GLOBEC ADCP Data Collection on Georges Bank

Charles N. Flagg and Julio Candela

All the research vessels that have taken part in the GLOBEC program on Georges Bank from May 1994 through to the present have been equipped with acoustic Doppler current profilers. The resulting data sets are providing an unprecedented spatial and temporal description of currents and backscattered intensity for the area. The majority of the data have come from cruises on the Endeavor and Oceanus with smaller data sets from the Albatross IV, Seward Johnson, and Iselin. Because the cruise schedules have emphasized the spring bloom period, the densest coverage has been during the first six or seven months of each year although mooring and process study cruises have extended the coverage into the fall occasionally. The narrow-band ADCP data (Endeavor and Oceanus) have been processed at Brookhaven while the broad-band ADCP data (Albatross, Johnson, and Iselin) have been processed at Woods Hole. The two types of instruments operate somewhat differently and result in slightly different data. In particular, broad-band ADCPs are not capable of measuring backscatter intensity. Table 1 lists all the cruises whose ADCP data have been retrieved and processed, and where it is archived. The time line for the narrow-band ADCP data archived at Brookhaven is shown in Figure 1. All the narrow-band ADCP data that have been processed can be accessed through a web site ( which permits user defined time windows and temporal and spatial averaging. The data are returned via ftp, either as ASCII or MATLAB files. We have also developed a four component detiding algorithm in MATLAB for Georges Bank which, based upon data from 1994 and 1995, will predict the barotropic tidal velocities given a location and time. This routine is available either through the Brookhaven web site or an anonymous ftp site at Woods Hole (ftp:, and then: cd globec/detide).