scholarly journals Seasonal and interannual variability of coccolithophore blooms in the North East-Atlantic Ocean from a 18-year time-series of satellite water-leaving radiance

2016 ◽  
Author(s):  
Laurie Perrot ◽  
Francis Gohin ◽  
Diana Ruiz-Pino ◽  
Luis Lampert
Keyword(s):  
Time Series ◽  
Interannual Variability ◽  
Spectral Radiance ◽  
Co2 Uptake ◽  
East Atlantic ◽  
Atlantic Region ◽  
Seasonal And Interannual Variability ◽  
North East ◽  
The North ◽  
The Impact

Abstract. Evaluate the impact of anthropogenic CO2 uptake and acidification on the most abundant calcareous phytoplankton, coccolithophores, requires a better knowledge of the temporal and spatial evolution of their blooms. Here we determine, from satellite radiance, the seasonal and interannual variability of coccolithophore blooms for 18 years (1998 to 2015) across the North-East Atlantic region covering the Bay of Biscay and the Celtic Sea. The identification of coccolithophores is carried out using a modified version of the fuzzy method developed by Moore (2009) applied to a time series of SeaWiFS (1998–2003) and MODIS (2003–2015) spectral radiance. After identification of the coccolith pixels, the abundance of coccoliths is assessed from a data base of non-algal Suspended Particulate Matter (SPM), a product initially developed for estimating the content of mineral particles, mainly due to resuspension effects, in coastal waters. The results, in terms of identification and quantification, are consistent with in situ observations in the area and with those of algorithms addressing coccolithophore blooms at global scale (CALCITE and PHYSAT). Although a regular pattern in the phenology of the blooms is observed, starting south in April in Biscay and moving northwards until July near Ireland, there is a high seasonal and interannual variability in the extent of the blooms. Year 2014 shows very low concentrations of coccoliths from space (twice less than average) and anomalies point out the maximum level for 2001. The cause of the seasonal and interannual variability of the coccolithophores blooms in this Atlantic region remains an open question.

The Intertidal Zone of the North-East Atlantic Region

2019 ◽  
pp. 7-46
Author(s):  
Stephen J. Hawkins ◽  
Kathryn E. Pack ◽  
Louise B. Firth ◽  
Nova Mieszkowska ◽  
Ally J. Evans ◽  
...  
Keyword(s):  
Intertidal Zone ◽  
East Atlantic ◽  
Atlantic Region ◽  
North East ◽  
The North

scholarly journals An interrupted time-series analysis of the impact of emergency department reconfiguration on regional emergency department trolley numbers in Ireland from 2005 to 2015

BMJ Open ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. e029261 ◽  
Author(s):  
Brenda Lynch ◽  
John Browne ◽  
Claire Mary Buckley ◽  
Orla Healy ◽  
Paul Corcoran ◽  
...  
Keyword(s):  
Emergency Department ◽  
Time Series ◽  
Time Series Analysis ◽  
Interrupted Time Series Analysis ◽  
Series Analysis ◽  
North East ◽  
The North ◽  
Number Of Patients ◽  
Geographical Regions ◽  
The Impact

ObjectivesTo understand the impact of emergency department (ED) reconfiguration on the number of patients waiting for hospital beds on trolleys in the remaining EDs in four geographical regions in Ireland using time-series analysis.SettingEDs in four Irish regions; the West, North-East, South and Mid-West from 2005 to 2015.ParticipantsAll patients counted as waiting on trolleys in an ED for a hospital bed in the study hospitals from 2005 to 2015.InterventionThe system intervention was the reconfiguration of ED services, as determined by the Department of Health and Health Service Executive. The timing of these interventions varied depending on the hospital and region in question.ResultsThree of the four regions studied experienced a significant change in ED trolley numbers in the 12-month post-ED reconfiguration. The trend ratio before and after the intervention for these regions was as follows: North-East incidence rate ratio (IRR) 2.85 (95% CI 2.04 to 3.99, p<0.001), South IRR 0.68 (95% CI 0.51 to 0.89, p=0.006) and the Mid-West IRR 0.03 (95% 1.03 to 2.03, p=0.03). Two of these regions, the South and the Mid-West, displayed a convergence between the observed and expected trolley numbers in the 12-month post-reconfiguration. The North-East showed a much steeper increase, one that extended beyond the 12-month period post-ED reconfiguration.ConclusionsFindings suggest that the impacts of ED reconfiguration on regional level ED trolley trends were either non-significant or caused a short-term shock which converged on the pre-reconfiguration trend over the following 12 months. However, the North-East is identified as an exception due to increased pressures in one regional hospital, which caused a change in trend beyond the 12-month post reconfiguration.

