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Charles N. Flagg
Robert E. Wilson
Claudia Hinrichs
Tom Wilson

School of Marine and Atmospheric Sciences
Stony Brook University
Stony Brook, NY 11794-5000
The Great South Bay Project


    The goal of the Great South Bay program is to gain a thorough understanding of the biogeochemistry of the Bay and its effect on pelagic and benthic communities.  Currently this effort is supported by the NY Department of State in which observations and models are combined in support of the development of an ecosystem based management approach to address the ecological problems besetting the Bay.  This webpage shows some of the hydrodynamic model results to date and presents physical observational data collected over the past  several years.  Currently, the hydrodynamic model is undergoing a major upgrade so as to deal more effectively with the complex topography of the western portions of the Bay.  The model results presented below deal with one aspect of the Bay, that is the potential impact of a large breach in Fire Island.  The model is also being used to study the impact of tides and winds on the distribution and dispersal of passive tracers and plankton.   This page also presents much of the observational data from temperature and salinity sensors that have been deployed around the eastern portion of the Bay since 2004.  Since 2010 some of these instruments have been enhanced to measure sea level, chlorophyll and turbidity.  And since the middle of 2010 real-time data from the Smith Point bridge and a telemetering buoy south of Sayville have also become available.  All the observational data are available below.

Hurricane Sandy and breaches at Old Inlet, Coast Guard Cut, and Moriches Inlet

Real time data from the Bellport dock is presented below in the  Great South Bay Observatory section.

Hurricane Sandy caused significant over washes and three breaches in Fire Island in the area between the historic Old Inlet area and Moriches Inlet.  Aerial video and photos were obtained Saturday, November 3rd, 5 days after the storm's passage.  A short description and photos of the breaches is available here while youtube videos are listed below.

As a follow-up to the November 3rd aerial survey and after the nor'easter that occurred on November 7 and 8, a second aerial overflight of the Old Inlet area was carried out on November 11, 2012.  Photos and a discussion of the results of that flight are available here.  In addition, we recovered an oceanographic sensor from the Bellport marina on November 10, 2012 which had recorded the sea level, temperature and salinity variations caused by the hurricane and subsequent nor-easter.  Click on the thumbnail to the right to see the time series plots of the data while a discussion of the data is given here.  The youtube video of the November 11th flight is below.

Another weekly aerial survey of the inlet was carried out on Sunday November 18th which showed that the sand island connecting Pelican Island to Fire Island had been cut by a new channel to the west.  A series of photos showing the evolution of the inlet is given here.

On Saturday December 1, 2012 there was a meeting at Bellport's community center to discuss the breach in the Old Inlet area.  A power point presentation given at that meeting shows how the dynamics of the Great South Bay and the ocean resulted in the formation of the breach and how the breach has affected the tides, wind driven storm surge and the salinity of the eastern end of the Bay.

A follow-up meeting on the developments of the breach, now referred to as New Inlet, took place on March 23, 2013 at the Bellport Middle School.  Charles Flagg gave a power point presentation to the meeting attended by about 500 people to hear position reports from the FINS and the NYDEC, and presentations by Charles Flagg, Kevin McAlaster and Joe Gagliano. 

Presentations by Charles Flagg, Christopher Gobler, Chris Soler, Jim Gilmore, Tony Graves and Joe Gagliano took place at the Bellport Middle School on December 21, 2013 to outline the current status of the New Inlet and initiation of the NPS's Environmental Impact Statement project.  Flagg's power point presentation is available here.

A series of reports on the breach development are listed below.

