EL NIÑO AND LA NIÑA EFFECTS ON PRECIPITATION IN THE SAVANNAH RIVER DRAINAGE BASIN AND ESTUARINE SALINITY

The goal of this study was to determine if the salinity of the Savannah River estuary is influenced by El Niño events. Extreme interannual variations in salinity have a significant impact on estuarine plants and animals. The southeast United States is thought to be rainier in El Niño years. This project examined whether there is greater precipitation specifically in the Savannah River drainage basin in El Niño years than in La Niña years. Winter season total precipitation was calculated by summing December through February values in regions adjacent to the Savannah River in Georgia and South Carolina. Years of strong and weak El Niño and La Niña events were identified back to 1950. The average winter precipitation for the strong El Niño years was 97.65 ± 21.30 inches, compared to the weak and strong La Niña winters which averaged only 71.44 ± 17.55 and 72.04 ± 26.94 inches of precipitation, respectively. Weak El Niño winters had intermediate precipitation totals with an average of 77.85 ± 12.19 inches. Year-to-year variations in winter precipitation correlated well among the subregions of the drainage basin except for the southern and mountainous regions of South Carolina (correlation coefficient = 0.36). The greater precipitation in strong El Niño winters will be compared to river discharge and salinity records for the Savannah River estuary.