216 false 150 135 15 75
Line -16777216 false 150 135 285 75
bug
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Circle -7500403 true true 110 127 80
Circle -7500403 true true 110 75 80
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Line -7500403 true 150 100 220 30
butterfly
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Polygon -7500403 true true 150 165 89 198 75 225 75 255 105 270 135 255 150 240
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Line -16777216 false 150 105 105 60
car
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Polygon -7500403 true true 300 180 279 164 261 144 240 135 226 132 213 106 203 84 185 63 159 50 135 50 75 60 0 150 0 165 0 225 300 225 300 180
Circle -16777216 true false 180 180 90
Circle -16777216 true false 30 180 90
Polygon -16777216 true false 162 80 132 78 134 135 209 135 194 105 189 96 180 89
Circle -7500403 true true 47 195 58
Circle -7500403 true true 195 195 58
circle
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Circle -7500403 true true 0 0 300
circle 2
false
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cow
false
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Polygon -7500403 true true 200 193 197 249 179 249 177 196 166 187 140 189 93 191 78 179 72 211 49 209 48 181 37 149 25 120 25 89 45 72 103 84 179 75 198 76 252 64 272 81 293 103 285 121 255 121 242 118 224 167
Polygon -7500403 true true 73 210 86 251 62 249 48 208
Polygon -7500403 true true 25 114 16 195 9 204 23 213 25 200 39 123
cylinder
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dot
false
0
Circle -7500403 true true 90 90 120
face happy
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Circle -16777216 true false 60 75 60
Circle -16777216 true false 180 75 60
Polygon -16777216 true false 150 255 90 239 62 213 47 191 67 179 90 203 109 218 150 225 192 218 210 203 227 181 251 194 236 217 212 240
face neutral
false
0
Circle -7500403 true true 8 7 285
Circle -16777216 true false 60 75 60
Circle -16777216 true false 180 75 60
Rectangle -16777216 true false 60 195 240 225
face sad
false
0
Circle -7500403 true true 8 8 285
Circle -16777216 true false 60 75 60
Circle -16777216 true false 180 75 60
Polygon -16777216 true false 150 168 90 184 62 210 47 232 67 244 90 220 109 205 150 198 192 205 210 220 227 242 251 229 236 206 212 183
fish
false
0
Polygon -1 true false 44 131 21 87 15 86 0 120 15 150 0 180 13 214 20 212 45 166
Polygon -1 true false 135 195 119 235 95 218 76 210 46 204 60 165
Polygon -1 true false 75 45 83 77 71 103 86 114 166 78 135 60
Polygon -7500403 true true 30 136 151 77 226 81 280 119 292 146 292 160 287 170 270 195 195 210 151 212 30 166
Circle -16777216 true false 215 106 30
flag
false
0
Rectangle -7500403 true true 60 15 75 300
Polygon -7500403 true true 90 150 270 90 90 30
Line -7500403 true 75 135 90 135
Line -7500403 true 75 45 90 45
flower
false
0
Polygon -10899396 true false 135 120 165 165 180 210 180 240 150 300 165 300 195 240 195 195 165 135
Circle -7500403 true true 85 132 38
Circle -7500403 true true 130 147 38
Circle -7500403 true true 192 85 38
Circle -7500403 true true 85 40 38
Circle -7500403 true true 177 40 38
Circle -7500403 true true 177 132 38
Circle -7500403 true true 70 85 38
Circle -7500403 true true 130 25 38
Circle -7500403 true true 96 51 108
Circle -16777216 true false 113 68 74
Polygon -10899396 true false 189 233 219 188 249 173 279 188 234 218
Polygon -10899396 true false 180 255 150 210 105 210 75 240 135 240
house
false
0
Rectangle -7500403 true true 45 120 255 285
Rectangle -16777216 true false 120 210 180 285
Polygon -7500403 true true 15 120 150 15 285 120
Line -16777216 false 30 120 270 120
leaf
false
0
Polygon -7500403 true true 150 210 135 195 120 210 60 210 30 195 60 180 60 165 15 135 30 120 15 105 40 104 45 90 60 90 90 105 105 120 120 120 105 60 120 60 135 30 150 15 165 30 180 60 195 60 180 120 195 120 210 105 240 90 255 90 263 104 285 105 270 120 285 135 240 165 240 180 270 195 240 210 180 210 165 195
