Atmosphere to ocean momentum transfer by sea ice

Lead Research Organisation: University College London
Department Name: Earth Sciences

Abstract

In response to global warming, the ice covers of the Arctic and Antarctic are changing, with a significant reduction in the summer extent of Arctic sea ice. The reduction of Arctic sea ice is more rapid and extreme than climate models predict, suggesting that these models do not adequately represent the processes controlling this reduction.
The reduced summer Arctic sea ice cover, and changes to the winter sea ice cover, affect the mechanical and thermodynamic coupling between the air and ocean. In fact, observations show that the sea ice cover has become more mobile in the last 15 years and that there has been an increase in the mean ocean circulation beneath the sea ice. Since, over the same period, there has not been an observed increase in wind strength, this suggests that changes to the sea ice cover itself are responsible for an enhanced ice motion and transfer of wind stress to the ocean beneath sea ice.
Our project hypothesis is: Changes in the Arctic sea ice cover have resulted in a more efficient transfer of momentum between the air and ocean, resulting in spin up of sea ice and the Arctic Ocean. We will test this hypothesis with a combination of new data, theory and numerical modelling.
We will investigate how changes in the roughness of the ice cover, e.g. through a more dilute ice cover having more floe edges exposed, change the drag forces exerted by the air on the ice and the ice on the ocean. We will investigate how a reduction in the ice cover may reduce the resistance of the ice cover to the wind, allowing it to move more easily. In particular we address the question: to what extent is acceleration of the Arctic sea ice gyre the result of decreased ice forces versus increased drag?
We will use climate models containing new physics calibrated with, and derived from, new observations, to examine the prediction that: Changes in the sea ice cover will continue to lead to enhanced momentum transfer between the air and ocean, resulting in a more mobile and responsive ice cover and enhanced flow and mixing in the Arctic Ocean.
Although we focus our analysis on the Arctic Ocean, where sea ice changes have been more dramatic, we will also examine air-ice-ocean momentum exchanges in the Southern Ocean.
This proposal brings together leading researchers in sea ice dynamics, remote sensing, ocean and climate modelling, and builds upon existing expertise in satellite observation, theory, and modelling of sea ice in the Centre for Polar Observation and Modelling.
In addition to the scientific outcomes, the proposed work will result in new sea ice drag physics being incorporated into a sea ice climate model and delivered to climate modelling groups. This will directly help scientists investigating and predicting future changes to the sea ice cover in the Arctic and Southern Oceans and also help scientists trying to understand and predict changes in the global climate system.

Planned Impact

Arctic sea ice reduction has become a totemic indicator of climate change with impacts on iconic species such as polar bears and the Beluga whale, as well as indigenous human populations. The reduction of Arctic sea ice extent has generated widespread interest with numerous articles in the popular press, radio, television and internet.
Reduction in the sea ice cover is already opening up shipping routes and the potential for oil exploration has generated political statements and actions including, for example, the placement of the Russian flag at the North Pole and Denmark's declaration of sea bed rights up to the North Pole. Lloyd's of London, with Chatham House, published a report called "Arctic Opening" in 2012, with business (including insurance) expansion in mind. A Royal Society meeting on Arctic sea ice: the evidence, models, and global impacts is being organised by the PI in September 2014.
Continued reduction of the sea ice cover is expected to cause enhanced ocean mixing with a consequent impact on water mass transformation and supply of nutrients to the euphotic zone, which are necessary for primary production. The change in ocean and ice is expected to have implications for climate in NW Europe.
A major practical impact of this proposal is in the generation of a more realistic treatment of air to ice to ocean momentum transfer by form drag in the sea ice component of several climate models. The new treatment of air-sea ice-ocean momentum transfer will affect regional ice predictions used to inform government policy and those with financial and societal interest, such as the insurance, shipping and oil industries, as well as Inuit community groups.
The new treatment of form drag will also lead to improved climate prediction studies, used to guide national and international policy on issues related to climate change.

Publications

10 25 50
 
Description This grant is just starting but we have already obtained some important results

- In a publication in JGR 'The impact of variable sea ice roughness on changes in Arctic Ocean surface stress: A model study' we found that the new form drag parameterization developed by CoI Michel Tsamados has the potential to modify significantly the momentum transfer from the atmosphere to the ocean in the Arctic. In fact when switched on the new parameterization results in a negative trend of the Arctic basin integrated total momentum transfer over the satellite period (1979-2016) while when the parameterization is switched off the trend is positive. We have been able using a state of the art sea ice model to show that this is related to the smoothing of the ice associated to its overall thinning

- The second paper has now been published in the Cryosphere.

