From Meters to Kilometers: A Look at Ocean-Color Scales of Variability, Spatial Coherence, and the Need for Fine-Scale Remote Sensing in Coastal Ocean Optics

Sensor Capability and Atmospheric Correction in Ocean Colour Remote Sensing

“…This can be achieved with satellites in a geostationary orbit, although it is unlikely that complete global coverage will be achieved any time soon. In order to characterise complex coastal waters, a spatial resolution <100 m was recommended [95,96]. However, studies as part of the HyspIRI Airborne campaign found that a spatial resolution of 60 m would be unsuitable for monitoring certain areas that contain diverse mixtures of phytoplankton, in particular in inland waters [26].…”

“…Nowadays, space-based sensors possess more and more detailed spatial resolutions. A spatial resolution of 100 m has been recommended in order to characterise coastal waters [95,96]. However, a more detailed resolution is required for areas that contain a high diversity of phytoplankton in certain coastal and inland waters [26,46].…”

Sub-kilometer length scales in coastal waters

“…However, there are relatively few studies closer to shore that have addressed this same question on the smaller scales. One such study examining spatial scales by Bissett et al (2004) showed the optimal sampling distance decreased by as much as two orders of magnitude as one moved from 20 km offshore to within 5 km of shore in the remotely sensed ocean color PHILLS II image. This study determined that at distances offshore greater than $20 km the optimal sampling distance approached 5 km and that within 5 km the optimal sampling distance ranged 50-200 m.…”

“…However, due to sampling constraints in terms of resolution, lack of synoptic or semi-synoptic measurements and spatial and temporal aliasing these studies focused on larger scale variability within coastal regions. More recently studies by Bissett et al (2004)), Cunningham et al (2003), Yu et al (2002), and Chang et al (2002) had higher resolution and were nearer to synoptic measurements, and were thus able to look at variability on smaller spatial scales. As coastal waters make up only a fraction of the world's total oceans, yet represent up to 30% of the ocean's productivity and more than 90% of global fish catch (Holligan and Reiners, 1992), our ability to understand plankton variability and the drivers of that variability across the entire range of spatial scales is of critical importance.…”

Current Advances in Uncertainty Estimation of Earth Observation Products of Water Quality

“…Few studies were carried out to address the scale difference between point and aerospace measurements directly. Most of these studies have used re-sampling to smooth out the scale differences in the match-up sites, see (Bailey & Werdell, 2006;Bissett et al, 2004;Harding Jr. et al, 2005;Hu et al, 2000). For example, Hyde et al (2007) applied a correction algorithm to SeaWiFS products of chlorophyll-a to overcome the mismatch which was partially due to sampling size differences.…”