This is not my current page - as of 15th December 2013 I no longer work at JAMSTEC. Come and find me at or email jules(at)

I'll leave this up for posterity and redirection purposes
(JAMSTEC may kill it at any time).

Julia Hargreaves 

I am a senior scientist  in the paleoclimate group, which is part of the global warming division of the Research Institute for Global Change (RIGC), formerly known as FRCGC, and based in Yokohama, Japan. My email address is

Japan Uncertainty Modelling Project:

JUMP logo

In April 2012, the second phase of JUMP began! Our new website may be accessed by clicking on the JUMP logo above.

The JUMP name and logo remain, although several institutes in Japan have changed name. JUMP is based at the RIGC, which is part of JAMSTEC, and includes researchers working on similar topics from RIGC, NIES (National Institute for Environmental Studies), AORI (formerly CCSR, University of Tokyo) and NIED (National Research Institute for Earth Science and Disaster Prevention). Running for 5 years, from April 2012, we are funded by two new projects from the ministries of Environment and Science. The former structure of the whole "Leading Project" was dissolved by JAMSTEC management upon the cessation of the previous funding stream so, despite the unusually strong success (compared to other Japanese projects), of JUMP over the last 5 years, it not now part of the formal structure of JAMSTEC. The goal of JUMP remains investigating and reducing uncertainty associated with various aspects of climate change prediction ranging over the multi-decadal to centennial time scale. Paleoclimate studies remain a strong aspect of our research activities.

History of JUMP: In April 2007 James and I were funded through two different five-year Japanese projects, the Ministry of Environments "S5" and MEXT's "Kakushin". In order to aid management of these projects I invented JUMP, the Japan Uncertainty Modelling Project or, our answer to the UK Met Office's QUMP. At that time there was a team of five researchers working on uncertainty related issues at FRCGC with wider collaborative links to both the National Institute for Environmental Studies in Tsukuba and the Center for Climate System Research in Kashiwa, which is part of the University of Tokyo. In April 2009 JUMP went public in Japan, ceasing to be a covert underground operation known only to the outside world. Our JAMSTEC chapter officially existed as the Uncertainty Estimation Research Group, of which I was the leader within the so called "Towards AR5, Leading Project". The list of members of this first phase of JUMP can be found at our former site.

Research Interests:

The research of JUMP is focussed on reducing uncertainty in prediction of future climate change. We have investigated many different components of the climate system including: sea-ice, ice sheets, terrestrial carbon cycle, ocean biogeochemistry, global and regional temperature and precipitation, and climate feedbacks. We mainly use state-of-the-art GCMs and intermediate complexity models, focussing on both single and multi-model ensembles. The periods of interest studied have included the Last Glacial Maximum, the mid-Holocene, the Last Millennium, the Historical period, as well as the future.

Over the last few years my personal research interest has been on using paleoclimate information to learn about future climate change.  Most recently I have been using statistical methods to assess the ensemble of climate models run for the Last Glacial Maximum and mid-Holocene in the Paleoclimate Inter-comparison projects (PMIP, PMIP2 and PMIP3). First steps in using these ensemble to constrain future climate have begun.

Whenever I come across a really difficult mathematical problem I call up my pet mathematician.

Climate of the Past Special Issues:

I am presently co-editor of a special issue related to the results from the third Paleoclimate Inter-comparison project PMIP3. The issue is called Progress in paleoclimate modelling and submissions are still welcome. Please email the lead editor of this special issue, Masa Kageyama, if you have any queries about this special issue.

I was lead editor of the special issue for  Climate of the Past called Modelling Late Quaternary Climate. The issue was completed in 2007 and is available free to all on-line [discussion, final]. A hard-copy version has been produced, and it is still possible to order a copy by emailing Nadine Deisel. This special issue arose from the EGU Climate session, "Modelling the Climates of the Late Quaternary" held at the 2006 meeting in Vienna.

The EGU journal, Geoscientific Model Development:

Frustrated with the un-reproduceable state of much work published using complex computer models, we (Dan Lunt, Rolf Sander, Ian Rutt, Andy Ridgwell, me and James) decided to try to start a new journal where models, technical modelling advancements and model inter-comparison projects could be properly published, including source code and manuals. Several other people also thought this was a good idea and thus an orange on-line EGU journal was formed:

"Geoscientific Model Development (GMD) is an international scientific journal dedicated to the publication and public discussion of the description, development and evaluation of numerical models of the Earth System and its components."