Polygon -7500403 true true 135 195 135 240 120 255 105 255 105 285 135 285 165 240 165 195
line
true
0
Line -7500403 true 150 0 150 300
line half
true
0
Line -7500403 true 150 0 150 150
pentagon
false
0
Polygon -7500403 true true 150 15 15 120 60 285 240 285 285 120
person
false
0
Circle -7500403 true true 110 5 80
Polygon -7500403 true true 105 90 120 195 90 285 105 300 135 300 150 225 165 300 195 300 210 285 180 195 195 90
Rectangle -7500403 true true 127 79 172 94
Polygon -7500403 true true 195 90 240 150 225 180 165 105
Polygon -7500403 true true 105 90 60 150 75 180 135 105
plant
false
0
Rectangle -7500403 true true 135 90 165 300
Polygon -7500403 true true 135 255 90 210 45 195 75 255 135 285
Polygon -7500403 true true 165 255 210 210 255 195 225 255 165 285
Polygon -7500403 true true 135 180 90 135 45 120 75 180 135 210
Polygon -7500403 true true 165 180 165 210 225 180 255 120 210 135
Polygon -7500403 true true 135 105 90 60 45 45 75 105 135 135
Polygon -7500403 true true 165 105 165 135 225 105 255 45 210 60
Polygon -7500403 true true 135 90 120 45 150 15 180 45 165 90
square
false
0
Rectangle -7500403 true true 30 30 270 270
square 2
false
0
Rectangle -7500403 true true 30 30 270 270
Rectangle -16777216 true false 60 60 240 240
star
false
0
Polygon -7500403 true true 151 1 185 108 298 108 207 175 242 282 151 216 59 282 94 175 3 108 116 108
target
false
0
Circle -7500403 true true 0 0 300
Circle -16777216 true false 30 30 240
Circle -7500403 true true 60 60 180
Circle -16777216 true false 90 90 120
Circle -7500403 true true 120 120 60
tree
false
0
Circle -7500403 true true 118 3 94
Rectangle -6459832 true false 120 195 180 300
Circle -7500403 true true 65 21 108
Circle -7500403 true true 116 41 127
Circle -7500403 true true 45 90 120
Circle -7500403 true true 104 74 152
triangle
false
0
Polygon -7500403 true true 150 30 15 255 285 255
triangle 2
false
0
Polygon -7500403 true true 150 30 15 255 285 255
Polygon -16777216 true false 151 99 225 223 75 224
truck
false
0
Rectangle -7500403 true true 4 45 195 187
Polygon -7500403 true true 296 193 296 150 259 134 244 104 208 104 207 194
Rectangle -1 true false 195 60 195 105
Polygon -16777216 true false 238 112 252 141 219 141 218 112
Circle -16777216 true false 234 174 42
Rectangle -7500403 true true 181 185 214 194
Circle -16777216 true false 144 174 42
Circle -16777216 true false 24 174 42
Circle -7500403 false true 24 174 42
Circle -7500403 false true 144 174 42
Circle -7500403 false true 234 174 42
turtle
true
0
Polygon -10899396 true false 215 204 240 233 246 254 228 266 215 252 193 210
Polygon -10899396 true false 195 90 225 75 245 75 260 89 269 108 261 124 240 105 225 105 210 105
Polygon -10899396 true false 105 90 75 75 55 75 40 89 31 108 39 124 60 105 75 105 90 105
Polygon -10899396 true false 132 85 134 64 107 51 108 17 150 2 192 18 192 52 169 65 172 87
Polygon -10899396 true false 85 204 60 233 54 254 72 266 85 252 107 210
Polygon -7500403 true true 119 75 179 75 209 101 224 135 220 225 175 261 128 261 81 224 74 135 88 99
wheel
false
0
Circle -7500403 true true 3 3 294
Circle -16777216 true false 30 30 240
Line -7500403 true 150 285 150 15
Line -7500403 true 15 150 285 150
Circle -7500403 true true 120 120 60
Line -7500403 true 216 40 79 269
Line -7500403 true 40 84 269 221
Line -7500403 true 40 216 269 79
Line -7500403 true 84 40 221 269
x
false
0
Polygon -7500403 true true 270 75 225 30 30 225 75 270
Polygon -7500403 true true 30 75 75 30 270 225 225 270
@#$#@#$#@
NetLogo 4.0
@#$#@#$#@
@#$#@#$#@
@#$#@#$#@
@#$#@#$#@
@#$#@#$#@
default
0.0
-0.2 0 0.0 1.0
0.0 1 1.0 0.0
0.2 0 0.0 1.0
link direction
true
0
Line -7500403 true 150 150 90 180
Line -7500403 true 150 150 210 180
@#$#@#$#@