Publication Date:
2022-05-25
Description:
Author Posting. © The Authors, 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Continental Shelf Research 26 (2006): 885-901, doi:10.1016/j.csr.2006.01.017.
Description:
The effects of the 1997-98 and 2002-04 El Ni˜no on the upper waters in the con-
tinental shelf and slope regions off northwestern Baja California are explored with
data from eight cruises taken in late spring from 1998 to 2004 and the summers of
1997 and 1998. Geostrophic velocities were calculated referenced to a specific vol-
ume anomaly surface separating the southward flowing California Current waters
from the waters advected to the north by the California Undercurrent. The result-
ing fields show equatorward flow near the surface except in the summer of 1997,
when a poleward jet was found in the upper 40 dbars. This shallow jet advected
anomalously warm and salty waters characteristic of the 1997-98 El Ni˜no, with its
core found within 20-30 kms from the coast. By spring of 1998, the waters brought
into the region by the jet had mixed across the pycnoline with the salty California
Undercurrent waters below, resulting in high salinity levels on the density surfaces
corresponding to the otherwise fresh California Current waters (25-26¾t). By con-
trast, the 2002-04 El Ni˜no stands out for the very fresh and cold waters found on
the same density surfaces in late spring of 2003 and 2004, marking a pronounced
presence of subarctic waters. The fresh conditions found on the latter years repre-
sent a nearshore expresion of the anomalous intrusion of subarctic waters observed
50-150 km from the coast of Southern California and Punta Eugenia, reported from
July 2002 until April 2003. Our results suggest that the presence of this intrusion
has continued to influence the region at least until May 2004.
Description:
This work was supported by
the US NSF (OCE-9986627 and OCE-0083976).
Keywords:
El Nino phenomena
;
Coastal currents
;
Coastal upwelling
;
Hydrography
;
California Current System
;
Mexico
;
Northwestern Baja California
;
Geographic bounding coordinates: (33◦00’N, 117◦45’W) – (31◦40’N, 116◦30’W)
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
1870213 bytes
Format:
application/pdf
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