Canary Current 12 Nov, 06 - 3:24

By this time, the trade winds have begun to settle in quite well and Nov 28 has been forcasted as the best possible time to leave. We expect cold weather for the first few weeks, due to the cold water Canary current. At this time of the year however, we expect also the currents to be at their peak strength, which should make for a faster crossing. Seems like a few cold days at sea will have to be the trade off.
The Canary Current flows along the African coast from north to south between 30°N and 10°N and offshore to 20°W. Like other eastern boundary currents, it is wide (1000 km) and slow (10-30 cm s-1), and it flows year-round towards the equator. Its surface waters are relatively cool because as it travels south it entrains upwelled water from the coast (Mittelstaedt 1991). On average, the current is about 500 m deep (Wooster et al. 1976) and flows at a speed of 10-15 cm s-1 (Zhou et al. 2000). The Canary Island Archipelago reaches depths of more than 3000 m and thus forms an obstacle to the flow of the Canary Current (Barton et al. 2000).
The Canary Current system contains coastal upwelling, filaments, and eddies (Johnson and Stevens 2000). Eddies with length scales of 100 to 300 km form along the coastal boundary of the current. The eddy kinetic energy values for the Canary Current are less than 100 cm2 s2.
A branch of the Azores Current joins the Canary Current along the continental slope between the Madeira Plateau and the Canary Islands.
Its core velocity can be more than 75 cm s-1 as it passes through the Canary archipelago. It moves parallel to the coastline up to 20°N, forming cyclonic gyres on the shelf along the way. When the current reaches the area of 15°N, it begins to flow west under the influence of the Equatorial Countercurrent. Although the two currents flow in the same direction, they do so at different speeds; this causes two anti-cyclonic gyres to form at the border between them. In spring the Canary Current weakens along with the trade winds, while the Equatorial Countercurrent strengthens. An anti-cyclonic gyre forms to the west of the current. The summer brings about further weakening of the trade winds, and this reduces the water inflow from the north. The Canary Current weakens further and spreads outward from the coast. The cyclonic gyres on the shelf weaken or disappear completely. The Equatorial Countercurrent, on the other hand, is at its peak and shifts north, separating the Canary Current from the coast. During autumn the Canary Current is at its weakest, but some of its characteristics are very similar to those during winter. The current passes through the Canary archipelago, the influence of the Equatorial Countercurrent is the same as in winter, and the strong cyclonic gyres form once again.
From RSMAS, Miami, Edu.
TODAYS PHOTO - The Canary Current