GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Online Resource
    Online Resource
    A NEMO-based model of 〈i〉Sargassum〈/i〉 distribution in the tropical Atlantic: description of the model and sensitivity analysis (NEMO-Sarg1.0)
    Copernicus GmbH ; 2021
    In:  Geoscientific Model Development Vol. 14, No. 6 ( 2021-07-01), p. 4069-4086
    Details
    In: Geoscientific Model Development, Copernicus GmbH, Vol. 14, No. 6 ( 2021-07-01), p. 4069-4086
    Abstract: Abstract. The tropical Atlantic has been facing a massive proliferation of Sargassum since 2011, with severe environmental and socioeconomic impacts. The development of large-scale modeling of Sargassum transport and physiology is essential to clarify the link between Sargassum distribution and environmental conditions, and to lay the groundwork for a seasonal forecast at the scale of the tropical Atlantic basin. We developed a modeling framework based on the Nucleus for European Modelling of the Ocean (NEMO) ocean model, which integrates transport by currents and waves, and physiology of Sargassum with varying internal nutrients quota, and considers stranding at the coast. The model is initialized from basin-scale satellite observations, and performance was assessed over the year 2017. Model parameters are calibrated through the analysis of a large ensemble of simulations, and the sensitivity to forcing fields like riverine nutrient inputs, atmospheric deposition, and waves is discussed. Overall, results demonstrate the ability of the model to reproduce and forecast the seasonal cycle and large-scale distribution of Sargassum biomass.
    Type of Medium: Online Resource
    ISSN: 1991-9603
    URL: Article
    DOI: 10.5194/gmd-14-4069-2021
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2021
    detail.hit.zdb_id: 2456725-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Zooplankton community response to the winter 2013 deep convection process in the NW M editerranean S ea
    American Geophysical Union (AGU) ; 2017
    In:  Journal of Geophysical Research: Oceans Vol. 122, No. 3 ( 2017-03), p. 2319-2338
    Details
    In: Journal of Geophysical Research: Oceans, American Geophysical Union (AGU), Vol. 122, No. 3 ( 2017-03), p. 2319-2338
    Abstract: In winter, phytoplankton and zooplankton biomasses were low within the Deep Convection Zone (DCZ) and higher on its periphery In spring, zooplankton biomass dominated by herbivorous species increased over the whole area especially in the DCZ In spring, all areas except the DCZ presented a top‐down control by zooplankton on the phytoplankton stock
    Type of Medium: Online Resource
    ISSN: 2169-9275 , 2169-9291
    URL: Issue
    URL: Article
    DOI: 10.1002/jgrc.v122.3
    DOI: 10.1002/2016JC012176
    Language: English
    Publisher: American Geophysical Union (AGU)
    Publication Date: 2017
    detail.hit.zdb_id: 2016804-4
    detail.hit.zdb_id: 161667-5
    detail.hit.zdb_id: 3094219-6
    SSG: 16,13
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    Synergy between Low Earth Orbit (LEO)—MODIS and Geostationary Earth Orbit (GEO)—GOES Sensors for Sargassum Monitoring in the Atlantic Ocean
    MDPI AG ; 2021
    In:  Remote Sensing Vol. 13, No. 8 ( 2021-04-08), p. 1444-
    Details
    In: Remote Sensing, MDPI AG, Vol. 13, No. 8 ( 2021-04-08), p. 1444-
    Abstract: Since 2011, massive stranding of the brown algae Sargassum has regularly affected the coastal waters of the West Caribbean, Brazil, and West Africa, leading to heavy environmental and socio-economic impacts. Ocean color remote sensing observations as performed by sun-synchronous satellite sensors such as MODIS (NASA), MERIS (ESA), or OLCI (ESA/Copernicus) are used to provide quantitative assessments of Sargassum coverage through the calculation of indices as the Alternative Floating Algae Index (AFAI). Sun-synchronous sensors usually provide at best one daytime observation per day of a given oceanic area. However, such a daily