Since
the late 1980s significant activities have been undertaken to understand
and document the extent of seagrass die-off in Florida Bay (primarily Thalassia
testudinum) and much has been learned due to the establishment of extensive
and ongoing water quality monitoring programs. However, little knowledge
or documented evidence on water quality in Florida Bay exists for the period
preceding the die-off initiation. Remotely sensed satellite reflectance
(turbidity) imagery is the best available data to fill this gap and allows
direct comparison of water quality and light availability trends in Florida
Bay both before and after the seagrass die-off events.
The NOAA Coastal Services Center's Coastal Remote Sensing program collaborated
with Dr. Richard Stumpf (currently with the NOAA National Centers for Coastal
Ocean Science, formerly with the U.S. Geological Survey [USGS]) to assemble
a data set of remotely sensed Advanced Very High Resolution Radiometer
(AVHRR) reflectance images, onto a CD-ROM covering
a period from 1985-1997. This product is derived from the visible band
of the AVHRR sensor and is a broad indicator of ocean surface sediment
concentration at 1 kilometer resolution. It can also be empirically related
to the diffuse attenuation coefficient and Secchi depth. The images are
in a GeoTIFF format suitable for import into GIS and image processing software.
Over 1000 usable scenes comprise this time series, and seasonal and monthly
image averages have also been derived. In addition to the reflectance images,
a coincident set of sea surface temperature images
are available. The images are co-registered with an accuracy of +/- 1 pixel
in a Universal Transverse Mercator (UTM) projection.
The goal
of this CD-ROM product is to provide a digital record of remotely sensed
water quality trends and patterns in Florida Bay in an easy-to-use format.
The interface to the satellite imagery will allow the CD-ROM to be used
as a working management tool for documenting past-to-present water quality
changes. To place the retrospective satellite observations in context with
related field measurements, ancillary data sets have been acquired from
the Florida Bay scientific and management communities. These data sets
include spatial coverage data such as digital
maps of seagrasses,
bathymetry,
and airborne-derived ocean color. Other data sets are location-specific
time-series data of environmental indicators, including chlorophyll and
nutrient concentrations, Secchi depth, total suspended solids, salinity,
and wind speed and direction. A Java
application on the CD-ROM allows the user to browse the satellite information
and query image geophysical values.
Some examples of the geographic information system (GIS) digital vector
coverages and ways in which these data sets can be integrated with reflectance
imagery can be found here.
To request a copy of this CD-ROM click here.
Near-real time reflectance image for Florida Bay from the NOAA-14 polar
orbiting satellite. Images from other locations and dates are available
from the Coastal Remote Sensing program at www.csc.noaa.gov/crs/composite/0day.
Another source of Florida
Bay satellite imagery from our partners at the USGS is also available.
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This page updated on
Tuesday, 24-Jul-2007 15:54:04 EDT