Calafat, Francisco Mir

Dangendorf, Sönke

Haigh, Ivan D.

Marcos, Marta

Frontiers in Marine Science

Ivan D. Haigh

Marta Marcos

Sönke Dangendorf

Francisco Mir Calafat

Frontiers - Publisher Connector

EDITORIAL
published: 22 February 2017
doi: 10.3389/fmars.2017.00046
Frontiers in Marine Science | www.frontiersin.org 1 February 2017 | Volume 4 | Article 46
Edited and reviewed by:
Isabel Iglesias,
Interdisciplinary Centre of Marine and
Environmental Research, Portugal
*Correspondence:
Ivan D. Haigh
i.d.haigh@soton.ac.uk
Specialty section:
This article was submitted to
Coastal Ocean Processes,
a section of the journal
Frontiers in Marine Science
Received: 14 December 2016
Accepted: 09 February 2017
Published: 22 February 2017
Citation:
Haigh ID, Marcos M, Dangendorf S
and Mir Calafat F (2017) Editorial: Sea
Level Variability and Change.
Front. Mar. Sci. 4:46.
doi: 10.3389/fmars.2017.00046
Editorial: Sea Level Variability and
Change
Ivan D. Haigh 1*, Marta Marcos 2, Sönke Dangendorf 3 and Francisco Mir Calafat 4
1Ocean and Earth Sciences, National Oceanography Centre, University of Southampton, Southampton, UK, 2Mediterranean
Institute for Advanced Studies (CSIC), Esporles, Spain, 3Department of Civil Engineering, Research Institute for Water and
Environment, University of Siegen, Siegen, Germany, 4National Oceanography Centre, Liverpool, UK
Keywords: sea level, coastal flooding, extreme events, tides, storm, storm surges, mean sea level
Editorial on the Research Topic
Sea Level Variability and Change
There is strong observational evidence that global mean sea levels are rising and there is great
concern that the rate of rise will accelerate throughout the twenty-first century and beyond,
significantly threatening coastal communities (Church et al., 2013; IPCC, 2014). With rapid
population growth and accompanying infrastructure development at the coast, modern society has
become increasingly vulnerable to even small changes in sea level. More than 600 million people
currently live in coastal areas with an elevation less than 10m above present-day mean sea level
(McGranahan et al., 2007). An assessment of 136 of the world’s largest port cities estimated that,
by the 2070s, the population exposed to flooding risk may grow by more than a factor of three in
these cities due to the combined effects of sea level rise, land subsidence, population growth, and
urbanization, with asset exposure increasing to more than 10 times that of current levels (Hallegatte
et al., 2013). Therefore, understanding future sea level rise and variability is an urgent issue of
utmost importance.
The 12 articles in this Research Topic assess sea level change and variability on a range of
different temporal (from minute to hundreds of years) and spatial (individual beach to global)
scales.
The first contribution to this Research Topic considers tides, which dominate sea level variability
in a large proportion of the world’s oceans. In a perspective article, Medvedev et al. evaluate the
nature of tides in three enclosed basins, namely the Baltic, Black, and Caspian seas. Oceanic tides
penetrate only weakly, or not at all, into these enclosed basins and consequently direct forcing of
tides dominates the variability. The authors use spectral analysis on long observation time series
and find that the formation and predominance of diurnal or semidiurnal tides in these seas appears
to depend on the frequency-selective properties of the respective basins.
The next four contributions deal with meteorological influences on sea level. Vilibic´ et al.
focus on meteotsunamis, which are atmospherically generated long ocean waves in the tsunami
frequency band. Understanding of meteotsunamis has advanced considerably during the last
two decades and the authors identify key research gaps and discuss different approaches for
developing meteotsunami warning systems. Pérez-Gómez et al. analyse the characteristics of two
high frequency sea level events recorded in European Atlantic waters, using sea level, wave,
atmospheric pressure and wind datasets. The first event was associated with possible wave-induced
“seiches” that occurred along the North coast of Spain during the storms of January/February
