68 research outputs found
Extreme wave activity during 2013/2014 winter and morphological impacts along the Atlantic coast of Europe
Studies of coastal vulnerability due to climate change tend to focus on the consequences of sea level rise, rather than the complex coastal responses resulting from changes to the extreme wave climate. Here we investigate the 2013/2014 winter wave conditions that severely impacted the Atlantic coast of Europe and demonstrate that this winter was the most energetic along most of the Atlantic coast of Europe since at least 1948. Along exposed open-coast sites, extensive beach and dune erosion occurred due to offshore sediment transport. More sheltered sites experienced less erosion and one of the sites even experienced accretion due to beach rotation induced by alongshore sediment transport. Storm wave conditions such as were encountered during the 2013/2014 winter have the potential to dramatically change the equilibrium state (beach gradient, coastal alignment, and nearshore bar position) of beaches along the Atlantic coast of Europe
Historical variation and trends in storminess along the Portuguese South Coast
This work investigates historical variation and
trends in storm climate for the South Portugal region, using
data from wave buoy measurements and from modelling, for
the period 1952 to 2009. Several storm parameters (annual
number of storms; annual number of days with storms; annual
maximum and mean individual storm duration and annual
99.8th percentile of significant wave height) were used
to analyse: (1) historical storminess trends; (2) storm parameter
variability and relationships; and (3) historical storminess
and its relationship to the North Atlantic Oscillation
(NAO). No statistically significant linear increase or decrease
was found in any of the storm parameters over the period of
interest. The main pattern of storm characteristics and extreme
wave heights is an oscillatory variability with intensity
peaks every 7â8 yr, and the magnitude of recent variations
is comparable with that of variations observed in the earlier
parts of the record. In addition, the results reveal that the
NAO index is able to explain only a small percentage of the
variation in storm wave height, suggesting that more local
factors may be of importance in controlling storminess in this
region.info:eu-repo/semantics/publishedVersio
Role of Atmospheric Indices in Describing Inshore Directional Wave Climate in the United Kingdom and Ireland
Improved understanding of how our coasts will evolve over a range of time scales (yearsâdecades) is critical for effective and sustainable management of coastal infrastructure. A robust knowledge of the spatial, directional and temporal variability of the inshore wave climate is required to predict future coastal evolution and hence vulnerability. However, the variability of the inshore directional wave climate has received little attention, and an improved understanding could drive development of skillful seasonal or decadal forecasts of coastal response. We examine inshore wave climate at 63 locations throughout the United Kingdom and Ireland (1980â2017) and show that 73% are directionally bimodal. We find that winterâaveraged expressions of six leading atmospheric indices are strongly correlated (r = 0.60â0.87) with both total and directional winter wave power (peak spectral wave direction) at all studied sites. Regional inshore wave climate classification through hierarchical cluster analysis and stepwise multiâlinear regression of directional wave correlations with atmospheric indices defined four spatially coherent regions. We show that combinations of indices have significant skill in predicting directional wave climates (R2 = 0.45â0.8; p<0.05). We demonstrate for the first time the significant explanatory power of leading winterâaveraged atmospheric indices for directional wave climates, and show that leading seasonal forecasts of the NAO skillfully predict wave climate in some regions.
Plain Language Summary
Understanding the seasonal variability in wave climate around our coasts is fundamental for improving our understanding of how coasts will respond to climate change and seaâlevel rise. Recent research has highlighted the importance of wave direction on coastal response. In this study we specifically explore the seasonal variability in wave direction throughout the inshore regions of the United Kingdom and Ireland at 63 locations between 1980 and 2017. We find that 73% of sites examined are directionally bimodal. We also find that combinations of six of the regions leading climate indices (NAO, AO, WEPA, EA, SCAND, EA/WR) are strongly correlated with both total and directional winter wave power at all the studied sites. We show that regression models using combinations of these climate indices have significant skill in predicting directional wave climates over the period 1980â2017. For the first time we show that 'seasonal ahead' forecasts of the NAO can skilfully predict wave climate in some regions of the United Kingdom and Ireland, which could be used as tool to support coastal hazard mitigation
The Sea State CCI dataset v1: towards a sea state climate data record based on satellite observations
Sea state data are of major importance for climate studies, marine engineering, safety at sea and coastal management. However, long-term sea state datasets are sparse and not always consistent, and sea state data users still mostly rely on numerical wave models for research and engineering applications. Facing the urgent need for a sea state climate data record, the Global Climate Observing System has listed âSea Stateâ as an Essential Climate Variable (ECV), fostering the launch in 2018 of the Sea State Climate Change Initiative (CCI). The CCI is a programme of the European Space Agency, whose objective is to realise the full potential of global Earth observation archives established by ESA and its member states in order to contribute to the ECV database. This paper presents the implementation of the ïŹrst release of the Sea State CCI dataset, the implementation and beneïŹts of a high-level denoising method, its validation against in situ measurements and numerical model outputs, and the future developments considered within the Sea State CCI project. The Sea State CCI dataset v1 is freely available on the ESA CCI website (http://cci.esa.int/data, last access: 25 August 2020) at ftp://anon-ftp.ceda.ac.uk/neodc/esacci/sea_state/data/v1.1_release/ (last access: 25 August 2020). Three products are available: a multi-mission along-track L2P product (http://dx.doi.org/ 10.5285/f91cd3ee7b6243d5b7d41b9beaf397e1, PiollĂ© et al., 2020a), a daily merged multi mission along-track L3 product (http://dx.doi.org/10.5285/3ef6a5a66e9947d39b356251909dc12b, PiollĂ© et al., 2020b) and a multimission monthly gridded L4 product (http://dx.doi.org/10.5285/47140d618dcc40309e1edbca7e773478, PiollĂ© et al., 2020c)
