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Fishery Bulletin 97(1), 1999 



Since late 1992, data have been collected by 

 TOPEX-POSEIDON (T-P) satellite altimetry and are 

 available in near-real time. The satellite covers the 

 ocean over a 10-day period, providing a temporal reso- 

 lution of 10 days; however, the spatial coverage is 

 along narrow tracks; therefore interpolation between 

 track is required for full spatial coverage. We used 

 this altimetry data to estimate geostrophic current 

 and ultimately to drive a simulation model of the 

 transport of spiny lobster larvae released from se- 

 lected banks in order to describe the spatial and sea- 

 sonal dynamics of larval transport. In particular, in 

 the NWHI, the spiny lobsters spawn in the summer, 

 during May-August, and in the winter, during No- 

 vember and December, and the larvae are estimated 

 to have a pelagic duration of 12 months (Polovina 

 and Moffitt, 1995). We investigated aspects of the 

 spatial and temporal dynamics of spiny lobster lar- 

 val transport by simulating the movement of larvae 

 from several representative banks from summer and 

 winter spawning over the 12-month larval duration. 



mental Satellite, Data and Information Service 

 (NESDIS), National Oceanic and Atmospheric Ad- 

 ministration (NOAA), Department of Commerce. 

 This project was a joint endeavor with the Naval 

 Oceanographic Office (NOO) and the Jet Propulsion 

 Laboratory (JPL). The altimetry data were first 

 transmitted from the satellite to JPL, where the or- 

 bit position was finalized with the aid of GPS track- 

 ing data. NOO scientists performed an initial adjust- 

 ment to the altimetry data using the JPL orbit infor- 

 mation, then the data were forwarded to NOAA 

 where a final orbit-related adjustment was made 

 after the complete 10-day cycle of data was received. 

 The data were aggregated into 1-degree latitude in- 

 tervals along the satellite track (Fig. 3 1 and were 

 expressed as a deviation from a 3-year (1993-95) 

 mean altimetry. These data can be downloaded from 

 an anonymous file transfer protocol (ftp) at 



falcon.grdl.noaa.gov in/pub/topex_real_time 



or from an internet webpage at 



Methods 



Topex altimetry data 



The altimetry data used in this study were obtained 

 from a 2-day Delayed Altimeter Data project of the 

 Laboratory for Satellite Altimetry, National Environ- 



http://ibis.grdl.noaa.gov/SAT/near_rt/ 

 topex_2day.html. 



The data were ready for public dissemination ap- 

 proximately 2 days after each 10-day satellite cycle 

 was completed. Altimetry data that were not aggre- 

 gated but were continuous along track lines are avail- 



180' 177'W 174'W 171 'W 168'W 165"W 162'W 159"W 156'W 153'W 150"W 147'W 



Figure 3 



Spatial grid of near-real time TOPEX-POSEIDON data from a 10-day cycle. 



