Postdoc Tel.: +49-441-798-3839 Mail:  takasumi.kurahashi [at] uni-oldenburg.de

CUR­RENT RE­SEARCH
- Numerical simulations of dissolved organic matter (DOM) in the ocean.

The response of marine DOM, especially DOC, to the future global change is an important issue because it is one of the largest reservoirs of organic carbon on the Earth’s surface, containing a similar amount as in the atmosphere. Nevertheless, our understanding about the DOM system and about its role in the future global change is still limited. Numerical simulation is a beneficial method to make future projections and to test hypotheses, which would bring us better knowledge of the dynamics of the system. Therefore, the enhancement of the model representation of DOM-related processes and its application call for urgent attention.

keywords: DOM, DOC, DOP, Bacteria, global change, Ocean modelling, UVicESCM

PRO­FES­SIONAL EX­PER­I­ENCE
12/2022-present   Postdoctoral researcher, ICBM, The University of Oldenburg.
01/​​​2010-11/2022   Re­searcher, MARUM, The Uni­versity of Bre­men.
05/​​​2015-09/​​​2016   Postdoc­toral Fel­low, Jac­obs Uni­versity Bre­men.
06/​​​2008-10/​​​2009   Vis­it­ing Fel­low, School of Geo­graph­ical Sci­en­ces, Uni­versity of Bris­tol.
04/​​​2008-12/​​​2009   Ja­pan So­ci­ety for the Pro­mo­tion of Sci­ence (JSPS) Re­search fel­low, Cen­ter fo Cli­mate Sys­tem Re­search, The Uni­versity of Tokyo.
04/​​​2004-03/​​​2008   Postdoc­toral re­searcher, Fron­tier Re­search Cen­ter for Global Change, JAM­STEC.
04/​​​2001-03/​​​2004   Ja­pan So­ci­ety for the Pro­mo­tion of Sci­ence (JSPS) Re­search fel­low, De­part­ment of Earth and Plan­et­ary Sci­ence, The Uni­versity of Tokyo.

EDU­CA­TION
03/​​2004   Ph.D.   "Evol­u­tion of the Sur­face En­vir­on­ment of Mars: Nu­mer­ical Stud­ies on the Cli­mate Sys­tem", De­part­ment of Earth and Plan­et­ary Sci­ence, Uni­versity of Tokyo.
03/​​2001   M.Sc.   De­part­ment of Earth and Plan­et­ary Sci­ence, Uni­versity of Tokyo.
03/​​1999   B.Sc.   De­part­ment of Geo­lo­gical Sci­ence, Uni­versity of Tokyo.

GEN­ERAL IN­TEREST
Nu­mer­ical mod­el­ing is an in­form­at­ive method that helps to de­scribe, understand, and pre­dict the be­ha­vi­ors of com­plex sys­tems in a quant­it­at­ive way. The con­sist­ent and gen­eral motive of my re­search is an in­terest in nu­mer­ical mod­el­ling of nat­ural phe­nom­ena, and of so­cial phe­nom­ena as well.

In nat­ural sci­ence, my main fo­cus is on the dy­nam­ics of the Earth sys­tem. In par­tic­u­lar, I have been al­ways in­ter­es­ted in the car­bon-cycle system of the Earth (and some other planets) be­cause it has a cru­cial in­flu­ence on the amount of CO2 in the at­mo­sphere that strongly af­fects the sur­face en­vir­on­ment of them through the global en­ergy bal­ance.

In the field of so­cial sci­ence, the dy­nam­ics of people’s opin­ions in a so­ci­ety is a ma­jor con­cern. Ana­lyz­ing so­cial dy­nam­ics with a sim­pli­fied nu­mer­ical model will of­fer a be­ne­fi­cial in­sight to help our gen­eral un­der­stand­ing of phe­nom­ena. That will also provide fun­da­men­tal ideas to design more real­istic mod­els for the pro­jec­tion into the fu­ture.

LIST OF PUB­LIC­A­TIONS FOR NAT­URAL SCI­ENCES
Kurahashi-Nakamura, Takasumi, A. Paul, U. Merkel, and M. Schulz, "Gla­cial state of the global car­bon cycle: time-slice sim­u­la­tions for the last gla­cial max­imum with an Earth-sys­tem model", Clim. Past, 18, 1997–2019, ht­tps://​​doi.org/​​10.5194/​​cp-18-1997-2022, 2022.

