scholarly journals Linking sardine recruitment in coastal areas to ocean currents using surface drifters and HF radar. A case study in the Gulf of Manfredonia, Adriatic Sea

2018 ◽  
Author(s):  
Roberta Sciascia ◽  
Maristella Berta ◽  
Daniel F. Carlson ◽  
Annalisa Griffa ◽  
Monica Panfili ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Early Life History ◽  
Ocean Currents ◽  
Hf Radar ◽  
Sustainable Resource Management ◽  
Surface Ocean ◽  
Spawning Areas ◽  
Surface Drifters ◽  
Particles Trajectories

Abstract. Understanding the role of ocean currents in the recruitment of commercially and ecologically important fish is an important step toward developing sustainable resource management guidelines. To this end, we attempt to elucidate the role of surface ocean transport in supplying recruits of European sardine (Sardinus pilchardus) to the Gulf of Manfredonia, a known recruitment area in the Adriatic Sea. Sardine early life history stages (ELHS) were collected during two cruises to provide observational estimates of age-size relationship and of their passive pelagic larval duration (PPLD). We combine these PPLDs with observations of surface ocean currents to test two hypotheses: (1) ELHS are transported from remote spawning areas (SAs) by ocean currents to the Gulf of Manfredonia; (2) sardines spawn locally and ELHS are retained by eddies. A historical surface drifter database is used to test hypotheses 1. Hypothesis 2 is tested by estimating residence times of surface drifters and virtual particles trajectories that were computed from high resolution observations of surface currents measured by a High Frequency (HF) radar network. Transport to the Gulf of Manfredonia from remote SAs seems more likely than local spawning and retention given a mismatch between observed PPLDs of 30–50 days and relatively short (

scholarly journals Linking sardine recruitment in coastal areas to ocean currents using surface drifters and HF radar: a case study in the Gulf of Manfredonia, Adriatic Sea

Ocean Science ◽  
2018 ◽  
Vol 14 (6) ◽  
pp. 1461-1482 ◽  
Author(s):  
Roberta Sciascia ◽  
Maristella Berta ◽  
Daniel F. Carlson ◽  
Annalisa Griffa ◽  
Monica Panfili ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Strong Dependence ◽  
Early Life History ◽  
Ocean Currents ◽  
Hf Radar ◽  
Residence Times ◽  
Sustainable Resource Management ◽  
Surface Ocean ◽  
Surface Drifters

Abstract. Understanding the role of ocean currents in the recruitment of commercially and ecologically important fish is an important step toward developing sustainable resource management guidelines. To this end, we attempt to elucidate the role of surface ocean transport in supplying recruits of European sardine (Sardina pilchardus) to the Gulf of Manfredonia, a known recruitment area in the Adriatic Sea. Sardine early life history stages (ELHSs) were collected during two cruises to provide observational estimates of their age–size relationship and their passive pelagic larval duration (PPLD). We combine these PPLDs with observations of surface ocean currents to test two hypotheses: (1) ELHSs are transported from remote spawning areas (SAs) by ocean currents to the Gulf of Manfredonia; (2) sardines spawn locally and ELHSs are retained by eddies. A historical surface drifter database is used to test hypothesis 1. Hypothesis 2 is tested by estimating residence times in the Gulf of Manfredonia using surface drifters and virtual particles trajectories that were computed from high-resolution observations of surface currents measured by a high-frequency (HF) radar network. Transport to the Gulf of Manfredonia from remote SAs seems more likely than local spawning and retention given a mismatch between observed PPLDs of 30–50 days and relatively short (<10-day) average residence times. The number and strength of connections between the gulf and remote SAs exhibit a strong dependence on PPLD. For PPLDs of 20 days or less, the gulf is connected to SAs on the western Adriatic coast through transport in the Western Adriatic Current (WAC). SAs on the east coast are more important at longer PPLDs. SAs in the northern and central Adriatic exhibit weak connections at all PPLD ranges considered. These results agree with otolith microstructure analysis, suggesting that the arrival of larvae in the gulf is characterized by repeated pulses from remote SAs. This is the first attempt to describe the processes related to Lagrangian connection to, and retention in, the Gulf of Manfredonia that will be complemented in the future using validated numerical ocean models and biophysical models.

scholarly journals Strongly Coupled Assimilation of a Hypothetical Ocean Current Observing Network within a Regional Ocean-Atmosphere Coupled Model: An OSSE Case Study of Typhoon Hato