More Accurate Insight into the Incidence of Human Rabies in Developing Countries through Validated Laboratory Techniques
International audienceNo abstract availabl
A recent increase in global wave power as a consequence of oceanic warming
Wind-generated ocean waves drive important coastal processes that determine flooding and erosion. Ocean warming has been one factor affecting waves globally. Most studies have focused on studying parameters such as wave heights, but a systematic, global and long-term signal of climate change in global wave behavior remains undetermined. Here we show that the global wave power, which is the transport of the energy transferred from the wind into sea-surface motion, has increased globally (0.4% per year) and by ocean basins since 1948. We also find long-term correlations and statistical dependency with sea surface temperatures, globally and by ocean sub-basins, particularly between the tropical Atlantic temperatures and the wave power in high south latitudes, the most energetic region globally. Results indicate the upper-ocean warming, a consequence of anthropogenic global warming, is changing the global wave climate, making waves stronger. This identifies wave power as a potentially valuable climate change indicator.Funding for this project was partly provided by RISKOADAPT (BIA2017-89401-R) Spanish Ministry of Science, Innovation and Universities and the ECLISEA project part of the Horizon 2020 ERANET ERA4CS (European Research Area for Climate Services) 2016 Call
Altimetry for the future: Building on 25 years of progress
In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the âGreenâ Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instrumentsâ development and satellite missionsâ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion
Variability in storm climate along the Gulf of Cadiz: the role of large scale atmospheric forcing and implications to coastal hazards
In the context of increased coastal hazards due
to variability in storminess patterns, the danger of coastal
damages and/or morphological changes is related to the
sum of sea level conditions, storm surge, maximum wave
height and run up values. In order to better understand the
physical processes that cause the variability of the above
parameters a 44 years reanalysis record (HIPOCAS) was
used. The HIPOCAS time-series was validated with real
wave and sea-level data using linear and vector correlation
methods. In the present work changes in the magnitude,
duration, frequency and approach direction of the Atlantic
storms over the Gulf of Cadiz (SW Iberian Peninsula)
were identified by computing various storm characteristics
such as maximum wave height, total energy per storm wave
direction and storm duration. The obtained time-series were
compared with large-scale atmospheric indices such as the
North Atlantic Oscillation (NAO) and the East Atlantic pattern.
The results show a good correlation between negative
NAO values and increased storminess over the entire Gulf of Cadiz. Furthermore, negative NAO values were correlated
with high residual sea level values. Finally, a joint
probability analysis of storm and sea level analysis resulted
in increased probabilities of the two events happening at
the same time indicating higher vulnerability of the coast
and increased coastal risks. The above results were compared
with coastal inundation events that took place over
the last winter seasons in the province of Cadiz.info:eu-repo/semantics/publishedVersio
A review of the human vs. porcine female genital tract and associated immune system in the perspective of using minipigs as a model of human genital Chlamydia infection
International audienceAbstractSexually transmitted diseases constitute major health issues and their prevention and treatment continue to challenge the health care systems worldwide. Animal models are essential for a deeper understanding of the diseases and the development of safe and protective vaccines. Currently a good predictive non-rodent model is needed for the study of genital chlamydia in women. The pig has become an increasingly popular model for human diseases due to its close similarities to humans. The aim of this review is to compare the porcine and human female genital tract and associated immune system in the perspective of genital Chlamydia infection. The comparison of women and sows has shown that despite some gross anatomical differences, the structures and proportion of layers undergoing cyclic alterations are very similar. Reproductive hormonal cycles are closely related, only showing a slight difference in cycle length and source of luteolysing hormone. The epithelium and functional layers of the endometrium show similar cyclic changes. The immune system in pigs is very similar to that of humans, even though pigs have a higher percentage of CD4+/CD8+ double positive T cells. The genital immune system is also very similar in terms of the cyclic fluctuations in the mucosal antibody levels, but differs slightly regarding immune cell infiltration in the genital mucosa - predominantly due to the influx of neutrophils in the porcine endometrium during estrus. The vaginal flora in Göttingen Minipigs is not dominated by lactobacilli as in humans. The vaginal pH is around 7 in Göttingen Minipigs, compared to the more acidic vaginal pH around 3.5â5 in women. This review reveals important similarities between the human and porcine female reproductive tracts and proposes the pig as an advantageous supplementary model of human genital Chlamydia infection
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