Primary productivity driven by escalating nutrient fluxes?

Lead Research Organisation: Bangor University
Department Name: Sch of Ocean Sciences

Abstract

The decline of Arctic Ocean seasonal sea ice cover over the past two decades is a major indicator of polar climate change. Over the same period satellite observations have implied that net primary productivity (NPP) has increased by at least 30%. However, the observed increase in net primary productivity is greater than the predicted response to the declining sea ice, and the consequent lengthening of the ice-free season. This implies that the nitrate-limited Arctic marine ecosystems may also be experiencing increasing nutrient availability. Whilst the impact of riverine nutrients is limited to coastal areas the greatest net primary production increases are observed over the shelf break regions. In these regions the primary source of nutrients is intruding Pacific and Atlantic Water. However this water can reside at depths of 100 or more metres and so physical mixing processes are required to transport nutrients up to the nutrient replete euphotic zone.

This leads us to hypothesize that the observed increases in net primary production in the shelf break regions are driven by escalating nutrient fluxes from the deep waters (Atlantic, Pacific) into the euphotic zone as a result of enhanced vertical mixing rates. However, there is a very strong seasonality in the availability of light in the Arctic, due to both the formation of sea ice and also changing day length - from the perpetual darkness of winter to the mid-night sun - enabling accumulation of nutrients close to the surface in winter and so implying a strong seasonal cycle in nutrient fluxes to the surface layer. Furthermore our own turbulence measurements have shown mixing in the Arctic to be highly intermittant (and in consequence fluxes varying by up to 3 orders of magnitude) on timescales as short as an hour. These facts imply that in order to quantify the flux of nutrients from intermediate depths towards the sea surface measurements are required which resolve timescales, from hourly to seasonally.

The aim of this project is to test the hypothesis that increased primary production is promoted by increased availability of nutrients resulting from increased nutrient fluxes. Data will be collected to test this hypothesis, including employing novel acoustic Doppler techniques developed at Bangor University, to make turbulent mixing rate and nutrient flux estimates using profilers and from moorings at contrasting locations around the Arctic shelf break and interior, on timescales from hourly to the full seasonal cycle. These will then be compared to baseline measurements made at these locations by ourselves and others during the recent 2007/8 International Polar Year. The new measurements will be integrated with coincident fluorescence timeseries measurement, within the framework of a biogeochemical model, to quantify the impact of the observed changes in the nutrient environment, on net primary productivity, and to deduce intra-seasonal ecosystem responses to specific flux events.

Planned Impact

As a result of climate change the Arctic is becoming a region of growing strategic and economic importance. In particular the retreat in seasonal sea ice cover is creating new prospects for investment and economic development. It is also thought to be influencing middle latitude severe weather trends, and has had an impact on the productivity of the region with consequences for fisheries. Our proposal is to improve understanding of how changing ice and ocean conditions may drive more vertical fluxes of nitrates into the surface sunlit zone and so promote photosynthesis and primary production.

To ensure impact, beyond academia, we have gained the support of key strategic stakeholders, Dstl (representing the MOD and Royal Navy) and the UK Met Office through the integration of the modelling with the Arctic PRIZE program, together with the NOC Enterprise and Research Impact team, who will be involved in the entirety of the project.

Further we will exploit the charismatic nature of Polar research to engage public interest more generally through production of video documentaries, and fieldwork blogs. In particular we will target STEM awareness through the development of a 'Polar' school outreach programme which will take advantage of ongoing STEM initiatives at Bangor University.

Finally, as this proposal is part of the larger NERC Arctic Change Programme we will work together with the NERC Arctic Office, and other funded Arctic Programmes, to ensure that PEANUTS impact activities are fully intergrated with those of the programme as a whole, ensuring that the programme impact is greater than the sum of the individual programme elements.

