Data Drilled for Stellwagen Bank National Marine Sanctuary

GeoTif images of chlorophyll, turbidity, and SST were created of the region. Then an EASI script was run on the geotifs to extract the data (drill the data) from specific points (or bitmaps) in each scene for the timeseries. After the output was created in text file format, they were opened up in Microsoft Excel and spreadsheets were created for each location. Chlorophyll, turbidity, and SST are all contained in one spreadsheet bearing the name of the location. The drilled data shows the files used for the data drill, the mean of the pixels used in the data drill, and the number of pixels used to calculate the mean for each image used.

To obtain data for specific locations for the entire time series for trend analysis andidentification of patterns.

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Depending on the data type the time period of content can either be from 1997-2005, or 1985-2004. Output Columns: For text files: The output from the .txt files is just a string of numbers extracted from each data file. Once the file is opened, the first item in the list is the name of the file used to extract the data, the second item is the mean value of the pixels containing good data for the region drilled, and the third item is the number of good pixels used to calculate the mean value. Sample output:NE199710.AVG_MO_CH6_4.5.1_UTM.tif, 48.8724823,447 The file used was the turbidity file from October 1997, the mean value extracted was 48.872423, the number of pixels used to calculate the mean was 447. For Excel spreadsheet files: The Excel spreadsheet files contain several columns for each data type. CHL First column: image used to extract data from Second column: mean extracted value from the image: Third column number of pixels used to calculate mean Fourth column: date for image used: Fifth column: mean extracted value converted in to chlorophyll in micrograms per liter Sixth column: grand mean, is the inter-annual monthly mean for the time series. This was calculated using the data from column five and copying it into the appropriately number year column on the right then calculating a mean. Seventh column: Standardized Anomaly, calculated as (Fifth col. - Sixth col.)/stdv of grand mean Turbidity First column: image used to extract data from Second column: mean extracted value from the image Third column: number of pixels used to calculate the mean Fourth column: date for image used Fifth column: mean extracted value converted into turbidity in 1/steradian Sixth column: grand mean, is the inter-annual monthly mean for the time series. This was calculated using the data from column five and copying it into the appropriately numbered year column on the right then calculating a mean. Seventh column: Standardized Anomaly, calculated as (observation - grand mean)/stdv of grand mean SST First column: image used to extract data from Second column: mean extracted value from the image Third column: number of pixels used to calculate the mean Fourth column: date for image used Fifth column: mean extracted value converted into degrees Celsius Sixth column: copy of column five for further calculations Seventh column: grand mean, is the inter-annual monthly mean for the time series. This was calculated using the data from column six and copying it into the appropriately numbered year column on the right then calculating a mean. Time series graphs are also provided in each Excel spreadsheet for all of the data for the time period.

These data were prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data have been used by NOAA, no warranty, expressed or implied, is made by NOAA as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by NOAA in the use of these data or related materials.NOAA makes no warranty regarding these data, expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA can not assume liability for and damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system.

Please contact the Stellwagen Banks NMS Research Coordinator for additional information on data access (david.wiley@noaa.gov);

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