Temporal evolution of sea surface temperatures in the coastal upwelling off North Africa

2021 ◽  
Author(s):  
Marie-Alexandrine Sicre ◽  
Eva Moreno ◽  
Vincent Klein ◽  
Anna Alves ◽  
Simon Puaud
Keyword(s):  
Coastal Upwelling ◽  
Southwest Monsoon ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Sediment Grain Size ◽  
Trade Winds ◽  
North West ◽  
North East ◽  
Surface Temperatures ◽  
Monsoon Winds

<p>This study presents new high-resolution reconstructions of sea surface temperatures (SSTs) obtained from alkenones off the coast of North West Africa between 19 °N and xx 27°N latitude. Sediment grain-size distributions were also generated to provide new information on the Moroccan and Mauritanian upwelling zone over the Industrial Era. Our data shows that over the past two centuries, SSTs gradually increased in the southernmost cores, while in the northernmost sites they show cooling. Changes in sea level pressure and temperature gradients between land and sea would have caused major changes in atmospheric circulation by disrupting and intensifying the system of North-East winds (Trade winds) and southwest Monsoon winds. With global warming, increase in the monsoon might be expected, causing the weakening easterly winds favorable to the formation of upwellings. Enhanced stratification of the water column would prevent upwelling to develop accounting for surface water warming with consequences on the ecosystems and fisheries.</p>

Holocene sea-surface temperatures and related coastal upwelling regime recorded by vermetid assemblages, southeastern Brazil (Arraial do Cabo, RJ)

2020 ◽  
Vol 425 ◽  
pp. 106183 ◽  
Author(s):  
Camila Areias ◽  
Paula Spotorno-Oliveira ◽  
Davide Bassi ◽  
Yasufumi Iryu ◽  
Merinda Nash ◽  
...  
Keyword(s):  
Coastal Upwelling ◽  
Sea Surface ◽  
Southeastern Brazil ◽  
Sea Surface Temperatures ◽  
Surface Temperatures

Southwest African climate independent of Atlantic sea surface temperatures during the Younger Dryas

2004 ◽  
Vol 61 (3) ◽  
pp. 318-324 ◽  
Author(s):  
Lydie M. Dupont ◽  
Jung-Hyun Kim ◽  
Ralph R. Schneider ◽  
Ning Shi
Keyword(s):  
River Mouth ◽  
Younger Dryas ◽  
Sea Surface ◽  
Published Data ◽  
Sea Surface Temperatures ◽  
Vegetation Development ◽  
Trade Winds ◽  
Surface Temperatures ◽  
Southward Shift ◽  
The Antarctic

To investigate land–sea interactions during deglaciation, we compared proxies for continental (pollen percentages and accumulation rates) and marine conditions (dinoflagellate cyst percentages and alkenone-derived sea surface temperatures). The proxies were from published data from an AMS-radiocarbon-dated sedimentary record of core GeoB 1023-5 encompassing the past 21,000 years. The site is located at ca. 2000 m water depth just north of the Walvis Ridge and in the vicinity of the Cunene River mouth. We infer that the parallelism between increasing sea surface temperatures and a southward shift of the savanna occurred only during the earliest part of the deglaciation. After the Antarctic Cold Reversal, southeast Atlantic sea surface temperatures no longer influenced the vegetation development in the Kalahari. Stronger trade winds during the Antarctic Cold Reversal and the Younger Dryas period probably caused increased upwelling off the coast of Angola. A southward shift of the Atlantic anti-cyclone could have resulted in both stronger trade winds and reduced impact of the Westerlies on the climate of southwestern Africa.

Sea-Surface Temperatures and the History of Monsoon Upwelling in the Northwest Arabian Sea during the Last 500,000 Years

1995 ◽  
Vol 43 (3) ◽  
pp. 355-361 ◽  
Author(s):  
Kay-Christian Emeis ◽  
David M. Anderson ◽  
Heidi Doose ◽  
Dick Kroon ◽  
Detlef Schulz-Bull
Keyword(s):  
Arabian Sea ◽  
Climate Models ◽  
Unsaturation Index ◽  
Sea Surface ◽  
Circulation System ◽  
Monsoon Circulation ◽  
Sea Surface Temperatures ◽  
Tropical Ocean ◽  
Surface Temperatures ◽  
Monsoon Winds

