iTRACE

iTRACE is an isotope-enabled Transient Climate Experiment for the last deglaciation

About

The iTRACE project offers a publicly accessible collection of climate model simulations, providing explicit simulations of water isotopes and climate change during the last deglaciation. Its primary objective is to comprehend deglacial climate change by comparing the modeled water isotope against paleoclimate proxies. The project also proves valuable in investigating the distinct roles played by ice sheets, greenhouse gases, orbital insolation, and meltwater fluxes in shaping past climate change.

Conducted in iCESM1.3, the iTRACE simulations are driven by realistic forcings. The dataset comprises four simulations, with all forcing run: ice_ghg_orb_wtr, and 3 factorized-forcing runs ice_ghg_orb, ice_orb, and itrace.0x. For in-depth technical information, interested users can refer to the accompanying paper or dissertation.

He, C., Liu, Z., Otto-Bliesner, B. L., Brady, E. C., Zhu, C., Tomas, R., Clark, P. U., Zhu, J., Jahn, A., &Gu, S. (2021), Hydroclimate footprint of pan-Asian monsoon water isotope during the last deglaciation, Science Advances, 7(4), eabe2611.

He, C. (2021), Deciphering the deglacial evolution of water isotope and climate in the Northern Hemisphere, The Ohio State University, 2021.

We kindly ask that you acknowledge the CESM Project and CISL supercomputing resources (doi:10.5065/D6RX99HX) and reference He et al. (2021) when presenting results based on the iTRACE in either oral or written form.



The iTRACE simulation quantitatively reproduced the last deglacial water isotope and hydroclimate change in the Asian monsoon system (He et al. 2021).



Project details

  • Simulation names:

  • [all-forcing run] b.e13.Bi1850C5.f19_g16.xxka.itrace.ice_ghg_orb_wtr.0x.cam.h0.variable.model-year.nc

  • [ice+ghg+orb run] b.e13.Bi1850C5.f19_g16.xxka.itrace.ice_ghg_orb.0x.cam.h0.variable.model-year.nc

  • [ice+orb run] b.e13.Bi1850C5.f19_g16.xxka.itrace.ice_orb.0x.cam.h0.variable.model-year.nc

  • [ice run] b.e13.Bi1850C5.f19_g16.xxka.itrace.0x.cam.h0.variable.model-year.nc

  • [NOTE] Some runs named in ice_ghg_orb_mwtr are also available at Climate Data Gateway. These are failed test runs, so please neglect them.

  • [NOTE] For all-forcing runs, please see the roadmap

  • Model version: iCESM1.3
  • Resolution: f19_g16
  • Period: 20,000-11,000 years before present
  • Time frequencies saved: monthly
  • Machine: Cheyenne
  • Compset: Bi1850C5

Data Acquisition

The data is available on the NCAR Casper /glade/campaign/cesm/collections/iTRACE and from the Climate Data Gateway at NCAR.

The following are step by step directions on how to download iTRACE data from the Climate Data Gateway.

Proceed to the iTRACE page.

Scroll to the bottom of that page under Child Datasets, and click on the component and time frequency you are interested in.

The files are organized by variable, listed at the end of each link. Click on the variable you are interested in.

Click on the Download Options button. At this point, if you have not logged into the Climate Data Gateway you can do so now. If you have not registered before, registration is free and quick.

Upon logging in you will see a ridiculously long list of files. Scroll down until you see files that start with the simulation names identified above. Once you have identified a file that you would like to download, click on the check box to the left of the file name. Note that you can select multiple files on this page at once. When you are finished selecting files, scroll to the top (or bottom) of the page and click on the Download Options for Selection box.

Click the Request File Transfer from Archive or choose an alternative method, and follow the status of the file transfer request

Some Known issues

Due to the abrupt ocean bathymetry change at 14 and 12ka, our model produced unrealistic short and abrupt shocks in some regions. Independent sensitivity experiments were conducted over several hundred years at 14 and 12ka, with ice-sheet and bathymetry changes implemented approximately 200 years apart. The results of these experiments reveal that the shock responses can be predominantly regarded as a linear superposition of the bathymetry and ice-sheet changes.





