Presenters:
Jacob Spier
Swany Cuc
California State University, Northridge
This study examines the multiyear trends in Chlorophyll-a concentrations and Sea Surface Salinity (SSS) in the coastal region of the Mississippi River using satellite-derived data from 2012-2022. Monthly median values of SSS and chlorophyll-a were calculated from 25 measurement locations to analyze temporal patterns and relationships between these variables. Seasonal Auto-Regressive Integrated Moving Average with Exogenous Variables (SARIMAX) model was used to quantify the influence of SSS on chlorophyll-a and for forecasting future values. Monthly boxplots and time series decomposition highlighted distinct seasonal trends in chlorophyll-a and SSS, with consistent monthly variations observed over the study period. Sea surface salinity as an external regressor demonstrated a significant negative relationship, with each unit increase in SSS corresponding to a decrease in chlorophyll-a levels by 0.0436 (p<0.01). Residual diagnostics confirmed the model effectively accounted for temporal autocorrelation.