SUMMARY OF COAST FLIGHT 16
Date: Fri, 03 Aug 2001 06:17:48 -0400
From: John Bane
Subject: COAST Flight Report - August 1
COAST Flight 16 was flown on August 1, 2001. This flight was the fifth in a series of approximately weekly flights flown between major COAST cruises. Measurements were made of: SST, subsurface ocean temperature, and upper-ocean color; atmospheric temperature, humidity and horizontal winds. Data were collected on four Big Box Lines (8, 6, 4 and 2), flying from south to north.
AXBTs were deployed as follows:
Line 2: 8 AXBTs
Line 6: 7 AXBTs
Vertical sections of meteorological variables were measured on lines 4 and 8, extending from 60 m to 800 m altitude. Winds throughout the region were westerly to southwesterly and light, with speeds generally less than ten knots. Atmospheric temperature varied little in the lowest 800 m, showing only a near-adiabatic decrease with height above the ocean surface. This is consistent with the structure we have seen on earlier flights during weak southerly winds.
The SST field showed some cool water nearshore, suggesting residual upwelled water from the period of northerly winds of about a week ago. A very interesting surface temperature front was observed north of Newport, extending from north of Line 2 to at least south of Line 3. Off Lincoln City this front was located between the 50m and 100m isobaths, and its orientation was such that it was closer to shore and sharper in the north and farther from shore and broader in the south, characteristics typical of an upwelling front in this area. We were able to make several crossings of the front using a zig-zag pattern, and the SST varied quite abruptly across the front, rising from around 11C inshore to around 14-15C offshore in only a few hundred meters. We deployed two additional AXBTs near the front on Line 2, one on each side between our normal stations 2A and 2B. The front was clearly visible by eye, with a slick containing some foam lines running right along the line of greatest SST gradient. We took some pictures of the surface features, and I will post one or two on the COAST web page if they turn out interesting. Perhaps the most impressive aspect of this front is its existence during a period of weak southerly winds, several days after the last northerly winds in this location.
Jack Barth joined us in Newport for the second half of this survey, and his insights were fresh and enlightening. He seemed to enjoy the flight, as he didn't appear nervous and never asked for a parachute....
(Disclaimer - These descriptions are from looking at computer graphical displays while aboard the aircraft, and closer inspection of post-flight data products will provide more accurate conclusions, some of which may differ from statements here.)
Data products will be available from http://www.marine.unc.edu/cool/COAST or they may be retrieved from the real-time results or 4-days-plus results areas. All of these are buttons off of the main COAST site.
August 3, 2001