48 research outputs found
Future wave climate over the west-European shelf seas
In this paper, we investigate changes in the wave climate of the west-European shelf seas under global warming scenarios. In particular, climate change wind fields corresponding to the present (control) time-slice 1961–2000 and the future (scenario) time-slice 2061–2100 are used to drive a wave generation model to produce equivalent control and scenario wave climate. Yearly and seasonal statistics of the scenario wave climates are compared individually to the corresponding control wave climate to identify relative changes of statistical significance between present and future extreme and prevailing wave heights. Using global, regional and linked global–regional wind forcing over a set of nested computational domains, this paper further demonstrates the sensitivity of the results to the resolution and coverage of the forcing. It suggests that the use of combined forcing from linked global and regional climate models of typical resolution and coverage is a good option for the investigation of relative wave changes in the region of interest of this study. Coarse resolution global forcing alone leads to very similar results over regions that are highly exposed to the Atlantic Ocean. In contrast, fine resolution regional forcing alone is shown to be insufficient for exploring wave climate changes over the western European waters because of its limited coverage. Results obtained with the combined global–regional wind forcing showed some consistency between scenarios. In general, it was shown that mean and extreme wave heights will increase in the future only in winter and only in the southwest of UK and west of France, north of about 44–45° N. Otherwise, wave heights are projected to decrease, especially in summer. Nevertheless, this decrease is dominated by local wind waves whilst swell is found to increase. Only in spring do both swell and local wind waves decrease in average height
Implementation and validation of a new operational wave forecasting system of the Mediterranean Monitoring and Forecasting Centre in the framework of the Copernicus Marine Environment Monitoring Service
Within the framework of the Copernicus Marine Environment Monitoring Service (CMEMS),
an operational wave forecasting system for the Mediterranean Sea has
been implemented by the Hellenic Centre for Marine Research (HCMR) and
evaluated through a series of preoperational tests and subsequently for 1
full year of simulations (2014). The system is based on the WAM model and it
has been developed as a nested sequence of two computational grids to ensure
that occasional remote swell propagating from the North Atlantic
correctly enters the Mediterranean Sea through the Strait of Gibraltar.
The Mediterranean model has a grid spacing of 1∕24°. It is driven with
6-hourly analysis and 5-day forecast 10 m ECMWF winds. It accounts for
shoaling and refraction due to bathymetry and surface currents, which are
provided in offline mode by CMEMS. Extensive statistics on the system
performance have been calculated by comparing model results with in situ and
satellite observations. Overall, the significant wave height is accurately
simulated by the model while less accurate but reasonably good results are
obtained for the mean wave period. In both cases, the model performs
optimally at offshore wave buoy locations and well-exposed Mediterranean
subregions. Within enclosed basins and near the coast, unresolved
topography by the wind and wave models and fetch limitations cause the wave
model performance to deteriorate. Model performance is better in winter when
the wave conditions are well defined. On the whole, the new forecast system
provides reliable forecasts. Future improvements include data assimilation
and higher-resolution wind forcing.</p
Duration of Treatment for Pseudomonas aeruginosa Bacteremia : a Retrospective Study
Introduction: There is no consensus regarding optimal duration of antibiotic therapy for Pseudomonas aeruginosa bacteremia. We aimed to evaluate the impact of short antibiotic course. Methods: We present a retrospective multicenter study including patients with P. aeruginosa bacteremia during 2009-2015. We evaluated outcomes of patients treated with short (6-10 days) versus long (11-15 days) antibiotic courses. The primary outcome was a composite of 30-day mortality or bacteremia recurrence and/or persistence. Univariate and inverse probability treatment-weighted (IPTW) adjusted multivariate analysis for the primary outcome was performed. To avoid immortal time bias, the landmark method was used. Results: We included 657 patients; 273 received a short antibiotic course and 384 a long course. There was no significant difference in baseline characteristics of patients. The composite primary outcome occurred in 61/384 patients in the long-treatment group (16%) versus 32/273 in the short-treatment group (12%) (p = 0.131). Mortality accounted for 41/384 (11%) versus 25/273 (9%) of cases, respectively. Length of hospital stay was significantly shorter in the short group [median 13 days, interquartile range (IQR) 9-21 days, versus median 15 days, IQR 11-26 days, p = 0.002]. Ten patients in the long group discontinued antibiotic therapy owing to adverse events, compared with none in the short group. On univariate and multivariate analyses, duration of therapy was not associated with the primary outcome. Conclusions: In this retrospective study, 6-10 days of antibiotic course for P. aeruginosa bacteremia were as effective as longer courses in terms of survival and recurrence. Shorter therapy was associated with reduced length of stay and less drug discontinuation