Kurahashi-Nakamura, Takasumi, A. Paul, G. Mun­hoven, U. Merkel, and M. Schulz, "Coup­ling of a sed­i­ment dia­gen­esis model (ME­DUSA) and an Earth sys­tem model (CESM1.2): a con­tri­bu­tion to­ward en­hanced mar­ine biogeo­chem­ical mod­el­ling and long-term cli­mate sim­u­la­tions", Geosci. Model Dev., 13, 825–840, ht­tps://​​​doi.org/​​​10.5194/​​​gmd-13-825-2020, 2020.

Breit­kreuz, C., A. Paul, T. Kurahashi‐Nakamura, M. Losch, and M. Schulz, "A dy­nam­ical re­con­struc­tion of the global monthly‐mean oxy­gen iso­topic com­pos­i­tion of sea­wa­ter", J. Geo­phys. Res. Oceans, ht­tps://​​​doi.org/​​​10.1029/​​​2018JC014300, 2018.

Kurahashi-Nakamura, Takasumi, A. Paul, and M. Losch, "Dy­nam­ical re­con­struc­tion of the global ocean state dur­ing the Last Gla­cial Max­imum", Pa­leocean­o­graphy, 32, doi:10.1002/​​​2016PA003001, 2017.

Kurahashi-Nakamura, Takasumi, M. Losch, and A. Paul, "Can sparse proxy data con­strain the strength of the At­lantic me­ri­di­onal over­turn­ing cir­cu­la­tion?", Geosci. Model Dev., 7, 419-432, doi:10.5194/​​​gmd-7-419-2014, 2014.

Kurahashi-Nakamura, Takasumi, A. Abe-Ou­chi, and Y. Ya­man­aka, “Ef­fects of phys­ical changes in the ocean on at­mo­spheric pCO2 dur­ing the last gla­cial max­imum", Clim. Dyn., DOI10.1007/​​​s00382-009-0609-5, 2010.

Kurahashi-Nakamura, Takasumi, A. Abe-Ou­chi, Y. Ya­man­aka and K. Misumi, “Com­pound ef­fects of Ant­arc­tic sea ice on at­mo­spheric pCO2 change dur­ing gla­cial–in­ter­gla­cial cycle", Geo­phys. Res. Lett., 34, L20708, doi:10.1029/​​​2007GL030898, 2007.

Kurahashi-Nakamura, Takasumi, and E. Tajika, “At­mo­spheric col­lapse and trans­port of car­bon di­ox­ide into the sub­sur­face on early Mars”, Geo­phys. Res. Lett., 33, L18205, doi:10.1029/​​​2006GL027170, 2006.

Kurahashi-Nakamura, Takasumi, and E. Tajika, “Evol­u­tion of the Mar­tian cli­mate: ef­fects of the ice sheets”, Seppyo, Journal of the Ja­pan­ese So­ci­ety of Snow and Ice, Vol. 67, No. 2, pp.133-145, 2005 (in Ja­pan­ese).

Nakamura, Takasumi, and E. Tajika, “Cli­mate change of Mars-like plan­ets due to ob­li­quity vari­ations: im­plic­a­tions for Mars”, Geo­phys. Res. Lett., 30, No. 13, 1685, doi:10.1029/​​​2002GL016725, 2003.

Nakamura, Takasumi, and E. Tajika, “Sta­bil­ity of the Mar­tian cli­mate sys­tem un­der the sea­sonal change con­di­tion of solar ra­di­ation”, Journal of Geo­phys­ical Re­search, vol.107, no.E11, 5094, doi:10.1029/​​​2001JE001561, 2002.

Nakamura, Takasumi, and E. Tajika, “The Mar­tian Cli­mate Sys­tem : Its Sta­bil­ity and Evol­u­tion”, Plan­et­ary People, Journal of the Ja­pan­ese So­ci­ety for Plan­et­ary Sci­ence, vol.10, no.4, pp.192-201, 2001 (in Ja­pan­ese).

Nakamura, Takasumi, and E. Tajika, “Sta­bil­ity and evol­u­tion of the cli­mate sys­tem of Mars”, Earth, Plan­ets, and Space, vol.53, pp.851-859, 2001.

LIST OF PUB­LIC­A­TIONS FOR SO­CIAL SCI­ENCE
Lorenz, Jan, T. Kurahashi-Nakamura, and S. Shi­k­ano, "Cycles of pub­lic policy mood through opin­ion dy­nam­ics un­der het­ero­gen­eous bounds of con­fid­ence" (in prep.).

Kurahashi-Nakamura, Takasumi, M. Mäs, and J. Lorenz, "Ro­bust clus­ter­ing in gen­er­al­ized bounded con­fid­ence mod­els", Journal of Ar­ti­fi­cial So­ci­et­ies and So­cial Sim­u­la­tion, 19, (4), 7, DOI:10.18564/​​​jasss.3220, 2016.