Evaluating the performance of CMIP3 and CMIP5 global climate models over the north-east Atlantic region

2014 ◽  
Vol 43 (9-10) ◽  
pp. 2663-2680 ◽  
Author(s):  
Jorge Perez ◽  
Melisa Menendez ◽  
Fernando J. Mendez ◽  
Inigo J. Losada
Keyword(s):  
Climate Models ◽  
Global Climate ◽  
Global Climate Models ◽  
East Atlantic ◽  
Atlantic Region ◽  
North East ◽  
The North

The taxonomy of some little-known Sipuncula from the north-east Atlantic region including new records

1986 ◽  
Vol 66 (2) ◽  
pp. 335-341 ◽  
Author(s):  
P. E. Gibbs
Keyword(s):  
Deep Sea ◽  
New Records ◽  
East Atlantic ◽  
Atlantic Region ◽  
North East ◽  
The North ◽  
The Status ◽  
Species Being ◽  
Deep Sea Fauna

INTRODUCTIONEarly investigations of the deep-sea fauna of the north-east Atlantic region resulted in many new Sipuncula species being described, notably by such workers as Koren & Danielssen (1877), Théel (1905), Sluiter (1900, 1912) and Southern (1913). Many of these species were erected from single, or few, specimens and some are still known only from the original records.This paper examines the status of certain species, mostly the seemingly-rare golfingiids described by Sluiter and Southern (see Table 1), the types of which were deposited in the collections of the Irish National Museum, Dublin (INMD) and the Musée Océanographique, Monaco-Ville (MOMV), and presents some new observations and records. The names of taxa follow the classification of Cutler & Gibbs (1985); Nephasoma Pergament and Apionsoma Sluiter, formerly considered as subgenera of Golfingia Lankester, are now elevated to generic rank.

scholarly journals Decadal Dynamics of the CO2 System and Associated Ocean Acidification in Coastal Ecosystems of the North East Atlantic Ocean

2021 ◽  
Vol 8 ◽  
Author(s):  
Jean-Philippe Gac ◽  
Pierre Marrec ◽  
Thierry Cariou ◽  
Emilie Grosstefan ◽  
Éric Macé ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Ocean Acidification ◽  
Dissolved Inorganic Carbon ◽  
Coastal Ecosystems ◽  
Total Alkalinity ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
The Impact

Weekly and bi-monthly carbonate system parameters and ancillary data were collected from 2008 to 2020 in three coastal ecosystems of the southern Western English Channel (sWEC) (SOMLIT-pier and SOMLIT-offshore) and Bay of Brest (SOMLIT-Brest) located in the North East Atlantic Ocean. The main drivers of seasonal and interannual partial pressure of CO2 (pCO2) and dissolved inorganic carbon (DIC) variabilities were the net ecosystem production (NEP) and thermodynamics. Differences were observed between stations, with a higher biological influence on pCO2 and DIC in the near-shore ecosystems, driven by both benthic and pelagic communities. The impact of riverine inputs on DIC dynamics was more pronounced at SOMLIT-Brest (7%) than at SOMLIT-pier (3%) and SOMLIT-offshore (&lt;1%). These three ecosystems acted as a weak source of CO2 to the atmosphere of 0.18 ± 0.10, 0.11 ± 0.12, and 0.39 ± 0.08 mol m–2 year–1, respectively. Interannually, air-sea CO2 fluxes (FCO2) variability was low at SOMLIT-offshore and SOMLIT-pier, whereas SOMLIT-Brest occasionally switched to weak annual sinks of atmospheric CO2, driven by enhanced spring NEP compared to annual means. Over the 2008–2018 period, monthly total alkalinity (TA) and DIC anomalies were characterized by significant positive trends (p-values &lt; 0.001), from 0.49 ± 0.20 to 2.21 ± 0.39 μmol kg−1 year−1 for TA, and from 1.93 ± 0.28 to 2.98 ± 0.39 μmol kg–1 year–1 for DIC. These trends were associated with significant increases of calculated seawater pCO2, ranging from +2.95 ± 1.04 to 3.52 ± 0.47 μatm year–1, and strong reductions of calculated pHin situ, with a mean pHin situ decrease of 0.0028 year–1. This ocean acidification (OA) was driven by atmospheric CO2 forcing (57–66%), Sea surface temperature (SST) increase (31–37%), and changes in salinity (2–5%). Additional pHin situ data extended these observed trends to the 2008–2020 period and indicated an acceleration of OA, reflected by a mean pHin situ decrease of 0.0046 year–1 in the sWEC for that period. Further observations over the 1998–2020 period revealed that the climatic indices North Atlantic Oscillation (NAO) and Atlantic Multidecadal Variability (AMV) were linked to trends of SST, with cooling during 1998–2010 and warming during 2010–2020, which might have impacted OA trends at our coastal stations. These results suggested large temporal variability of OA in coastal ecosystems of the sWEC and underlined the necessity to maintain high-resolution and long-term observations of carbonate parameters in coastal ecosystems.

scholarly journals Forecasting the mixed layer depth in the north east Atlantic: an ensemble approach, with uncertainties based on data from operational oceanic systems

2014 ◽  
Vol 11 (3) ◽  
pp. 1435-1472
Author(s):  
Y. Drillet ◽  
J. M. Lellouche ◽  
B. Levier ◽  
M. Drévillon ◽  
O. Le Galloudec ◽  
...  
Keyword(s):  
Mixed Layer ◽  
Forecast Error ◽  
Mixed Layer Depth ◽  
Layer Depth ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
Uncertainty Estimates ◽  
Operational Systems ◽  
The Impact