An integrated open-coastal biogeochemistry, ecosystem and biodiversity observatory of the eastern Mediterranean – the Cretan Sea component of the POSEIDON system
There is a general scarcity of oceanic observations that
concurrently examine air–sea interactions, coastal–open-ocean processes and
physical–biogeochemical processes, in appropriate spatiotemporal
scales and under continuous, long-term data acquisition schemes. In the
Mediterranean Sea, the resulting knowledge gaps and observing challenges
increase due to its oligotrophic character, especially in the eastern part
of the basin. The oligotrophic open Cretan Sea's biogeochemistry is
considered to be representative of a greater Mediterranean area up to
106 km2, and understanding its features may be useful on even
larger oceanic scales, since the Mediterranean Sea has been considered a
miniature model of the global ocean. The spatiotemporal coverage of biogeochemical (BGC)
observations in the Cretan Sea has progressively increased over the last
decades, especially since the creation of the POSEIDON observing system,
which has adopted a multiplatform, multivariable approach, supporting BGC
data acquisition. The current POSEIDON system's status includes open and
coastal sea fixed platforms, a Ferrybox (FB) system and Bio-Argo autonomous
floats that remotely deliver fluorescence as a proxy of chlorophyll-a
(Chl-a), O2, pH and pCO2 data, as well as BGC-related physical
variables. Since 2010, the list has been further expanded to other BGC
(nutrients, vertical particulate matter fluxes), ecosystem and biodiversity
(from viruses up to zooplankton) variables, thanks to the addition of
sediment traps, frequent research vessel (R/V) visits for seawater–plankton
sampling and an acoustic Doppler current profiler (ADCP) delivering
information on macrozooplankton–micronekton vertical migration (in the
epipelagic to mesopelagic layer). Gliders and drifters are the new (currently under
integration to the existing system) platforms, supporting BGC monitoring.
Land-based facilities, such as data centres, technical support
infrastructure, calibration laboratory and mesocosms, support and give added
value to the observatory. The data gathered from these platforms are used to
improve the quality of the BGC-ecosystem model predictions, which have
recently incorporated atmospheric nutrient deposition processes and
assimilation of satellite Chl-a data. Besides addressing open scientific
questions at regional and international levels, examples of which are
presented, the observatory provides user-oriented services to marine
policy makers and the society, and is a technological test bed for new
and/or cost-efficient BGC sensor technology and marine equipment. It is part
of European and international observing programs, playing a key role in
regional data handling and participating in harmonization and best practices
procedures. Future expansion plans consider the evolving scientific and
society priorities, balanced with sustainable management.</p
Notch inhibits Yorkie activity in Drosophila wing discs.
During development, tissues and organs must coordinate growth and patterning so they reach the right size and shape. During larval stages, a dramatic increase in size and cell number of Drosophila wing imaginal discs is controlled by the action of several signaling pathways. Complex cross-talk between these pathways also pattern these discs to specify different regions with different fates and growth potentials. We show that the Notch signaling pathway is both required and sufficient to inhibit the activity of Yorkie (Yki), the Salvador/Warts/Hippo (SWH) pathway terminal transcription activator, but only in the central regions of the wing disc, where the TEAD factor and Yki partner Scalloped (Sd) is expressed. We show that this cross-talk between the Notch and SWH pathways is mediated, at least in part, by the Notch target and Sd partner Vestigial (Vg). We propose that, by altering the ratios between Yki, Sd and Vg, Notch pathway activation restricts the effects of Yki mediated transcription, therefore contributing to define a zone of low proliferation in the central wing discs
Copernicus Ocean State Report, issue 6
The 6th issue of the Copernicus OSR incorporates a large range of topics for the blue, white and green ocean for all European regional seas, and the global ocean over 1993–2020 with a special focus on 2020
RNA sequencing analysis to capture the transcriptome landscape during skin ulceration syndrome progression in sea cucumber Apostichopus japonicus
Impact du changement climatique sur les vagues et la dérive littorale le long du littoral aquitain
Collocated model and observation datasets for the validation of the Copernicus Mediterranean Sea Waves Analysis and Forecast for the period 2018-2020.
