Examining the consistency of products derived from various ocean color sensors in open ocean (Case 1) waters in the perspective of a multi-sensor approach

Morel, A.; Huot, Yannick; Gentili, Bernard; Werdell, P. Jeremy; Hooker, Stanford B.; Franz, Bryan A.

doi:10.1016/j.rse.2007.03.012

Cited by 517 publications

(513 citation statements)

References 45 publications

Supporting

Mentioning

468

Contrasting

Unclassified

Order By: Relevance

“…The timeframes of the data (1994-1999; 1992-2010) largely pre-dated the MODIS-Aqua satellite data (2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010), hence SeaWiFS data (1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010) were also used to validate and improve the photic depth product for the GBR ecosystem. Two operational photic depth algorithms have been implemented into the standard NASA ocean color satellite data processing environment, both of which are available via the SeaWiFS Data Analysis System (SeaDAS; http://oceancolor.gsfc.nasa.gov/seadas): an empirical algorithm based on Case-1 assumptions [21] and a semi-analytical algorithm based on the inherent optical properties (IOPs) of the water column [4]. The IOP approach, where photic depth is described as a function of spectral absorption and backscattering coefficients, was selected for this study as the water-clarity algorithm to determine light penetration depth in eutrophic, Case-2 coastal waters [6].…”

Section: Methodsmentioning

confidence: 99%

Satellite-Derived Photic Depth on the Great Barrier Reef: Spatio-Temporal Patterns of Water Clarity

et al. 2012

View full text Add to dashboard Cite

Detecting changes to the transparency of the water column is critical for understanding the responses of marine organisms, such as corals, to light availability. Long-term patterns in water transparency determine geographical and depth distributions, while acute reductions cause short-term stress, potentially mortality and may increase the organisms' vulnerability to other environmental stressors. Here, we investigated the optimal, operational algorithm for light attenuation through the water column across the scale of the Great Barrier Reef (GBR), Australia. We implemented and tested a quasi-analytical algorithm to determine the photic depth in GBR waters and matched regional Secchi depth (Z SD ) data to MODIS-Aqua (2002 and SeaWiFS (1997SeaWiFS ( -2010 satellite data. The results of the in situ Z SD /satellite data matchup showed a simple bias offset between the in situ and satellite retrievals. Using a Type II linear regression of log-transformed satellite and in situ data, we estimated Z SD and implemented the validated Z SD algorithm to generate a decadal satellite time series (2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012) values during the austral summer, most likely due to river runoff and increased vertical mixing, and a decline in water clarity between 2008-2012, reflecting a prevailing La Niña weather pattern. The decline in water clarity was most pronounced in the inshore area, where a significant decrease in mean inner shelf Z SD of 2.1 m (from 8.3 m to 6.2 m) occurred over the decade. Empirical Orthogonal Function Analysis determined the dominance of Mode 1 (51.3%), with the greatest variation in water clarity along the mid-shelf, reflecting the strong influence of oceanic intrusions on the spatio-temporal patterns of water clarity. The newly developed photic depth product has many potential applications for the GBR from water quality monitoring to analyses of ecosystem responses to changes in water clarity.

show abstract

Section: Methodsmentioning

confidence: 99%

Satellite-Derived Photic Depth on the Great Barrier Reef: Spatio-Temporal Patterns of Water Clarity

et al. 2012

View full text Add to dashboard Cite

show abstract

“…the depth where Photosynthetically Available Radiation (PAR) is reduced to 1% of its value just below the surface). The euphotic depth was estimated from surface TCHLa using the method of Morel et al (2007) and cross-checked with in-situ measurements of PAR. 2) To minimise the effect of seasonality, we separated the data collected during boreal spring and autumn (AMT cruises April-May-June and September-October-November).…”

Section: Hplc Pigment Datamentioning

confidence: 99%

Temporal changes in total and size-fractioned chlorophyll-a in surface waters of three provinces in the Atlantic Ocean (September to November) between 2003 and 2010