Abstract. Operational systems operated by Mercator Océan provide daily ocean forecasts, and combining these forecasts we can produce ensemble forecast and uncertainty estimates. This study focuses on the mixed layer depth in the North East Atlantic near the Porcupine Abyssal Plain for May 2013. This period is of interest for several reasons: (1) four Mercator Océan operational systems provide daily forecasts at a horizontal resolution of 1/4°, 1/12° and 1/36° with different physics; (2) glider deployment under the OSMOSIS project provides observation of the changes in mixed layer depth; (3) the ocean stratifies in May, but mixing events induced by gale force wind are observed and forecasted by the systems. A statistical approach and forecast error quantification for each system and for the combined products are presented. Skill scores indicate that forecasts are in any case better than persistence, and temporal correlations between forecast and observations are greater than 0.8 even for the 4 day forecast. The impact of atmospheric forecast error, and for the wind field in particular, is also quantified in terms of the forecast time delay and the intensity of mixing or stratification events.

scholarly journals The impact of aerosol size-dependent hygroscopicity and mixing state on the cloud condensation nuclei potential over the north-east Atlantic

2021 ◽  
Vol 21 (11) ◽  
pp. 8655-8675
Author(s):  
Wei Xu ◽  
Kirsten N. Fossum ◽  
Jurgita Ovadnevaite ◽  
Chunshui Lin ◽  
Ru-Jin Huang ◽  
...  
Keyword(s):  
Biological Activity ◽  
Chemical Composition ◽  
Cloud Condensation Nuclei ◽  
Mixing State ◽  
East Atlantic ◽  
Size Dependent ◽  
North East ◽  
The North ◽  
Internal Mixing ◽  
The Impact

Abstract. We present an aerosol cloud condensation nuclei (CCN) closure study over the north-east Atlantic Ocean using six approximating methods. The CCN number concentrations (NCCN) were measured at four discrete supersaturations (SSs; 0.25 %, 0.5 %, 0.75 % and 1.0 %). Concurrently, aerosol number size distribution, sub-saturation hygroscopic growth factor and bulk PM1 chemical composition were obtained at matching time resolution and after a careful data validation exercise. Method A used a constant bulk hygroscopicity parameter κ of 0.3; method B used bulk PM1 chemical composition measured by an aerosol mass spectrometer (AMS); method C utilised a single growth factor (GF) size (165 nm) measured by a humidified tandem differential mobility analyser (HTDMA); method D utilised size-dependent GFs measured at 35, 50, 75, 110 and 165 nm; method E divided the aerosol population into three hygroscopicity modes (near-hydrophobic, more-hygroscopic and sea-salt modes), and the total CCN number in each mode was cumulatively added up; method F used the full-size-scale GF probability density function (GF–PDF) in the most complex approach. The studied periods included high-biological-activity and low-biological-activity seasons in clean marine and polluted continental air masses to represent and discuss the most contrasting aerosol populations. Overall, a good agreement was found between estimated and measured NCCN with linear regression slopes ranging from 0.64 to 1.6. The temporal variability was captured very well, with Pearson's R value ranging from 0.76 to 0.98 depending on the method and air mass type. We further compared the results of using different methods to quantify the impact of size-dependent hygroscopicity and mixing state and found that ignoring size-dependent hygroscopicity induced overestimation of NCCN by up to 12 %, and ignoring a mixing state induced overestimation of NCCN by up to 15 %. The error induced by assuming an internal mixing in highly polluted cases was largely eliminated by dividing the full GF–PDF into three conventional hygroscopic modes, while assuming an internal mixing in clean marine aerosol did not induce significant error.

Latitudinal Displacements of the Gulf Stream and the Abundance of Plankton in the North-East Atlantic

1992 ◽  
Vol 72 (4) ◽  
pp. 919-921 ◽  
Author(s):  
A. H. Taylor ◽  
J. M. Colebrook ◽  
J. A. Stephens ◽  
N. G. Baker
Keyword(s):  
Time Series ◽  
North Atlantic ◽  
Gulf Stream ◽  
Storm Tracks ◽  
British Isles ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
The North Atlantic ◽  
North Wall

An earlier time-series of the annual mean latitude of the north wall of the Gulf Stream is updated to give a series of values from 1966 to 1990. The trend is similar to those seen in plankton from the Continuous Plankton Recorder Survey around the British Isles. This connection may reflect the displacement of storm tracks across the North Atlantic.

Modeling concentrations and fluxes of atmospheric CO2 in the North East Atlantic region

2001 ◽  
Vol 26 (10) ◽  
pp. 763-768 ◽  
Author(s):  
C. Geels ◽  
J.H. Christensen ◽  
A.W. Hansen ◽  
S. Killsholm ◽  
N.W. Larsen ◽  
...  
Keyword(s):  
Atmospheric Co2 ◽  
East Atlantic ◽  
Atlantic Region ◽  
North East ◽  
The North
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