Seasonal and El Niño–Southern Oscillation-related ocean variability in the Panama Bight
<p>In the Panama Bight, two different seasonal surface circulation patterns coincide with a strong mean sea level variation, as observed from 27 years of absolute dynamic topography (ADT) and the use of self-organizing maps. From January to April, a cyclonic gyre with a strong southwestward Pa...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-05-01
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| Series: | Ocean Science |
| Online Access: | https://os.copernicus.org/articles/19/685/2023/os-19-685-2023.pdf |
| Summary: | <p>In the Panama Bight, two different seasonal surface circulation patterns
coincide with a strong mean sea level variation, as observed from 27 years
of absolute dynamic topography (ADT) and the use of self-organizing maps.
From January to April, a cyclonic gyre with a strong southwestward Panama
Jet Surface Current (PJSC) dominates the basin circulation, forced by the
Panama surface wind jet that also produces upwelling, reducing sea surface
temperature (SST), increasing sea surface salinity (SSS) and causing an ADT
decrease. From June to December, the Choco surface wind jet enhances SST,
precipitation and river runoff, which reduces SSS, causing an ADT rise, which in turn forces a weak circulation in the bight, vanishing the PJSC. Interannual
variability in the region is strongly affected by El Niño–Southern Oscillation (ENSO); however this
climatic variability does not modify the seasonal circulation patterns in
the Panama Bight. In contrast, the positive (negative) ENSO phase increases
(decreases) SST and ADT in the Panama Bight, with a mean annual difference
of 0.9 <span class="inline-formula"><sup>∘</sup></span>C and 9.6 cm, respectively, between the two conditions,
while its effect on SSS is small. However, as the strong seasonal SST, SSS
and ADT ranges are up to 2.2 <span class="inline-formula"><sup>∘</sup></span>C, 2.59 g kg<span class="inline-formula"><sup>−1</sup></span> and 28.3 cm,
the seasonal signal dominates over interannual variations in the bight.</p> |
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| ISSN: | 1812-0784 1812-0792 |