2014 and the second was a series of small sea level oscillations detected after an earthquake in the
mid-Atlantic in February 2015. They consider these events in regard to the limitations of automatic
Haigh et al. Editorial: Sea Level Variability and Change
algorithms for tsunami warning. Wadey et al. undertake a
detail comparison of two key North Sea coastal flooding events
that have occurred in the last 60 years. These events are the
“Big Flood” of 31 January–1 February 1953 and the recent
5–6 December 2013 event. Using a range of oceanographic
and meteorological datasets they: contrast the meteorological
forcing; compare the high sea levels observed during both
events; compare the coastal flooding and impact; and discuss
the role of the improved flood defenses and storm surge
forecasting since 1953. Using a set of 220 tide gauges, Mawdsley
and Haigh investigate the temporal variations in storm surges
around the world and the spatial coherence of its variability.
They compare results derived from two parameters used to
represent storm surge (skew surge and the more traditional,
non-tidal residual) and compare inter-annual and multi-decadal
variations in skew surge with fluctuations in regional climate
indices. They find that using skew surge time-series improves
estimation of long-term trends in storm surges, because phase
offsets caused by time errors are not present in skew surge
time-series.
Three contributions deal with longer-term changes in mean
sea level. Hünicke and Zorita analyse mean sea level records in
the Baltic and parts of the North Sea with the aim of detecting
an acceleration of sea-level rise over the twentieth and twenty-
first centuries associated with climate change. Comparing a range
of statistical methods they find positive, but not statistically
significant, acceleration in the Baltic Sea area since 1900. They
highlight that the failure to detect a significant acceleration
in sea level could be due to the still small magnitude of the
acceleration paired with high inter-annual sea-level variability at
the regional scale, rather than the absence of acceleration linked
to climate change. Andersen and Piccioni present an updated
and improved version of the Danish Technical University’s
Arctic Ocean altimetric sea level time-series and use it to assess
trends in mean sea level in this region. They find a total sea
level rise of 2.2 ± 1.1 mm/yr and a significant increase of 15
mm/yr in the Beaufort Sea, corresponding to changes in the
Beaufort Gyre relating to wind driven phenomenon that leads
to freshwater accumulation. Using individual contributors the
authors were also able to assess and close the Arctic sea level
trend budget over the period 2005–2015 within the error bars,
for the first time. Using optimal estimation, Fu analyses statistical
properties of decadal global mean sea level variability, which
is of importance to understanding its longer-term evolution
with climate change. He finds that the estimated standard
error of the trend determined from the global mean sea level
record from radar altimetry is about 0.3 mm/yr on decadal
scales, which is comparable to the widely quoted 0.4 mm/yr
systematic error and can therefore not be neglected in the error
budget.
Another two contributions to this Research Topic are related
to the interplay between changes in sea level and coastal
morphology. Ulm et al. investigate the impact a loss of a Barrier
island would have on water levels and waves along the coastline
of Tampa Bay. Barrier Islands make up an eight of the world’s
coastlines and buffer the mainland coastal areas from storm
surge and wave energy. Using a numerical model, they find that
that loss of the Egmont Key Island at the entrance to Tampa
Bay would result in significantly increased water level and wave
heights in the Bay. Le Cozannet et al. consider the applicability
of the widely-used Bruun rule in predicting shoreline retreat on
sandy beaches with sea level rise. Considering probabilistic sea-
level rise scenarios, they propagated these uncertainties through
the sediment balance equation, that sums the Bruun effect with
other drivers in an attempt to better understand where and when
the Bruun rule can be (in)validated. Their results confirm that