Publications

10 25 50
 
Description Through collaborations partly supported by this grant we have

1. demonstrated that the changes in the inflowing Atlantic Water is important for driving recent warming and salinisation of the Barents Sea and associated loss of sea ice.
2.Shown that the slope currents along the Arctic continental slope are increasing in strength and variability, at the same time that the stratification and maker mixing mechanisms have changed.
3. Documented new mechanisms for the mixing of warm deep water and its nutrients to the surface in both the Eastern and Western Arctic. Mechanisms that are likely to increase in frequency with the decline of sea ice.
4. Provided evidence for the importance of late summer nutrient fluxes for the development of phytoplankton blooms.
Exploitation Route We expect our completed work to inform continuing research within the project, but also be used by scientists studying the impacts of changing ocean conditions on ecosystems (NERC/BMBF's Changing Arctic Programme) and earth system modellers looking to improve predictions of future climate. Beyond the scientific community, the interactions between the ocean and sea ice have implications for shipping, naval activity and maritime insurance policy, as well as indigenous communities. Our work has also been included in parliamentary debates, and we will continue to seek educate policy makers and the general public.
Sectors Aerospace, Defence and Marine,Communities and Social Services/Policy,Education,Environment,Government, Democracy and Justice,Security and Diplomacy,Transport

 
Description Our results and the results of Changing Arctic Ocean colleagues are featured in the new STEM toy Changing Arctic Ocean Challenge. These packs have already begun to be used in schools in the UK and Germany to teach students about climate change in the Arctic. Hundreds of packs were distributed at both the exhibition at the Greenwich Museum that took to celebrate the arrival of the RRS Sir David Attenborough to London in November 2021, and also at COP26.
First Year Of Impact 2021
Sector Education
Impact Types Cultural,Societal

 
Description AWI 
Organisation Alfred-Wegener Institute for Polar and Marine Research
Country Germany 
Sector Private 
PI Contribution We have shared data that we collected and analysed and collaborated on published scientific articles.
Collaborator Contribution They have shared data that they collected, and collaborated on published scientific articles.
Impact At present there are two scientific publications in the Journal of Physical Oceanography (Lenn et al, 2011 and Janout & Lenn, 2014), with two more manuscripts in preparation. We have also collaborated on ongoing observations and expect these to also culminate in more research that will be published in the future on topics that pertain to freshwater dispersion within the Arctic and its impact on climate.
Start Year 2009
 
Description ArctiCONNECT 
Organisation University of Exeter
Country United Kingdom 
Sector Academic/University 
PI Contribution I am a co-PI on this new NERC consortium grant (November 1 2020 start date), and my collaboration with James Screen (lead PI) arose from our discussion of results for the Barents Sea ocean, sea ice and atmosphere that are an outcome of PEANUTS.
Collaborator Contribution We have all just begun work on this grant.
Impact This project is in its infancy but will have impact on improving climate and weather prediction for the UK.
Start Year 2020
 
Description Bob Pickart- AON 
Organisation Woods Hole Oceanographic Institution
Country United States 
Sector Charity/Non Profit 
PI Contribution We contributed a high-frequency acoustic Doppler current profiler instrument to a mooring deployed on the Arctic Beaufort Sea slope by the WHOI group
Collaborator Contribution Bob Pickart of Woods Hole Oceanography Institution and PI on the long-term Arctic Observing Network mooring programme provided ship and staff time for the deployment of our instrument on their mooring, as well as the mooring hardware. We anticipate collaborating with them on the results of these observations
Impact This mooring will be recovered in 2020, when we shall have the first look at the data.
Start Year 2018
 
Description Ilker Fer- Nansen Legacy 
Organisation University of Bergen
Country Norway 
Sector Academic/University 
PI Contribution We contributed 20-30 instruments to resolve turbulent nutrient fluxes and its impact on primary production to a mooring deployed as part of the Norwegian Nansen Legacy Physical Processes study. My post-doc Ben Lincoln, joined the Nansen Legacy cruise in September 2018 to deploy our instruments and subsequently participated in the remaining cruise program of scientific sampling over rest of the 2-week cruise We anticipate collaborating with Ilker Fer and his group in the analysis of results arising from the measurements made from the moorings and mooring array.
Collaborator Contribution Our Nansen Legacy partner Ilker Fer and colleagues provided ship time for the deployment of our instruments and the mooring hardware to which the PEANUTS instruments were attached. This represents a significant contribution of funding in kind.
Impact The ocean physics groups at Bangor and Bergen have been interested in working together previously and are delighted to have this opportunity to do so. We anticipate deepening this collaboration through observations to be made during the upcoming MOSAIC drift.
Start Year 2018
 
