The relationship between suspended particulate matter and turbidity at a mooring station in a coastal environment: consequences for satellite-derived products

• Autorzy: Jafar-Sidik M. , Gohin F. , Bowers D. , Howarth J. , Hull T.
• Języki publikacji: EN

Abstrakty

EN

From a data set of observations of Suspended Particulate Matter (SPM) concentration, Turbidity in Formazin Turbidity Unit (FTU) and fluorescence-derived chlorophyll-a at a mooring station in Liverpool Bay, in the Irish Sea, we investigate the seasonal variation of the SPM: Turbidity ratio. This ratio changes from a value of around 1 in winter (minimum in January— February) to 2 in summer (maximum in May—June). This seasonal change can be understood in terms of the cycle of turbulence and of the phytoplankton population that affects the nature, shape and size of the particles responsible for the Turbidity. The data suggest a direct effect of phytoplankton on the SPM:Turbidity ratio during the spring bloom occurring in April and May and a delayed effect, likely due to aggregation of particles, in July and August. Based on the hypothesis that only SPM concentration varies, but not the mass-specific backscattering coefficient of particles bbp *, semi-analytical algorithms aiming at retrieving SPM from satellite radiance ignore the seasonal variability of bbp * which is likely to be inversely correlated to the SPM:Turbidity ratio. A simple sinusoidal modulation of the relationship between Turbidity and SPM with time helps to correct this effect at the location of the mooring. Without applying a seasonal modulation to bbp *, there is an underestimation of SPM in summer by the Ifremer semi-analytical algorithm (Gohin et al., 2015) we tested. SPM derived from this algorithm, as expected from any semi-analytical algorithm, appears to be more related to in situ Turbidity than to in situ SPM throughout the year.

Słowa kluczowe

EN

suspended particulate matter; turbidity; coastal environment; seasonal variation; phytoplankton; chlorophyll a; Irish Sea

• Wydawca: -
• Czasopismo: Oceanologia
• Rocznik: 2017
• Tom: 59
• Numer: 3
• Opis fizyczny: p.365-378,fig.,ref.

Twórcy

autor

Jafar-Sidik M.

• Borneo Marine Research Institute, Universiti Malaysia Sabah, 88450 Kota Kinabalu, Sabah, Malaysia
• School of Ocean Sciences, Bangor University, Anglesey, U.K.

autor

Gohin F.

• Ifremer, Dyneco/Pelagos, Centre Ifremer de Brest, BP 70, F-29280 Plouzane, Brittany, France

autor

Bowers D.

• School of Ocean Sciences, Bangor University, Anglesey, U.K.

autor

Howarth J.

• National Oceanography Centre, Joseph Proudman Building, Liverpool, U.K.

autor

Hull T.

• Centre for Environment, Fisheries and Aquaculture Science (Cefas), Lowestoft, U.K.

Identyfikatory

DOI

10.1016/j.oceano.2017.04.003