Spatio-Temporal Variability Of Hydrophysical Conditions At Bahia Independencia, Pisco - Peru, From 1995 To 2004

Bahia Independencia (Independence Bay) is a marine system whose structure and function, have been subject of various biological studies. From in situ assessment reports (IMARPE, DHN) and satellite data (QuikSCAT), variations in spatio-temporal hydrophysical conditions, based on winds, ocean circulation, temperature and salinity were described. For the analysis, descriptive statistics, correlation tests, multivariate analysis, analysis of variance (ANOVA) and maps with color scales were applied.Spatial distribution patterns whose formation is attributed to local factors were identified. On the surface there are latitudinal gradients of temperature and of salinity to a lesser extent, with higher values in the north of the bay, because of water drift due to wind stress and the influence of Laguna Grande, a semi-enclosed formation at the northern end of the Bay. Near the bottom level, in the north, temperature and salinity distributions reflect the upwelling circulation, evidenced by circulating water transversely to the long axis of the bay. Conversely, in the south, surface and near bottom circulations were coupled, determining clockwise and counter-clockwise fluxes, creating small areas with similar characteristics of salinity. The bay is normally intruded by upwelling Equatorial Subsurface Waters, and sometimes by mixed waters with Subtropical Surface Waters (ESSW). In the extreme 1997-98 El Nino the SSW occupied all the bay area.