Remote Sensing of Water Turbidity and Sedimentation and Their Relationship to Algal Blooms

Frequently-anticipated questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How should this data set be cited?

   Richard P. Stumpf Megan L. Frayer, Unpublished material, Remote Sensing of Water Turbidity and Sedimentation and Their Relationship to Algal Blooms.

   Online Links:

   • <http://sofia.usgs.gov/projects/sed_turbidity/>

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -81.25

   East_Bounding_Coordinate: -80.3

   North_Bounding_Coordinate: 25.8

   South_Bounding_Coordinate: 24.75

3. What does it look like?

4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 01-Dec-1989

   Ending_Date: 1999

   Currentness_Reference: Publication date

5. What is the general form of this data set?

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?

   2. What coordinate system is used to represent geographic features?

7. How does the data set describe geographic features?

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Richard P. Stumpf

2. Who also contributed to the data set?

3. To whom should users address questions about the data?
   Rob Wertz
   U.S. Geological Survey
   Manager - Data Management Group
   600 Fourth Street South
   St. Petersburg, FL 33701
   USA
   

   727 803-8747 ext. 3045 (voice)
   727 803-2030 (FAX)
   rwertz@usgs.gov
   

Why was the data set created?

The project is conducting comparisons between chlorophyll values collected from the shipboard monitoring programs and pre-cruise reflectances to assess whether there is a link between resuspension events and algal blooms. The next stage in the project is to expand the AVHRR data set backward to before the seagrass dieoffs and to incorporate Landsat data for limited high resolution analysis.

How was the data set created?

1. From what previous works were the data drawn?

2. How were the data generated, processed, and modified?

   Date: 2000 (process 1 of 1)

   The Advanced Very High Resolution Radiometer (AVHRR) on NOAA 600 usable scenes are available from some 1500 covering a period from December 1989 to the present. AVHRR has a pixel size of about 1.1 km. The data sets are processed for water reflectance, which is related to water turbidity variables such as attenuation, Secchi depths, total particulate matter, and nephelometric turbidity. Tentative relationships with these variables have been made. (Sea surface temperature is also determined.) High reflectance corresponds to high attenuation or particulate loads or shallow Secchi depth. The individual scenes are also processed to obtain monthly and seasonal means, with winter corresponding to the period of December to March and summer to June through September. Initial analyses include the points corresponding to fixed stations occupied at a monthly interval by FIU or FDEP. In examining the average reflectance of the entire Bay, the satellite imagery does not show a trend between December 1989 and September 1996. The seasonal pattern of high turbidity in winter and low in summer is evident. Trends over the time period appear in subsections of the Bay. A substantial increase in water reflectance is evident in the north-central Bay (which has been documented in field studies, this region includes Rankin Lake and Johnson Key. However these appear to have different phasing, with Johnson Key showing an increase in turbidity about two years earlier than Rankin Lake. Both sites show the decline in both winter and summer. Twin Key, which has the clearest water in the Bay, has shown a slight increase. The southwest portion of the Bay, west of Sprigger Bank, has shown a decrease in reflectance, indicating clearer water.

   Person who carried out this activity:
   

   Rob Wertz
   U.S. Geological Survey
   Manager - Data Management Group
   600 Fourth Street South
   St. Petersburg, FL 33701
   USA
   

   727 803-8747 ext. 3045 (voice)
   727 803-2030 (FAX)
   rwertz@usgs.gov
   

3. What similar or related data should the user be aware of?

   Ransibrahmanakul, Varis Stumpf, Richard P., 2002, The Use of AVHRR Satellite Data for Estimating Spatially Varying Critical Wind Stress in Florida Bay: Journal of Coastal Research v. 18, no. 2, Coastal Education and Research Foundation (CERF), Royal Palm Beach, FL.

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?

2. How accurate are the geographic locations?

3. How accurate are the heights or depths?

4. Where are the gaps in the data? What is missing?

   unavailable

5. How consistent are the relationships among the observations, including topology?

   not applicable

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: none

Use_Constraints: none

1. Who distributes the data set? (Distributor 1 of 1)
   Rob Wertz
   U.S. Geological Survey
   Manager - Data Management Group
   600 Fourth Street South
   St. Petersburg, FL 33701
   USA
   

   727 803-8747 ext. 3045 (voice)
   727 803-2030 (FAX)
   rwertz@usgs.gov
   

2. What's the catalog number I need to order this data set?

   Florida Bay satellite images

3. What legal disclaimers am I supposed to read?

   The data have no implied or explicit guarantees.

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	GIF
     Network links:	<http://coastal.er.usgs.gov/flbay/>

   • Cost to order the data: none

Who wrote the metadata?

Dates:

Last modified: 04-Oct-2006

Metadata author:

Heather Henkel
U.S. Geological Survey
600 Fourth Street South
St. Petersburg, FL 33701
USA

727 803-8747 ext 3028 (voice)
727 803-2030 (FAX)
sofia-metadata@usgs.gov

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

U.S. Department of the Interior, U.S. Geological Survey, Center for Coastal Geology
Comments and suggestions? Contact: Heather Henkel - Webmaster
Generated by mp version 2.8.18 on Wed Oct 04 19:04:24 2006