Manuscript #: 2013GL055189 Title: Climate-driven sea level anomalies modulate coastal groundwater dynamics and discharge Authors: Meagan Eagle Gonneea1, Ann E. Mulligan2 and Matthew A. Charette1* Affiliations: 1Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA. 2Marine Policy Center, Woods Hole Oceanographic Institution, Woods Hole, MA, USA. *To whom questions should be addressed. E-mail: mcharette@whoi.edu Description of supplemental material: Supplemental text: Contains a description of the Waquoit Bay coastal aquifer salinity structure as well as the statistical methods used to analyze the relationship between sea level, groundwater level, hydraulic gradient and aquifer salinity through time. Figure S1: Salinity structure of the coastal aquifer in April 2003, June 2004 and June 2005. Figure S2: a) Tidal time series of salinity at monitoring wells and b) 6-minute Woods Hole mean sea level during the same time period. Figure S3: Relationship between coastal aquifer salinity and inland and coastal groundwater levels and sea level. Figure S4: a) Mean sea level anomaly along the northeast US coast Jan. 2004 to May 2011 and b.) Woods Hole, MA predicted sea level due to the solar annual tidal component and measured sea level. Figure S5: Cross correlation analysis of head gradient and a) sea level, b) CCC1 coastal (46 m from MSL) groundwater levels and c) USGS inland (10 km from MSL) groundwater levels. 95% confidence intervals are shown in dashed lines. Figure S6: Cross correlation analysis for coastal (46 m from MSL) groundwater levels and a) inland (USGS, 10 km from MSL) groundwater and b) MSL. 95% confidence intervals are shown in dashed lines. Figure S7: Cross correlation analysis for salinity and a) head gradient between CCC1 and MSL, b) sea level, c) coastal CCC1 groundwater levels and d) inland USGS groundwater levels. 95% confidence intervals are shown in dashed lines. Figure S8: Mean sea level anomaly from Woods Hole, MA, and three-month running mean NAO index from a) Jan. 1980 to Oct. 2011 and b) Jan. 2004 to Oct. 2011, and c) cross correlation between sea level and NAO. 95% confidence intervals are shown in dashed lines.