WATER SERVICE - COASTAL PRODUCTS PRODUCT DESCRIPTION

Transcription

1 WATER SERVICE - COASTAL PRODUCTS PRODUCT DESCRIPTION Delivery Kerstin Stelzer, Ana Ruescas, Uwe Lange - Brockmann Consult GmbH Overview The products within the water quality service provide the parameters Chlorophyll concentration (CHL) Total suspended matter concentration (TSM) Dissolved organic matter absorption (CDOM) Signal depths (Z90) They are provided as monthly averages in raster data sets in two different resolutions: 300m and 1200m. Each raster data set comes with a short description (metadata) file. The products are stored in geotiff and KMZ. Overview images are provided which show the monthly averages of each year. Besides the image data, times series plots are delivered showing the evolution of the respective parameters for user-defined areas of interest (AOIs). Finally, matrix plots are provided that show the values for each month and year for interpretation of the yearly evolution of the parameters (heatmaps). The products have been specified in more detail in the Service Readiness Document. During processing, some adjustments were needed compared to the original service specification: MERIS FR (300m) images were not available for all months of the requested time period due to acquisition constraints. Therefore, MERIS RR (1200m) monthly averages are provided for the full period of MERIS lifetime in addition. MODIS data have been generated in 1km resolution for the years MODIS for 2012 will be delivered later. The image data have been delivered in google earth KMZ format in addition to the geotiff format. NetCDF formats can be provided on request. This document describes the different image data products and time series plots. 1

2 Image Products Parameters: Total suspended matter concentration (TSM), Chlorophyll Concentration (CHL), Signal Depth (Z90), Coloured Dissolved Organic Matter (CDOM) Unit: TSM: g/m³; CHL: mg/m³; Z90: depth in m; CDOM: 1/m Sensors: MERIS FR (300m) and MERIS RR (1200m), MODIS (1000m) Spatial resolutions: 300m, 1000m and 1200m Temporal aggregation: monthly Area: Gulf of Mexico Processed year: (PLUS for 1200m) Formats: GeoTIFF (32bit), PNG, KMZ The image products cover the Gulf of Mexico and they are available in different resolutions and formats. The parameters CHL, TSM, Z90 and CDOM are available as monthly averages for the years 2003 to Two different spatial resolutions are provided (300 and 1200m pixel size). However, the Gulf of Mexico is not fully covered by the 300m products in all months due acquisition constraints. Thus, some of the monthly averages do not contain any data. CHL and TSM is also provided for the years 2013 and 2014 in 1km resolution. All image products are available as geotiff and GoogleEarch KMZ files. The following maps show one example for each parameter monthly average. Figure 1. Monthly average of suspended matter concentration for the Gulf of Mexico (March 2011, MERIS RR, 1200m) 2

3 Figure 2. Monthly average of chlorophyll concentration for the Gulf of Mexico (March 2011, MERIS RR, 1200m) Figure 3. Monthly average of the coloured dissolved org. matter (CDOM) for the Fulf of Mexico (March 2011, MERIS RR, 1200m) 3

4 Figure 4. Monthly average of the signal depth Z90 for the Gulf of Mexico (March 2011, MERIS RR, 1200m) In order to get a good overview of the provided image products, we compiled all monthly averages of one year in an overview image (Figure 5 and Figure 6). They are available for all years and parameters. Large scale structures can be detected and the data availability can be assessed. White spots indicate where no data is available. They are caused by cloud coverage, processing or algorithm failure or no availability of input data (as often the case for MERIS 300m data). 4