Publications using iTRACE

Journal Articles

  1. The Greenland spatial fingerprint of Dansgaard–Oeschger events in observations and models
    Christo Buizert, Todd A Sowers, Kyle Niezgoda, Thomas Blunier, Vasileios Gkinis, Margaret Harlan,  Chengfei He, Tyler R Jones, Helle A Kjaer, Jesper B Liisberg, and  others
    Proceedings of the National Academy of Sciences, 2024
  2. Open ocean convection drives enhanced eastern pathway of the Glacial Atlantic Meridional Overturning Circulation
    Sifan Gu, Zhengyu Liu, Hong Chin Ng, Jean Lynch-Stieglitz, Jerry F McManus, Michael Spall, Alexandra Jahn,  Chengfei He, Lingwei Li, Mi Yan, and  others
    Proceedings of the National Academy of Sciences, 2024
  3. Enhanced ocean heat storage efficiency during the last deglaciation
    Chenyu Zhu, Saray Sanchez, Zhengyu Liu, Peter U Clark,  Chengfei He, Lingfeng Wan, Jiuyou Lu, Chenguang Zhu, Lingwei Li, Shaoqing Zhang, and  others
    Science Advances, 2024
  4. CP
    A multi-model assessment of the early last deglaciation (PMIP4 LDv1): a meltwater perspective
    Brooke Snoll, Ruza Ivanovic, Lauren Gregoire, Sam Sherriff-Tadano, Laurie Menviel, Takashi Obase, Ayako Abe-Ouchi, Nathaelle Bouttes,  Chengfei He, Feng He, and  others
    Climate of the Past, 2024
  5. QSR
    Changes in Indo-Pacific Warm Pool hydroclimate and vegetation during the last deglaciation
    Meredith Parish, James Russell, Bronwen Konecky, Xiaojing Du,  Chengfei He, Satria Bijaksana, and Hendrik Vogel
    Quaternary Science Reviews, 2024
  6. Comm.Earth & Env.
    Last Glacial Maximum cooling induced positive moisture balance and maintained stable human populations in Australia
    Haidee Cadd, Alan N Williams, Wanchese M Saktura, Tim J Cohen, Scott D Mooney,  Chengfei He, Bette Otto-Bliesner, and Chris SM Turney
    Communications Earth & Environment, 2024
  7. JCLI
    Dipole Response of Millennial Variability in Tropical South American Precipitation and δ18 O p During the Last Deglaciation: Part I: Rainfall Response
    Yuntao Bao, Zhengyu Liu, and  Chengfei He
    Journal of Climate, 2023
  8. JCLI
    Dipole Response of Millennial Variability in Tropical South American Precipitation and δ18 O p During the Last Deglaciation: Part II: δ18 O p response
    Yuntao Bao, Zhengyu Liu, and  Chengfei He
    Journal of Climate, 2023
  9. JCLI
    Reconstruction of past Antarctic temperature using present seasonal δ18 O-inversion layer temperature: Unified Slope Equations and Applications
    Z Liu,  Chengfei He, M Yan, C Buizert, BL Otto-Bliesner, F Lu, and C Zeng
    Journal of Climate, 2023
  10. JCLI
    Antarctic Warming during Heinrich Stadial 1 in a Transient Isotope-Enabled Deglacial Simulation
    Chenyu Zhu, Jiaxu Zhang, Zhengyu Liu, Bette L Otto-Bliesner,  Chengfei He, Esther C Brady, Robert Tomas, Qin Wen, Qing Li, Chenguang Zhu, and  others
    Journal of Climate, 2022
  11. GRL
    Termination 1 Millennial-scale Rainfall Events over the Sunda Shelf
    F Buckingham, SA Carolin, JW Partin, JF Adkins, KM Cobb, CC Day, Q Ding,  Chengfei He, and  others
    Geophysical Research Letters, 2022
  12. GRL
    Local Insolation Drives Afro-Asian Monsoon at Orbital-Scale in Holocene
    Qin Wen, Zhengyu Liu, Jiang Zhu, Mi Yan,  Chengfei He, Jing Han, Jian Liu, and Yishuang Liang
    Geophysical Research Letters, 2022
  13. speleo2_large.jpg
    Hydroclimate footprint of pan-Asian monsoon water isotope during the last deglaciation
    Chengfei He, Zhenyu Liu, BL Otto-Bliesner, EC Brady, C Zhu, R Tomas, PU Clark, J Zhu, A Jahn, S Gu, and  others
    Science Advances, 2021
  14. Antarctic surface temperature and elevation during the Last Glacial Maximum
    Christo Buizert, TJ Fudge, William HG Roberts, Eric J Steig, Sam Sherriff-Tadano, Catherine Ritz, Eric Lefebvre, Jon Edwards, Kenji Kawamura, Ikumi Oyabu,  Chengfei He, and  others
    Science, 2021
  15. greenland.jpg
    Abrupt Heinrich Stadial 1 cooling missing in Greenland oxygen isotopes
    Chengfei He, Zhengyu Liu, Bette L Otto-Bliesner, Esther C Brady, Chenyu Zhu, Robert Tomas, Christo Buizert, and Jeffrey P Severinghaus
    Science Advances, 2021
  16. GRL
    Shallowing Glacial Antarctic Intermediate Water by Changes in Sea Ice and Hydrological Cycle
    Lingwei Li, Zhengyu Liu, Chenyu Zhu,  Chengfei He, and Bette Otto-Bliesner
    Geophysical Research Letters, 2021
  17. Deglacial variability of South China hydroclimate heavily contributed by autumn rainfall
    Chengfei He, Zhengyu Liu, Bette L Otto-Bliesner, Esther C Brady, Chenyu Zhu, Robert Tomas, Sifan Gu, Jing Han, and Yishuai Jin
    Nature communications, 2021
  18. P&P
    Testing Methods for Reconstructing Glacial Antarctic Circumpolar Current Transport in an Isotope-Enabled Climate Model
    Lingwei Li, Zhengyu Liu, Jean Lynch-Stieglitz,  Chengfei He, Sifan Gu, Jiaxu Zhang, and Bette Otto-Bliesner
    Paleoceanography and Paleoclimatology, 2021
  19. QSR
    Deglacial trends in Indo-Pacific warm pool hydroclimate in an isotope-enabled Earth system model and implications for isotope-based paleoclimate reconstructions
    Xiaojing Du, James M Russell, Zhengyu Liu, Bette L Otto-Bliesner, Yu Gao, Chenyu Zhu, Delia W Oppo, Mahyar Mohtadi, Yan Yan, Valier V Galy, and  Chengfei He
    Quaternary Science Reviews, 2021
  20. QSR
    A mechanistic understanding of oxygen isotopic changes in the Western United States at the Last Glacial Maximum
    Clay Tabor, Marcus Lofverstrom, Jessica Oster, Barbara Wortham, Cameron Wet, Isabel Montañez, Alan Rhoades, Colin Zarzycki,  Chengfei He, and  others
    Quaternary Science Reviews, 2021