2021 ◽  
Author(s):  
Luke Phillipson ◽  
Yi Li ◽  
Ralf Toumi
Keyword(s):  
Coupled Model ◽  
Ocean Currents ◽  
Hf Radar ◽  
Ocean Current ◽  
Coastal Current ◽  
Strongly Coupled ◽  
Ocean Atmosphere ◽  
Atmospheric Observations ◽  
Surface Drifters ◽  
The Impact

AbstractThe forecast of tropical cyclone (TC) intensity is a significant challenge. In this study, we showcase the impact of strongly coupled data assimilation with hypothetical ocean currents on analyses and forecasts of Typhoon Hato (2017). Several observation simulation system experiments were undertaken with a regional coupled ocean-atmosphere model. We assimilated combinations of (or individually) a hypothetical coastal current HF radar network, a dense array of drifter floats and minimum sea-level pressure. During the assimilation, instant updates of many important atmospheric variables (winds and pressure) are achieved from the assimilation of ocean current observations using the cross-domain error covariance, significantly improving the track and intensity analysis of Typhoon Hato. As compared to a control experiment (with no assimilation), the error of minimum pressure decreased by up to 13 hPa (4 hPa / 57 % on average). The maximum wind speed error decreased by up to 18 knots (5 knots / 41 % on average). By contrast, weakly coupled implementations cannot match these reductions (10% on average). Although traditional atmospheric observations were not assimilated, such improvements indicate there is considerable potential in assimilating ocean currents from coastal HF radar, and surface drifters within a strongly coupled framework for intense landfalling TCs.

scholarly journals Strongly Coupled Assimilation of a Hypothetical Ocean Current Observing Network within a Regional Ocean-Atmosphere Coupled Model: An OSSE Case Study of Typhoon Hato

2021 ◽  
Author(s):  
Luke Phillipson ◽  
Yi Li ◽  
Ralf Toumi
Keyword(s):  
Coupled Model ◽  
Ocean Currents ◽  
Hf Radar ◽  
Ocean Current ◽  
Coastal Current ◽  
Strongly Coupled ◽  
Ocean Atmosphere ◽  
Atmospheric Observations ◽  
Surface Drifters ◽  
The Impact

&lt;p&gt;The forecast of tropical cyclone (TC) intensity is a significant challenge. &amp;#160;In this study, we showcase the impact of strongly coupled data assimilation with hypothetical ocean currents on analyses and forecasts of Typhoon Hato (2017).&amp;#160;&lt;/p&gt;&lt;p&gt;Several observation simulation system experiments were undertaken with a regional coupled ocean-atmosphere model. We assimilated combinations of (or individually) a hypothetical coastal current HF radar network, a dense array of drifter floats and minimum sea-level pressure. During the assimilation, instant updates of many important atmospheric variables (winds and pressure) are achieved from the assimilation of ocean current observations using the cross-domain error covariance, significantly improving the track and intensity analysis of Typhoon Hato. As compared to a control experiment (with no assimilation), the error of minimum pressure decreased by up to 13 hPa (4 hPa / 57 % on average). The maximum wind speed error decreased by up to 18 knots (5 knots / 41 % on average).&amp;#160;&lt;/p&gt;&lt;p&gt;By contrast, weakly coupled implementations cannot match these reductions (10% on average). Although traditional atmospheric observations were not assimilated, such improvements indicate there is considerable potential in assimilating ocean currents from coastal HF radar, and surface drifters within a strongly coupled framework for intense landfalling TCs.&lt;/p&gt;

Bora wind and heavy persistent precipitation: atmospheric water balance and role of air-sea fluxes over the Adriatic Sea

2017 ◽  
Vol 143 (703) ◽  
pp. 1165-1177 ◽  
Author(s):  
Silvio Davolio ◽  
Riccardo Henin ◽  
Paolo Stocchi ◽  
Andrea Buzzi
Keyword(s):  
Water Balance ◽  
Adriatic Sea ◽  
Atmospheric Water ◽  
Bora Wind

scholarly journals Biogeochemical processes in sediments of the Manfredonia Gulf (Southern Adriatic Sea): early diagenesis of carbon and nutrient and benthic exchange

2004 ◽  
Vol 1 (1) ◽  
pp. 803-823 ◽  
Author(s):  
F. Spagnoli ◽  
G. Bartholini ◽  
M. Marini ◽  
P. Giordano
Keyword(s):  
Adriatic Sea ◽  
Water Interface ◽  
Biogeochemical Processes ◽  
Pore Waters ◽  
Dissolved Nutrients ◽  
Dissolved Iron ◽  
High Sedimentation ◽  
Western Adriatic Current ◽  
A Site