low-energy gently sloping beaches with little human impacts and
small gradients in longshore drift and sheltered from storms are
the most relevant to assess the validity of the Bruun rule in the
sediment balance equation.
The final two contributions deal with impacts of sea level
change on coastal communities. Sorensen et al. investigate
couplings between sea state and flood hazard at present and
in the future for the town of Thyboron in Denmark. Using
a range of datasets and stakeholder interviews, their study
includes a detailed analysis of change and variability in the
groundwater table, precipitation, land motion, geotechnical
ground properties, sewerage systems, and other infrastructure.
They find that apart from obvious adverse effects from future
storm surge events, knowledge about the coupled effects
of the abovementioned parameters needs to be taken into
account to reach optimal mitigation and adaptation measures.
Wolff et al. assess sea-level rise related coastal flood impacts
for Emilia-Romagna in Italy using the Dynamic Interactive
Vulnerability Assessment (DIVA) modeling framework.
Their results emphasize that the scale of assessment and
resolution of the input data can have significant implications
for the results of coastal flood impact assessments. They
highlight that understanding and communicating these
implications is essential for effectively supporting decision
makers in developing long-term robust and flexible adaptation
plans.
Overall, these papers illustrate the multi-disciplinary nature of
sea level research, cross-cuttingmany fields of research including:
oceanography, meteorology, geology, coastal morphodynamics,
engineering, and the social-economic aspects. Collectively,
the articles in this Research Topic represent an interesting
range of perspectives and original studies that contribute to
understanding the dynamic nature of sea level and its impacts
across a wide range of time and space scales. Enjoy reading
them!
AUTHOR CONTRIBUTIONS
IH, MM, SD, and FM co-wrote this editorial.
ACKNOWLEDGMENTS
We thank the authors of the papers included in this Research
Topic for their excellent contributions.
Frontiers in Marine Science | www.frontiersin.org 2 February 2017 | Volume 4 | Article 46
Haigh et al. Editorial: Sea Level Variability and Change
REFERENCES
Church, J. A., Clark, P. U., Cazenave, A., Gregory, J. M., Jevrejeva, S., Levermann,
A., et al. (2013). “Sea Level Change. Climate Change 2013: The Physical Science
Basis,” in Contribution of Working Group I to the Fifth Assessment Report of
the Intergovernmental Panel on Climate Change, eds T. F. Stocker, D. Qin, G.-
K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex,
and P. M. Midgley (Cambridge, UK; New York, NY: Cambridge University
Press).
Hallegatte, S., Green, C., Nicholls, R. J., and Corfee-Morlot, J. (2013).
Future flood losses in major coastal cities. Nat. Clim. Change 3, 802–806.
doi: 10.1038/nclimate1979
IPCC (2014). “Climate Change 2014: “Synthesis Report,” in Contribution of
Working Groups, I, II and III to the Fifth Assessment Report of the
Intergovernmental Panel on Climate Change, eds R. K. Pachauri and L. A.Meyer
(Geneva: Core Writing Team; IPCC), 151.
McGranahan, G., Balk, D., and Anderson, B. (2007). The rising tide: assessing the
risks of climate change and human settlements in low elevation coastal zones.
Environ. Urban. Copyr. 19, 17–37. doi: 10.1177/0956247807076960
Conflict of Interest Statement: The authors declare that the research
was conducted in the absence of any commercial or financial
relationships that could be construed as a potential conflict of
interest.
Copyright © 2017 Haigh, Marcos, Dangendorf and Mir Calafat. This is an open-
access article distributed under the terms of the Creative Commons Attribution
License (CC BY). The use, distribution or reproduction in other forums is permitted,
provided the original author(s) or licensor are credited and that the original
publication in this journal is cited, in accordance with accepted academic practice.
No use, distribution or reproduction is permitted which does not comply with these
terms.
Frontiers in Marine Science | www.frontiersin.org 3 February 2017 | Volume 4 | Article 46


