<p>There are many studies quantifying temporal CO2 variability for a static location. Conducting such studies isn't particularly difficult, the cost of equipment is low, and it's an easy way to publish meaningful results. You may have a hard time wading through all of the publications to select the few that mean anything to you, specifically.</p>

<p>A quick 2 minute search found this paper (among a slew of others), entitled, <a href="http://home.olemiss.edu/~suman/Suman2002indianforester.pdf" rel="nofollow noreferrer">Diurnal and Seasonal Variation of CO2 levels of surface air in Garwhal Himalaya</a>
in which this graph highlights daily CO2 variations over the course of a year, in mmol/mol. You'll have to look up the conversion to ppm CO2:</p>

<p><a href="https://i.sstatic.net/ME17X.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ME17X.png" alt="enter image description here"></a></p>

<p>You may to search using these key words: <a href="https://www.google.com/search?q=CO2%20variation%20as%20a%20function%20of%20vegetation#q=CO2%20variability,%20diurnal,%20yearly" rel="nofollow noreferrer">CO2 variability, diurnal, yearly</a>
<a href="http://www.hydrol-earth-syst-sci.net/13/987/2009/hess-13-987-2009.pdf" rel="nofollow noreferrer">Seasonal and diurnal variations in moisture, heat and CO2 fluxes over a typical steppe prairie in Inner Mongolia, China</a></p>

<p><a href="http://onlinelibrary.wiley.com/doi/10.1034/j.1600-0889.2003.00061.x/pdf" rel="nofollow noreferrer">Temporal variations of atmospheric CO2 concentration in a temperate deciduous forest in central Japan</a></p>

<p><a href="http://meteo.lcd.lu/papers/co2_patterns/co2_patterns.html" rel="nofollow noreferrer">Seasonal and Diurnal CO2 Patterns at Diekirch, LU</a></p>

<p><a href="http://faculty.geog.utoronto.ca/Chen/Chen%27s%20homepage/PDFfiles/p96_2004JD005546.pdf" rel="nofollow noreferrer">Interannual variability in the atmospheric CO2 rectification over aboreal forest region</a></p>

CC BY-SA 3.0
2017-04-19T05:04:24.833Z
This is great - having some *hand-selected examples* of the kinds of papers I should be looking for seems to be all I really need to get started. I will have to learn how to convert $\mu$mol/mol to ppmV, I'll keep an eye on that when it comes up. Also need to keep an eye on the years that the data was recorded, considering it's changing so rapidly. Thanks!
uhoh
CC BY-SA 3.0
2017-04-19T14:24:26.390Z
1 $\mu$mol/mol is equal to 1 ppmV, as mole is proportional to volume, see https://en.wikipedia.org/wiki/Parts-per_notation#SI-compliant_expressions and this NOAA figure https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmosphere#/media/File:Global_distribution_of_Carbon_Dioxide.jpg
Lukas
CC BY-SA 3.0
2017-04-20T06:32:42.847Z
@Lukas almost but not quite. "[...mole fractions (which is identical to volume fraction only for ideal gases).](https://en.wikipedia.org/wiki/Parts-per_notation#Mass_fraction_vs._mole_fraction_vs._volume_fraction)" Now you've got me interested, so I've just asked [this follow-up question](https://earthscience.stackexchange.com/q/10157/6031). Also, the plot of concentration versus latitude is very relevant. Thanks for both!
uhoh
CC BY-SA 4.0
2022-11-22T22:44:50.380Z
For those looking for the 'Seasonal and Diurnal CO2 Patterns at Diekirch, LU, it is gone, but can be found at: https://web.archive.org/web/20220623202105/https://meteo.lcd.lu/papers/co2_patterns/co2_patterns.html
anastrophe
CC BY-SA 3.0
2017-04-19T04:10:43.333Z
2017-04-19T04:18:12.723Z
2017-04-19T04:18:12.723Z
Knob Scratcher
<p>This is a good question because it prompts one to think about the many and varied natural sources of CO2 in the atmosphere. Of course your measuring apparatus will only show NET CO2, i.e. Sources-Sinks. So you need to think about CO2 sinks too.
Start by making a list of all the possible sources and sinks. Then consider which apply in any given location for the apparatus. 
I would suggest that one of the main sources would be plant life so you will find quite a difference between an instrument in a tropical rainforest compared to a dry desert.</p>

<p>The ocean measurements will be interesting as oceans contain dissolved CO2 and it tends to come out as the temperature goes up. In reality a bit more complicated owing to exact surface exchange mechanisms, partial pressure of CO2 in the atmosphere , etc.
You starting guess of +/- 10-20ppm looks low compared to my own guess. I would have said +/- 50-100 but it would indeed have been a guess like yours.</p>