Abstract. In order to understand the mechanisms responsible of the recycle of carbon and nutrients at the sediment-water interface and to understand the role of sediments in nutrients mass balance in coastal water, cores were collected (pore waters and solid phases) and benthic fluxes (oxygen, dissolved nutrients, dissolved iron and managanese, alkalinity and TCO2) were measured in two stations in the Gulf of Manfredonia (Southern Adriatic Sea). Stations were chosen to include a site, in the offshore part of the gulf, under the influence of western Adriatic current and another site, in the inner part of the gulf, under influence of gyres occurring inside the gulf. Both stations were placed in areas characterized by high sedimentation rate. Fluxes at sediment water interface show higher values in S2 site during the summer. Bio-irrigation seems to be the main transport mechanism characterizing both sites, with more evident effects during summer in S1 site.

scholarly journals <i>Brief communication</i> "The 2013 Erebus Glacier tongue calving event"

2013 ◽  
Vol 7 (2) ◽  
pp. 1749-1760
Author(s):  
C. L. Stevens ◽  
P. Sirguey ◽  
G. H. Leonard ◽  
T. G. Haskell
Keyword(s):  
Ocean Circulation ◽  
Ocean Currents ◽  
Mcmurdo Sound ◽  
Glacier Tongue ◽  
Surface Ocean ◽  
Fast Ice

Abstract. The Erebus Glacier Tongue, a~small floating glacier in southern McMurdo Sound, is one of the best-studied ice tongues in Antarctica. Despite this, its calving on the 27 February 2013 (UTC) was around 10 yr earlier than previously predicted. The calving was likely a result of ocean currents and the absence of fast ice. The subsequent trajectory of the newly-created iceberg supports previous descriptions of the surface ocean circulation in southern McMurdo Sound.

scholarly journals Different processes shape prokaryotic and picoeukaryotic assemblages in the sunlit ocean microbiome

2018 ◽  
Author(s):  
Ramiro Logares ◽  
Ina M. Deutschmann ◽  
Caterina. R. Giner ◽  
Anders K. Krabberød ◽  
Thomas S. B. Schmidt ◽  
...  
Keyword(s):  
Ecosystem Function ◽  
Sequence Data ◽  
Scale Effects ◽  
Dispersal Limitation ◽  
Global Scale ◽  
Global Ocean ◽  
Ecosystem Functions ◽  
Ecological Processes ◽  
Surface Ocean

ABSTRACTThe smallest members of the sunlit-ocean microbiome (prokaryotes and picoeukaryotes) participate in a plethora of ecosystem functions with planetary-scale effects. Understanding the processes determining the spatial turnover of this assemblage can help us better comprehend the links between microbiome species composition and ecosystem function. Ecological theory predicts thatselection,dispersalanddriftare main drivers of species distributions, yet, the relative quantitative importance of these ecological processes in structuring the surface-ocean microbiome is barely known. Here we quantified the role of selection, dispersal and drift in structuring surface-ocean prokaryotic and picoeukaryotic assemblages by using community DNA-sequence data collected during the global Malaspina expedition. We found that dispersal limitation was the dominant process structuring picoeukaryotic communities, while a balanced combination of dispersal limitation, selection and drift shaped prokaryotic counterparts. Subsequently, we determined the agents exerting abiotic selection as well as the spatial patterns emerging from the action of different ecological processes. We found that selection exerted via temperature had a strong influence on the structure of prokaryotic communities, particularly on species co-occurrences, a pattern not observed among communities of picoeukaryotes. Other measured abiotic variables had limited selective effects on microbiome structure. Picoeukaryotes presented a higher differentiation between neighbouring communities and a higher distance-decay when compared to prokaryotes, agreeing with their higher dispersal limitation. Finally, drift seemed to have a limited role in structuring the sunlit-ocean microbiome. The different predominance of ecological processes acting on particular subsets of the ocean microbiome suggests uneven responses to environmental change.SIGNIFICANCE STATEMENTThe global ocean contains one of the largest microbiomes on Earth and changes on its structure can impact the functioning of the biosphere. Yet, we are far from understanding the mechanisms that structure the global ocean microbiome, that is, the relative importance of environmentalselection,dispersaland random events (drift). We evaluated the role of these processes at the global scale, based on data derived from a circumglobal expedition and found that these ecological processes act differently on prokaryotes and picoeukaryotes, two of the main components of the ocean microbiome. Our work represents a significant contribution to understand the assembly of marine microbial communities, providing also insights on the links between ecological mechanisms, microbiome structure and ecosystem function.

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