temporal revisit rate is not fully satisfactory to monitor the dynamics of Sargassum aggregation due to their potentially significant drift over the course of the day as a result of oceanic currents and sea surface wind stress. In addition, the sun glint and the presence of clouds limit the use of low earth orbit observations, especially in tropical zones. The high frequency sampling provided by geostationary sensors can be a relevant alternative approach in synergy with ocean color sun-synchronous sensors to increase the temporal resolution of the observations, thus allowing efficient monitoring of Sargassum dynamics. In this study, data acquired by a geostationary satellite sensor located at 36,000 km from Earth, namely GOES-16 (NASA/NOAA), which was primarily designed for meteorology applications, are analyzed to investigate the Sargassum dynamics. The results demonstrate that a GOES-16 hourly composite product is appropriate to identify Sargassum aggregations using an index commonly used for vegetation monitoring, namely NDVI (Normalized Difference Vegetation Index). It is also shown that GOES hourly observations can significantly improve the simulated drift obtained with a transport circulation model, which uses geostrophic current, wind, and waves. This study thus highlights the significant relevance of the effective synergy between sun-synchronous and geostationary satellite sensors for characterizing the Sargassum dynamics. Such a synergy could be summarized as follows: (i) A sun-synchronous sensor enables accurate Sargassum detection and quantitative estimates (e.g., fractional coverage) through AFAI Level-2 products while (ii) a geostationary sensor enables the determination of the displacement features of Sargassum aggregations (velocity, direction).
    Type of Medium: Online Resource
    ISSN: 2072-4292
    URL: Article
    DOI: 10.3390/rs13081444
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2513863-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    New insights into global biogeography, population structure and natural selection from the genome of the epipelagic copepod Oithona
    Wiley ; 2017
    In:  Molecular Ecology Vol. 26, No. 17 ( 2017-09), p. 4467-4482
    Details
    In: Molecular Ecology, Wiley, Vol. 26, No. 17 ( 2017-09), p. 4467-4482
    Abstract: In the epipelagic ocean, the genus Oithona is considered as one of the most abundant and widespread copepods and plays an important role in the trophic food web. Despite its ecological importance, little is known about Oithona and cyclopoid copepods genomics. Therefore, we sequenced, assembled and annotated the genome of Oithona nana . The comparative genomic analysis integrating available copepod genomes highlighted the expansions of genes related to stress response, cell differentiation and development, including genes coding Lin12‐Notch‐repeat ( LNR ) domain proteins. The Oithona biogeography based on 28S sequences and metagenomic reads from the Tara Oceans expedition showed the presence of O. nana mostly in the Mediterranean Sea ( MS ) and confirmed the amphitropical distribution of Oithona similis . The population genomics analyses of O. nana in the Northern MS , integrating the Tara Oceans metagenomic data and the O. nana genome, led to the identification of genetic structure between populations from the MS basins. Furthermore, 20 loci were found to be under positive selection including four missense and eight synonymous variants, harbouring soft or hard selective sweep patterns. One of the missense variants was localized in the LNR domain of the coding region of a male‐specific gene. The variation in the B‐allele frequency with respect to the MS circulation pattern showed the presence of genomic clines between O. nana and another undefined Oithona species possibly imported through Atlantic waters. This study provides new approaches and results in zooplankton population genomics through the integration of metagenomic and oceanographic data.
