NERC RESEARCH STUDENTSHIPS
NAME OF LEAD SUPERVISOR
Prof. R.C. Upstill-Goddard (MAST)
NAME(S) OF CO-SUPERVISOR(S) Dr P.D. Nightingale. Theme Leader: Marine
Biogeochemical Cycles Volatiles Research Group, Plymouth Marine Laboratory, PL1 3DH.
TITLE OF PROJECT (250 CHARACTERS INCLUDING SPACES)
New tracers for evaluating oceanographic mixing and air-sea gas exchange
SUMMARY OF RESEARCH PROGRAMME: (UP TO 2 SIDES A4)
A brief description of the proposed research is required, including details of research training. Any associated research grants should be mentioned
with reference numbers.
Gaseous tracers are exceptionally powerful tools used to provide fundamental insights into oceanographic
processes. They are broadly used in two ways: by exploiting changes in their atmospheric histories that are
initially imprinted in surface seawater (transient tracers) and via their controlled addition to seawater at
specified locations (deliberate tracers). The key requirements of a gaseous tracer are that it is
biogeochemically inert, has a very low (preferably zero) natural background and can be analysed to high
precision in seawater. A transient tracer should additionally have a measurably increasing atmospheric
mixing ratio (i.e. several % yr-1) and a long atmospheric lifetime (defined as the ratio of its total atmospheric
burden to its integrated global loss rate).
Sulphur hexafluoride (SF6), an inert non-toxic gas with a low environmental background is a well established
deliberate tracer, having been used extensively in release experiments in the open ocean and on continental
shelves to evaluate vertical and horizontal ocean mixing [1-2], air-sea gas exchange in conjunction with 3He
[3-6], deep water formation [7] and for “labelling” surface waters during Lagrangian iron fertilization
experiments [8-10]. More recently the potential of SF6 as a transient tracer in the ocean has also been
examined [11-13]. Chlorofluorocarbons (CFCs) have been widely used as transient tracers to examine the
formation, circulation and mixing of subsurface waters ventilated (i.e. contacted the atmosphere) between the
late 1950s and the early 1990s. Waters contacting the atmosphere absorb transient tracer “fingerprints” via
gas equilibration and these fingerprints are preserved during subsequent downward transport. Profiling of
transient tracer concentrations with depth in conjunction with their known atmospheric histories thus yields
information on the ventilation ages of water masses. Using two or more transient tracers together (e.g. CFC11/CFC-12 or CFC-11/CFC-113) and measuring their concentration ratios eliminates the effects of dilution by
water mass mixing and can potentially yield ventilation ages with annual resolution [14]. However, as a direct
consequence of the Montreal Protocol the value of CFCs as transient tracers for waters ventilated after about
1990 is seriously compromised by their declining atmospheric mixing ratios. While SF6 has the potential to
be used in this regard because it currently has a rapidly increasing atmospheric mixing ratio [15-16], in
practice its use as a transient tracer is largely compromised by its conflicting use as a sub-surface deliberate
tracer, which leads to contamination of its transient fingerprint. Indeed the SF6 tracer community, at the 13th
AGU Ocean Sciences Meeting in 2006, issued a recommendation that the use of SF6 in subsurface ocean
tracer release experiments should be halted immediately in order to preserve its value as a transient tracer.
Clearly, the development of alternative gaseous tracers for large-scale oceanographic experiments would
eliminate interference between these two uses for SF6 and provide now overdue replacements for the CFCs.
Recently a new gaseous tracer, trifluoromethyl sulphur pentafluoride (SF5CF3) was shown to have the
potential to replace SF6 as transient tracer [17] but there remains a pressing need for a new generation of both
transient and deliberate tracers in oceanography.
Recent work highlights a number of potential candidate compounds. The atmospheric lifetimes of 27 longlived hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs), the first and second generation
CFC replacements respectively, have been determined [18] and several of these have been continuously
monitored at a high-Alpine site since 2000, yielding high resolution recent atmospheric histories and source
function data [19]. Some of these in particular (e.g. HFC134a, HCFCs 123, 141b and 142b) show promise in
that they appear to have sufficiently long atmospheric lifetimes and atmospheric growth rates of at least
several percent per year [18]. Although the atmospheric inventories of these compounds will inevitably
decline because they are targeted by the Montreal and Kyoto Protocols, they nevertheless have the potential to
be valuable transient tracers during the coming decades, while their use as deliberate tracers is only indirectly
affected by the Montreal or Kyoto agreements.
