Breadcrumb

Pronouns: she/her
Bio
My research topics include climate and paleoclimate modeling, polar climate, climate model evaluation, Arctic Ocean and sea ice variability, Arctic freshwater dynamics, cryosphere, oceanography, and modeling of isotopes.
Education
- PhD: McGill University, 2010
- Dipl: Free University of Berlin, 2004
- Exchange student: University of Washington in Seattle, 2001
Awards
- Alexander von Humboldt Fellowship for experienced researchers, Alexander von Humboldt Foundation, 2022
- Faculty Early Career Development (CAREER) Award, National Science Foundation, 2019
- Advanced Study Program Postdoctoral Fellowship, National Center for Atmospheric Research, 2012
- Christine Mirzayan National Academies Policy Fellowship, National Academy of Sciences, 2010
- PhD Fellowship, German National Academic Foundation, 2006
- Outstanding student scholarship, German National Academic Foundation, 2001
- Fulbright Travel Award, The Fulbright Program, 2001
- Exchange Fellowship, Free University of Berlin and University of Washington, 2001
Research
Current projects are described on the Polar and Paleoclimate Modeling research group pages.
Research overview
Climate models are a powerful tool to understand dynamics in the climate system: they offer the unique advantage of providing a self-consistent dataset that can be used to study mechanisms, perform sensitivity studies, and test hypotheses. While model studies have provided critical insights on climate system functioning, it is important to remember that they are approximations of the real world. Connecting model results with observational data is therefore essential, and much of my research is motivated by the desire to improve model-data comparisons, for example through model developments that make model variables more comparable to observed data.
I am particularly interested in the climate of the polar regions, particularly the Arctic Ocean. Beside its breathtaking beauty, the Arctic Ocean is also the region where we see the largest climate changes occurring. Given that observational data in the Arctic is very limited, model studies are a great tool to better understand Arctic climate processes and their global impacts. In order to better predict future changes in the Arctic, for example when certain regions of the Arctic Ocean will become consistently accessible to commercial shipping during the summer, it is crucial to improve our understanding of the observed changes, as well as the shortcomings of the current generation of climate models. One of my main research foci is to understand the role of natural variability versus forced trends in the Arctic ocean and sea ice system during the 20th and 21st century. In this work, my main focus is on the Arctic sea ice and oceanic freshwater dynamics.
In addition to the present day changes, polar regions also played a key role in the past: Glaciations were initiated in the high northern latitudes, and Dansgaard-Oeschger and Heinrich events, which are among the most rapid climate change events on record, also originated in the high northern latitudes. We know about these past changes from paleo records (e.g., from ice cores and ocean sediment cores). Model simulations are uniquely suited to test hypotheses based on paleo records and to examine the physical mechanisms that led to these large climate shifts, as they provide consistent datasets and allow for sensitivity studies. My paleo-research is currently focussed on the climate at the Last Glacial Maximum (21 ka BP), during the deglaciation (21 ka BP to ~11 ka BP), and the climate of the Holocene (11 ka BP to the present), with the main focus on changes in the ocean circulation during these times.
Publications
Recent publications
Asymmetric Cooling of the Atlantic and Pacific Arctic During the Past Two Millennia: A Dual Observation-Modeling Study
Publication Date: 2018-11-28
Type: Journal Article
Reduced probability of ice-free summers for 1.5 degrees C compared to 2 degrees C warming
Publication Date: 2018-05-01
Type: Journal Article
Investigating the Direct Meltwater Effect in Terrestrial Oxygen-Isotope Paleoclimate Records Using an Isotope-Enabled Earth System Model
Publication Date: 2017-12-28
Type: Journal Article
Episodic Neoglacial expansion and rapid 20th century retreat of a small ice cap on Baffin Island, Arctic Canada, and modeled temperature change
Publication Date: 2017-11-16
Type: Journal Article
Asynchronous warming and delta O-18 evolution of deep Atlantic water masses during the last deglaciation
Publication Date: 2017-10-17
Type: Journal Article
Community climate simulations to assess avoided impacts in 1.5 and 2 degrees C futures
Sanderson BM; Xu Y; Tebaldi C; Wehner M; O'Neill B; Jahn A; Pendergrass AG; Lehner F; Strand WG; Lin L...
- Sanderson BM
- Xu Y
- Tebaldi C
- Wehner M
- O'Neill B
- Jahn A
- Pendergrass AG
- Lehner F
- Strand WG
- Lin L
Publication Date: 2017-09-19
Type: Journal Article
Reduced ENSO variability at the LGM revealed by an isotope-enabled Earth system model
Publication Date: 2017-07-16
Type: Journal Article
Amplified North Atlantic warming in the late Pliocene by changes in Arctic gateways
Publication Date: 2017-01-28
Type: Journal Article
The CMIP6 Sea-Ice Model Intercomparison Project (SIMIP): understanding sea ice through climate-model simulations
Publication Date: 2016-09-23
Type: Journal Article
How predictable is the timing of a summer ice-free Arctic?
Publication Date: 2016-09-01
Type: Journal Article
CLIMATE VARIABILITY AND CHANGE SINCE 850 CE An Ensemble Approach with the Community Earth System Model
Otto-Bliesner BL; Brady EC; Fasullo J; Jahn A; Landrum L; Stevenson S; Rosenbloom N; Mai A; Strand G...
- Otto-Bliesner BL
- Brady EC
- Fasullo J
- Jahn A
- Landrum L
- Stevenson S
- Rosenbloom N
- Mai A
- Strand G
Publication Date: 2016-05-01
Type: Journal Article
An assessment of the Arctic Ocean in a suite of interannual CORE-II simulations. Part III: Hydrography and fluxes
Ilicak M; Drange H; Wang Q; Gerdes R; Aksenov Y; Bailey D; Bentsen M; Biastoch A; Bozec A; Boening C...