- Other applications of the methods and ideas developed for the Arctic have been tested and published in the context of air-ice-interactions in the Southern Ocean. See for example

Variability of the Ross Gyre, Southern Ocean: drivers and responses revealed by satellite altimetry
TS Dotto, A Naveira Garabato, S Bacon, M Tsamados, PR Holland, ...

Stress and deformation characteristics of sea ice in a high-resolution, anisotropic sea ice model
H Heorton, DL Feltham, M Tsamados
Philosophical Transactions of the Royal Society A: Mathematical, Physical
Geophysical Research Letters 45 (12), 6195-6204

- In a paper under review in the Cryosphere 'Characterizing Arctic sea ice topography using high-resolution IceBridge data CoI Tsamados in collaboration with researchers from NASA and PI Daniel Feltham have developed a new method to retrieve the 2D sea ice topography from airborne measurements from the Operation IceBridge.
Exploitation Route The project is just only starting
Sectors Aerospace, Defence and Marine,Communities and Social Services/Policy,Environment,Transport

 
Description Again this project is underway but it is expected that the
 
Description NERC standard grant
Amount £641,970 (GBP)
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 01/2018 
End 06/2020
 
Title monthly fields of dynamic ocean topography (DOT) between 60N and 81.5N, for the period 2003-2014 
Description The data consists of monthly fields of dynamic ocean topography (DOT) between 60N and 81.5N, for the period 2003-2014. Envisat data are used for 2003-2011 and CryoSat-2 data are used for 2012-2014. Sea surface height estimates from leads in sea ice-covered regions of the Arctic have been combined with regular open ocean estimates of sea surface height, and data from the two satellites have been cross-calibrated in the mission overlap period (November 2011 - March 2012). 
Type Of Material Database/Collection of data 
Year Produced 2016 
Provided To Others? Yes  
Impact Several publications are in preparation or under review based on this work. Also 2 PhD students cosupervised by CoI Tsamados are currently using this datasets. 
URL http://www.cpom.ucl.ac.uk/dynamic_topography/
 
Description IceBridge data processing 
Organisation National Aeronautics and Space Administration (NASA)
Country United States 
Sector Public 
PI Contribution I have contributed in the processing of the data. I have also helped connect the new dataset to current climate related question regarding the importance of the sea ice topography in the controlling the fluxes of momentum and heat at the ice-ocean and ice-atmosphere interfaces. I have also contributed to the mathematical derivations.
Collaborator Contribution The partners have provided state of the art remote sensing data from the ongoing NASA Operation IceBridge project that was devised to bridge the gap between the two NASA satellite missions ICESAT and ICESAT2
Impact A paper is under revision in the Cryosphere "http://www.the-cryosphere-discuss.net/tc-2015-199/"
Start Year 2014
 
Description Participation in the Mission Advisory Group for the new Sea surface KInematics Multiscale monitoring (SKIM) satellite mission 
Organisation French Research Institute for the Exploitation of the Sea
Country French Polynesia 
Sector Academic/University 
PI Contribution Collaboration with scientists from Europe
Collaborator Contribution SKIM is an ESA satellite mission (now in phase A, possible launch in 2025) that will measure surface currents and ice drift (within 10 cm/s at 40 km resolution) waves spectra (down to 20 m wavelength) over the whole globe from the Antarctic to 82°N. SKIM is one of the 2 missions pre-selected to become Earth Explorer 9. Final selection in 2019.
Impact This new collaboration could result in a new satellite in orbit with a UK participation via UCL
Start Year 2018
 
Description Contributing to the design and content of a Massive Open Online Course (MOOC) funded by the European Space Agency. 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Undergraduate students
Results and Impact This is a project that has been funded by ESA and on which I am currently working. So far I was involved with recording several hours of interviews and footage in the Arctic with a professional equipment lent by ImperativeSpace during my participation in the MOSAiC Arctic expedition.
Year(s) Of Engagement Activity 2020
 
Description Data Sciences for Climate and Environment workshop at the Alan Turing Institute 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Data Sciences for Climate and Environment

Organisers: Michel Tsamados (University College London); Chris Oates (Newcastle University), Richard Smith, (University of North Carolina), and Ruth Petrie, (Rutherford Appleton Laboratory)

Date: 26 March 2018

Venue: The Alan Turing Institute


The Lloyd's Register Foundation (LRF) programme on data-centric engineering at the Alan Turing Institute is delighted to partner with the Statistical and Applied Mathematical Sciences Institute (SAMSI) to present this topical workshop on Data Sciences for Climate and Environment. The LRF programme, which brings together world-leading researchers from around the UK, aims to address the data-centric engineering needs of society and industry - an important component of which is to better understand the risks posed to infrastructure and society by the natural environment.