December 14, 2012 report on the new inlet through November is available here.
On January 5, 2013 another aerial over flight took place and a photo summary of the evolving breach at Old Inlet to the present is available here.
January 14, 2013 report on the inlet that goes through December is available here.
The January 30th report on the status of the inlet is available here.
The February 27th report on the bay and inlet with new bathymetry of the inlet is here.
The March 15th report on the inlet and the impact of east-coast wide water level fluctuations is here.
The June 28th report on the inlet's evolution. the cross-sectional area and changes in the Bay-wide salinity is here.
The 10th report on the inlet's condition, issued Dec 12, 2013 is here.
The 11th report on the inlet's condition, issued Oct 20, 2014 is here.
The 12th report on the inlet's condition, issued Jan 9, 2015 is here.
The 14th report on the inlet's condition, issued Aug 7, 2015 is here.
The 15th report on the inlet's condition, issued March 16, 2016 is here.
The 16th report on the inlet's condition, issued Sept 14, 2016 is here.
The 17th report on the inlet/breach's condition, issued July 12, 2017 is here.

Below is the series of aerial photos of the New Inlet from the south looking north across Fire Island.  The aerial photography has been a community effort with pilots Rich Giannotti, Don Richards, Charlie Flagg and Vinny Petruso and photographers Charlie Flagg, Mike Ferrigno, Rich Weismann, Justin Flagg, Brian Wasser, Jamie Shreeve, John Vahey, Brad Furman, Chris Gobler, Michael Busch, Art Leiz, Alejandra Sanchez-Franks and Claudia Hinrichs, Andrew Becker, Deborah Sack

April 2005  (CF)
Nov 3, 2012 (CF&RG)

NPS_Trimmed Flight Video
Nov 11, 2012 (CF&RG)

Nov 20, 2012 (RW&RG)

Dec 20, 2012 (MF&RG)

Jan 6, 2013 (JF&CF)

Jan 27, 2013 (CF&DR)

Feb 2, 2013 (BW&CF)

Feb 14, 2013 (CF&RG)

Mar 10, 2013 (CF&RG)

Mar 29, 2013 (JS&CF)

Apr 4, 2013 (MF&RG)

Apr 17, 2013 (CF&VP)

Apr 18, 2013 (JV)

May 12, 2013 (CF)

May 31, 2013 (CF)

June 16, 2013 (BF & CF)

July 7, 2013 (CG & CF)

Aug 5, 2013 (MB&CF)

Sept 15, 2013 (CF)

Oct 19, 2013 (CF)

Nov 6, 2013 (CF)

Dec 8, 2013 (CF)

Dec 19, 2013 (JF&CF)

Jan 8, 2013 (AL)

Jan 21, 2014 (CF)

Feb 20, 2014 (CF)

Mar 24, 2014 (CF)

Apr 22, 2014 (CF)
May 18, 2014 (CF)

June 8, 2014 (CF&RG)

June 24, 2014 (CF)

July 31, 2014 (CF&RG)

Aug 28, 2014 (CF)

Sept 8, 2014 (JV)

Sept 26, 2014 (CF)

Oct 30, 2014 (CF)

Nov 30, 2014 (ASF&CF)

Dec 14, 2014 (CF)

Dec 29,2014 (RS&CF)

Jan 17, 2015 (JV&SCPD)

Jan 29, 2015 (RG)

Feb 28, 2015 (CF)

Mar 29. 2015 (CF)

Apr 6, 2015 (JV)

Apr 12, 2015 (JV)

Apr 26, 2015 (CF)

May 26, 2015 (CF)

June 30, 2015 (RG&CF)

July 23, 2015 (RG&CF)

Aug 12, 2015 (CF&SG)

Aug 28, 2015 (CF&CH)

Sept 25, 2015 (CF)

Oct 6, 2015 (RG)

Oct 7, 2015 (CF)

Oct 21, 2015 (RG)

Oct 26, 2015 (CF)

Nov 25, 2015 (RG&CF)

Dec 5, 2015 (RG&CF)

Jan 6, 2016 (RG&CF)

Jan 31, 2016 (RG&CF)

Mar 1, 2016 (JV)

Mar 8, 2016 (RG&CF)

Apr 13, 2016 (CF)

May 11, 2016 (CF)

June 1, 2016 (CF)

June 30, 2016 (CF)

July 20, 2016 (CF)

Aug 5, 2016 (RG&CF)

Sept 8, 2016 (RG&CF)

Oct 6, 2016 (CF)

Oct 7, 2016 (JV)

Nov 8, 2016 (CF)