CC BY-SA 3.0
2017-04-20T01:17:21.717Z
Thanks for your perspective. You are right, it seems I've stumbled upon something much more complex than I'd realized, which is making it a really fun exercise!
uhoh
CC BY-SA 3.0
2017-04-20T06:07:05.200Z
To measure the CO2 contribution from an individual source or sink would either have to be done by replicating some aspect of it in a lab experiment and then scaling it up / adjusting it to the real world OR constructing some apparatus in the real world around the source/sink (some kind of big box ?). So isolating accurate figures for various contributions is going to be difficult, error bars are going to be large.
user7733
CC BY-SA 3.0
2017-04-20T06:15:01.557Z
Luckily that doesn't stop us from thinking about them! I'm sure I've seen pictures of real 'big box' experiments somewhere, but not sure how the impact on temperature and humidity was accounted for.
uhoh
CC BY-SA 3.0
2017-04-19T20:10:12.337Z
2017-04-19T20:10:12.337Z
user7733
<p>I'd like to have a rough idea of how large local surface CO2 concentration vary due to natural processes.</p>

<p><strong>For example, a purely hypothetical experiment:</strong></p>

<p>If I set up some CO2 monitors in a wide variety of locations around the globe (e.g. mid-ocean, jungle, desert, plains, tundra, mountaintop, beach...), say at 2 meters off the ground, and took some measures to avoid close proximity to substantial anthropogenic CO2 sources (industrial, transportation, population, farms) and fires or episodic geological sources (e.g. <a href="https://earthscience.stackexchange.com/questions/10145/#comment19754_10145">volcanos or magma pockets under lakes</a> per @jamesqf), roughly speaking what might the variation look like? </p>

<p>A starting guess might be that they'd all be nearly featureless, around 400ppm, with only say +/- 10 or 20 ppm daily and yearly oscillations. Of course there is a whole lot of important science within those variations, but for the purposes of this question, I'd call those variations small.</p>

<p>Would my detector in a forest or jungle see higher peaks, or deeper troughs than one in a desert, or mid-ocean? What might the biggest excursions be? Might it ever reach down to 300 or up to 500 ppm <em>due to natural processes</em>?</p>

<p>The reason I'm asking is that while I tried to so some searches, it is very popular to show data from urban and suburban locations, where peaks of 500 or 600 ppm or even higher are seen that are attributed to wind direction and concentrated man-made sources, and that variation is not what I'm after. Here is just one example (<a href="https://weather.usu.edu/htm/file39359/24-hour-co2-concentration" rel="noreferrer">48 hours</a> and <a href="http://weather.usu.edu/htm/co2-concentration" rel="noreferrer">yearly</a>) but there are many much larger studies published with sensors in urban areas.</p>

CC BY-SA 3.0
2017-04-18T19:45:34.120Z
If you include volcanic activity as a natural process, it can increase enough to be lethal.  There's a lake in Africa - Lake Nyos: https://en.wikipedia.org/wiki/Lake_Nyos - which accumulates CO2 from underlying magma and suddenly releases it.
jamesqf
CC BY-SA 3.0
2017-04-18T19:54:54.137Z
@jamesqf yikes! I'll add "or other natural phenomena" to the appropriate sentence. Yes I believe I remember watching a documentary on TV about the Lake Nyos 1986 event, but that was quite a while ago. Thanks for the multiple reminders!
uhoh
<atmosphere><co2>
How large can local surface CO2 concentration vary due to natural processes?
uhoh
# How large can local surface CO2 concentration vary due to natural processes?

(Asked by: username_0 on 2017-04-18)

I'd like to have a rough idea of how large local surface CO2 concentration vary due to natural processes.

**For example, a purely hypothetical experiment:**

If I set up some CO2 monitors in a wide variety of locations around the globe (e.g. mid-ocean, jungle, desert, plains, tundra, mountaintop, beach...), say at 2 meters off the ground, and took some measures to avoid close proximity to substantial anthropogenic CO2 sources (industrial, transportation, population, farms) and fires or episodic geological sources (e.g. [volcanos or magma pockets under lakes](https://earthscience.stackexchange.com/questions/10145/#comment19754_10145) per @username_1), roughly speaking what might the variation look like?

A starting guess might be that they'd all be nearly featureless, around 400ppm, with only say +/- 10 or 20 ppm daily and yearly oscillations. Of course there is a whole lot of important science within those variations, but for the purposes of this question, I'd call those variations small.

Would my detector in a forest or jungle see higher peaks, or deeper troughs than one in a desert, or mid-ocean? What might the biggest excursions be? Might it ever reach down to 300 or up to 500 ppm *due to natural processes*?

The reason I'm asking is that while I tried to so some searches, it is very popular to show data from urban and suburban locations, where peaks of 500 or 600 ppm or even higher are seen that are attributed to wind direction and concentrated man-made sources, and that variation is not what I'm after. Here is just one example ([48 hours](https://weather.usu.edu/htm/file39359/24-hour-co2-concentration) and [yearly](http://weather.usu.edu/htm/co2-concentration)) but there are many much larger studies published with sensors in urban areas.

**Tags:** atmosphere, co2

> **Comments:**
> **username_1**: If you include volcanic activity as a natural process, it can increase enough to be lethal.  There's a lake in Africa - Lake Nyos: https://en.wikipedia.org/wiki/Lake_Nyos - which accumulates CO2 from underlying magma and suddenly releases it.  
> **username_0**: @username_1 yikes! I'll add "or other natural phenomena" to the appropriate sentence. Yes I believe I remember watching a documentary on TV about the Lake Nyos 1986 event, but that was quite a while ago. Thanks for the multiple reminders!  

