Skip to content

The impact of diurnal variability in sea surface temperature on the central Atlantic air-sea CO2 flux

by H Kettle, C J Merchant, C D Jeffery, M J Filipiak, C L Gentemann
Atmospheric Chemistry and Physics ()
Get full text at journal


The effect of diurnal variations in sea surface temperature (SST) on the air-sea flux of CO2 over the central Atlantic ocean and Mediterranean Sea (60 S-60 N, 60 W-45 E) is evaluated for 2005-2006. We use high spatial resolution hourly satellite ocean skin temperature data to determine the diurnal warming (Delta SST). The CO2 flux is then computed using three different temperature fields - a foundation temperature (T-f, measured at a depth where there is no diurnal variation), T-f plus the hourly Delta SST and T-f plus the monthly average of the Delta SSTs. This is done in conjunction with a physically-based parameterisation for the gas transfer velocity (NOAA-COARE). The differences between the fluxes evaluated for these three different temperature fields quantify the effects of both diurnal warming and diurnal covariations. We find that including diurnal warming increases the CO2 flux out of this region of the Atlantic for 2005 2006 from 9.6 Tg C a(-1) to 30.4 Tg C a(-1) (hourly Delta SST) and 31.2 Tg C a(-1) (monthly average of Delta SST measurements). Diurnal warming in this region, therefore, has a large impact on the annual net CO2 flux but diurnal covariations are negligible. However, in this region of the Atlantic the uptake and outgassing of CO2 is approximately balanced over the annual cycle, so although we find diurnal warming has a very large effect here, the Atlantic as a whole is a very strong carbon sink (e. g. -920 Tg C a(-1) Takahashi et al., 2002) making this is a small contribution to the Atlantic carbon budget.

Cite this document (BETA)

Readership Statistics

16 Readers on Mendeley
by Discipline
50% Earth and Planetary Sciences
25% Environmental Science
6% Mathematics
by Academic Status
56% Researcher
25% Student > Ph. D. Student
6% Student > Bachelor

Sign up today - FREE

Mendeley saves you time finding and organizing research. Learn more

  • All your research in one place
  • Add and import papers easily
  • Access it anywhere, anytime

Start using Mendeley in seconds!

Sign up & Download

Already have an account? Sign in