Dec 8, 2016 (CF)

Jan 15, 2017 (CF&JF)

Feb 4, 2017 (CF)

Mar 13, 2017 (CF)

Mar 24, 2017 (JV)

Apr 9, 2017 (CF)

May 10, 2017 (CF)

June 4, 2017 (CF)

June 11, 2017 (CF&JF)

June 22, 2017 (CF)

July 16, 2017 (CF)

July 30, 2017 (CF)

Aug 8, 2017 (AB)

Aug 14, 2017 (CF)

Sept 8, 2017 (CF)

Sept 20, 2017 (CF)

Sept 24, 2017 (CF)

Sept 24, 2017 (CF)

Oct 20, 2017 (CF)

Nov 20, 2017 (CF)

Nov 28, 2017 (CF)

Jan 27, 2018 (CF)

Feb 27, 2018 (CF)

Mar 26, 2018 (CF)

Apr 21-22, 2018 (CF)

Apr 25, 2018 (CF&YH)

May 22, 2018 (JV)

May 25, 2018 (CF)

July 13, 2018 (CF)

Aug 5, 2018 (CF)

Aug 7, 2018 (CF)

Aug 10, 2018 (CF)

Sept 16, 2018 (CF&DS)

Oct 19, 2018 (CF)

With Mark Lang's help
 the series of overflights
of the breach have
produced detailed photo
mosaics of the inlet and
back bay area.

January 27, 2013
February 2, 2013

February 14, 2013

March 10, 2013

Mar 29, 2013

Apr 17, 2013
May 12, 2013
May 31, 2013
June 16, 2013
July 7, 2013
Aug 5, 2013

Sept 15, 2013
Oct 19, 2013

Nov 6, 2013

Dec 8, 2013

Dec 19, 2013

Jan 21, 2014

Feb 20, 2014

Mar 24, 2014

Apr 22, 2014

May 18, 2014

June 24, 2014

July 31, 2014

Aug 28, 2014

Sept 26, 2014

Oct 30, 2014

Nov 30, 2014

Dec 14, 2014

Dec 29, 2014

Feb 28, 2015

Mar 29, 2015

Apr 26, 2015

May 26, 2015

June 30, 2015

July 23, 2015

Aug 12, 2015

Aug 28,2015

Oct 7, 2015

Oct 26, 2015

Dec 5, 2015

Jan 6, 2016

Jan 31, 2016

Mar 8, 2016

Apr 13, 2016

May 11, 2016

June 1, 2016

June 30, 2016

Aug 5, 2016

Sept 8, 2016

Oct 6, 2016

Nov 8, 2016

Dec 8, 2016

Jan 15, 2017

Feb 4, 2017

Mar 13, 2017

Apr 9, 2017

May 10, 2017

June 11, 2017

July 16, 2017

Aug 14, 2017

Sept 8, 2017

Sept 24, 2017

Oct 20, 2017

Nov 28, 2017

Jan 27, 2018

Feb 27, 2018

Mar 26, 2018

Apr 26, 2018

May 25, 2018

July 13, 2018

Aug 10, 2018

Sept 16, 2018

Oct 19, 2018

Mark Lang has assembled all the geo-referenced photo mosaics into a kml file that can be viewed using Google Earth.  By clicking between images and using the fade in-out button you can clearly see how the inlet is changing with time.  The URL for the kml file is:

Hydrodynamic Modeling

Great South Bay Observatory Data Collection

Location of Observatory Components
    Data are being collected from eight stations on the Great South Bay using SeaCat instruments measuring temperature and salinity.  The stations include, from east to west on the north shore: Smith Point, Bellport, Blue Point, Islip and Tanner Park, and the US Coast Guard Station and Barrett Beach on Fire Island.  The instruments are deployed for as much as three months at a time, less in the summer due to heavy biofouling.
SBE 16 SeaCat SBE 16 Plus SeaCat with WetLabs FLNTUS
Real-Time Data
    In addition to the delayed-mode SeaCat data, meteorological data are being collected from the south tower of the Smith Point bridge and these data are available in real time below.  That data includes temperature and salinity from the Smith Point SeaCat, short and long wave radiation from Eppley pyronometers, and wind speed, wind direction, air temperature, humidity, barometric pressure and rainfall rate from a Vaisala WXT520. 
   On October 6th, 2010 we deployed GSB #1 buoy south of Sayville at 40o 41.6'N, 73
o 05.1'W.  This buoy reports wind speed and direction, air temperature and humidity, photosynthetically active radiation (PAR), water temperature and salinity, chlorophyll-a fluorescence and turbidity. On December 29, 2010 ice forming in the Bay carried the buoy quite a ways as the ice sheets broke up and started to move around.  The ice finally released the buoy south of Islip in mid-February at which time we towed the buoy to the West Sayville Marina on February 17th.  After checking on the systems and repainting, the buoy was towed out and re-anchored near its original location, 40 41.552 N, 73 5.144 W, on March 23, 2011.  The winter of 2011-2012 was particularly mild and we did not have any trouble with ice flows but significant ice build up in January 2013 captured the buoy again and dragged it first south and then some two miles west.  It will be returned to its proper location as soon as possible.
Great South Bay Buoy #1

2011Buoy Movement Due to Ice


2013 Buoy Track

Current Buoy Position

Real-Time Data and Plots

Smith Point Bridge
GSB Buoy #1 south of Sayville Bellport Marina

Wind, Air Temp, Humidity, Barometric Pressure and Rainfall

Water Temperature, Salinity, Short & Long Wave Radiation

Hour-Averaged Data Files:

Buoy #1 data:
Wind, Air Temp, Humidity, PAR,
Water Temp, Salinity, Chlorophyll-a
and Turbidity

Hour-Averaged Data Files:
Plot of Bellport data for
 the past 60 days

Recent averaged data file
BPRT_2013 data
BPRT_2014 data
BPRT_2015 data
BPRT_2016 data

The plot and data file include NAVD88 water level, detided water level, temperature, salinity, fluorescence  and turbidity.  The real time sensor is located at the end of the marina dock. 
Bellport Realtime Observations
Date/Time: Oct 23, 2018 02:12 GMT
NAVD88 WL 0.30 m
Water Temp 11.16 Deg C
Salinity 25.57 psu
Fluorescence 0.11 volts
Turbidity 0.34 volts

Delayed-Mode SeaCat Data from sites around Great South Bay

Note:  All times and dates are in Greenwich Mean Time (GMT).


Blue Point
Islip Hatch/Fish Pier

Tanner Park

Smith Point
USCG Fire Island Inlet

Barrett Beach

Carmans River

Old Inlet

Click on the sites listed below to see the plots of the individual deployments for greater detail
Barrett Beach   Bellport   Blue Point  Carmans River  Islip Hatchery   Tanner Park   USCG FI  Smith Point

To download the data for the entire records for each location, click on the links in the table below.  The matlab
files have the complete 6-minute edited data while the ASCII files contain the hour-averaged data in a form
better suited for non-Matlab users.

Right-click to download any of the data files
Matlab Data Files
ASCII Data files
Barret Beach on Fire Island
Barrett Beach matfile
Barrett Beach dat file
Bellport Marina
Bellport matfile Bellport dat file
Blue Point Hatchery Marina
Blue Point matfile Blue Point dat file
Carmans River
Carmans River matfile
Carmans River dat file
Islip Hatchery
Islip Hatchery matfile Islip Hatchery dat file
Tanner Park
Tanner Park matfile Tanner Park dat file
USCG Fire Island Base
USCG Fire Island Inlet matfile
USCG Fire Island dat file
Smith Point Bridge
Smith Point matfile

Useful Websites

Current Precipitation Map
    A map of the United States showing precipitation.

NDBO Buoy 44025
    Shows a 3-meter discus buoy South of Long Island.
Islip Airport Weather
Brookhaven Airport Weather
Local Towns Weather
    Gives basic weather information for seven towns around Long Island.
    Click on the Current Marine Data and the corresponding area to see wave height and wind data over the oceans.