How useful are progressive vector diagrams for studying coastal ocean transport?

Progressive vector diagrams (PVDs) have been used to estimate transport in the coastal ocean from point measurements of velocity time series, although they strictly only approximate true particle trajectories in regions where the currents are spatially uniform. Currents in most coastal regions vary significantly in both spaceandtime,makingcoastaltransportestimatesfromPVDsquestionable.Here,weusedsynopticsurfacecur rentsmeasuredoverperiodsofseveralmonthsbyHFradarsintwocoastalareaswithdistinctlydifferentcircu lationfeatures(theGulfofEilat,adeep,semi-enclosedbasin,andtheDelawareBaymouth,acoastalestuarine outflow)toassessthetimescalesoverwhichPVDpathscomputedfromvelocitytimeseriesatfixedpointssep aratefromparticletrajectoriescomputedfromtwo-dimensionalmeasuredhorizontalcurrentsthatvaryinboth spaceandtime.Inbothstudyregions,PVDsandparticletrajectoriesseparateby1kmoverameantimeperiod of 7‐10 h with no significant month-to-month variation in either region. The separation time statistics pre sentedhereshouldserveasastrongcautionforinvestigatorsmotivatedtoestimatetransportusingonlypoint measurements.

[1]  George Haller,et al.  Pollution release tied to invariant manifolds: A case study for the coast of Florida , 2005 .

[2]  S. Brenner,et al.  Annual SST cycle in the Eastern Mediterranean, Red Sea and Gulf of Elat , 2003 .

[3]  Robert Tibshirani,et al.  Bootstrap Methods for Standard Errors, Confidence Intervals, and Other Measures of Statistical Accuracy , 1986 .

[4]  A. Genin.  Changes in the circulation and current spectrum near the tip of the narrow, seasonally mixed Gulf of Elat (Aqaba) , 1998 .

[5]  S. Monismith,et al.  Evidence for Submesoscale Barriers to Horizontal Mixing in the Ocean from Current Measurements and Aerial Photographs , 2009 .

[6]  H. Gildor,et al.  Possible effects of downwelling on the recruitment of coral reef fishes to the Eilat (Red Sea) coral reefs , 2007 .

[7]  David M. Kaplan,et al.  Spatial interpolation and filtering of surface current data based on open‐boundary modal analysis , 2007 .

[8]  Jerrold E. Marsden,et al.  The correlation between surface drifters and coherent structures based on high-frequency radar data in Monterey Bay , 2009 .

[9]  David M. Kaplan,et al.  HF radar observations of surface circulation off Bodega Bay (northern California, USA) , 2005 .

[10]  William J. Emery,et al.  Data Analysis Methods in Physical Oceanography , 1998 .

[11]  A. Ogston,et al.  Sediment resuspension and transport patterns on a fringing reef flat, Molokai, Hawaii , 2004, Coral Reefs.

[12]  F. Al-Horani,et al.  Patterns of summer vertical and horizontal currents in coastal waters of the northern Gulf of Aqaba, Red Sea , 2006 .

[13]  J. Fiechter,et al.  Physical processes impacting passive particle dispersal in the Upper Florida Keys , 2008 .

[14]  S. Brenner,et al.  Simulation of wind-driven circulation in the Gulf of Elat (Aqaba) , 2000 .

[15]  D E Barrick,et al.  MAPPING SURFACE CURRENTS WITH CODAR , 1985 .

[16]  F. Lekien,et al.  Computation and approximation of the length scales of harmonic modes with application to the mapping of surface currents in the Gulf of Eilat , 2009 .

[17]  Jerrold E. Marsden,et al.  Open-boundary modal analysis: Interpolation, extrapolation, and filtering , 2004 .

[18]  Stephen Wiggins,et al.  Synoptic Lagranian maps: Application to surface transport in Monterey Bay , 2006 .

[19]  S. Monismith,et al.  Tides and sea level in the Gulf of Aqaba (Eilat) , 2004 .

[20]  K. Gurgel,et al.  High-frequency radars : physical limitations and recent developments , 1999 .

[21]  R. Garvine,et al.  Transport of blue crab larvae by surface currents off Delaware Bay, USA , 1989 .