Thanks in large part to the EGU's assistance, GMD is a success and I still enjoy being an executive editor of the journal.

In 2013 the journal executive editors published an Editorial:
GMD Executive Editors [J. Annan, J. Hargreaves, D. Lunt (Chief Editor), A. Ridgwell, I. Rutt and R. Sander], The publication of geoscientific model developments v1.0, Geosci. Model Dev., 6, 12331242, 2013 doi:10.5194/gmd-6-1233-2013 [pdf]

The EGU journal, Earth System Dynamics:

I always thought that there should be a sister journal to Climate of the Past, called Climate of the Future, but somehow the idea never got very far up the flagpole of the EGU publications committee. Instead the EGU chose to incorporate this aspect into a new more wide-ranging journal called Earth System Dynamics. I serve as a topical editor of this journal, which seems to be developing into a home for interesting and sometimes unusual or contentious papers.  

My Publications(updated August 2013): H-index=19
topics - paleoclimate, ensemble methods/uncertainty, future climate, carbon cycle/biogeochemistry, astrophysics/astronomy, solar-terrestrial science


62.J.C. Hargreaves and J.D. Annan, Can we trust climate models?, invited opinion article for WIREs Climate Change, submitted August 2013.

61. G. A. Schmidt, J. D. Annan, P. J. Bartlein, B. I. Cook, E. Guilyardi, J. C. Hargreaves, S. P. Harrison, M. Kageyama, A. N. LeGrande, B. Konecky, S. Lovejoy, M. E. Mann, V. Masson-Delmotte, C. Risi, D. Thompson, A. Timmermann, L.-B. Tremblay, and P. Yiou, Using paleo-climate comparisons to constrain future projections in CMIP5, Clim. Past Discuss., 9, 775-835, 2013.

60. K. Tachiiri, J.C. Hargreaves, J.D. Annan, C. Huntingford, and M. Kawamiya, Allowable carbon emissions for a medium mitigation scenario. [submitted to Tellus]

59. S.L.Smith, J.D. Annan, and J.C. Hargreaves Affinity: the meaningful trait-based alternative to the half-saturation constant for microbial ecology. Submitted to Limnology and Oceanography (sub June 2012).

In Press/Published online:

58. T. Yokohata, J.D. Annan, M. Collins, C.S. Jackson, H. Shiogama, M. Watanabe, S. Emori, M. Yoshimori, M. Abe, M.J. Webb, and J.C. Hargreaves. Reliability and importance of structural diversity of climate model ensembles. Climate Dynamics (sub July 2012). [pdf]



Editorial: GMD Executive Editors [J. Annan, J.C. Hargreaves, D. Lunt (Chief Editor), A. Ridgwell, I. Rutt and R. Sander], The publication of geoscientific model developments v1.0, Geosci. Model Dev., 6, 12331242, 2013 doi:10.5194/gmd-6-1233-2013 [pdf]

EOS article: Julia Hargreaves, Klaus Keller and Tamsin Edwards, Examining Risks, Extreme Events, and Abrupt Changes (page 280) <> Article first published online: 6 AUG 2013 | DOI: 10.1002/2013EO320007  [pdf]

57. J.C. Hargreaves, J.D. Annan, R. Ohgaito, A. Paul, and A. Abe-Ouchi. Skill and reliability of climate model ensembles at the Last Glacial Maximum and mid-Holocene. üClim. Past, 9, 811823, 2013 doi:10.5194/cp-9-811-2013 (sub July 2012, acc Feb 2013, pub Mar 2013). [pdf]

56. Emma J. Stone, Daniel J. Lunt, James D. Annan and Julia.C. Hargreaves, Quantification of Greenland ice-sheet contribution to Last Interglacial sea-level rise. üClim. Past, 9, 621639, 2013 doi:10.5194/cp-9-621-2013 (sub July 2012, acc Feb 2013, pub March 2013). [pdf]