The collocated values are used for skill evaluation of the Mediterranean Sea Waves Analysis and Forecast system for a three-year-long period (Korres et al., 2022). The list of datasets includes:
The collocated model (analysis) – buoy values for significant wave height Hs (Insitu_Hs.mat)
The collocated model (analysis) – buoy values for spectral moments (0,2) wave period Tm (Insitu_Tm.mat)
The collocated model (first – guess) – satellite values for significant wave height Hs (Satellite_Hs.mat)
The collocated model – satellite values for wind speed U10 (Satellite_U10.mat)
Each .mat file contains a header for the variables included. Collocations can be used to estimate standard quality metrics (e.g. scatter index, bias, root-mean-squared-difference). Procedures to produce these model-observation collocated datasets and determine the overall skill assessment are described in detail in Ravdas et al. (2018) and Oikonomou et al. (2022). The buoy (in-situ) measurements are obtained from the product INSITU_GLO_WAV_DISCRETE_MY_013_045 (EU Copernicus Marine Service Product, 2022a), and associated variables contain a quality flag (“time_qc”, “position_qc”, “buoy_Hs_qc”, “buoy_Tm_qc”) (de Alfonso et al., 2022a,b). In addition, the model first-guess significant wave height and the wind speed forcing (Hersbach et al., 2023) are collocated with available satellite observations (EU Copernicus Marine Service Product, 2022b) over the entire model domain.
References
de Alfonso, M., Manzano, F., and Gallardo, A. (2022a): EU Copernicus Marine Service Quality Information Document for the In Situ TAC Product, INSITU_GLO_WAV_DISCRETE_MY_013_045, Issue 5.0, Mercator Ocean International, https://catalogue.marine.copernicus.eu/documents/QUID/CMEMS-INS-QUID-013-045.pdf
de Alfonso, M., Manzano, F., Gallardo, A., and In Situ TAC (2022b): EU Copernicus Marine Service Product User Manual for Multi-Year WAVE In Situ Product, INSITU_GLO_WAV_DISCRETE_MY_013_045, Issue 2.0, Mercator Ocean International, https://catalogue.marine.copernicus.eu/documents/PUM/CMEMS-INS-PUM-013-045.pdf
EU Copernicus Marine Service Product (2022a): Multi-Year WAVE In Situ Product, Mercator Ocean International, [dataset], https://doi.org/10.17882/70345
EU Copernicus Marine Service Product (2022b): Global Ocean L 3 Significant Wave Height From Reprocessed Satellite Measurements, Mercator Ocean International, [dataset], https://doi.org/10.48670/moi-00176
Hersbach, H., Bell, B., Berrisford, P., Biavati, G., Horányi, A., Muñoz Sabater, J., Nicolas, J., Peubey, C., Radu, R., Rozum, I., Schepers, D., Simmons, A., Soci, C., Dee, D., Thépaut, J-N. (2023): ERA5 hourly data on single levels from 1940 to present. Copernicus Climate Change Service (C3S) Climate Data Store (CDS), DOI: 10.24381/cds.adbb2d47 (Accessed on 26-09-2023)
Korres, G., Oikonomou, C., Denaxa, D., & Sotiropoulou, M. (2022): Mediterranean Sea Waves Analysis and Forecast (CMEMS MED-Waves, MEDWAΜ4 system) (Version 1) [Data set]. Copernicus Monitoring Environment Marine Service (CMEMS). https://doi.org/10.25423/CMCC/MEDSEA_ANALYSISFORECAST_WAV_006_017_MEDWAM4
Oikonomou, C., Denaxa D., and Korres, G. (2022): EU Copernicus Marine Service Quality Information Document for the Mediterranean Sea Waves Reanalysis, MEDSEA_ANALYSISFORECAST_WAV_006_017, Issue 2.2, Mercator Ocean International, https://catalogue.marine.copernicus.eu/documents/QUID/CMEMS-MED-QUID-006-017.pdf.
Ravdas, M., Zacharioudaki, A., and Korres, G. (2018): Implementation and validation of a new operational wave forecasting system of the Mediterranean Monitoring and Forecasting Centre in the framework of the Copernicus Marine Environment Monitoring Service, Nat. Hazards Earth Syst. Sci., 18, 2675–2695, https://doi.org/10.5194/nhess-18-2675-201