Description SIO-Jen & Matthew 
Organisation University of California, San Diego (UCSD)
Department Scripps Institution of Oceanography
Country United States 
Sector Academic/University 
PI Contribution My PhD students Ben Barton joined the US ONR-funded SODA cruise aboard the R/V Sikuliaq to the Beaufort Sea in September 2018. His principle duty for the PEANUTS project was to collect water samples for analysis of nutrients and nitrogen isotopes, as well as micro plastics sampling. Apart from carrying out these activities, Ben also joined in with the rest of the sampling programme aboard that cruise, contributing his time and effort.
Collaborator Contribution Profs. Jennifer MacKinnon and Matthew Alford who lead the Scripps component of the SODA programme provided valuable access to ship time in the Beaufort Gyre. We have begun collaborating with them on analysis of the results from that cruise.
Impact We have at least on manuscript in the works.
Start Year 2018
 
Description US-Arctic 
Organisation Earth and Space Research (ESR)
Country United States 
Sector Charity/Non Profit 
PI Contribution Collaborators at the University of Alaska, Fairbanks have and continue to lead long-term monitoring observations along the margins of the Eurasian Arctic. On two separate occasions, Bangor colleagues and I have participated in these cruises to make turbulence measurements to complement the repeat hydrography. Together the data have been used in several joint publications in respected peer-reviewed journals and the collaboration continues through the sharing of data between partners in ongoing efforts to study the effects of shear on double diffusion that has been funded by the US. National Science Foundation. We have also hosted a collaborative visit of our ESR partner Dr Laurie Padman.
Collaborator Contribution They organise the long-term monitoring and carried a large part of the financial burden of the cruise costs (USD $75000 per day on a Russian Icebreaker). My partners have shared cruise and historical data with us and continue to collaborate on Arctic mixing studies.
Impact joint publications include: Dmitrenko, Igor A., Kirillov, Sergey A., Bloshkina, Ekaterina, Lenn, Yueng-Djern (2012). Tide-induced vertical mixing in the Laptev Sea coastal polynya. J. Geophys. Res., 117, C00G14 (id:2044) Igor V. Polyakov, Andrey V. Pnyushkov, Robert Rember, Vladimir V. Ivanov, Y.-D. Lenn, Laurie Padman, Eddy C. Carmack Mooring-Based Observations of Double-Diffusive Staircases over the Laptev Sea Slope. Journal of Physical Oceanography 42 95-109. PDF or website (id:2007) Polyakov, Igor V. , Vladimir A. Alexeev, Igor M. Ashik, Sheldon Bacon, Agnieszka Beszczynska-Möller, Eddy C. Carmack, Igor A. Dmitrenko, Louis Fortier, Jean-Claude Gascard, Edmond Hansen, Jens Hölemann, Vladimir V. Ivanov, Takashi Kikuchi, Sergey Kirillov, Yueng-Djern Lenn, Fiona A. McLaughlin, Jan Piechura, Irina Repina, Leonid A. Timokhov, Waldemar Walczowski, Rebecca Woodgate (2011). Fate of Early 2000s Arctic Warm Water Pulse. Bulletin of the American Meterological Society, 92(5), 561-566. (id:1914) Yueng-Djern Lenn, Tom P. Rippeth, Chris P. Old, Sheldon Bacon, Igor Polyakov, Vladimir Ivanov, Jens Hölemann (2011). Intermittent Intense Turbulent Mixing under Ice in the Laptev Sea Continental Shelf. Journal of Physical Oceanography, 41(3), 531-547 (id:1924) Yueng-Djern Lenn, Wiles, P. J., Torres-Valdes, S., Abrahamsen, E. P., Rippeth, T. P., Simpson, J. H., Bacon, S., Laxon, S. W., Polyakov, I., Ivanov, V., Kirillov, S. (2009) Vertical mixing at intermediate depths in the Arctic boundary current. Geophysical Research Letters, 36 (5). 5, pp. doi:10.1029/2008GL036792 (id:1724)
Start Year 2007
 