- Ilicak M
- Drange H
- Wang Q
- Gerdes R
- Aksenov Y
- Bailey D
- Bentsen M
- Biastoch A
- Bozec A
- Boening C
Publication Date: 2016-04-01
Type: Journal Article
An assessment of the Arctic Ocean in a suite of interannual CORE-II simulations. Part II: Liquid freshwater
Wang Q; Ilicak M; Gerdes R; Drange H; Aksenov Y; Bailey DA; Bentsen M; Biastoch A; Bozec A; Boening C...
- Wang Q
- Ilicak M
- Gerdes R
- Drange H
- Aksenov Y
- Bailey DA
- Bentsen M
- Biastoch A
- Bozec A
- Boening C
Publication Date: 2016-03-01
Type: Journal Article
An assessment of the Arctic Ocean in a suite of interannual CORE-II simulations. Part I: Sea ice and solid freshwater
Wang Q; Ilicak M; Gerdes R; Drange H; Aksenov Y; Bailey DA; Bentsen M; Biastoch A; Bozec A; Boening C...
- Wang Q
- Ilicak M
- Gerdes R
- Drange H
- Aksenov Y
- Bailey DA
- Bentsen M
- Biastoch A
- Bozec A
- Boening C
Publication Date: 2016-03-01
Type: Journal Article
COMMENTARY: Influence of internal variability on Arctic sea-ice trends
Publication Date: 2015-02-01
Type: Journal Article
Carbon isotopes in the ocean model of the Community Earth System Model (CESM1)
Publication Date: 2015-01-01
Type: Journal Article
Can regional climate engineering save the summer Arctic sea ice?
Publication Date: 2014-02-16
Type: Journal Article
Implications of Arctic sea ice changes for North Atlantic deep convection and the meridional overturning circulation in CCSM4-CMIP5 simulations
Publication Date: 2013-03-28
Type: Journal Article
Arctic Ocean freshwater: How robust are model simulations?
Jahn A; Aksenov Y; de Cuevas BA; de Steur L; Hakkinen S; Hansen E; Herbaut C; Houssais M-N; Karcher M; Kauker F...
- Jahn A
- Aksenov Y
- de Cuevas BA
- de Steur L
- Hakkinen S
- Hansen E
- Herbaut C
- Houssais M-N
- Karcher M
- Kauker F
Publication Date: 2012-08-10
Type: Journal Article
True to Milankovitch: Glacial Inception in the New Community Climate System Model
Publication Date: 2012-04-01
Type: Journal Article
Twenty-First-Century Arctic Climate Change in CCSM4
Publication Date: 2012-04-01
Type: Journal Article
Late-Twentieth-Century Simulation of Arctic Sea Ice and Ocean Properties in the CCSM4
Jahn A; Sterling K; Holland MM; Kay JE; Maslanik JA; Bitz CM; Bailey DA; Stroeve J; Hunke EC; Lipscomb WH...
- Jahn A
- Sterling K
- Holland MM
- Kay JE
- Maslanik JA
- Bitz CM
- Bailey DA
- Stroeve J
- Hunke EC
- Lipscomb WH
Publication Date: 2012-03-01
Type: Journal Article
Recent Advances in Arctic Ocean Studies Employing Models from the Arctic Ocean Model Intercomparison Project
Proshutinsky A; Aksenov Y; Kinney JC; Gerdes R; Golubeva E; Holland D; Holloway G; Jahn A; Johnson M; Popova E...
- Proshutinsky A
- Aksenov Y
- Kinney JC
- Gerdes R
- Golubeva E
- Holland D
- Holloway G
- Jahn A
- Johnson M
- Popova E
Publication Date: 2011-09-01
Type: Journal Article
Inter-annual to multi-decadal Arctic sea ice extent trends in a warming world
Publication Date: 2011-08-11
Type: Journal Article
A tracer study of the Arctic Ocean's liquid freshwater export variability
Publication Date: 2010-07-23
Type: Journal Article
Pages
Teaching
Past courses
- ATOC1060: Our Changing Environment
- Discusses Earth's climate for non-science majors
- ATOC5051: Introduction to Physical Oceanography
- Introduction to physical oceanography for graduate students
- ATOC6800: Scientific Writing
- Focuses on how to write compelling scientific journal articles, for graduate students
- ATOC4850/ATOC5850: Numerical Methods Laboratory
- Introduction to numerical methods in ATOC, for undergraduate and graduate students
- ATOC3700: Research Experience in Atmospheric and Oceanic Sciences
- Course based research experience for undergraduate students, learning about research and doing actual research
Current students
Former students and postdocs
Postdocs
- Hannah Zanowski, Postdoctoral scholar, 2019-2021
- Yafang Zhong, Postdoctoral Research Associate, co-advised
Graduate students
- Patricia DeRepentigny, PhD 2021
- Abigail Smith, PhD 2021
Graduate student assistants
- Rory Laiho, Graduate Student Assistant
- Aaron Schroeder, Graduate Student Assistant
Undergraduates
- Nate Farmer, Undergraduate Research Assistant, 2022
- Daphne Quint, Undergraduate Research Assistant, 2022
- Rajan Patel, Undergraduate Research Assistant, 2022
- Patrick Ugrinow, Undergraduate Research Assistant, 2022
- Sara Jean Reinelt, Undergraduate Research Assistant
- Kerrie Dochen, Undergraduate Researcher
- Ivonne Martinez, Summer REU student, co-advised
Outreach
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