The impact of diurnal variability in sea surface temperature on the central Atlantic air-sea CO<sub>2</sub> flux
The effect of diurnal variations in sea surface temperature (SST) on the air-sea flux of CO<sub>2</sub> 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...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2009-01-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/9/529/2009/acp-9-529-2009.pdf |
| _version_ | 1811298172465577984 |
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| author | M. J. Filipiak C. D. Jeffery C. J. Merchant H. Kettle C. L. Gentemann |
| author_facet | M. J. Filipiak C. D. Jeffery C. J. Merchant H. Kettle C. L. Gentemann |
| author_sort | M. J. Filipiak |
| collection | DOAJ |
| description | The effect of diurnal variations in sea surface temperature (SST) on the air-sea flux of CO<sub>2</sub> 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 (ΔSST). The CO<sub>2</sub> flux is then computed using three different temperature fields – a foundation temperature (<i>T<sub>f</sub></i>, measured at a depth where there is no diurnal variation), <i>T</i><sub><i>f</i></sub>, plus the hourly ΔSST and <i>T<sub>f</sub></i>, plus the monthly average of the ΔSSTs. 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 CO<sub>2</sub> flux out of this region of the Atlantic for 2005–2006 from 9.6 Tg C a<sup>−1</sup> to 30.4 Tg C a<sup>−1</sup> (hourly ΔSST) and 31.2 Tg C a<sup>−1</sup> (monthly average of ΔSST measurements). Diurnal warming in this region, therefore, has a large impact on the annual net CO<sub>2</sub> flux but diurnal covariations are negligible. However, in this region of the Atlantic the uptake and outgassing of CO<sub>2</sub> 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<sup>−1</sup> Takahashi et al., 2002) making this is a small contribution to the Atlantic carbon budget. |
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| id | doaj.art-d5cccf21689f4ad49d851c18d307a037 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-04-13T06:15:41Z |
| publishDate | 2009-01-01 |
| publisher | Copernicus Publications |
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| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-d5cccf21689f4ad49d851c18d307a0372022-12-22T02:58:51ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242009-01-0192529541The impact of diurnal variability in sea surface temperature on the central Atlantic air-sea CO<sub>2</sub> fluxM. J. FilipiakC. D. JefferyC. J. MerchantH. KettleC. L. GentemannThe effect of diurnal variations in sea surface temperature (SST) on the air-sea flux of CO<sub>2</sub> 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 (ΔSST). The CO<sub>2</sub> flux is then computed using three different temperature fields – a foundation temperature (<i>T<sub>f</sub></i>, measured at a depth where there is no diurnal variation), <i>T</i><sub><i>f</i></sub>, plus the hourly ΔSST and <i>T<sub>f</sub></i>, plus the monthly average of the ΔSSTs. 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 CO<sub>2</sub> flux out of this region of the Atlantic for 2005–2006 from 9.6 Tg C a<sup>−1</sup> to 30.4 Tg C a<sup>−1</sup> (hourly ΔSST) and 31.2 Tg C a<sup>−1</sup> (monthly average of ΔSST measurements). Diurnal warming in this region, therefore, has a large impact on the annual net CO<sub>2</sub> flux but diurnal covariations are negligible. However, in this region of the Atlantic the uptake and outgassing of CO<sub>2</sub> 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<sup>−1</sup> Takahashi et al., 2002) making this is a small contribution to the Atlantic carbon budget.http://www.atmos-chem-phys.net/9/529/2009/acp-9-529-2009.pdf |
| spellingShingle | M. J. Filipiak C. D. Jeffery C. J. Merchant H. Kettle C. L. Gentemann The impact of diurnal variability in sea surface temperature on the central Atlantic air-sea CO<sub>2</sub> flux Atmospheric Chemistry and Physics |
| title | The impact of diurnal variability in sea surface temperature on the central Atlantic air-sea CO<sub>2</sub> flux |
| title_full | The impact of diurnal variability in sea surface temperature on the central Atlantic air-sea CO<sub>2</sub> flux |
| title_fullStr | The impact of diurnal variability in sea surface temperature on the central Atlantic air-sea CO<sub>2</sub> flux |
| title_full_unstemmed | The impact of diurnal variability in sea surface temperature on the central Atlantic air-sea CO<sub>2</sub> flux |
| title_short | The impact of diurnal variability in sea surface temperature on the central Atlantic air-sea CO<sub>2</sub> flux |
| title_sort | impact of diurnal variability in sea surface temperature on the central atlantic air sea co sub 2 sub flux |
| url | http://www.atmos-chem-phys.net/9/529/2009/acp-9-529-2009.pdf |
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