Ocean carbon uptake widely underestimated

Date:
September 4, 2020
Source:
University of Exeter
Summary:
The world's oceans soak up more carbon than most scientific models
suggest, according to new research.



FULL STORY ==========================================================================
The world's oceans soak up more carbon than most scientific models
suggest, according to new research.


========================================================================== Previous estimates of the movement of carbon (known as "flux") between
the atmosphere and oceans have not accounted for temperature differences
at the water's surface and a few metres below.

The new study, led by the University of Exeter, includes this -- and
finds significantly higher net flux of carbon into the oceans.

It calculates CO2 fluxes from 1992 to 2018, finding up to twice as much
net flux in certain times and locations, compared to uncorrected models.

"Half of the carbon dioxide we emit doesn't stay in the atmosphere but
is taken up by the oceans and land vegetation 'sinks'," said Professor
Andrew Watson, of Exeter's Global Systems Institute.

"Researchers have assembled a large database of near-surface
carbon dioxide measurements -- the "Surface Ocean Carbon Atlas" (http://www.socat.info) - - that can be used to calculate the flux of
CO2 from the atmosphere into the ocean.



========================================================================== "Previous studies that have done this have, however, ignored small
temperature differences between the surface of the ocean and the depth
of a few metres where the measurements are made.

"Those differences are important because carbon dioxide solubility
depends very strongly on temperature.

"We used satellite data to correct for these temperature differences,
and when we do that it makes a big difference -- we get a substantially
larger flux going into the ocean.

"The difference in ocean uptake we calculate amounts to about 10 per cent
of global fossil fuel emissions." Dr Jamie Shutler, of the Centre for Geography and Environmental Science on Exeter's Penryn Campus in Cornwall, added: "Our revised estimate agrees much better than previously with
an independent method of calculating how much carbon dioxide is being
taken up by the ocean.

"That method makes use of a global ocean survey by research ships
over decades, to calculate how the inventory of carbon in the ocean
has increased.

"These two 'big data' estimates of the ocean sink for CO2 now agree
pretty well, which gives us added confidence in them."

========================================================================== Story Source: Materials provided by University_of_Exeter. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Andrew J. Watson, Ute Schuster, Jamie D. Shutler, Thomas Holding,
Ian G.

C. Ashton, Peter Landschu"tzer, David K. Woolf, Lonneke
Goddijn-Murphy.

Revised estimates of ocean-atmosphere CO2 flux are consistent with
ocean carbon inventory. Nature Communications, 2020; 11 (1) DOI:
10.1038/ s41467-020-18203-3 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/09/200904090312.htm

--- up 1 week, 4 days, 6 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)