| ![[NOAA]](images/noaalogo11.gif) | U.S. Dept. of Commerce / NOAA / OAR / ERL / PMEL / FOCI / Visualizations | ![[FOCI]](images/foci_logo_sm.gif) | 
| Drifter 
        trajectory animations | 
| About the data |  | |
| From 1986-1998 
        Fisheries Oceanography Coordinated 
        Investigations (a program of NOAA) deployed more than 200 drifters 
        in the North Pacific Ocean 
        and Bering Sea. Most drifters had drogues centered at 40m. In the 
        following animations, the latest 10 days of a trajectory are shown in 
        yellow, and the earlier history in red. The major 
        current systems (Alaskan Stream, Bering Slope Current, Aleutian North 
        Slope Current, Kamchatka Current and Alaska Coastal Current) are clearly 
        evident in the trajectories. Funding for this project was provided by NOAA (COP, OCSEAP and OAR). |  | Select animation | 
| About these animations | 
| These animations are comprised of a number of images which are continually updated by a JavaScript function. These images overlay an image showing the bathymetry of the Bering Sea. Each overlay image is comprised of a transparent background, with only the two colors of the drifter tracks visible. This allows us to reduce the file size of the images significantly (from 50K down to approximately 2K per image).This method does, however, have the limitation that only 4.0 browsers are able to view the animations. The number of images comprising each animation varies between 130 and 200 images and are pre-loaded by the animation script. This is a large number of images to load - so be warned that it could take some time if you are browsing the Internet over a slow connection. Some hints: 
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| About the drifters | 
| SVP (Surface Velocity Program) type drifters, with a holey sock drogue centered at 40m are being used. Data is relayed to NOAA by means of the ARGOS system. The drifter data format is the standard SVP data format. Average life expectancy of the drifters is 8 months. |