The impact of advective transport by the South Indian Ocean Countercurrent on the Madagascar plankton bloom

Huhn, Florian; Kameke, Alexandra von; Pérez‐Muñuzuri, V.; Olascoaga, M. J.; Beron-Vera, F. J.

doi:10.1029/2012gl051246

Cited by 54 publications

(65 citation statements)

References 34 publications

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“…The ability of attracting LCSs to delimit transport barriers that shape and separate marine systems with distinct physical-biogeochemical properties was recently shown in a number of studies (Lehahn et al, 2007;d'Ovidio et al, 2010;Huhn et al, 2012). Here, this ability is tested through continuous in situ measurements of temperature and fluorescence at three sections across the DPB, which is delimited by the unstable manifold adjacent to the patch's southern edge (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Formation of mesoscale Chl patterns often results from horizontal stirring (Martin, 2003) that may be generated by meandering of the surface alongshore currents (Gertman et al, 2010). As recently shown, transport barriers induced by the stirring may control the spatial distribution of phytoplankton, through the formation of dynamical boundaries that prevent mixing between water bodies with different physical and biogeochemical characteristics (Lehahn et al, 2007;Huhn et al, 2012). Multi-satellite observations show that such dynamical boundaries may separate between ecological niches that are dominated by different phytoplankton types (d'Ovidio et al, 2010), and can form quasi-isolated planktonic systems that are separated from their surroundings for several months (Lehahn et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

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Intrusion of coastal waters into the pelagic eastern Mediterranean: in situ and satellite-based characterization

et al. 2013

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A combined dataset of near-real-time multi-satellite observations and in situ measurements from a high-resolution survey is used for characterizing physical-biogeochemical properties of a patch stretching from the coast to the open sea in the Levantine Basin (LB) of the eastern Mediterranean (EM). Spatial analysis of the combined dataset indicates that the patch is a semi-enclosed system, bounded within the mixed layer and separated from ambient waters by transport barriers induced by horizontal stirring. As such, the patch is characterized by physical-biogeochemical properties that significantly differ from those of the waters surrounding it, with lower salinity and higher temperatures, concentrations of silicic acid and chlorophyll a, and abundance of Synechococcus and picoeukaryote cells. Based on estimates of patch dimensions (∼40 km width and ∼25 m depth) and propagation speed (∼0.09 m s⁻¹), the volume flux associated with the patch is found to be on the order of 0.1 Sv. Our observations suggest that horizontal stirring by surface currents is likely to have an important impact on the ultra-oligotrophic Levantine Basin ecosystem, through (1) transport of nutrients and coastally derived material, and (2) formation of local, dynamically isolated niches. In addition, this work provides a satellite-based framework for planning and executing high-resolution sampling strategies in the interface between the coast and the open sea

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Intrusion of coastal waters into the pelagic eastern Mediterranean: in situ and satellite-based characterization

et al. 2013

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“…Huhn et al . [] note that the plankton front propagates faster than the transport velocity of the jet.…”

Section: Introductionmentioning

confidence: 99%

The Madagascar Bloom: A serendipitous study

Srokosz

Quartly

2013

JGR Oceans

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[1] The late austral summer (February-April) phytoplankton bloom that occurs east of Madagascar exhibits significant interannual variability and at its largest extent covers~1% of the world's ocean surface area. The bloom raises many intriguing questions about how it begins, is sustained, propagates to the east, exports carbon, and ends. It has been observed and studied using satellite ocean color observations, but the lack of in situ data makes it difficult to address these questions. Here we describe observations that were made serendipitously on a cruise in February 2005. These show clearly for the first time the simultaneous existence of a deep chlorophyll maximum at~70-110 m depths (seen in SeaSoar fluorimeter data) and a surface chlorophyll signature [seen in Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite ocean color data]. The observations also show the modulation of the biological signature at the surface by the eddy field but not of the deep chlorophyll maximum. Trichodesmium dominates the bloom nearer to Madagascar, while the diatom Rhizosolenia clevei (and its symbiont Richelia intracellularis) dominates further from the island. The surface bloom seen in the SeaWiFS data is confined to the shallow (~30 m) mixed layer. It is hypothesized that the interannual variability in bloom intensity may be due to variations in coastal upwelling and thus the supply of iron, which is a micronutrient that can limit diazotroph growth.

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“…It occurs typically early in the year and then spreads eastward for the next weeks, creating a feature called a plankton wave (Srokosz, 2004). This feature is one of the largest phytoplankton blooms in the world ocean, and has received much attention in the recent years (e.g., Huhn, von Kameke, Pérez-Muñuzuri, Olascoaga, & Beron-Vera, 2012;Lévy et al, 2007;Longhurst, 2001;Raj, Peter, & Pushpadas, 2010;Srokosz, 2004;Srokosz & Quartly, 2013;Uz, 2007). Interannual variability of this phytoplankton bloom is linked to the upwelling along the south coast of Madagascar, precipitation along the east coast of Madagascar, light limitation and local mesoscale circulation features (Raj et al, 2010).…”

Section: Temporal Variations In Sciamachy Marine Chl-a Fluorescencementioning

confidence: 99%

Global retrieval of marine and terrestrial chlorophyll fluorescence at its red peak using hyperspectral top of atmosphere radiance measurements: Feasibility study and first results

Wolanin

Розанов

Dinter

et al. 2015

Remote Sensing of Environment

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Keywords:Sun-induced fluorescence Retrieval SCIAMACHY GOME-2 Fraunhofer-line approach Hyperspectral remote sensing Ocean-atmosphere coupled radiative transfer Chlorophyll fluorescence is directly linked to the physiology of phytoplankton or plants. Here, we present a new satellite remote sensing approach to retrieve chlorophyll fluorescence at its red peak (~685 nm) by using measurements from the hyperspectral instruments SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) and Global Ozone Monitoring Experiment-2 (GOME-2). This method, which is based on the Differential Optical Absorption Spectroscopy (DOAS) technique, was used to exploit narrow spectral structures resulting from the filling-in of the Fraunhofer Fe I line, which originates from fluorescence. The reference spectra for chlorophyll fluorescence were calculated by the coupled ocean-atmosphere radiative transfer model SCIATRAN. We compared our results on marine chlorophyll fluorescence observations with the MODIS Terra normalized Fluorescence Line Height (nFLH) product for the average of years 2003-2011 and year 2009. Our method also enables the retrieval of chlorophyll fluorescence above land vegetation scenes. The results for the fluorescence observed above terrestrial vegetation for July and December 2009 were compared to MODIS Enhanced Vegetation Index (EVI). The comparisons show good spatial agreement between different retrievals providing evidence for the good performance of our algorithm. The method presented is generic and can be applied to other hyperspectral instruments in the future. Having established the retrieval technique, extensive studies of chlorophyll fluorescence will improve global knowledge on physiology and photosynthetic efficiency, in both the marine and terrestrial realms, and its dependence on environmental factors.

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The impact of advective transport by the South Indian Ocean Countercurrent on the Madagascar plankton bloom

Cited by 54 publications

References 34 publications

Intrusion of coastal waters into the pelagic eastern Mediterranean: in situ and satellite-based characterization

Intrusion of coastal waters into the pelagic eastern Mediterranean: in situ and satellite-based characterization

The Madagascar Bloom: A serendipitous study

Global retrieval of marine and terrestrial chlorophyll fluorescence at its red peak using hyperspectral top of atmosphere radiance measurements: Feasibility study and first results

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