Editorial: Sea Level Variability and Change

Crossref

In June 2015 we held a workshop on the beautiful island of Mallorca, Spain with a focus on sea level variability and change. Over 120 sea level experts from around the world attended this workshop, from a range of different disciplines. The main aims of the workshop were to: 1.) Evaluate the current state-of-knowledge of sea level science; 2.) Identify gaps and unresolved questions in any aspect of sea level science; and 3.) Design future research to address these issue. All aspects of sea level changes were covered, from global to regional, observations and modelling, processes driving mean sea level changes and extremes, from the geological scale to the instrumental era and future projections and including impacts on the coastal zones. This E-Book presents papers that came out of that workshop. Overall, these papers illustrate the multi-disciplinary nature of sea level research, cross-cutting many fields of research including: oceanography, meteorology, geology, coastal morphodynamics, engineering and the social-economic aspects. Collectively, theses articles represent an interesting range of perspectives and original studies that contribute to understanding the dynamic nature of sea level and its impacts across a wide range of time and space scales. Enjoy reading them

Sonke Dangendorf

Francisco Calafat

Directory of Open Access Books (DOAB)

Sea Level Variability and Change

NERC Open Research Archive

EDITORIALpublished: 22 February 2017doi: 10.3389/fmars.2017.00046Frontiers in Marine Science | www.frontiersin.org 1 February 2017 | Volume 4 | Article 46Edited and reviewed by:Isabel Iglesias,Interdisciplinary Centre of Marine andEnvironmental Research, Portugal*Correspondence:Ivan D. Haighi.d.haigh@soton.ac.ukSpecialty section:This article was submitted toCoastal Ocean Processes,a section of the journalFrontiers in Marine ScienceReceived: 14 December 2016Accepted: 09 February 2017Published: 22 February 2017Citation:Haigh ID, Marcos M, Dangendorf Sand Mir Calafat F (2017) Editorial: SeaLevel Variability and Change.Front. Mar. Sci. 4:46.doi: 10.3389/fmars.2017.00046Editorial: Sea Level Variability andChangeIvan D. Haigh 1*, Marta Marcos 2, Sönke Dangendorf 3 and Francisco Mir Calafat 41Ocean and Earth Sciences, National Oceanography Centre, University of Southampton, Southampton, UK, 2MediterraneanInstitute for Advanced Studies (CSIC), Esporles, Spain, 3Department of Civil Engineering, Research Institute for Water andEnvironment, University of Siegen, Siegen, Germany, 4National Oceanography Centre, Liverpool, UKKeywords: sea level, coastal flooding, extreme events, tides, storm, storm surges, mean sea levelEditorial on the Research TopicSea Level Variability and ChangeThere is strong observational evidence that global mean sea levels are rising and there is greatconcern that the rate of rise will accelerate throughout the twenty-first century and beyond,significantly threatening coastal communities (Church et al., 2013; IPCC, 2014). With rapidpopulation growth and accompanying infrastructure development at the coast, modern society hasbecome increasingly vulnerable to even small changes in sea level. More than 600 million peoplecurrently live in coastal areas with an elevation less than 10m above present-day mean sea level(McGranahan et al., 2007). An assessment of 136 of the world’s largest port cities estimated that,by the 2070s, the population exposed to flooding risk may grow by more than a factor of three inthese cities due to the combined effects of sea level rise, land subsidence, population growth, andurbanization, with asset exposure increasing to more than 10 times that of current levels (Hallegatteet al., 2013). Therefore, understanding future sea level rise and variability is an urgent issue ofutmost importance.The 12 articles in this Research Topic assess sea level change and variability on a range ofdifferent temporal (from minute to hundreds of years) and spatial (individual beach to global)scales.The first contribution to this Research Topic considers tides, which dominate sea level variabilityin a large proportion of the world’s oceans. In a perspective article, Medvedev et al. evaluate thenature of tides in three enclosed basins, namely the Baltic, Black, and Caspian seas. Oceanic tidespenetrate only weakly, or not at all, into these enclosed basins and consequently direct forcing oftides dominates the variability. The authors use spectral analysis on long observation time seriesand find that the formation and predominance of diurnal or semidiurnal tides in these seas appearsto depend on the frequency-selective