The overall goal of this studentship is to identify existing anthropogenic gases that can be used both as
transient and deliberate oceanographic tracers, and to develop methods for their high-precision analysis in
seawater. The student will be supervised by Professor R. Upstill-Goddard (MAST) and Dr P.D. Nightingale
(Plymouth Marine Laboratory). PML has exceptionally agreed to sponsor this studentship under CASE award
rules (See attached letter of support and note that CASE student support is currently not a high PML priority)
because it recognises this studentship as a potentially strategic contribution to the PML marine tracer
programme and its contribution to Oceans 2025 (http://www.oceans2025.org/). The proposed supervisory
arrangement (one internal UNEW and one external supervisor) is in accord with SAGE faculty rules (RUG
has discussed this with the SAGE PG Dean) and currently applies to two other students currently supervised
by RUG. The two supervisors (RUG and PDN) pioneered the use of SF6 in gas exchange studies at sea [3-4]
and PDN provides support for all UK (and some non-UK) based seagoing activities requiring deliberate tracer
releases. The supervisors therefore have the expertise required to support his work and they constitute one of
only two such groupings worldwide (the other is in the US). They have actively collaborated in deliberate
tracer work since the early 1990s [e.g. 4].
The student will initially carry out a literature search (at Newcastle) to identify likely candidate compounds
based on their published physical and chemical properties; important among these are solubility and
diffusivity, which are required to be accurately known. Where these data are not available the student will
carry out preliminary measurements using established methods. The student will thus identify a suite of
compounds with sufficiently large solubility and diffusivity contrasts to be of value as deliberate and/or
transient tracers. A series of storage experiments in seawater will then be initiated (at PML) to evaluate any
aqueous removal mechanisms [20] and to determine the timescales of such processes in comparison with
SF6/4He. We envisage these activities to be completed during the first 12 months. During his/her second year
the student will select the most appropriate gases based on the results of the storage experiments and optimise
the analytical methodology for each based on the analytical techniques for CFCs, HCFCs and HFCs in air (by
gas chromatography mass-spectrometry, GCMS) that are already rather well-described [19]. GCMS and
PTRMS (Proton Transfer Reaction Mass Spectrometry) capability and expertise already exists at PML for use
in halocarbon/CFC and other volatile organic compound analyses, and the associated hardware for isolating
these gases from seawater was largely developed there. The student will subsequently design and carry out
trial deliberate tracer releases and measurements, either in coastal waters off Plymouth or in a
Northumberland lake previously used by RUG for deliberate tracer release experiments. Opportunities to
participate in ocean going cruises will be exploited as appropriate. While the student will be based in MAST
at Newcastle the experimental programme will inevitably require him/her to spend a substantial amount of
time at PML as implied above; we envisage as much as 12-18 months in total. This will be supported by full
technical back-up provided by experienced members of the PML tracer group. PML have agreed to meet the
costs of all consumables, local travel and fieldwork (e.g. ship costs) associated with this. Additional
accommodation costs will be requested as part of the student nomination process. We expect the student to
present his/her results at both national and international conferences and to publish them in leading
international journals (see reference list below for examples).
The long established collaboration between MAST and PML has already seen the successful completion of
one PhD and several others are ongoing. Both supervisors’ research groups are well established with state of
the art analytical facilities and a high level of expertise, which will ensure successful knowledge transfer.
MAST participates in a successful programme of student training in key research and management skills, and
follows a procedure for ensuring regular supervision meetings reporting student progress twice yearly. This
involves a supervisory committee comprising supervisors and at least one other member of MAST academic
staff.
References:
[1] Ledwell, J. R., et al., Nature, 364, 701–703, 1993; [2] Ledwell, J. R., et al., Nature, 403, 179–182, 2000; [3] Watson,
A.J., R.C. Upstill-Goddard & P.S. Liss, Nature 349, 145-147, 1991; [4] Nightingale, P.D., G. Malin, C.S. Law, A.J.
