|Application||Spatial Resolutiona||Wavelength Resolution||Repeat Timeb||Coverage||Sensor Type||References|
|Monitor coral reefs||10 m best, 50 m OK for mapping entire reef systems||Multispectral||Annual||Coastal, 30 N to 30 S, so Geostationary OK||3||Hochberg, 2011 Lubin et al., 2001|
|Monitor sea grass beds and kelp forests and biomass||3-30 m for biomass (100 m for mapping)||Multispectral||Twice a year||Coastal and estuarine, 60 N to 60 S||3||Cavanaugh et al., 2011 Hill and Zimmerman, 2010|
|Near-Real Time Applications:|
|Naval application for shallow water bathymetry and bottom classification||1-10 m||Hyperspectral best, multispectral is still useful||On demand||Coastal waters, as needed||1-4||Dekker et al., in press Mobley et al., 2005|
|Monitoring oil spills||100 m||Multispectral||Hourly||Episodic regional events||4||Hu et al., 2009|
|Detection of HABs||100 m to 1 km||Multi, but hyper better||1 day to monitor blooms||Coastal and estuarine waters||1 and 2||Ruddick et al., 2008|
a Minimum to sustain current capabilities, not necessarily optimal.
b Equatorial revisit.
The extensive list of research and societal applications presented in this chapter demonstrates that ocean color is fundamental to and irreplaceable for a wide array of applications at local to global spatial scales and near-real time to decadal time scales.
Exploring the full potential of ocean color research will require more than sustaining current efforts including major advances in sensor capabilities, atmospheric corrections, and algorithm and product development as further described in Chapter 5. Ocean color has been recognized as an essential climate variable5 by Global Climate Observing System6 (GCOS). To detect long-term climate trends in marine phytoplankton abundance, long time-series of sufficient quality are required, making it imperative that we maintain and advance satellite capabilities. With the anticipated impacts of climate change on the marine ecosystem, monitoring the changes will be essential to managing the diminishing resources in the ocean.
Further, the expanding use of ocean color products in research and resource management demands a range of spatial and temporal product specifications that are beyond the ability of a single satellite mission to deliver (see Chapters 4 and 5 for details). Wavelength resolution requirements range from only a few bands (to determine chlorophyll) to hyperspectral data (for coastal and naval applications as well as for advanced algorithms for atmospheric correction and the separation of phytoplankton absorption from CDOM; see Chapter 3). A polar orbiting satellite can provide a global image about every three days at relative coarse spatial resolution and meet requirements for applications that need a global synoptic view, such as climate research. The same satellite, however, cannot deliver multiple images per day at the high spatial resolution required by the Navy or by an oil spill response. Those scenarios require a GEO satellite (Appendix D).
Conclusion: A mix of orbits and sensors are required to meet the indisputable demand for a continuous ocean color record that will help us to understand changes in the global climate system, assess the health of the marine ecosystem, and sustain important fisheries, among other crucial societal tasks.
5 See http://www.wmo.int/pages/prog/gcos/index.php?name=Essential ClimateVariables; accessed June 10, 2010.