Australia, Blog, coastal flooding, Journal paper, science, sea level, storm surge

New paper just published – land sinks around parts of Australia with passage of tropical cyclones.

We have just had a new paper (‘Non-linear motions of Australian geodetic stations induced by non-tidal ocean loading and the passage of tropical cyclones’) published in the journal of Journal of Geodesy – see here.

In this paper we examined movements in land around Australia using time-series from stations fitted with continuous GPS. Most people think the land is completely stable, but actually the land moves each day by a few millimetres for a variety of reasons. Here we show that land around parts of Australia sunk when cyclone Yasi crossed the Australian coast in January/February 2011. This cyclone generated a large storm surge and the extra weight of this large volume of water near the coast actually resulting in the land dropping slightly.

A earlier study (see here) showed the same thing happens around the North Sea coastlines when big storm surges happen there.

 

 

 

 

Blog, science

Our Oceans Conference

In June, the US Department of State will host the “Our Ocean” Conference – see link. I enjoyed watching this introductory video by Secretary Kerry. I particularly liked the quote by great ocean explorer Jacques Cousteau:

‘For most of history man has had to fight nature to survive. In this century he is beginning to realise in  order to live, he must be must project it’.

 

Australia, Blog, coast, coastal flooding, extreme events, flooding, Journal paper, science, sea level, storm surge, tides

New paper, just published: Australian Sea Levels – Trends, Regional Variability and Influencing Factors

While there has been significant progress in describing and understanding global-mean sea-level rise, the regional departures from this global-mean rise are more poorly described and understood. In this new paper, which you can view here, we present a comprehensive analysis of Australian sea-level data from the 1880s to the present, including an assessment of satellite-altimeter data since 1993.

We find that After the influence of El Niño Southern Oscillation is removed and allowing for the impact of Glacial Isostatic Adjustment and atmospheric pressure effects, Australian mean sea-level trends are close to global-mean trends from 1966 to 2010, including an increase in the rate of rise in the early 1990s. Given that past changes in Australian sea level are similar to global-mean changes over the last 45 years, it is likely that future changes over the 21st century will be consistent with global changes.

 

Blog, coast, science, sea level

Back to the future to determine if sea level rise is accelerating

Here is the press release from my recent paper published in Nature Communications – ‘Time-scales for detecting a significant acceleration in sea level rise’.

———-

Scientists from Ocean and Earth Southampton and National Oceanography Centre Southampton have developed a new method for revealing how sea levels might rise around the world throughout the 21st century to address the controversial topic of whether the rate of sea level rise is currently increasing.

The international team of researchers, led by the University of Southampton and including scientists from the National Oceanography Centre, the University of Western Australia, the University of South Florida, the Australian National University and the University of Seigen in Germany, analysed data from 10 long-term sea level monitoring stations located around the world. They looked into the future to identify the timing at which sea level accelerations might first be recognised in a significant manner.

Lead author Dr Ivan Haigh, Lecturer in Coastal Oceanography at the University of Southampton, says: “Our results show that by 2020 to 2030, we could have some statistical certainty of what the sea level rise situation will look like for the end of the century. That means we’ll know what to expect and have 70 years to plan. In a subject that has so much uncertainty, this gives us the gift of long-term planning.

“As cities, including London, continue to plan for long-term solutions to sea level rise, we will be in a position to better predict the long-term situation for the UK capital and other coastal areas across the planet. Scientists should continue to update the analysis every 5 to 10 years, creating more certainty in long-term planning – and helping develop solutions for a changing planet.”

The study found that the most important approach to the earliest possible detection of a significant sea level acceleration lies in improved understanding (and subsequent removal) of interannual (occurring between years, or from one year to the next) to multidecadal (involving multiple decades) variability in sea level records.

“The measured sea levels reflect a variety of processes operating at different time scales,” says co-author Dr Francisco Calafat, from the National Oceanography Centre. He adds, “One of the main difficulties in detecting sea level accelerations is the presence of decadal and multi-decadal variations. For example, processes associated with the North Atlantic Oscillation have a strong influence on the sea levels around the UK over multi-decadal periods.  Such processes introduce a large amount of ‘noise’ into the record, masking any underlying acceleration in the rate of rise. Our study shows, that by adequately understanding these processes and removing their influence, we can detect accelerations much earlier.”

Co-author Professor Eelco Rohling, from the Australian National University and formerly of the University of Southampton, adds: “By developing a novel method that realistically approximates future sea level rise, we have been able to add new insight to the debate and show that there is substantial evidence for a significant recent acceleration in the sea level rise on a global and regional level. However, due to the large ‘noise’ signals at some local coastal sites, it won’t be until later this decade or early next decade before the accelerations in sea level are detection at these individual tide gauge sites.”

The findings of the study, funded by the Natural Environmental Research Council (iGlass consortium), are published in this months issue of the journal Nature Communications.

Blog, coast, Journal paper, science, sea level

New journal paper in Nature Communications – Timescales for detecting a significant acceleration in sea level rise

Very pleased to announce our new paper – published this month in Nature Communcations, called ‘Timescales for detecting a significant acceleration in sea level rise’.

The paper is open access and you can read it here:

http://www.nature.com/ncomms/2014/140414/ncomms4635/full/ncomms4635.html