    Type of Medium: Online Resource
    ISSN: 0962-1083 , 1365-294X
    URL: Issue
    URL: Article
    DOI: 10.1111/mec.2017.26.issue-17
    DOI: 10.1111/mec.14214
    RVK:
    WA 15000
    Language: English
    Publisher: Wiley
    Publication Date: 2017
    detail.hit.zdb_id: 2020749-9
    detail.hit.zdb_id: 1126687-9
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 5
    Online Resource
    Online Resource
    Long-distance particle transport to the central Ionian Sea
    Copernicus GmbH ; 2021
    In:  Biogeosciences Vol. 18, No. 24 ( 2021-12-14), p. 6377-6392
    Details
    In: Biogeosciences, Copernicus GmbH, Vol. 18, No. 24 ( 2021-12-14), p. 6377-6392
    Abstract: Abstract. Together with T–S properties, particle abundance in situ measurements are useful to discriminate water masses and derive circulation patterns. In the upper layers of the Ionian Sea, the fresher Atlantic Waters (AW) recently crossing the Sicily Channel meet the resident and saltier AW, which circulated cyclonically in the eastern basin and modified after evaporation and eventually cooling. In May 2017, during the PEACETIME cruise, fluorescence and particle abundance sampled at high resolution revealed unexpected heterogeneity in the central Ionian Sea. Surface salinity measurements, together with altimetry-derived and hull-mounted acoustic Doppler current profiler (ADCP) currents, describe a zonal pathway of AW entering the Ionian Sea, consistent with the so-called cyclonic mode in the North Ionian Gyre. The ION-Tr transect, located between 19–20∘ E at approximately 36∘ N, turned out to be at the crossroads of three water masses, mostly coming from the west, north and an isolated anticyclonic eddy northeast of ION-Tr. Using Lagrangian numerical simulations, we suggest that the contrast in particle loads along ION-Tr originates from particles transported from these three different water masses. Waters from the west, identified as AW carried by a strong southwestward jet, were moderate in particle load, probably originating from the Sicily Channel. The water mass from the north, carrying abundant particles, probably originated in the northern Ionian Sea, or further away from the south Adriatic Sea. Waters from the eddy, depleted in particles and chl a, may originate from south of the Peloponnese, where the Pelops eddy forms. The central Ionian Sea hence appears as a mosaic area, where waters of contrasted biological history meet. This contrast is particularly clear in spring, when blooming and non-blooming areas co-occur. Interpreting the complex dynamics of physical–biogeochemical coupling from discrete measurements made at isolated stations at sea is a challenge. The combination of multiparametric in situ measurements at high resolution with remote sensing and Lagrangian modeling appears as one adequate way to address this challenge.
    Type of Medium: Online Resource
    ISSN: 1726-4189
    URL: Article
    URL: Article
    DOI: 10.5194/bg-18-6377-2021
    DOI: 10.5194/bg-18-6377-2021-supplement
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2021
    detail.hit.zdb_id: 2158181-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 6
    Online Resource
    Online Resource
    A global marine particle size distribution dataset obtained with the Underwater Vision Profiler 5
    Copernicus GmbH ; 2022
    In:  Earth System Science Data Vol. 14, No. 9 ( 2022-09-22), p. 4315-4337
    Details
    In: Earth System Science Data, Copernicus GmbH, Vol. 14, No. 9 ( 2022-09-22), p. 4315-4337
    Abstract: Abstract. Marine particles of different nature are found throughout the global ocean. The term “marine particles” describes detritus aggregates and fecal pellets as well as bacterioplankton, phytoplankton, zooplankton and nekton. Here, we present a global particle size distribution dataset obtained with several Underwater Vision Profiler 5 (UVP5) camera systems. Overall, within the 64 µm to about 50 mm size range covered by the UVP5, detrital particles are the most abundant component of all marine particles; thus, measurements of the particle size distribution with the UVP5 can yield important information on detrital particle dynamics. During deployment, which is possible down to 6000 m depth, the UVP5 images a volume of about 1 L at a frequency of 6 to 20 Hz. Each image is segmented in real time, and size measurements of particles are automatically stored. All UVP5 units used to generate the dataset presented here were inter-calibrated using a UVP5 high-definition unit as reference. Our consistent particle size distribution dataset contains 8805 vertical profiles collected between 19 June 2008 and 23 November 2020. All major ocean basins, as well as the Mediterranean Sea and the Baltic Sea, were sampled. A total of 19 % of all profiles had a maximum sampling depth shallower than 200 dbar, 38 % sampled at least the upper 1000 dbar depth range and 11 % went down to at least 3000 dbar depth. First analysis of the particle size distribution dataset shows that particle abundance is found to be high at high latitudes and in coastal areas where surface productivity or continental inputs are elevated. The lowest values are found in the deep ocean and in the oceanic gyres. Our dataset should be valuable for more in-depth studies that focus on the analysis of regional, temporal and global patterns of particle size distribution and flux as well as for the development and adjustment of regional and global biogeochemical models. The marine particle size distribution dataset (Kiko et al., 2021) is available at https://doi.org/10.1594/PANGAEA.924375.
