|Title||The dynamics of suspended particulate matter (SPM) and chlorophyll-a from intratidal to annual time scales in a coastal turbidity maximum|
|Author(s)||Hout, C.M. van der; Witbaard, R.; Bergman, M.J.N.; Duineveld, G.C.A.; Rozemeijer, M.J.C.; Gerkema, T.|
|Source||Journal of Sea Research 127 (2017). - ISSN 1385-1101 - p. 105 - 118.|
|Publication type||Refereed Article in a scientific journal|
|Keyword(s)||Bed shear stress - Chlorophyll-a - In-situ observations - Season - SPM - Wave climate|
The analysis of 1.8. years of data gives an understanding of the response to varying forcing of suspended particulate matter (SPM) and chlorophyll-a (CHL-a) in a coastal turbidity maximum zone (TMZ). Both temporal and vertical concentration variations in the near-bed layer (0-2. m) in the shallow (11. m deep) coastal zone at 1. km off the Dutch coast are shown. Temporal variations in the concentration of both parameters are found on tidal and seasonal scales, and a marked response to episodic events (e.g. storms). The seasonal cycle in the near-bed CHL-a concentration is determined by the spring bloom. The role of the wave climate as the primary forcing in the SPM seasonal cycle is discussed. The tidal current provides a background signal, generated predominantly by local resuspension and settling and a minor role is for advection in the cross-shore and the alongshore direction. We tested the logarithmic Rouse profile to the vertical profiles of both the SPM and the CHL-a data, with respectively 84% and only 2% success. The resulting large percentage of low Rouse numbers for the SPM profiles suggest a mixed suspension is dominant in the TMZ, i.e. surface SPM concentrations are in the same order of magnitude as near-bed concentrations.