55. J.D. Annan and J.C. Hargreaves. A new global reconstruction of temperature changes
at the Last Glacial Maximum. Clim. Past, 9, 367376, doi:10.5194/cp-9-367-2013, 2013. (sub Sep 2012, acc Jan 2013, pub Feb 2013).[pdf]


54. J.C. Hargreaves, J.D. Annan, M. Yoshimori and A. Abe-Ouchi. Can the Last Glacial Maximum constrain climate sensitivity? GRL, Vol. 39, L24702, doi:10.1029/2012GL053872, 2012. (submitted Sep 2012, published Dec 2012).[pdf]

53. H. Shiogama, M. Watanabe, M. Yoshimori, T. Yokohata, T. Ogura, J.D. Annan, J.C. Hargreaves, M. Abe, Y. Kamae, R. Oishi, R. Nobui, S. Emori, T. Nozawa, A. Abe-Ouchi and M. Kimoto. Perturbed Physics Ensemble using the MIROC5 Coupled Atmosphere-Ocean GCM without Flux Corrections: Experimental Design and Results. Climate Dynamics, DOI: 10.1007/s00382-012-1441-x, Volume 39, Issue 12, pp 3041-3056, (sub Aug 2011, pub online July 2012, pub on paper Dec 2012). [online][pdf]

52. J.D. Annan and J.C. Hargreaves. Identification of climatic state with limited proxy data. Clim. Past 8 pp 1141-1151, 2012. (sub Jan 2012, acc + pub June 2012)[online]

51. J.J. Day, J. C. Hargreaves, J. D. Annan and A. Abe-Ouchi. Sources of multi-decadal variability in Arctic sea ice extent. Environmental Research Letters 7 034011 doi:10.1088/1748-9326/7/3/034011 (sub May 2012, acc July 2012, pub July 2012)

50. M. Watanabe, H. Shiogama, T. Yokohata, Y. Kamae, M. Yoshimori, T. Ogura, J.D. Annan,J.C. Hargreaves, S. Emori, and M. Kimoto. Using a Multiphysics Ensemble for Exploring Diversity in CloudShortwave Feedback in GCMs. J. Climate, 25, 54165431. doi: Sept 2011, acc Feb 2012, in print Aug 2012). [online]

9. K. Tachiiri, A. Ito, T. Hajima, J.C. Hargreaves, J. D. Annan,  and M. Kawamiya, Nonlinearity of Land Carbon Sensitivities in Climate Change Simulations, Journal of the Meteorological Society of Japan, Journal of the Meteorological Society of Japan, vol 90A, pp 259-274, DOI:10.2151/jmsj.2012-A13 (sub. Mar 2011, acc Oct 2011, pub June 2012)  [online]

48. T. Yokohata, J.D. Annan, M. Collins, C.S. Jackson, M. Tobis, M.J. Webb, J.C. Hargreaves, Reliability of multi-model and structurally different single-model ensembles, Climate Dynamics, Climate Dynamics, Volume 39, Numbers 3-4 (2012), 599-616, DOI: 10.1007/s00382-011-1203-1. (sub. Mar 2011, acc+online Aug 2011, in print Aug 2012) [pdf] [link]

47. L.Das, J.D. Annan, J.C. Hargreaves and S. Emori, Improvements over three generations of climate model simulations in Eastern India, Climate Research, 51: 201216, 2012 (accepted October 2011, published March 2012).


46. M. Yoshimori, J. C. Hargreaves, J. D. Annan, T. Yokohata, and A. Abe-Ouchi,Dependency of Feedbacks on Forcing and Climate State in Physics Parameter Ensembles, Journal of Climate, 24, 6440-6455 (sub. Aug 2010, acc and pub online May 2011, in print Dec 2011) [pdf] [link]

45. J.D. Annan,J.C. Hargreaves and K. Tachiiiri, On the observational assessment of climate model performance, GRL, VOL. 38, L24702, 5 pages,  doi:10.1029/2011GL049812,2011. (sub Aug 2011, acc and published online Nov 2011). [link] [pdf]

44. L. Das, J.D. Annan, J.C. Hargreaves, S. Emori, Centennial scale warming over Japan: are the rural stations really rural?, Atmos. Sci. Let.  DOI:10.1002/asl.350, Vol. 12, Issue 4, 362367, 2011. (sub. Nov 2010, acc and pub online May 2011, hardcopy Oct/Dec 2011)  [pdf] [link]