    Type of Medium: Online Resource
    ISSN: 1866-3516
    URL: Article
    DOI: 10.5194/essd-14-4315-2022
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2022
    detail.hit.zdb_id: 2475469-9
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 7
    Online Resource
    Online Resource
    Impact of Tropical Cyclones on Pelagic Sargassum
    American Geophysical Union (AGU) ; 2022
    In:  Geophysical Research Letters Vol. 49, No. 6 ( 2022-03-28)
    Details
    In: Geophysical Research Letters, American Geophysical Union (AGU), Vol. 49, No. 6 ( 2022-03-28)
    Abstract: Tropical cyclones occur in the region of massive proliferation of Sargassum since 2011 High winds in tropical cyclones induce decrease of Sargassum coverage No recovery of Sargassum after cyclone crossing
    Type of Medium: Online Resource
    ISSN: 0094-8276 , 1944-8007
    URL: Article
    DOI: 10.1029/2021GL097484
    Language: English
    Publisher: American Geophysical Union (AGU)
    Publication Date: 2022
    detail.hit.zdb_id: 2021599-X
    detail.hit.zdb_id: 7403-2
    SSG: 16,13
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 8
    Online Resource
    Online Resource
    Modeling the impact of declining sea ice on the Arctic marine planktonic ecosystem
    American Geophysical Union (AGU) ; 2010
    In:  Journal of Geophysical Research: Oceans Vol. 115, No. C10 ( 2010-10)
    Details
    In: Journal of Geophysical Research: Oceans, American Geophysical Union (AGU), Vol. 115, No. C10 ( 2010-10)
    Abstract: We have developed a coupled 3‐D pan‐Arctic biology/sea ice/ocean model to investigate the impact of declining Arctic sea ice on the marine planktonic ecosystem over 1988–2007. The biophysical model results agree with satellite observations of a generally downward trend in summer sea ice extent during 1988–2007, resulting in an increase in the simulated photosynthetically active radiation (PAR) at the ocean surface and marine primary productivity (PP) in the upper 100 m over open water areas of the Arctic Ocean. The simulated Arctic sea ice thickness has decreased steadily during 1988–2007, leading to an increase in PAR and PP in sea ice‐covered areas. The simulated total PAR in all areas of the Arctic Ocean has increased by 43%, from 146 TW in 1988 to 209 TW in 2007; the corresponding total PP has increased by 50%, from 456 Tg C yr −1 in 1988 to 682 Tg C yr −1 in 2007. The simulated PAR and PP increases mainly occur in the seasonally and permanently ice‐covered Arctic Ocean. In addition to increasing PAR, the decline in sea ice tends to increase the nutrient availability in the euphotic zone by enhancing air‐sea momentum transfer, leading to strengthened upwelling and mixing in the water column and therefore increased nutrient input into the upper ocean layers from below. The increasing nutrient availability also contributes to the increase in the simulated PP, even though significant surface nutrient drawdown in summer is simulated. In conjunction with increasing surface absorption of solar radiation and rising surface air temperature, the increasing surface water temperature in the Arctic Ocean peripheral seas further contributes to the increase in PP. As PP has increased, so has the simulated biomass of phytoplankton and zooplankton.