Watson, P.S. Liss, M.I. Liddicoat, J.Boutin, & R.C. Upstill-Goddard, Glob. Biogeochem. Cyc., 14, 373-387, 2000; [5]
Wanninkhof, R., W. Asher, R. Weppernig, H. Chen, P. Schlosser, C. Langdon, and R. Sambrotto, J. Geophys. Res., 98,
20,237– 20,248, 1993; [6] Ho, D. T., C. S. Law, M. J. Smith, P. Schlosser, M. Harvey, and P. Hill, Geophy. Res.Lett., 33,
L16611, doi:10.1029/2006GL026817, 2006; [7] Watson, A. J., et al., Nature, 401, 902– 904, 1999; [8] Coale, K. H., et
al., Nature, 383, 495– 501, 1996 ; [9] Coale, K. H., et al., Science, 304, 408– 414, 2004; [10] Boyd, P. W., et al. Nature,
407, 695– 702, 2000; [11] Law, C. S., and A. J. Watson, Geophys. Res. Lett., 28, 815– 818, 2001; [12] Tanhua, T., et al.
Deep Sea Res II, 51, 2683–2699, 2004; [13] Bullister, J. L., et al. Deep Sea Res. I, 49, 175– 187, 2002; [14] Bullister, J.
L., and R. F. Weiss, , Deep Sea Res. I, 35, 839–853, 1988; [15] Geller, L. S., J. W. Elkins, J. M. Lobert, A. D. Clarke, D.
F. Hurst, J. H. Butler, and R. C. Myers, Geophys. Res. Lett., 24, 675– 678, 1997; [16] Maiss, M., and C. A. M.
Brenninkmeijer, Environ. Sci. Technol., 32, 3077– 3086, 1998; [17] Ho, D.T., Ledwell, J.R., and Smethie, W.M. Jr.,
Geophys. Res. Lett., 35, L04602, doi:10.1029/2007GL032799, 2008; [18] Naik, V., Jain, A.K., Patten, K.O. and
Wuebbles, D.J., J. Geophys. Res., 105, 6903-6914, 2000; [19] Reimann, S., Vollmer, M.K., Folini, D., Steinbacher, M.,
Hill, M., Buchmann, B., Zander, R., and Mathieu, E., Sci. Tot. Env., 391, 224-231, 2008; [20] Wild O., Rattigan O.V.,
Jones R.L., Pyle J.A., and Cox R.A., J. Atmos. Chem., 25, 167-199, 1996.
Name of all supervisors
(including CASE)
Present post
Length of
research
experience
Number of students currently being supervised who are in
the:
1st year
2nd year
3rd year
3rd year+
TOTAL
Prof. R. Upstill-Goddard
Univ. Academic
20
0
0
3
2
5
Dr. P. D. Nightingale
Band 5 Scientist
17
0
0
2
1
4
Recent publications by supervisor(s) relevant to research area:
Jickells, T.D, Liss, P.S., Broadgate, W., Turner, S., Kettle, A.J., Read, J, Baker, J, Cardenas, L.M, Carse, F, HamrenLarssen, M, Spokes, L, Steinke, M, Thompson, A, Watson, A, Archer, S.D, Bellerby, R.G.J, Law, C.S, Nightingale, P.D,
Liddicoat, M.I, Widdicombe, C.E, Bowie, A, Gilpin, L.C, Moncoiffé, G, Savidge,G, Preston, T, Hadziabdic, P, Frost, T,
Upstill-Goddard, R, Pedrós-Alió, C, Simó, R, Jackson, A, Allen, A, and DeGrandpre, M.D. (2008). A Lagrangian
Biogeochemical Study Of An Eddy In The North East Atlantic. Prog. Oceanogr., 76, 366-398.
Upstill-Goddard, R.C. (2006). Air-sea gas exchange in the coastal zone. Est. Coast. Shelf Sci., 70, 388-404.
Jacobs, C., Kjeld, J. F., Nightingale, P.D., Upstill-Goddard, R., Larsen, S. and Oost, W. (2002). Possible errors in
CO2 air-sea transfer velocity from deliberate tracer releases and eddy covariance measurements due to near-surface
concentration gradients. J. Geophys. Res. 107, 3128, doi:10.1029/2001JC000983.
Jacobs, C, Nightingale P.D, Kjeld J, Upstill-Goddard R.C, Larsen S & Oost W (2002). Comparison of the deliberate
tracer method and eddy covariance measurements to determine the air/sea transfer velocity of CO 2, Geophysical
Monograph, 127, 225-231 (AGU).
Nightingale P.D, Liss P.S. and Schlosser P (2000). Measurements of air-sea gas transfer during an open ocean algal
bloom. Geophys. Res. Let., 27, 2117-2120, 2000.