AbstractArabian Sea sediments record changes in the upwelling system off Arabia, which is driven by the monsoon circulation system over the NW Indian Ocean. In accordance with climate models, and differing from other large upwelling areas of the tropical ocean, a 500,000-yr record of productivity at ODP Site 723 shows consistently stronger upwelling during interglaciations than during glaciations. Sea-surface temperatures (SSTs) reconstructed from the alkenone unsaturation index (UK′37) are high (up to 27°C) during interglaciations and low (22-24°C) during glaciations, indicating a glacial-interglacial temperature change of >3°C in spite of the dampening effect of enhanced or weakened upwelling. The increased productivity is attributed to stronger monsoon winds during interglacial times relative to glacial times, whereas the difference in SSTs must be unrelated to upwelling and to the summer monsoon intensity. The winter (NE) monsoon was more effective in cooling the Arabian Sea during glaciations then it is now.

scholarly journals Advances in Egyptian Mediterranean Coast Climate Change Monitoring

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1870
Author(s):  
Matteo Gentilucci ◽  
Abdelraouf A. Moustafa ◽  
Fagr Kh. Abdel-Gawad ◽  
Samira R. Mansour ◽  
Maria Rosaria Coppola ◽  
...  
Keyword(s):  
Climate Change ◽  
Fish Species ◽  
Mitochondrial Gene ◽  
Mediterranean Coast ◽  
Sea Surface ◽  
Homogeneity Test ◽  
Sea Surface Temperatures ◽  
Climate Trends ◽  
Surface Temperatures ◽  
Lessepsian Species

This paper characterizes non-indigenous fish species (NIS) and analyses both atmospheric and sea surface temperatures for the Mediterranean coast of Egypt from 1991 to 2020, in relation to previous reports in the same areas. Taxonomical characterization depicts 47 NIS from the Suez Canal (Lessepsian/alien) and 5 from the Atlantic provenance. GenBank accession number of the NIS mitochondrial gene, cytochrome oxidase 1, reproductive and commercial biodata, and a schematic Inkscape drawing for the most harmful Lessepsian species were reported. For sea surface temperatures (SST), an increase of 1.2 °C to 1.6 °C was observed using GIS software. The lack of linear correlation between annual air temperature and annual SST at the same detection points (Pearson r) could suggest a difference in submarine currents, whereas the Pettitt homogeneity test highlights a temperature breakpoint in 2005–2006 that may have favoured the settlement of non-indigenous fauna in the coastal sites of Damiette, El Arish, El Hammam, Alexandria, El Alamain, and Mersa Matruh, while there seems to be a breakpoint present in 2001 for El Sallum. This assessment of climate trends is in good agreement with the previous sightings of non-native fish species. New insights into the assessment of Egyptian coastal climate change are discussed.

scholarly journals Absolute seasonal temperature estimates from clumped isotopes in bivalve shells suggest warm and variable greenhouse climate

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Niels J. de Winter ◽  
Inigo A. Müller ◽  
Ilja J. Kocken ◽  
Nicolas Thibault ◽  
Clemens V. Ullmann ◽  
...  
Keyword(s):  
Seasonal Variability ◽  
Sea Water ◽  
Isotope Composition ◽  
Sea Surface ◽  
Mean Annual Temperature ◽  
Seasonal Temperature ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
Temperature Reconstructions ◽  
Bivalve Shells

AbstractSeasonal variability in sea surface temperatures plays a fundamental role in climate dynamics and species distribution. Seasonal bias can also severely compromise the accuracy of mean annual temperature reconstructions. It is therefore essential to better understand seasonal variability in climates of the past. Many reconstructions of climate in deep time neglect this issue and rely on controversial assumptions, such as estimates of sea water oxygen isotope composition. Here we present absolute seasonal temperature reconstructions based on clumped isotope measurements in bivalve shells which, critically, do not rely on these assumptions. We reconstruct highly precise monthly sea surface temperatures at around 50 °N latitude from individual oyster and rudist shells of the Campanian greenhouse period about 78 million years ago, when the seasonal range at 50 °N comprised 15 to 27 °C. In agreement with fully coupled climate model simulations, we find that greenhouse climates outside the tropics were warmer and more seasonal than previously thought. We conclude that seasonal bias and assumptions about seawater composition can distort temperature reconstructions and our understanding of past greenhouse climates.

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