Description US-Arctic 
Organisation University of Alaska
Country United States 
Sector Academic/University 
PI Contribution Collaborators at the University of Alaska, Fairbanks have and continue to lead long-term monitoring observations along the margins of the Eurasian Arctic. On two separate occasions, Bangor colleagues and I have participated in these cruises to make turbulence measurements to complement the repeat hydrography. Together the data have been used in several joint publications in respected peer-reviewed journals and the collaboration continues through the sharing of data between partners in ongoing efforts to study the effects of shear on double diffusion that has been funded by the US. National Science Foundation. We have also hosted a collaborative visit of our ESR partner Dr Laurie Padman.
Collaborator Contribution They organise the long-term monitoring and carried a large part of the financial burden of the cruise costs (USD $75000 per day on a Russian Icebreaker). My partners have shared cruise and historical data with us and continue to collaborate on Arctic mixing studies.
Impact joint publications include: Dmitrenko, Igor A., Kirillov, Sergey A., Bloshkina, Ekaterina, Lenn, Yueng-Djern (2012). Tide-induced vertical mixing in the Laptev Sea coastal polynya. J. Geophys. Res., 117, C00G14 (id:2044) Igor V. Polyakov, Andrey V. Pnyushkov, Robert Rember, Vladimir V. Ivanov, Y.-D. Lenn, Laurie Padman, Eddy C. Carmack Mooring-Based Observations of Double-Diffusive Staircases over the Laptev Sea Slope. Journal of Physical Oceanography 42 95-109. PDF or website (id:2007) Polyakov, Igor V. , Vladimir A. Alexeev, Igor M. Ashik, Sheldon Bacon, Agnieszka Beszczynska-Möller, Eddy C. Carmack, Igor A. Dmitrenko, Louis Fortier, Jean-Claude Gascard, Edmond Hansen, Jens Hölemann, Vladimir V. Ivanov, Takashi Kikuchi, Sergey Kirillov, Yueng-Djern Lenn, Fiona A. McLaughlin, Jan Piechura, Irina Repina, Leonid A. Timokhov, Waldemar Walczowski, Rebecca Woodgate (2011). Fate of Early 2000s Arctic Warm Water Pulse. Bulletin of the American Meterological Society, 92(5), 561-566. (id:1914) Yueng-Djern Lenn, Tom P. Rippeth, Chris P. Old, Sheldon Bacon, Igor Polyakov, Vladimir Ivanov, Jens Hölemann (2011). Intermittent Intense Turbulent Mixing under Ice in the Laptev Sea Continental Shelf. Journal of Physical Oceanography, 41(3), 531-547 (id:1924) Yueng-Djern Lenn, Wiles, P. J., Torres-Valdes, S., Abrahamsen, E. P., Rippeth, T. P., Simpson, J. H., Bacon, S., Laxon, S. W., Polyakov, I., Ivanov, V., Kirillov, S. (2009) Vertical mixing at intermediate depths in the Arctic boundary current. Geophysical Research Letters, 36 (5). 5, pp. doi:10.1029/2008GL036792 (id:1724)
Start Year 2007
 
Description BBC News interview about climate change in the Arctic Barents Sea. 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I was invited to participate in a live interview on the BBC News Channel about the impact of the warming and increasing salt content of the Arctic Barents Sea on 5/2/2019. I was interviewed by Reeta Chakrabati on the 8 pm news programme. My father (climate change denier and TV addict) has become much more open to the science about climate change since then.
Year(s) Of Engagement Activity 2019
URL https://www.changing-arctic-ocean.ac.uk/news/2019/01/arctic-climate-change/
 
Description BBC Radio Cymru Science Cafe interview. 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact I, alongside Changing Arctic Ocean ARISE investigators Claire Mahaffey & Rachel Jeffereies (University of Liverpool), participated in a BBC Radio Wales Science Cafe discussion with interviewer Adam Walton about how our research is documenting change in the Arctic Ocean. This was broadcast across Wales on the 5/2/2019 and is available to listen on the BBC Sounds App. The current interest from the BBC about the Arctic has made us all aware of the need to be ready to respond to media requests and I have signed up for media engagement training to assist me in the event of future requests. Indeed, my PEANUTS co-investigator has just competed and interview off BBC Radio 4 that will be featured in their piece about UK science in the Arctic.
Year(s) Of Engagement Activity 2019
URL https://www.bbc.co.uk/programmes/m0002bzk
 
Description Changing Arctic Ocean Challenge: STEM toy for Changing Arctic Ocean programme 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact I lead the production of the Changing Arctic Ocean Challenge which is a top-trumps-style card game that features the interdisciplinary research from all 16 projects of the NERC/BMBF Changing Arctic Ocean. 3100 packs were printed and each project has a store of 100 packs to distribute at their public engagement events, and several hundred packs are being held in reserve for distribution at the COP26 event in November 2021. At present, distribution is limited to contacts amongst the investigators, but we have sent shipments to all our international partners as well and packs will reach other funding agencies such as the US Office of Naval Research. These games have been enthusiastically received thus far, and have been used in schools for teaching about the Arctic Ocean already, we estimate that between 51-100 packs have been distributed, but anticipate this to increased dramatically over the course of 2021 as social restrictions are lifted.
Year(s) Of Engagement Activity 2021
URL https://twitter.com/YuengP/status/1363153294588342275
 