43. J.C. Hargreaves, A. Paul, R. Ohgaito, A. Abe-Ouchi, J. D. Annan, Are paleoclimate model ensembles consistent with the MARGO data synthesis? Climate of the Past 7, 917933, doi:10.5194/cp-7-917-2011, 2011. (sub. Feb 2011, accepted July 2011, published August 2011).[pdf][link]

42. J.D. Annan and J.C. Hargreaves, Reply to Henriksson et al.'s comment on "Using multiple observationally-based constraints to estimate climate sensitivity" by Annan and Hargreaves, CP, 7, 587-589, (sub. Jan 2011, acc May 2011, pub Jun 2011).

41. J. D. Annan and J. C. Hargreaves, Understanding the CMIP3 multi-model ensemble, Journal of Climate, 24,45294538. doi: 10.1175/2011JCLI3873.1, 2011. (sub. May 2010, acc, pub. online Mar 2011, pub hardcopy August 2011) [pdf] [link] 

40. J.D. Annan and J.C. Hargreaves. On the generation and interpretation of probabilistic estimates of climate sensitivity. Volume 104, Numbers 3-4, 423-436, 2011  DOI:10.1007/s10584-009-9715-y Climatic Change, (Published Online First Oct 2009, finally published in hardcopy mid 2011!) [pdf]


39. K. Tachiiri, J.C. Hargreaves, J.D. Annan, A. Oka, A. Abe-Ouchi, and M. Kawamiya: Development of a system emulating the global carbon cycle in Earth system models, GMD,  3, 365-376,sub., Dec 2009, acc. Jul 2010, pub. Aug 2010) [pdf] [link]

38. J.C. Hargreaves Skill and uncertainty in climate models, WIREs, 1(4), 1757-7799 (submitted Nov 2009, accepted May 2010, published June 2010) [pdf] [link]

37. J. D. Annan and J. C. Hargreaves, Reliability of the CMIP3 ensemble. Geophys. Res. Lett., 37, L02703, doi:10.1029/2009GL041994, 2010 (submitted and accepted, December 2009, published Jan 2010) [pdf] [link]

36. T. Yokohata, M Webb, M Collins, K Williams, M. Yoshimori, J.C. Hargreaves and J.D. Annan Structural similarities and differences in climate responses to CO2 increase between two perturbed physics ensembles by general circulation models. Journal of Climate, 23(6) 1392-1410 , 2010. (Accepted Sep 2009, published 15 March 2010)
[pdf] [link]

35. J.D. Annan and J.C. Hargreaves, Ecient identication of a ocean thermodynamics in a physical/biogeochemical ocean model with an iterative Importance Sampling method, Ocean Modelling, 32, 205215, 2010. (submitted Aug 2009, Accepted Feb 2010, Published Mar 2010) [pdf] [link]


34. J.C. Hargreaves and J.D. Annan, On the importance of the paleoclimate modelling for improving predictions of future climate change. Climate of the Past, 5, 803-814, 2009.[link] [pdf]

33. Manabu Abe, Hideo Shiogama,Julia C. Hargreaves, James D. Annan, Toru Nozawa and Seita Emori; Correlation between Inter-Model Similarities in Spatial Pattern for Present and Projected Future Mean Climate, SOLA, Vol. 5, pp.133-136 (2009), published Aug 2009 [link] [pdf]

32. J.C. Hargreaves and J.D. Annan, Comment on Aerosol radiative forcing and climate sensitivity deduced from the Last Glacial Maximum to Holocene transition, by P. Chylek and U. Lohmann, Geophys. Res. Lett., Clim. Past, 5, 143-145, published Apr 2009. [link] [pdf]


31. G.-K. Plattner, R. Knutti, F. Joos, T. F. Stocker, W. von Bloh, V. Brovkin, D. Cameron, E. Driesschaert, S. Dutkiewicz, M. Eby, N. R. Edwards, T. Fichefet, J. C. Hargreaves, C. D. Jones, M. F. Loutre, H. D. Matthews, A. Mouchet, S. A. Mueller, S. Nawrath, A. Price, A. Sokolov, K. M. Strassmann, and A. J. Weaver, Long-term climate commitments projected with climate - carbon cycle models, Journal of Climate, 21, (12), 2721-2751, 2008. [pdf]