Collectively, we are modelling and monitoring our planet better than we have ever done in our history, as a result of sustained efforts from the climate modelling community and space agencies and the private sector worldwide. Climate and weather models can now be run at finer spatial resolutions (10km or better), therefore enabling more realistic simulations of smaller and smaller scale processes (i.e. tropical cyclones in the atmosphere or eddies in the ocean) that can have severe impacts on our planet.

At the same time there is a rapid growth in the number of satellites orbiting the Earth (221 launched in 2015, around 5000 in total) with a significant fraction of these satellites dedicated to Earth Observation using a large variety of sensors working at different electromagnetic frequencies (optical, radar, infrared, etc.). Our ability to store, process and share efficiently the vast amounts of data that are produced (~Pb yearly) by the modelling and remote sensing communities is a pre-requisite for the good functioning of these often publicly funded large programmes.

In this one-day workshop our speakers will present on how the new tools developed in data sciences can be applied to questions relating to climate and the environment to help us address the great challenges that our society is facing in a rapidly changing planet. Our event will be structured around five keynote speakers highlighting five separate topics described below and followed by a panel dialogue between our experts and the audience on the topic of Data Sciences for the Climate and the Environment.
Year(s) Of Engagement Activity 2018
URL https://www.turing.ac.uk/events/data-sciences-climate-environment/
 
Description Interview in online scientific page CarbonBrief - 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Inside MOSAiC
The world's largest polar research expedition is currently underway in the Arctic. The year-long expedition, known as the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC), involves 300 researchers from 19 countries. From a ship trapped in the sea ice, scientists are taking measurements that could help to transform climate models. Carbon Brief's science writer Daisy Dunne joined the expedition for its first six weeks in the autumn of 2019. This is the second of four articles focused on the MOSAiC expedition.
Year(s) Of Engagement Activity 2020
URL https://interactive.carbonbrief.org/when-will-the-arctic-see-its-first-ice-free-summer/
 
Description Interview in scientific online magazine Carbbon Brief 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact The world's largest polar research expedition is currently underway in the Arctic. The year-long mission, known as the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC), involves 600 people from 19 countries. From a ship trapped in the sea ice, scientists are taking a diverse range of measurements that could help to transform climate models. Carbon Brief's science writer Daisy Dunne joined the expedition for its first six weeks in the autumn of 2019. This is the first of four articles focused on MOSAiC research.
Year(s) Of Engagement Activity 2020
URL https://www.carbonbrief.org/inside-mosaic-how-a-year-long-arctic-expedition-is-helping-climate-scien...
 
Description Interview in scientific online magazine E&E News - 'We're in the ice!' Vessel shudders as it enters Arctic floe 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact ON BOARD THE AKADEMIK FEDOROV, Barents Sea - Michel Tsamados has studied sea ice for nearly a decade, but until this week he'd never seen it in person.

A physicist at University College London, Tsamados conducts most of his work using satellite data, studying the remote Arctic from afar. That changed late Wednesday night, when the 38-year-old researcher finally witnessed, up close, the focus of his life's work. Standing on the deck of Russian research vessel Akademik Fedorov, cruising through the Arctic Ocean around 81 degrees latitude, he watched a small, gray blob drift into focus. It was his first ice floe.
Year(s) Of Engagement Activity 2020
URL https://www.eenews.net/stories/1061172967
 
Description Interview in scientific online magazine Quanta - The Voyage to the End of Ice 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Interview in

The Voyage to the End of Ice
Arctic ice is disappearing - the question is how fast. Summer sea ice could endure 100 more years, or it could vanish later this decade, with disastrous consequences for the rest of the planet. To nail down the answer, an expedition to the top of the world has to untangle the knotty physics of ice.
Year(s) Of Engagement Activity 2020
URL https://www.quantamagazine.org/the-voyage-to-the-end-of-ice-20200116/
 
Description UCL Lunch hour lecture on "Are we waking up the sleeping Arctic Ocean" 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact UCL lunch hour lectures are a prestigious series of lectures open to the public and held every week at UCL

https://www.youtube.com/watch?v=_yhdnP8suFo
Year(s) Of Engagement Activity 2016
URL https://www.youtube.com/watch?v=_yhdnP8suFo