Description Contribution to Changing Arctic Ocean presentation at COP26, Cryosphere Pavillion 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact I contributed a recorded talk to a video presentation about the science and poiicy impact of the Changing Arctic Ocean for COP26, and provided 500+ packs of Changing Arctic Ocean STEM card game packs to distribute at the centre.
Year(s) Of Engagement Activity 2021
 
Description I'm a scientist get me out of here, Hydrogen Zone 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact I'm a Scientist, Get me out of here hosted several 50-minute with 194 students from 7 schools across the UK where scientists engaged online with the students who asked questions. 100% of active students were from target schools: 42% from widening participation schools and 58% from underserved schools. The Hydrogen zone session ran during August/September 2021. I was voted Hydrogen Zone winner (favorite scientist) and received £500 for Bangor University's STEM engagement activities.
Year(s) Of Engagement Activity 2021
URL https://about.imascientist.org.uk/2022/hydrogen-zone-report-2021/
 
Description I'm a scientist, Get me out of here. 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact I'm a scientist. Get me out of here provides opportunities for school teachers to book online discussions sessions with scientists according to subject area. In June/July 2020, I participated in 10 50-minute long sessions with about 200 school children usually of age 11 and older asking questions about careers in science and our biggest discoveries. These were very engaging sessions and allowed us to continue to do outreach during the first lockdown and beyond. I'm continue my involvement with this organization as time allows.
Year(s) Of Engagement Activity 2020
URL https://imascientist.org.uk/
 
Description Popular science article in TheConversation 
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 This article was written to translate the results of the Barton et al., 2018 paper in JPO for a general audience, and has reached over 5500 readers since 30 August 2018 when it was published. It also inspired a level discussion online with 63 comments generated, including some from climate denialists (probably why the discussion was so lively). The article was retweeted 82 times and shared on Facebook 196 times. Since the publication of this article, I have been approached by The Conversation to consider authoring article on other topics.
Year(s) Of Engagement Activity 2018
URL https://theconversation.com/extreme-weather-in-europe-linked-to-less-sea-ice-and-warming-in-the-bare...
 
Description STEM activities with schools 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Details of events I co-ordinated and lead as Schools Liaison for Bangor's School of Ocean Sciences. Every event features some practical aspect where students can participate in a science activity. Note numbers given are for students who participated only, but we often find that it is the teachers on whom we also make important and lasting impressions.

10/7/2017: Lymm High School careers day. (20+ students, 3 firm acceptance for Bangor U places)
21/7/2017: Culceth High School, year 12 Biology workshop & lecture (64 students)
29/9/2017: Overleigh St Mary's C of E School, Year 2 science (60 children)
7/2/2018: Welsh Government Serene Network event at Venue Cymru (~10 invited students)
8/3/2018: Culceth High School Careers Fair Years 8-11 (1000+ children)
10/4/2018: Christleton International Studio visit to SOS by International Baccalaureate Students (30 students)
17/5/2018: Derby College Year 10 visit (65 students)
19/6/2018: Girls into STEM* (year 9 from Daffyd Hughes School & Denbigh High School, 28 students total)
21/6/2018: Daffyd Hughes School remaining Year 9 triple science students (39 students)
28/6/2018: Holy Cross Sixth Form College (18 students)
3/7/2018: Bangor University Summer School? (15 students)
10/7/2018: Girls into STEM* (30 students)
12/7/2018: National Citizens Service, year 12 students from Chester (140 students)
19/7/2018: BCA college visit, 30 year 8 students.
25/9/2018: Girls into STEM (28 students)
4/12/2018: Girls into STEM (27 students)

As a result of these visits, students typically find themselves more engaged with science and some become convinced to pursue careers in ocean sciences.
Year(s) Of Engagement Activity 2017,2018
 
Description School visits, University Ocean Days (2019) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact As Director of STEM and Schools Engagement at the School of Ocean Sciences, Bangor University, I co-ordinated numerous visits from schools to the department from across North Wales. In addition, I participated in the Bangor Youth Climate Summit organized by our School of Education who invited over 100 school children to Bangor to discuss how climate issues relate to them. Altoghether these activities reached 1-500 school children across North Wales and the Northwest England.

As with all my colleagues, I participated in multiple university open days.
Year(s) Of Engagement Activity 2019,2020