    Type of Medium: Online Resource
    ISSN: 0148-0227
    URL: Article
    DOI: 10.1029/2009JC005387
    Language: English
    Publisher: American Geophysical Union (AGU)
    Publication Date: 2010
    detail.hit.zdb_id: 2033040-6
    detail.hit.zdb_id: 3094104-0
    detail.hit.zdb_id: 2130824-X
    detail.hit.zdb_id: 2016813-5
    detail.hit.zdb_id: 2016810-X
    detail.hit.zdb_id: 2403298-0
    detail.hit.zdb_id: 2016800-7
    detail.hit.zdb_id: 161666-3
    detail.hit.zdb_id: 161667-5
    detail.hit.zdb_id: 2969341-X
    detail.hit.zdb_id: 161665-1
    detail.hit.zdb_id: 3094268-8
    detail.hit.zdb_id: 710256-2
    detail.hit.zdb_id: 2016804-4
    detail.hit.zdb_id: 3094181-7
    detail.hit.zdb_id: 3094219-6
    detail.hit.zdb_id: 3094167-2
    detail.hit.zdb_id: 2220777-6
    detail.hit.zdb_id: 3094197-0
    SSG: 16,13
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 9
    Online Resource
    Online Resource
    Assessing biases in computing size spectra of automatically classified zooplankton from imaging systems: A case study with the ZooScan integrated system
    Elsevier BV ; 2012
    In:  Methods in Oceanography Vol. 1-2 ( 2012-4), p. 3-21
    Details
    In: Methods in Oceanography, Elsevier BV, Vol. 1-2 ( 2012-4), p. 3-21
    Type of Medium: Online Resource
    ISSN: 2211-1220
    URL: Article
    DOI: 10.1016/j.mio.2012.06.001
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2012
    detail.hit.zdb_id: 2681578-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 10
    Online Resource
    Online Resource
    Filtering out false Sargassum detections using context features
    Frontiers Media SA ; 2022
    In:  Frontiers in Marine Science Vol. 9 ( 2022-9-23)
    Details
    In: Frontiers in Marine Science, Frontiers Media SA, Vol. 9 ( 2022-9-23)
    Abstract: Since 2011, the distribution extent of pelagic Sargassum algae has substantially increased and now covers the whole Tropical North Atlantic Ocean, with significant inter-annual variability. The ocean colour imagery has been used as the only way to monitor regularly such a vast area. However, the detection is hampered by cloud masking, sunglint, coastal contamination and other phenomena. All together, they lead to false detections that can hardly be discriminated by classic radiometric analysis, but may be overcome by considering the shape and the context of the detections. Here, we built a machine learning model base exclusively on spatial features to filter out false detections after the detection process. Moderate-Resolution Imaging Spectroradiometer (MODIS, 1 km) data from Aqua and Terra satellites were used to generate daily map of Alternative Floating Algae Index (AFAI). Based on this radiometric index, Sargassum presence in the Tropical Atlantic North Ocean was inferred. For every Sargassum aggregations, five contextual indices were extracted (number of neighbours, surface of neighbours, temporal persistence, distance to the coast and aggregation texture) then used by a random forest binary classifier. Contextual features at large-scale were most important in the classifier. Trained with a multi-annual (2016-2020) learning set, the model performs the filtering of daily false detections with an accuracy of ~ 90%. This leads to a reduction of detected Sargassum pixels of ~ 50% over the domain. The method provides reliable data while preserving high spatial and temporal resolutions (1 km, daily). The resulting distribution is consistent with the literature for seasonal and inter-annual fluctuations, with maximum coverage in 2018 and minimum in 2016. This dataset will be useful for understanding the drivers of Sargassum dynamics at fine and large scale and validate future models. The methodology used here demonstrates the usefulness of contextual features for complementing classical remote sensing approaches. Our model could easily be adapted to other datasets containing erroneous detections.
    Type of Medium: Online Resource
    ISSN: 2296-7745
    URL: Article
    DOI: 10.3389/fmars.2022.960939
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2022
    detail.hit.zdb_id: 2757748-X
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...