Satellite-Measured Phytoplankton and Environmental Factors in North Patagonian Gulfs

Phytoplankton dynamics based on satellite inherent optical properties and oceanographic conditions in a patagonian gulf frontal system in relation to the adjacent continental shelf waters

“…This low annual variability can be explained by the high tidal energy flow that prevents the stratification of the water column (Tonini and Palma, 2017;). In the case of the SSMG and GSJ windows, they showed broad annual variability with a high peak also in November (aphy443 = 0.04-0.08 m -1 , Chla-sat = 3.46-4.39 mg m -1 ) and low values in winter (August, 0.02 m -1 ; 1.00 mg m -1 ), fitting to the unimodal function using either aphy443 or Chla-sat parameters (r 2 ~ 0.7, Supplementary Materials, Table I and II), in agreement with previous studies using shorter time series (2003( -2009( , Williams et al, 2018a. Particularly in the SSMG window, moderate values there were sustained during summer-early autumn (from February to April: 0.04± 0.005 m-1; 1.33±0.01 mg m -1 ) probably due to the continuous injection of nutrients leading by the interaction of tidal currents with the topography (Williams et al, 2013(Williams et al, , 2021.…”

“…The Chla-sat annual cycle in SJG has already been characterized by an annual harmonic function with relatively high values in spring-summer (Williams et al, 2018a). As a novelty, the present work highlights the differences between the western and eastern hydrographic domains supported by aphy443 as a proxy for phytoplankton biomass.…”

“…The contribution of each harmonic (annual and semi-annual) to the cycle was determined by fitting monthly climatological data to each harmonic separately (second and third terms of Eq. 1, respectively, as stated in Williams et al (2018a).…”

“…After this first inspection and taking into consideration prior research in the area (Williams et al, 2018a(Williams et al, , 2021Amoroso and Gagliardini, 2010), the study system was partitioned into 5 windows: Península Valdés (PV, 9x9 pixels), Punta Norte (PN, 6x5 pixels), south of SMG (SSMG, 7x6 pixels), and western and eastern domains of SJG (WD and ED respectively, 4x3 pixels) (Fig. 1a).…”

“…The PAR cycle showed a typical annual signal evidenced with high percentage of variance explained by the annual harmonic (Williams et al, 2018a), with minimum values from May to July (15.41 to 13.51 E m -2 d -1 ) and maximum values from November to January (54.86 to 60.12 E m -2 d -1 ). In general, the annual cycle of Z1% (euphotic depth) also showed strong annual signal and positive correlation with PAR and SST, with minimum mean values in June (24 m), and maximum values from December to February (~ 30 m).…”