Ağırbaş

Martinez‐Vicente

Brewin

et al. 2015

Journal of Marine Systems

View full text Add to dashboard Cite

Phytoplankton total chlorophyll concentration (TCHLa) and phytoplankton size structure are two important ecological indicators in biological oceanography. Using high performance liquid chromatography (HPLC) pigment data, collected from surface waters along the Atlantic Meridional Transect (AMT), we examine temporal changes in TCHLa and phytoplankton size class (PSC: micro-, nano-and pico-phytoplankton) between 2003 and 2010 (September to November cruises only), in three ecological provinces of the Atlantic Ocean. The HPLC data indicate no significant change in TCHLa in northern and equatorial provinces, and an increase in the southern province. These changes were not significantly different to changes in TCHLa derived using satellite oceancolour data over the same study period. Despite no change in AMT TCHLa in northern and equatorial provinces, significant differences in PSC were observed, related to changes in key diagnostic pigments (fucoxanthin, peridinin, 19′-hexanoyloxyfucoxanthin and zeaxanthin), with an increase in small cells (nano-and picophytoplankton) and a decrease in larger cells (micro-phytoplankton). When fitting a three-component model of phytoplankton size structure -designed to quantify the relationship between PSC and TCHLa to each AMT cruise, model parameters varied over the study period. Changes in the relationship between PSC and TCHLa have wide implications in ecology and marine biogeochemistry, and provide key information for the development and use of empirical ocean-colour algorithms. Results illustrate the importance of maintaining a timeseries of in-situ observations in remote regions of the ocean, such as that acquired in the AMT programme.

show abstract

“…We assumed an average k(PAR) light attenuation coefficient of 0.15 for the study region; this value was previously reported for the water column above a seagrass meadow in the Canary Islands (Tuya et al, 2002). Values of k(PAR) may have been alternatively derived from remote sensing using the K(490) product data for offshore waters (Morel et al, 2007). However, remote sensing derived k(PAR) is not suitable for coastal waters.…”

Section: Natural Influences: Satellite-derived Datamentioning

confidence: 99%

Decadal changes in the structure of Cymodocea nodosa seagrass meadows: Natural vs. human influences

Tuya

Ribeiro-Leite²,

Arto-Cuesta³

et al. 2014

Estuarine, Coastal and Shelf Science

View full text Add to dashboard Cite

Keywords: seagrass water quality decline human-mediated impact Canary Islands a b s t r a c t Seagrass meadows are deteriorating worldwide. However, numerous declines are still unreported, which avoid accurate evaluations of seagrass global trends. This is particularly relevant for the western African coast and nearby oceanic archipelagos in the eastern Atlantic. The seagrass Cymodocea nodosa is an 'ecological engineer' on shallow soft bottoms of the Canary Islands. A comparative decadal study was conducted in 21 C. nodosa seagrass meadows at Gran Canaria Island to compare the structure (shoot density, leaf length and cover) between 2003 and 2012. Overall, 11 meadows exhibited a severe regression, while 10 remained relatively stable. During this period, natural influences (sea surface temperature, Chlorophyll-a concentration and PAR light, as well as the number of storm episodes detaching seagrasses) had a low predictive power on temporal patterns in seagrass structure. In contrast, proximity from a range of human-mediated influences (e.g. the number of outfalls and ports) seem to be related to the loss of seagrass; the rate of seagrass erosion between 2003 and 2012 was significantly predicted by the number of human-mediated impacts around each meadow. This result highlights promoting management actions to conserve meadows of C. nodosa at the study region through efficient management of local impacts.

show abstract

Examining the consistency of products derived from various ocean color sensors in open ocean (Case 1) waters in the perspective of a multi-sensor approach

Cited by 517 publications

References 45 publications

Satellite-Derived Photic Depth on the Great Barrier Reef: Spatio-Temporal Patterns of Water Clarity

Satellite-Derived Photic Depth on the Great Barrier Reef: Spatio-Temporal Patterns of Water Clarity

Temporal changes in total and size-fractioned chlorophyll-a in surface waters of three provinces in the Atlantic Ocean (September to November) between 2003 and 2010

Decadal changes in the structure of Cymodocea nodosa seagrass meadows: Natural vs. human influences

Contact Info

Product

Resources

About