properties of the respective basins.The next four contributions deal with meteorological influences on sea level. Vilibic´ et al.focus on meteotsunamis, which are atmospherically generated long ocean waves in the tsunamifrequency band. Understanding of meteotsunamis has advanced considerably during the lasttwo decades and the authors identify key research gaps and discuss different approaches fordeveloping meteotsunami warning systems. Pérez-Gómez et al. analyse the characteristics of twohigh frequency sea level events recorded in European Atlantic waters, using sea level, wave,atmospheric pressure and wind datasets. The first event was associated with possible wave-induced“seiches” that occurred along the North coast of Spain during the storms of January/February2014 and the second was a series of small sea level oscillations detected after an earthquake in themid-Atlantic in February 2015. They consider these events in regard to the limitations of automaticHaigh et al. Editorial: Sea Level Variability and Changealgorithms for tsunami warning. Wadey et al. undertake adetail comparison of two key North Sea coastal flooding eventsthat have occurred in the last 60 years. These events are the“Big Flood” of 31 January–1 February 1953 and the recent5–6 December 2013 event. Using a range of oceanographicand meteorological datasets they: contrast the meteorologicalforcing; compare the high sea levels observed during bothevents; compare the coastal flooding and impact; and discussthe role of the improved flood defenses and storm surgeforecasting since 1953. Using a set of 220 tide gauges, Mawdsleyand Haigh investigate the temporal variations in storm surgesaround the world and the spatial coherence of its variability.They compare results derived from two parameters used torepresent storm surge (skew surge and the more traditional,non-tidal residual) and compare inter-annual and multi-decadalvariations in skew surge with fluctuations in regional climateindices. They find that using skew surge time-series improvesestimation of long-term trends in storm surges, because phaseoffsets caused by time errors are not present in skew surgetime-series.Three contributions deal with longer-term changes in meansea level. Hünicke and Zorita analyse mean sea level records inthe Baltic and parts of the North Sea with the aim of detectingan acceleration of sea-level rise over the twentieth and twenty-first centuries associated with climate change. Comparing a rangeof statistical methods they find positive, but not statisticallysignificant, acceleration in the Baltic Sea area since 1900. Theyhighlight that the failure to detect a significant accelerationin sea level could be due to the still small magnitude of theacceleration paired with high inter-annual sea-level variability atthe regional scale, rather than the absence of acceleration linkedto climate change. Andersen and Piccioni present an updatedand improved version of the Danish Technical University’sArctic Ocean altimetric sea level time-series and use it to assesstrends in mean sea level in this region. They find a total sealevel rise of 2.2 ± 1.1 mm/yr and a significant increase of 15mm/yr in the Beaufort Sea, corresponding to changes in theBeaufort Gyre relating to wind driven phenomenon that leadsto freshwater accumulation. Using individual contributors theauthors were also able to assess and close the Arctic sea leveltrend budget over the period 2005–2015 within the error bars,for the first time. Using optimal estimation, Fu analyses statisticalproperties of decadal global mean sea level variability, whichis of importance to understanding its longer-term evolutionwith climate change. He finds that the estimated standarderror of the trend determined from the global mean sea levelrecord from radar altimetry is about 0.3 mm/yr on decadalscales, which is comparable to the widely quoted 0.4 mm/yrsystematic error and can therefore not be neglected in the errorbudget.Another two contributions to this Research Topic are relatedto the interplay between changes in sea level and coastalmorphology. Ulm et al. investigate the impact a loss of a Barrierisland would have on water levels and waves along the coastlineof Tampa Bay. Barrier Islands make up an eight of the world’scoastlines and buffer the mainland coastal areas from stormsurge and wave energy. Using a numerical model, they find thatthat loss of the Egmont Key Island at the entrance to TampaBay would result in significantly increased water level and waveheights in the Bay. Le Cozannet et al. consider the applicabilityof the widely-used Bruun rule in predicting shoreline retreat onsandy beaches