The COLOR-CAMPAIGNS mission was undertaken within the framework of the RIVERCOLOR program (TOSCA/CNES) aboard the ship "Côtes de la Manche" co-financed by the INSU (AO Navires littorals). The stations sampled during the two legs (LEG1 and LEG2) are shown in Figure 1. The total number of stations is 33 for LEG1 and 41 for LEG2. The two legs targeted two key periods of the hydrological cycle: a flood in March 2014 and a low water level in July 2014. Each leg lasted 6 days and involved 6 scientists each time.

Figure 1: Location of stations sampled during LEG1 (left) and LEG2 (right).

The instruments implemented and the data acquired are described in Table 1. The optical instruments (Figure 2, top, including the LISST, ACS and ECO-VSF) have only been deployed outside the most turbid areas, unlike the TRIOS sensors (Figure 2, bottom left) systematically deployed for measuring radiometric parameters. The radiometric and optical data were processed and validated on land at the end of each leg. For biogeochemical parameters, samples (Niskin bottle) were taken, simultaneously with optical measurements, at the surface and 1 meter from the bottom, filtered (GF/F filters with a diameter of 47 mm and a porosity of 0.7 ?m, Figure 2, bottom right), kept cool until disembarkation for Chl-a measurement and oven-dried during the mission for MES and COP. All weighings were made in the laboratory.

Table 1: Instruments deployed and data collected

Figure 2: Instruments deployed during the two COLOR-CAMPAIGNS legs.

Figure 3 shows an example of measurements for biogeochemical parameters.

Figure 3: Distribution of SPM and Chl-a values along the river-plume gradient.

Figure 4 shows an example of measurements for radiometric parameters.

Figure 4: Example of directional reflectance spectra (Rrs) for different stations located along the river-plume gradient.

Figure 5 shows some examples of measurements of inherent optical properties.

Figure 5: Depth-averaged spectra for the backscatter coefficient (top left), the absorption coefficient (bottom left) and the attenuation coefficient (top right) for station CC1_ST04.