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link to Assateague Island study
link to Sandy Hook study
Data used for this study were compiled from multiple U.S Geological Survey (USGS) and National Oceanographic and Atmospheric Administration (NOAA) sources. Tide-elevation data were compiled from USGS published records for the Great South Bay at Watch Hill on Fire Island, NY tidal gage (USGS station ID 01305575), which is located on the Fire Island barrier island about 6 miles east of the study area at the Watch Hill marina (fig. 1). Tides at this station are estimated to be about 40 to 45 minutes later than those at the Sunken Forest, as determined from the NOAA Center for Operational Oceanographic Products and Services (CO-OPS) Seaview Ferry Dock tidal prediction station (NOAA station ID 8514779), located just to the west of the study area near Ocean Beach. For part of the study period, the USGS also collected meteorological data (precipitation and wind speed and direction) at USGS station 01305575. Meteorological data from this station are provisional and unpublished; however, they compare well to nearby NOAA National Centers for Environmental Information (NCEI) climatological records from Long Island-Islip MacArthur Airport (about 10 miles to the north of the study area), are the closest continuous-recording dataset available, and were collected at the same location as the published tide data, so the USGS provisional data were used as a guide to select and compare storm events for this study.
link to Assateague Island study
link to Sandy Hook study
Data used for this study were compiled from multiple U.S Geological Survey (USGS) and National Oceanographic and Atmospheric Administration (NOAA) sources. Tide-elevation data were compiled from USGS published records for the Great South Bay at Watch Hill on Fire Island, NY tidal gage (USGS station ID 01305575), which is located on the Fire Island barrier island about 6 miles east of the study area at the Watch Hill marina (fig. 1). Tides at this station are estimated to be about 40 to 45 minutes later than those at the Sunken Forest, as determined from the NOAA Center for Operational Oceanographic Products and Services (CO-OPS) Seaview Ferry Dock tidal prediction station (NOAA station ID 8514779), located just to the west of the study area near Ocean Beach. For part of the study period, the USGS also collected meteorological data (precipitation and wind speed and direction) at USGS station 01305575. Meteorological data from this station are provisional and unpublished; however, they compare well to nearby NOAA National Centers for Environmental Information (NCEI) climatological records from Long Island-Islip MacArthur Airport (about 10 miles to the north of the study area), are the closest continuous-recording dataset available, and were collected at the same location as the published tide data, so the USGS provisional data were used as a guide to select and compare storm events for this study.
Figure 1. Location of Sunken Forest study area, U.S. Geological Survey tidal gage on Great South Bay at Watch Hill on Fire Island, NY (USGS station ID 01305575), the National Oceanographic and Atmospheric Administration (NOAA) Climatic Station at Long Island-Islip MacArthur Airport, and the NOAA Center for Operational Oceanographic Products and Services (CO-OPS) Seaview Ferry Dock tidal prediction station (NOAA station ID 8514779).
Groundwater-level and specific conductance data were compiled from published USGS records for five monitoring wells installed by the USGS for this study in the Sunken Forest on Fire Island National Seashore (hereafter referred to as FIIS). Marsh Well (USGS station ID 403922073064401) and Deep Well (USGS station ID 403922073064402) are both installed approximately 80 feet (ft) from the shoreline of the Great South Bay and are 60 ft away from each other; Middle Well (USGS station ID 403921073064801) is installed 180 ft from the shoreline; Inland Well 1 (USGS station ID 403921073070401) is installed approximately 300 ft from the shoreline; and Inland Well 2 (USGS station ID 403919073064801) is installed approximately 380 ft from the shoreline. Depth to water table in the Sunken Forest is generally less than 10 ft. Four of the five wells installed (Marsh Well, Middle Well, Inland Well 1, and Inland Well 2) were installed 1 to 3 ft below the water table. The fifth well (Deep Well) was installed 4 to 8 ft below the water table. The location of wells in the Sunken Forest are shown in figure 2.
Water-level data at 15-minute intervals using a submersible water-level sensor was collected for the Marsh Well from September 13, 2017 to June 15, 2018 and September 13, 2018 to February 14, 2019; for the Deep Well from September 18, 2017 to April 18, 2018; for the Middle Well from September 13, 2017 to December 13, 2017 and September 13, 2018 to February 14, 2019; for Inland Well 1 from September 13, 2017 to November 22, 2017, December 13, 2017 to December 28, 2017, and January 24, 2018 to June 15, 2018; and Inland Well 2 from September 13, 2017 to January 24, 2018, March 30, 2018 to June 15, 2018, and September 13, 2018 to February 14, 2019.
Specific conductance data at 15-minute intervals using a submersible specific-conductance sensor was collected for the Marsh Well from September 13, 2017 to June 15, 2018; for the Deep Well from September 18, 2017 to April 8, 2018; for the Middle Well from September 13, 2017 to December 13, 2017 and September 14, 2018 to February 14, 2019; and Inland Well 1 from September 13, 2017 to November 22, 2017, December 13, 2017 to December 28, 2017, and January 24, 2018 to June 15, 2018. No specific conductance data was collected at Inland Well 2.
Water levels at the Marsh Well and Deep Well respond closely to astronomical tides in Great South Bay, with semidiurnal water-level fluctuations of about 0.25 to 0.5 ft recorded at these wells during non-storm conditions. At the more inland wells (Middle Well, Inland Well 1, and Inland Well 2) water levels generally show a more dampened response during normal astronomical tides, most likely due to their further distance from the Bay. For specific conductance, the Marsh Well and Deep Well had the highest maximum values of 10,800 microsiemens per centimeter (µS/cm) and 5,080 µS/cm respectively. The more inland wells (Middle Well and Inland Well 1) generally show a lower maximum specific conductance of 3,400 µS/cm and 630 µS/cm respectively, most likely due to their further distance from the Bay. Semidiurnal fluctuations in specific conductance related to astronomical tides were recorded at the Marsh Well during some non-storm periods; these semidiurnal fluctuations were not evident at the Deep Well, Middle Well, or Inland Well 1.
Storm events for this study were selected when the maximum storm-tide elevation reached 2.0 ft (NAVD88) or greater or single-day precipitation total was 1.25 inches or greater as recorded at USGS station 01305575. Using these criteria, 18 events were selected during the study period (table 1). Of the 18 events, 3 unique events were selected for more in-depth analysis to determine the magnitude and timing of water-level and specific-conductance changes at the wells (tables 2 and 3). The three events selected were a precipitation-only event (storm event 2) that occurred on September 30, 2017; a relatively short duration high wind, coastal flooding, and heavy precipitation event (storm event 3) with a primary wind direction from the south and west that occurred on October 29 to 30, 2017; and a long duration high wind, coastal flooding, and heavy precipitation event (storm event 6) with a primary wind direction from the east to northeast that occurred on March 2 to 8, 2018. These events are discussed in more detail below.
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Last updated: December 5, 2022