Nightingale, P.D., Malin, G., Law, C. S., Watson, A. J., Liss, P. S., Liddicoat, M.I. Boutin, J. and Upstill-Goddard,
R.C. (2000). In situ evaluation of air-sea gas exchange parameterizations using novel conservative and volatile tracers.
Glob. Biogeochem. Cyc. 14, 373-387
PART 3 – TO BE COMPLETED BY THE CASE PARTNER (S)
(FOR OPEN CASE STUDENTSHIPS ONLY COMPLETE IF THERE ARE ANY CHANGES FROM YOUR
ORIGINAL APPLICATION)
10.
CO-OPERATING BODY (CASE) DETAILS - to be completed by the CASE partner(s) where applicable
Name and Address of Co-operating (CASE) body:
1.
2.
Plymouth Marine Laboratory
Prospect Place
Plymouth
PL1 3DH
Co-operating (CASE) Body Supervisor (s)
Title:
Initials:
Surname:
Department
Current Position
1.Dr
1.P.D.
1.Nightingale
1.Biogeochemistry
1.Theme Leader
2.
2.
2.
2.
2.
Tel:
Fax:
E-mail:
1.01752 633100
1.01752 633101
1. pdn@pml.ac.uk
2.
2.
2.
Description of work to be undertaken by the student at the premises of the CASE body and its role within the project:
The PML tracer group under the leadership of Dr P.D. Nightingale have further developed the use of the
deliberate tracers SF6 and 3He, which was initially pioneered by A.J. Watson and R. Upstill-Goddard at the
MBA. They have substantial experience (more than 16 years) in using these tracers along with others in
release experiments in the open ocean and on continental shelves to evaluate vertical and horizontal ocean
mixing, air-sea gas exchange, deep water formation, and for “labelling” surface waters during Lagrangian iron
fertilization experiments (e.g.IronEx 2, SOIREE, EisenEx). They are the only group in Europe capable of
providing these measurements and their expertise is therefore fundamentally important to this studentship.
The student will learn basic GCMS and PTRMS techniques at PML and develop techniques for candidate
tracers under the supervision of Dr Nightingale and with the support of his highly experienced staff. Training
will involve relevant aspects of state-of-the-art cryogenic trapping/GCMS, complex system design and
maintenance. The student will benefit from working for extended periods within a stimulating environment
and be exposed to multidisciplinary marine science through interacting with leading UK and international
experts.
The student will be based in MAST at Newcastle but will spend a prolonged period at PML for method
development (see support case above).
Nature and frequency of contacts between the CASE body, student and supervisor (must be maintained throughout the duration of the award as
appropriate to the demands of the project):



Twice yearly routine progress meetings between student CASE and University supervisor.
Extended period of student study at PML: frequent meetings between student and CASE supervisor
3-monthly visits to PML by RUG for progress meetings involving all three.
Financial and other contributions from the CASE body (NOTE: CASE bodies must make a minimum contribution of £1000pa towards the student’s
maintenance, and it is expected that any additional support that is required for the student’s travel and subsistence whilst working at the CASE body’s
premises will be provided by the CASE partner).



£1000 p.a. for student maintenance
PML will meet all local travel, consumable and fieldwork costs for the duration of student study
visits to PML
Contribution to subsistence costs
Total value of funds to student for the whole award
£ To be agreed
The following section has been amended to comply with the Data Protection Act 1998. Further information can be
found at www.nerc.ac.uk/funding/forms/Data_guidance.doc). Each Supervisor on this studentship must complete this
section. Details of the nominated student will not be publicised.
By signing this you are confirming that you accept the terms and conditions laid out in the NERC studentship
handbook.
a. CASE Supervisor (1)
NERC believes in making details of its awards and their recipients available on the NERC website. In making this
application, it is assumed that you consent to this. If you do not consent to this, please tick this box.
Signature:
Date:
Name in Capitals:
b. CASE Supervisor (2)
NERC believes in making details of its awards and their recipients available on the NERC website. In making this
application, it is assumed that you consent to this. If you do not consent to this, please tick this box.
Signature:
Date:
Name in Capitals:
11.
AUTHORISATION FOR CASE COLLABORATION AND FINANCIAL CONTRIBUTION BY THE
APPROPRIATE AUTHORITY:
Signed:
Title:
Date:
Position held:
Initials:
Has this company/organisation co-operated on a previous CASE studentship?
Surname:
Y
N