5 Figure 5. Overview image showing the monthly averages of TSM for

6 Figure 6. Overview image showing the monthly averages of CHL for

7 Time Series Products Parameters: Total suspended matter concentration (TSM), Chlorophyll Concentration (CHL), Signal Depth (Z90), Coloured Dissolved Organic Matter (CDOM) Unit: TSM: g/m³; CHL: mg/m³; Z90: depth in m; CDOM: 1/m Sensors: MERIS FR (300m) and MERIS RR (1200m), MODIS (1000m) Temporal aggregation: 10 days and monthly Area: user-defined Areas of Interest (AOI) Processed year: Formats: PNG Area of interests have been defined by the users for different river mouth areas for the generation of the time series and heatmaps. Those areas have been slightly adapted to the river plumes that could be seen in the TSM images. Furthermore, the areas with bottom reflection have been erased from the areas in order to reduce the influence of erroneous TSM values. Figure 7 provides an overview of those AOIs. Figure 7. Areas of interest for Time Series generation of water quality products (black polygons). The values within the AOIs have been extracted with different temporal aggregation: 10-days averages; used for the time series plot o For each AOI and each parameter the time series for the years (Figure 12) o For each parameter and each year the time series for all AOIs in one plot (Figure 13) Monthly averages; used for heatmaps (Figure 14) 7

8 The spatial-temporal aggregation of the values has the advantage that the small scale temporal and spatial variability is reduced compared to pixel-wise and daily extractions. The following figures show examples of time series plots for the period May 2002 December 2012 for the different parameters for the Jamapa river mouth. Figure 8. Time series plot of TSM at the river outflow Jamapa; 10d averages Figure 9. Time series plot of CHL at the river outflow Jamapa; 10d averages 8

9 Figure 10. Time series plot of Z90 at the river outflow Jamapa; 10d averages Figure 11. Time series plots of CDOM at the river outflow Jamapa; 10d averages 9

10 Figure 12. Time series plot of TSM at the river outflow of Tuxpan and Usumacinta; 10d averages for comparison. 10

11 The next time series shows a comparison of all AOIs for the year It enables the comparison of the different river outflows within one year. The time series are available for and for all parameters. Figure 13. Time series of total suspended matter for all AOIs in 2007 and

12 The following figure shows an example of a heatmap. In this data visualization, the concentrations of one parameter are displays per month for each year. This enables the direct comparison of the seasonal development of the parameters between the different years. Figure 14. Matrix showing the monthly chlorophyll concentration for the Jamapa AOI for the years (heatmap). 12

13 Last but not least, daily values have been extracted for demonstrating the TSM concentration evolution at the river mouths. Here, an area of 3x3 pixels is extracted for 3 positions ranging from the river mouth to clear water. This enables to investigate the development of the single river plumes, their size and intensity of the concentrations within the plumes. Formats & Storage The products are provided in different formats. 1. The concentration and depth data (floating values) have been stored in single band geotiff format. Example: \CHL\RasterData\geoTIFF\300m\MERIS_L3_ _ _300m_chl.tif Recommendation for software tools to work with the data: ArcGIS Usage: investigation of values and spatial structures in each individual monthly average and parameter 2. Colored images are stored in PNG und GoogleEarth KMZ format. Example: TSM\RasterData\KMZ\1200m\MERIS_L3_ _ _1200m_tsm.kmz 3. Overview Images for each year showing 12 monthly averages, each. Example: CHL\YearlyOverviewImages\MERIS_L3_2006_300m_chl_wb_chl_red_30_overview.png Usage: Overview of the development of patters within a yearly cycle of the respective parameter 4. Metadata: each monthly average product (geotiff) comes with a metadata textfile describing in short the parameter, production and characteristics of the raster data set such as spatial resolution, units, extension. Example: \CHL\RasterData\geoTIFF\300m \MERIS_L3_ _ _300m_chl.txt 5. All Time series plots are provided as PNG files. Storage: \<parameter>\timeseries Usage: comparison of temporal evolution between i. different AOIs ii. different years 6. The Heatmaps are provided as PNG files. 13

14 Storage: \<parameter>\heatmaps Usage: The heatmaps can be used to compare the evolution of concentrations between several years. List of Abbreviations 10d AOI CDOM CHL FR MERIS MODIS OD RR SRD TSM WB Z90 10 days Area of Interest Coloured dissolved organic matter Chlorophyll Concentration Full Resolution (300m) Medium Resolution Imaging Spectrometer Moderate Imageging Spectrometer Operational Documentation Reduced Resolution (1200m) Service Readiness Document Total suspended matter concentration World Bank Visible / Signal Depth 14