I use a Bayesian data assimilation method to generate 2D reconstructions of various climate states in the past centuries. I use a prior estimate from a climate model simulation and update that estimate using proxy observations from ice cores, coral records, and tree rings from across the globe. The reconstructions were originally published in O'Connor et al., 2021a in GRL.
My research focuses on reconstructions in the Southern Hemisphere, where westerly winds and sea level pressure influence numerous important processes, including glacier retreat in Antarctica and Southern Ocean carbon uptake. Most climate observations in Antarctica started only ~40 years ago (~1979), making it very difficult to contextualize recent activity and project future changes in Antarctica.
In O'Connor et al., 2021a, we use data assimilation to produce annual reconstructions of winds, pressure, and temperatures in the Southern Hemisphere over the full 20th century. We do this by combining data from a global database of paleoclimate proxy records (such as ice cores, corals, and tree rings) with physical relationships captured in climate model simulations.
My research focuses on reconstructions in the Southern Hemisphere, where westerly winds and sea level pressure influence numerous important processes, including glacier retreat in Antarctica and Southern Ocean carbon uptake. Most climate observations in Antarctica started only ~40 years ago (~1979), making it very difficult to contextualize recent activity and project future changes in Antarctica.
In O'Connor et al., 2021a, we use data assimilation to produce annual reconstructions of winds, pressure, and temperatures in the Southern Hemisphere over the full 20th century. We do this by combining data from a global database of paleoclimate proxy records (such as ice cores, corals, and tree rings) with physical relationships captured in climate model simulations.
The figure on the right shows covariances between winds in West Antarctica and global temperatures, as captured by a climate model. Red and blue regions reflect regions where proxy data covary with West Antarctic winds. The yellow dots show locations of proxy data.
Interact with the reconstructions using our interactive web application
Click the image above to go to an interactive paleoclimate visualization web app I developed with my undergraduate research assistant, Jordan Tucker.
Download the reconstruction data
All reconstruction data published in O'Connor et al., 2021a are available for download as netCDF files on Zenodo.
Feel free to contact me at [email protected] for questions or collaborations!
Feel free to contact me at [email protected] for questions or collaborations!
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Relevant publications
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2021
2022 2023 2024 2024 In review |
O’Connor, G.K. Steig, E.J., Hakim, G.J. (2021a). Strengthening Southern Hemisphere westerlies and Amundsen Sea Low deepening over the 20th century revealed by proxy-data assimilation. Geophysical Research Letters, 48, e2021GL095999. https://doi.org/10.1029/2021GL095999
Holland, P.R., O’Connor, G.K., Bracegirdle, T.J., Dutrieux, P., Naughten, K.A., Steig, E.J., Schneider, D.P., Jenkins, A., Smith, J.A. (2022). Anthropogenic and internal drivers of wind changes over the Amundsen Sea, West Antarctica, during the 20th and 21st centuries. The Cryosphere, 16(12), 5085-5105. https://doi.org/10.5194/tc-16-5085-2022 O’Connor, G.K., Holland, P.R., Steig, E.J., Dutrieux, P., Hakim, G.J. (2023). Characteristics and rarity of the strong 1940s westerly wind event over the Amundsen Sea, West Antarctica. The Cryosphere, 17(10), 4399-4420. https://doi.org/10.5194/tc-17-4399-2023 Fogt, R.L., Dalaiden, Q., O’Connor, G.K. (2024). A comparison of South Pacific Antarctic sea ice and atmospheric circulation reconstructions since 1900. Climate of the Past, 20(1), 53-76. https://doi.org/10.5194/cp-20-53-2024 Dalaiden, Q., Abram, N.J., Goosse, H., Holland, P.R., O’Connor, G.K., Topal, D. (2024). Tropical and anthropogenic drivers shape multi-decadal atmospheric circulation variability over West Antarctica. Geophysical Research Letters, 51(16), e2024GL109137, https://doi.org/10.1029/2024GL109137. Schneider, D.P., Yin, Z., O’Connor, G.K., Blanchard-Wrigglesworth, E., Cast, Z. I., Datta, R., Espinosa, Z. Increased Antarctic snowfall mitigates sea level rise less than projected due to meltwater influence on sea surface temperature. In review at PNAS. https://doi.org/10.22541/essoar.172411232.25724214/v2 |
