Back to Search
Start Over
EXTREME UPWELLING EVENTS: IN THE SEAS OF THE ALOR KECIL, ALOR ISLAND, INDONESIA.
- Source :
-
Oceanography . Mar2023, Vol. 36 Issue 1, p28-37. 10p. - Publication Year :
- 2023
-
Abstract
- Upwelling is a process by which deep, colder, higher-nutrient waters are brought to the sea surface. In the tropics, an indicator that an upwelling event has occurred is lowering of sea surface temperatures (SSTs) to 25°-27°C from a mean of ~28°C. Based on more than one year of in situ data, we observed an unusual extreme upwelling event (EUE) when the near-surface temperature (NST) dropped by 10°C within one hour during the spring tide in Mulut Kumbang Strait of Alor Kecil. The extreme minimum NST during this EUE was ~12°C, and the upward displacement speed of the cold water was ~0.012 m s-1. The increase in salinity from ~30 ‰ to 34 ‰-36‰ during the decrease in NST indicates a deep source for the cold water mass. From bathymetry and CTD data, the source of the cold water mass was a deep basin (>300 m) located at the southern part of Pantar Strait. In this basin, the temperature at 270 m depth can be as low as 8°C. We suggest that tidal sloshing (i.e., the back-and-forth movement of water) brings the cold water mass through a channel that connects this deep basin to Mulut Kumbang Strait. Interactions between semi- diurnal (M2, S2, and N2) tidal components strongly modulate the tidal signal with a period of nearly one month. That EUEs only occur from August to November also suggests a strong monsoonal influence. Because tides are predictable, we suggest that future EUEs are predictable. [ABSTRACT FROM AUTHOR]
- Subjects :
- *OCEAN temperature
*WATER masses
*SPRING
*TIDAL basins
Subjects
Details
- Language :
- English
- ISSN :
- 10428275
- Volume :
- 36
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Oceanography
- Publication Type :
- Academic Journal
- Accession number :
- 162483765
- Full Text :
- https://doi.org/10.5670/oceanog.2023.107