CO2 Release from Thawing Permafrost

1 collaborator

BACKGROUND

Climate change is happening most quickly in polar regions. Increasing temperatures affect amount and quality of sea ice, size of glaciers, and quality of permafrost. These changes impact sea level, global weather patterns, polar ecosystems, and access to natural resources. Travel and commercial shipping routes, pollution levels, social patterns and government policies on energy and defense are also impacted.

Understanding polar science helps to clarify the significance of these events.

RESEARCH QUESTION BEHIND THE SIMULATION

Nine million square miles of permafrost are found globally. Carbon from decayed plants and animals is stored in the permafrost. As temperatures warm, permafrost thaws, releasing stored carbon into watersheds as disolved organic matter. Bacteria interacts with carbon and promotes oxidation to form carbon dioxide (CO2). What is the relationship between sunlight, bacteria, and CO2 production?

MODEL PARAMETERS

The model simulates an arctic ecosystem. Permafrost is represented by a dark pink color. Permafrost is soil that remains below zero degrees C for at least two years.

Carbon molecules are shown as black dots. Bacteria is found in the watershed. CO2 is represented by a black and pink model.

The amount of sunshine, or solar radiation may be varied (Remember, in polar summers the sun does not set. Cloud coverage influences amount of sun reaching the ground.)

HOW TO USE MODEL

Adjust the slider to regulate amount of sunshine.
Observe amount of CO2 produced in relation to amount of sunshine.

THINGS TO NOTICE

Notice the order of events. Carbon from soil moves into water. Bacteria in water oxidize carbon, creating CO2. CO2 travels through water and is released into the atmosphere.

Watching the graph, notice the rate of CO2 production in relation to amount of sunlight. As sunlight increases, CO2 is more rapidly produced.

PROBING QUESTIONS

What is the source of carbon in the soil? (Decayed plants and animals) Why does permafrost thaw? (Increased temperature) What is the difference between "melt" and "thaw"? When an item melts, it changes form, going from a solid to liquid. When an objet thaws, it remains a solid, but is less compact. Permafrost thaws. Permafrost does not melt.

RELATED MODELS

See models related to climate change.

CREDITS AND REFERENCES

The model is based on research conducted from Toolik Field Station, Alaska, by Rose Cory and George Kling, University of Michigan. See original publications at http://www.sciencemag.org/content/345/6199/925.short and http://www.pnas.org/content/110/9/3429.short .

Model created by Regina Brinker, Granada High School, Livermore, California and is based on field with with Dr. Cory through the PolarTREC program. See http://www.polartrec.com/expeditions/arctic-sunlight-and-microbial-interactions-2014

Contact Regina Brinker at brinker.science@gmail.com

Comments and Questions

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Click to Run Model

to setup

  ca

  reset-ticks

  ask patches [if pycor >= 0 [set pcolor 95]]          ;makes the blue sky
  ask patches [if pycor  < 0[ set pcolor 95]]      ;sets active layer
  ask patches [if pycor <= -3 [set pcolor 85]]     ;sets permafrost


  ask patches [if pycor <= -3 and (pxcor = -16  or pxcor = 16) [set pcolor 132]] ;this makes the sides of the lake
  ask patches [if pycor <= -4 and (pxcor = -15 or pxcor = 15) [set pcolor 132]]
  ask patches [if pycor <= -4 and (pxcor = -14  or pxcor = 14) [set pcolor 132]]
  ask patches [if pycor <= -6 and( pxcor = -13  or pxcor = 13) [set pcolor 132]]
  ask patches [if pycor <= -7 and( pxcor = -12  or pxcor = 12) [set pcolor 132]]
  ask patches [if pycor <= -7 and( pxcor = -11  or pxcor = 11) [set pcolor 132]]
  ask patches [if pycor <= -8 and( pxcor = -10  or pxcor = 10) [set pcolor 132]]
  ask patches [if pycor <= -8 and( pxcor = -9  or pxcor = 9) [set pcolor 132]]
  ask patches [if pycor <= -9 and( pxcor = -8  or pxcor = 8) [set pcolor 132]]
  ask patches [if pycor <= -9 and( pxcor = -7  or pxcor = 7) [set pcolor 132]]
  ask patches [if pycor <= -9 and( pxcor = -6  or pxcor = 6) [set pcolor 132]]


  ask patches [if pycor <= -10 [set pcolor 132]]       ;water
  crt 1 [set shape "sun"  set size 4 set color 45 setxy xcor -10 setxy ycor 10]   ;create sun
  ;crt 10 [set shape "carbondioxide" set size 5 setxy random-xcor random-ycor if [(xcor <=  -3) or (xcor >= -15) ]]



ask n-of 40 patches with [ pcolor = 132] [sprout 1 [ set size 2 set shape "dot" set color black set label "C" ]]    ;makes carbon atoms in permafrost
end 

to go

  tick

  ask turtles with [shape = "line half" ][if any? turtles with [ shape = "line half" and (xcor <= -15 or xcor >= 12 or ycor <= -15 or ycor >= 15)] [die]] ;line half represents sun rays

  ask patch -10  10 [sprout sunlight [set shape "line half" set color 45 set size 3]]   ;create sunlight with slider

 ;ask n-of 1 patches with [pcolor = 85]  [ if random 100 < sunlight [set pcolor 67]] ;permafrost thaws, changes color

while [count turtles with [shape = "caterpillar"] <= 10] [ask n-of 10 patches with [ pcolor = 132] [sprout 1[set shape "caterpillar" set color 125 set size 1]] ]  ;creates bacteria in water  set ticks = 2

  ask turtles with [shape = "line half"] [forward 1]



  wait .1


ask turtles with [shape = "dot"]
[ifelse [pcolor] of patch-ahead 1 = 95 [left 169 forward 1][forward 1]
ifelse [pcolor] of patch-ahead 1 = 135 [right 169 forward 1][forward 1]
if ycor < -3 and (xcor < 6 and xcor > -6)  [ ask patch-here[sprout (.05 * sunlight) [set shape "carbondioxide" set size 3]]die]]       ;carbon moves into water and forms CO2

ask turtles with [shape = "caterpillar"]
[
  if [pcolor] of patch-ahead 1 = 138 [right 180 forward 1]
  ifelse [pcolor] of patch-ahead 1 = 95   [left 169 forward 1][forward 1]
  if [pcolor] of patch-ahead 1 = 135 [right 30 forward 1]
  if [pcolor] of patch-ahead 1 = 95   [left 169 forward 1]
]

ask turtles with [shape = "carbondioxide"]
[
  if [pcolor] of patch-ahead 1 = 132 [right 180 forward 1]
]


moveup
end 

to moveup

  ask turtles with [shape = "carbondioxide"][ifelse xcor >= 9 and xcor <= 16 and pcolor != 95[set heading 0 right random 10 left random 10 forward 1][rt random 360 fd 1]]

   ask turtles with [shape = "carbondioxide"][if ycor = 0 [die]]

  ask turtles with [shape = "carbondioxide"][if ycor = -12 and  xcor < 9[set heading 180 right random 10 left random 10]]
end

There is only one version of this model, created almost 9 years ago by Regina Brinker.

Attached files

File	Type	Description	Last updated
CO2 Release from Thawing Permafrost.png	preview	Preview for 'CO2 Release from Thawing Permafrost'	almost 9 years ago, by Regina Brinker	Download

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