Sciences and Exploration Directorate

Lettie Roach

(Associate Research Scientist)

Org Code: 611

Mail Code: 611
New York, NY 10025


Brief Bio

I am an Associate Research Scientist at the Center for Climate Systems Research, Columbia University based at NASA Goddard Institute for Space Studies (GISS) in New York City.

I am broadly interested in Earth's climate system, with a focus on the polar regions. My research is motivated by a desire to understand the physics of coupled interactions between ice and climate. I typically work with climate models of varying levels of complexity, in combination with observations, aiming to improve climate projections.


Postdoctoral Research Associate

University of Washington - Seattle

2019 - 2021

Associate Research Scientist

NASA GISS/Columbia University - New York City

2021 - Present


2016-2019 Geophysics PhD, Victoria University of Wellington

2011-2015 Mathematical Physics MPhys, University of Edinburgh

Selected Publications


Roach, L. A., I. Eisenman, T. J. Wagner, and A. Donohoe. 2023. Asymmetry in the Seasonal Cycle of Zonal‐Mean Surface Air Temperature Geophysical Research Letters 50 (10): [10.1029/2023gl103403]

Goosse, H., S. Allende Contador, C. M. Bitz, et al. E. Blanchard-Wrigglesworth, C. Eayrs, T. Fichefet, K. Himmich, P.-V. Huot, F. Klein, S. Marchi, F. Massonnet, B. Mezzina, C. Pelletier, L. Roach, M. Vancoppenolle, and N. P. van Lipzig. 2023. Modulation of the seasonal cycle of the Antarctic sea ice extent by sea ice processes and feedbacks with the ocean and the atmosphere The Cryosphere 17 (1): 407-425 [10.5194/tc-17-407-2023]

Roach, L. A., E. Blanchard‐Wrigglesworth, S. Ragen, et al. W. Cheng, K. C. Armour, and C. M. Bitz. 2022. The Impact of Winds on AMOC in a Fully‐Coupled Climate Model Geophysical Research Letters 49 (24): [10.1029/2022gl101203]

Cooper, V. T., L. A. Roach, J. Thomson, et al. S. D. Brenner, M. M. Smith, M. H. Meylan, and C. M. Bitz. 2022. Wind waves in sea ice of the western Arctic and a global coupled wave-ice model Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 380 (2235): [10.1098/rsta.2021.0258]

Montiel, F., A. L. Kohout, and L. A. Roach. 2022. Physical Drivers of Ocean Wave Attenuation in the Marginal Ice Zone Journal of Physical Oceanography 52 (5): 889-906 [10.1175/jpo-d-21-0240.1]

Roach, L. A., I. Eisenman, T. J. Wagner, E. Blanchard-Wrigglesworth, and C. M. Bitz. 2022. Asymmetry in the seasonal cycle of Antarctic sea ice driven by insolation Nature Geoscience 15 (4): 277-281 [10.1038/s41561-022-00913-6]

Roach, L. A., and E. Blanchard‐Wrigglesworth. 2022. Observed Winds Crucial for September Arctic Sea Ice Loss Geophysical Research Letters 49 (6): [10.1029/2022gl097884]

Horvat, C., and L. A. Roach. 2022. WIFF1.0: a hybrid machine-learning-based parameterization of wave-induced sea ice floe fracture Geoscientific Model Development 15 (2): 803-814 [10.5194/gmd-15-803-2022]

Notz, D., J. Dörr, D. A. Bailey, et al. E. Blockley, M. Bushuk, J. B. Debernard, E. Dekker, P. DeRepentigny, D. Docquier, N. S. Fučkar, J. C. Fyfe, A. Jahn, M. Holland, E. Hunke, D. Iovino, N. Khosravi, F. Massonnet, G. Madec, S. O'Farrell, A. Petty, A. Rana, L. Roach, E. Rosenblum, C. Rousset, T. Semmler, J. Stroeve, B. Tremblay, T. Toyoda, H. Tsujino, and M. Vancoppenolle. 2020. Arctic Sea Ice in CMIP6 Geophysical Research Letters 47 [10.1029/2019gl086749]

Horvat, C., L. A. Roach, R. Tilling, et al. C. M. Bitz, B. Fox-Kemper, C. Guider, K. Hill, A. Ridout, and A. Shepherd. 2019. Estimating the sea ice floe size distribution using satellite altimetry: theory, climatology, and model comparison The Cryosphere 13 (11): 2869-2885 [10.5194/tc-13-2869-2019]