Further thoughts on CO2 Cycle

Found some O2 data for Alert Alaska. Plotting this on the same graph as Barrow give the plot below.

This shows that O2 is the inverse of CO2 with the peak of O2 occurring (as near as can be determined from the sparse data) at the minimum of CO2. They appear to be in synchronism.

To me this shows that the O2 and CO2 are linked to the same process.

From http://www.elcamino.edu/faculty/tnoyes/Readings/10AR.pdf this plot shows that there is a peak phytoplankton growth in summer at the poles which is significantly higher than spring or autumn growths.

Phytoplankton in sunlight photosynthesises using CO2 and creating O2. In the dark O2 is used in phytoplankton respiration and CO2 is released.

Decomposition requires warm temperatures for the bacteria to work.At the end of summer temperatures are falling rapidly so decomposition will not release CO2 rapidly and certainly would not continue into December. This suggests that spring growth and autumn decomposition would not cause the CO2 dip.

Conclusion:
The CO2 dip is caused by the action of sunlight on phytoplankton.

The Full O2 record with CO2

CO2 cycle revisited

A previous post had a look at the CO2 cycle and questioned the cause.
This post adds a couple more years of data but still does not solve the dip cause.

Latest Data Showing the approx dip measurement points:

Depth of dip replotted.

Note the innaccuracy of determining the depth gives a different plot to the last investigation.

The cause?

Ice covering phyto plankton - as more is exposed to sunlight photosynthesis overcomes respiration and co2 is absorbed from the sea wich then absorbs it from the air.

http://www.ldeo.columbia.edu/~marra/PhytoRespGRLv5.pdf

Change at equinox considering respiration/photosynthesis in phytoplankton and plants
Daylight time is greater than dark time prior to 22nd September and less than dark after this date? Trouble is the dip is around the end of August and the 1st week in September.
Why should the dip be earlier?

Growth/decay of land plants
Growth - ok CO2 is converted to biomass
Decay - much too slow over the winter months to return the CO2

Water temperature.
Warm water takes up less CO2 than cold so is wrong direction for dip.


Most likely
 equinox and length of day/night affecting the respiration/photosynthesis balance?
Depth of dip is greatest at Barrow and gets smaller the further south you go. Eventually the phase of the dip changes as you would expect for the southern hemisphere.


Still no further forward!

CO2 data - why the yearly humps?

Question:
Is the annual uptake of CO2 by “something” increasing
Answer: Yes by 0.17ppm per year
Co2 is increasing by 1.6ppm/year
for Point Barrow see:

The annual carbon dioxide sink is absorbing more CO2 over ther period considered

Is this caused by warmer conditions promoting more growth or by an increased greening caused by more CO2 or increased greening caused by CO2 and temperature?

It would appear it is not simply CO2 – As can be seen the annual difference has dropped since 2004. CO2 is in a continuous rising cycle. Temperature has stalled and dropped since 2003.

It would therefore appear to be mainly temperature.
There is an annual dip in CO2 caused by something water temp/flora/algae/etc.
http://img175.imageshack.us/img175/9698/manyco219992001.jpg see bove
If absorbed by flora/algae (living stuff) then presumably the rise from the dip would be less than the fall into the dip - some CO2 would be retained by the growth. This is not apparent.
If it is sea water then its the wrong way up - summer would be higher CO2 (warm water). Also sea water is not saturated by CO2 so would it breathe with temperature?

Since 1974 the depth of the annual dip in CO2 (Start April end August) has increase from 14.5 to 20ppm approx:


If warming is happening then sea water and air temp will be warmed to the same value where absorption occurs earlier each year:
days from Jan 1st = -1.945E-04x + 2.377E+02
plot here:


Note that in Barrow there is little/no change in the date of minimum (.0002 days/year) but temperature has significantly increased.