with sea level rise. Considering probabilistic sea-level rise scenarios, they propagated these uncertainties throughthe sediment balance equation, that sums the Bruun effect withother drivers in an attempt to better understand where and whenthe Bruun rule can be (in)validated. Their results confirm thatlow-energy gently sloping beaches with little human impacts andsmall gradients in longshore drift and sheltered from storms arethe most relevant to assess the validity of the Bruun rule in thesediment balance equation.The final two contributions deal with impacts of sea levelchange on coastal communities. Sorensen et al. investigatecouplings between sea state and flood hazard at present andin the future for the town of Thyboron in Denmark. Usinga range of datasets and stakeholder interviews, their studyincludes a detailed analysis of change and variability in thegroundwater table, precipitation, land motion, geotechnicalground properties, sewerage systems, and other infrastructure.They find that apart from obvious adverse effects from futurestorm surge events, knowledge about the coupled effectsof the abovementioned parameters needs to be taken intoaccount to reach optimal mitigation and adaptation measures.Wolff et al. assess sea-level rise related coastal flood impactsfor Emilia-Romagna in Italy using the Dynamic InteractiveVulnerability Assessment (DIVA) modeling framework.Their results emphasize that the scale of assessment andresolution of the input data can have significant implicationsfor the results of coastal flood impact assessments. Theyhighlight that understanding and communicating theseimplications is essential for effectively supporting decisionmakers in developing long-term robust and flexible adaptationplans.Overall, these papers illustrate the multi-disciplinary nature ofsea level research, cross-cuttingmany fields of research including:oceanography, meteorology, geology, coastal morphodynamics,engineering, and the social-economic aspects. Collectively,the articles in this Research Topic represent an interestingrange of perspectives and original studies that contribute tounderstanding the dynamic nature of sea level and its impactsacross a wide range of time and space scales. Enjoy readingthem!AUTHOR CONTRIBUTIONSIH, MM, SD, and FM co-wrote this editorial.ACKNOWLEDGMENTSWe thank the authors of the papers included in this ResearchTopic for their excellent contributions.Frontiers in Marine Science | www.frontiersin.org 2 February 2017 | Volume 4 | Article 46Haigh et al. Editorial: Sea Level Variability and ChangeREFERENCESChurch, J. A., Clark, P. U., Cazenave, A., Gregory, J. M., Jevrejeva, S., Levermann,A., et al. (2013). “Sea Level Change. Climate Change 2013: The Physical ScienceBasis,” in Contribution of Working Group I to the Fifth Assessment Report ofthe Intergovernmental Panel on Climate Change, eds T. F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex,and P. M. Midgley (Cambridge, UK; New York, NY: Cambridge UniversityPress).Hallegatte, S., Green, C., Nicholls, R. J., and Corfee-Morlot, J. (2013).Future flood losses in major coastal cities. Nat. Clim. Change 3, 802–806.doi: 10.1038/nclimate1979IPCC (2014). “Climate Change 2014: “Synthesis Report,” in Contribution ofWorking Groups, I, II and III to the Fifth Assessment Report of theIntergovernmental Panel on Climate Change, eds R. K. Pachauri and L. A.Meyer(Geneva: Core Writing Team; IPCC), 151.McGranahan, G., Balk, D., and Anderson, B. (2007). The rising tide: assessing therisks of climate change and human settlements in low elevation coastal zones.Environ. Urban. Copyr. 19, 17–37. doi: 10.1177/0956247807076960Conflict of Interest Statement: The authors declare that the researchwas conducted in the absence of any commercial or financialrelationships that could be construed as a potential conflict ofinterest.Copyright © 2017 Haigh, Marcos, Dangendorf and Mir Calafat. This is an open-access article distributed under the terms of the Creative Commons AttributionLicense (CC BY). The use, distribution or reproduction in other forums is permitted,provided the original author(s) or licensor are credited and that the originalpublication in this journal is cited, in accordance with accepted academic practice.No use, distribution or reproduction is permitted which does not comply with theseterms.Frontiers in Marine Science | www.frontiersin.org 3 February 2017 | Volume 4 | Article 46

Editorial: Sea level variability and change

Mir Calafat, Francisco

Digital.CSIC

http://nora.nerc.ac.uk/517451/1/fmars-04-00046.pdf

Editorial: Sea level variability and change

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