30. A. Ridgwell, I. Zondervan, J.C. Hargreaves, J. Bijma, T. Lenton, Significant long-term increase of fossil fuel CO2 uptake from reduced marine calcification, Biogeosciences, 4, 481-492, 2007  [online discussion] [final version] [pdf]

29. T.M. Lenton, R. Marsh, A.R. Price, D.J. Lunt, Y. Aksenov, J.D. Annan, T. Cooper-Chadwick, S.J. Cox, N.R. Edwards, S. Goswami, J.C. Hargreaves, P.P. Harris, Z. Jiao, V.N. Livina, A.J. Payne, I.C. Rutt, J.G. Shepherd, P. J. Valdes, G. Williams, M.S. Williamson, and A. Yool, Effects of atmospheric dynamics and ocean resolution on bi-stability of the thermohaline circulation examined using the Grid ENabled Integrated Earth system modelling (GENIE) framework, Climate Dynamics, 26, 6, 591-613, 2007 [online first] DOI:10.1007/s00382-007-0254-9.

28. A. Ridgwell, J.C. Hargreaves, N.R. Edwards, J.D. Annan, T.M. Lenton, R. Marsh, A. Yool, and A. Watson, An efficient Earth System Model of Global biogeochemical cycling (I) Marine geochemical data assimilation, Biogeosciences, 4, 87-104, 2007. [online discussion] [final version] [pdf]

27. A. Ridgwell and J.C. Hargreaves, Ocean sediment data assimilation within an Earth system model: The importance of deep-sea carbonates in the long-term sequestration of fossil fuel CO2, GBC,  21, doi:10.1029/2006GB002764 (2007).

26. J.D. Annan and J.C. Hargreaves, Efficient estimation and ensemble generation in climate modelling, Philisophical Transactions of the Royal Society A,  365, 1857, 2077-2088, 2007 [pdf].

[I was lead editor of this SI - this editorial was not peer-reviewed] Modelling Late Quaternary Climate, Eds. J.C. Hargreaves, N. Weber, P. Braconnot and J. Guiot, Climate of the Past, Special Issue, 2007.

25. J.C. Hargreaves, A. Abe-Ouchi and J.D. Annan, Linking glacial and future climates through an ensemble of GCM simulations,  Climate of the Past, 3, 77-87, 2007[final revised version][online discussion][pdf]

24. S. L. Smith, B. E. Casareto, M. P. Niraula, Y. Suzuki, J.C. Hargreaves, J. D. Annan and Y. Yamanaka. Assimilating Data from Incubations into a Multi-Element Ecosystem Model, Journal of Marine Systems, vol. 64, no.1-4, p135-152. 2007 [pdf]


23. J.D. Annan and J.C. Hargreaves, Using multiple observationally-based constraints to estimate climate sensitivity, Geophysical Research Letters, 33 (6): Art. No. L06704, Mar 18, 2006 [pdf]

22. J.C. Hargreaves and J.D. Annan, Using ensemble prediction methods to examine regional climate variation under global warming scenarios, Ocean Modelling, 11 (1-2): 174-192 2006 [pdf]


21. J.D. Annan, D.J. Lunt DJ, J.C. Hargreaves and P.J. Valdes, Parameter estimation in an atmospheric GCM using the Ensemble Kalman Filter, Nonlinear Processes in Geophysics, 12 (3): 363-371 2005 [pdf]

20. J. D. Annan, J. C. Hargreaves, R. Ohgaito, A. Abe-Ouchi, S. Emori. Efficiently constraining climate sensitivity with paleoclimate simulations.  SOLA Vol 1 pages 181-184, 2005 [pdf]

19. J.D. Annan JD, J.C. Hargreaves, N.R. Edwards and R. Marsh, Parameter estimation in an intermediate complexity earth system model using an ensemble Kalman filter, Ocean Modelling, 8 (1-2): 135-154 2005 [pdf]


