Temporal evolution of temperatures in the Red Sea and the Gulf of Aden based on in situ observations (1958–2017)
<p>The Red Sea holds one of the most diverse marine ecosystems in the world, although fragile and vulnerable to ocean warming. Several studies have analysed the spatio-temporal evolution of temperature in the Red Sea using satellite data, thus focusing only on the surface layer and covering th...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-01-01
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| Series: | Ocean Science |
| Online Access: | https://www.ocean-sci.net/16/149/2020/os-16-149-2020.pdf |
| Summary: | <p>The Red Sea holds one of the most diverse marine
ecosystems in the world, although fragile and vulnerable to ocean warming.
Several studies have analysed the spatio-temporal evolution of
temperature in the Red Sea using satellite data, thus focusing only on the
surface layer and covering the last <span class="inline-formula">∼30</span> years. To better
understand the long-term variability and trends of temperature in the
whole water column, we produce a 3-D gridded temperature product (TEMPERSEA)
for the period 1958–2017, based on a large number of in situ observations,
covering the Red Sea and the Gulf of Aden. After a specific quality control,
a mapping algorithm based on optimal interpolation have been applied to
homogenize the data. Also, an estimate of the uncertainties of the product
has been generated. The calibration of the algorithm and the uncertainty
computation has been done through sensitivity experiments based on synthetic
data from a realistic numerical simulation.</p>
<p>TEMPERSEA has been compared to satellite observations of sea surface
temperature for the period 1981–2017, showing good agreement especially in
those periods when a reasonable number of observations were available. Also,
very good agreement has been found between air temperatures and
reconstructed sea temperatures in the upper 100 m for the whole period
1958–2017, enhancing confidence in the quality of the product.</p>
<p>The product has been used to characterize the spatio-temporal variability of
the temperature field in the Red Sea and the Gulf of Aden at different timescales (seasonal, interannual and multidecadal). Clear differences have been
found between the two regions suggesting that the Red Sea variability is
mainly driven by air–sea interactions, while in the Gulf of Aden the
lateral advection of water plays a relevant role. Regarding long-term
evolution, our results show only positive trends above 40 m depth, with
maximum trends of 0.045 <span class="inline-formula">+</span> 0.016 <span class="inline-formula"><sup>∘</sup></span>C decade<span class="inline-formula"><sup>−1</sup></span> at 15 m, and
the largest negative trends at 125 m (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M5" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">0.072</mn><mo>+</mo><mn mathvariant="normal">0.011</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="76pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="48c55c72dddecbc845c6722f85d0a768"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="os-16-149-2020-ie00001.svg" width="76pt" height="10pt" src="os-16-149-2020-ie00001.png"/></svg:svg></span></span> <span class="inline-formula"><sup>∘</sup></span>C decade<span class="inline-formula"><sup>−1</sup></span>). Multidecadal variations have a strong impact on the trend
computation and restricting them to the last 30–40 years of data can bias
high the trend estimates.</p> |
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| ISSN: | 1812-0784 1812-0792 |