---

## 2 answers

### Answer by username_2 on 2017-04-19. Score: 4 | Accepted answer

There are many studies quantifying temporal CO2 variability for a static location. Conducting such studies isn't particularly difficult, the cost of equipment is low, and it's an easy way to publish meaningful results. You may have a hard time wading through all of the publications to select the few that mean anything to you, specifically.

A quick 2 minute search found this paper (among a slew of others), entitled, [Diurnal and Seasonal Variation of CO2 levels of surface air in Garwhal Himalaya](http://home.olemiss.edu/~suman/Suman2002indianforester.pdf)
in which this graph highlights daily CO2 variations over the course of a year, in mmol/mol. You'll have to look up the conversion to ppm CO2:

[![enter image description here](https://i.sstatic.net/ME17X.png)](https://i.sstatic.net/ME17X.png)

You may to search using these key words: [CO2 variability, diurnal, yearly](https://www.google.com/search?q=CO2%20variation%20as%20a%20function%20of%20vegetation#q=CO2%20variability,%20diurnal,%20yearly)
[Seasonal and diurnal variations in moisture, heat and CO2 fluxes over a typical steppe prairie in Inner Mongolia, China](http://www.hydrol-earth-syst-sci.net/13/987/2009/hess-13-987-2009.pdf)

[Temporal variations of atmospheric CO2 concentration in a temperate deciduous forest in central Japan](http://onlinelibrary.wiley.com/doi/10.1034/j.1600-0889.2003.00061.x/pdf)

[Seasonal and Diurnal CO2 Patterns at Diekirch, LU](http://meteo.lcd.lu/papers/co2_patterns/co2_patterns.html)

[Interannual variability in the atmospheric CO2 rectification over aboreal forest region](http://faculty.geog.utoronto.ca/Chen/Chen%27s%20homepage/PDFfiles/p96_2004JD005546.pdf)

> **Comments:**
> **username_0**: This is great - having some *hand-selected examples* of the kinds of papers I should be looking for seems to be all I really need to get started. I will have to learn how to convert $\mu$mol/mol to ppmV, I'll keep an eye on that when it comes up. Also need to keep an eye on the years that the data was recorded, considering it's changing so rapidly. Thanks!  
> **username_3**: 1 $\mu$mol/mol is equal to 1 ppmV, as mole is proportional to volume, see https://en.wikipedia.org/wiki/Parts-per_notation#SI-compliant_expressions and this NOAA figure https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmosphere#/media/File:Global_distribution_of_Carbon_Dioxide.jpg  
> **username_0**: @username_3 almost but not quite. "[...mole fractions (which is identical to volume fraction only for ideal gases).](https://en.wikipedia.org/wiki/Parts-per_notation#Mass_fraction_vs._mole_fraction_vs._volume_fraction)" Now you've got me interested, so I've just asked [this follow-up question](https://earthscience.stackexchange.com/q/10157/6031). Also, the plot of concentration versus latitude is very relevant. Thanks for both!  
> **username_4**: For those looking for the 'Seasonal and Diurnal CO2 Patterns at Diekirch, LU, it is gone, but can be found at: https://web.archive.org/web/20220623202105/https://meteo.lcd.lu/papers/co2_patterns/co2_patterns.html  

---

### Answer by username_5 on 2017-04-19. Score: 3

This is a good question because it prompts one to think about the many and varied natural sources of CO2 in the atmosphere. Of course your measuring apparatus will only show NET CO2, i.e. Sources-Sinks. So you need to think about CO2 sinks too.
Start by making a list of all the possible sources and sinks. Then consider which apply in any given location for the apparatus.
I would suggest that one of the main sources would be plant life so you will find quite a difference between an instrument in a tropical rainforest compared to a dry desert.

The ocean measurements will be interesting as oceans contain dissolved CO2 and it tends to come out as the temperature goes up. In reality a bit more complicated owing to exact surface exchange mechanisms, partial pressure of CO2 in the atmosphere , etc.
You starting guess of +/- 10-20ppm looks low compared to my own guess. I would have said +/- 50-100 but it would indeed have been a guess like yours.

> **Comments:**
> **username_0**: Thanks for your perspective. You are right, it seems I've stumbled upon something much more complex than I'd realized, which is making it a really fun exercise!  
> **username_5**: To measure the CO2 contribution from an individual source or sink would either have to be done by replicating some aspect of it in a lab experiment and then scaling it up / adjusting it to the real world OR constructing some apparatus in the real world around the source/sink (some kind of big box ?). So isolating accurate figures for various contributions is going to be difficult, error bars are going to be large.  
> **username_0**: Luckily that doesn't stop us from thinking about them! I'm sure I've seen pictures of real 'big box' experiments somewhere, but not sure how the impact on temperature and humidity was accounted for.  

---