18. J.C. Hargreaves, J.D. Annan, N.R. Edwards and R. Marsh, An efficient climate forecasting method using an intermediate complexity Earth System Model and the ensemble Kalman filter, Climate Dynamics, 23 (7-8): 745-760 Dec 2004 [pdf]

17. J.D. Annan and J.C.Hargreaves, Efficient parameter estimation for a highly chaotic system, Tellus Series A - Dynamic Meteorology and oceanography, 56 (5): 520-526 OCT 2004 [pdf]


16. J.C. Hargreaves and A. Abe-Ouchi, Timing of ice-age terminations determined by wavelet methods, Paleoceanography, 18 (2): Art. No. 1035 May 16 2003 [pdf]

15. C. Huntingford, J.C. Hargreaves, T.M. Lenton and J.D. Annan, Extent of partial ice cover due to carbon cycle feedback in a zonal energy balance model, Hydrology and Earth System Sciences, 7 (2): 213-219 Apr 2003 [pdf]


14. J.C. Hargreaves and J.D. Annan, Assimilation of paleo-data in a simple Earth system model, Climate Dynamics 19 (5-6): 371-381 Aug 2002 [pdf]

13. J.C. Hargreaves, D.J.T. Carter, P.D. Cotton and J. Wolf, Using the SWAN wave model and satellite altimeter data to study the influence of climate change at the coast, The Global Atmosphere and Ocean System, 8 (1): 41-66, Mar 2002.


12. J.K.Hargreaves, A. Ranta, J.D. Annan and J.C. Hargreaves, Temporalfine structure of nighttime spike events in auroral radio absorption, studied by a wavelet method, Journal of Geophsyical Research - Space Physics, 106 (A11): 24621-24636, Nov 1 2001

11. J.C. Hargreaves and J.D. Annan, Comments on "Improvement of the short-fetch behavior in the wave ocean model (WAM)", Journal of Atmospheric and Oceanic Technology, 18 (4): 711-715 2001


10. J. Monbaliu, R. Padilla-Hernandez, J.C. Hargreaves, J.C.C. Albiach, W.M. Luo, M. Sclavo and H. Gunther, The spectral wave model, WAM, adapted for applications with high spatial resolution, Coastal Engineering, 41 (1-3): 41-62 Sep 2000

9.  D. Prandle D, J.C. Hargreaves, J.P. McManus, A.R. Campbell, K. Duwe, A. Lane, P. Mahnke, S. Sminwelland J. Wolf. Tide, wave and suspended sediment modelling on an open coast - Holderness, Coastal Engineering, 41 (1-3): 237-267 Sep 2000

Last Century

J.C. Hargreaves and J.D. Annan. The impact of fierce weather on lazy modelling. In The wind-driven air-sea interface, Ed. M. Banner, ADFA  Document Production Centre, Canberra, Australia, 125132, 1999

7.  J. Monbaliu, J.C. Hargreaves, J.C.C. Carretero, H. Gerritsen and R. Flather, Wave modelling in the PROMISE project, Coastal Engineering, 37 (3-4): 379-407 Aug 1999

6.  J.D. Annan and J.C. Hargreaves, Sea surface temperature assimilation for a three-dimensional baroclinic model of shelf seas Continental Shelf Research, 19 (11): 1507-1520 Sep 1999

5. J.C. Hargreaves, G. Gilmore, M.J. Irwin and D. Carter , A dynamical study of the Draco dwarf spheroidal galaxy, Monthly Notices of the Royal Astronomical Society, 282 (2): 305-312 Sep 15 1996

4.  J.C. Hargreaves, G. Gilmore, J.D. Annan, The influence of binary stars on dwarf spheroidal galaxy kinematics, MNRAS 279 (1): 108-120 Mar 1 1996

3. J.C. Hargreaves, The Dynamics of Dwarf Spheroidal Galaxies, PhD Thesis, University of Cambridge, 1995

2.  J.C. Hargreaves, G. Gilmore, M.J. Irwin and D. Carter , A dynamical study of the Ursa Minor dwarf spheroidal galaxy, MNRAS, 271: 693 Sep 15 1994

1.  J.C. Hargreaves, G. Gilmore, M.J. Irwin and D .Carter , A dynamical study of the Sextans dwarf spheroidal galaxy, MNRAS, 269: 957 Sep 15 1994