Research

I use a variety of research tools to study the Arctic climate system: from weather stations to satellites to atmospheric reanalysis to fully-coupled climate models. Most of the value I add involves designing workflows that produced dervied data products, often and/or combining multiple data sources and variables to focus on the interactions between aspects of the climate system.

My most common research topics include the studying extratropical cyclones in the Northern Hemisphere (especially the Arctic), Arctic sea ice (especially on regional and seasonal time scales), and extreme weather events. Often these topics overlap (e.g., the impact of extreme cyclones on summer Arctic sea ice). Because of its prominence in current discussions over economic development in northern Manitoba (and the Canadian North in general), much of my current research is focused on Hudson Bay.

Map of extratropical cyclone frequency (highest around Iceland and Alaska)

Extratropical Cyclones

Dataset: Northern Hemisphere Cyclones from ERA5 (1940 - recent)

Github: CEOS-NSIDC Extratropical Cyclone Tracking (CNECT) Code

Current & Recent Research Questions:

Do extratropical cyclones move slower in a warming warm?
What is the relative importance of thermodynamic v. dynamic drivers of projected Northern Hemisphere precipitation trends?
What is the relative importance of local v. external moisture sources for the historical increase in Arctic precipitation from extratropical cyclones?

Map of average days ice-free in the Canadian Arctic (from zero north of Ellesmere Island to 120 in Hudson Bay, to 365 off Nova Scotia)

Arctic Sea Ice

Dataset: Arctic Sea Ice Phenology from Passive Microwave Satellites (1979-2021)

Dataset: Arctic Sea Ice Phenology from CMIP6 Models (1950-2099)

Current & Recent Research Questions:

At what level of warming would the sea ice regime in Hudson Bay no longer support polar bear populations?
What are the drivers of pauses in autumn Arctic-wide sea ice expansion?
By how much have and will navigable periods for shipping within Hudson Bay and out through Hudson Strait change?

Graph showing that the winter of 2021-2022 had more blizzard days in Clyde River, Nunavut than any other year on record

Extreme Weather Events

Current & Recent Research Questions:

Work from Other Research Groups Using the CNECT Algorithm / Dataset

(This list is just ones I know about -- if you have used the algorithm or dataset in your work, please let me know!)

Allen, L. R., S. E. Yuter, M. A. Miller, and L. M. Tomkins, 2024: Hunting for gravity waves in non-orographic winter storms using 3+ years of regional surface air pressure network and radar observations. Atmos. Chem. Phys., 25, 1765–1790, https://doi.org/10.5194/acp-25-1765-2025.

Biernat, K. A., D. Keyser, and L. F. Bosart, 2023: A Climatological Comparison of the Arctic Environment and Arctic Cyclones between Periods of Low and High Forecast Skill of the Synoptic-Scale Flow. Mon. Weather Rev., 151, 1957–1978, https://doi.org/10.1175/mwr-d-22-0318.1.

——, L. F. Bosart, and D. Keyser, 2025: Features and Processes Influencing the Evolution and Forecast Skill of Strong Low-Skill Arctic Cyclones. Mon. Weather Rev., 153, 939–960, https://doi.org/10.1175/mwr-d-24-0102.1.

Guern-Lepage, A. L., and B. L. Tremblay, 2023: Disentangling Dynamic from Thermodynamic Summer Ice Area Loss from Observations (1979–2021): A Potential Mechanism for a “First-Time” Ice-Free Arctic. J. Clim., 36, 7693–7713, https://doi.org/10.1175/jcli-d-22-0628.1.

Liu, Y., and Y. He, 2023a: Cold season Arctic strong cyclones enhance Atlantification of the Arctic Ocean. Environ. Res. Lett., 18, 114049, https://doi.org/10.1088/1748-9326/ad0518.

——, and ——, 2023b: Effects of large-scale changes in environmental factors on the genesis of Arctic extreme cyclones. Environ. Res. Lett., 18, 044009, https://doi.org/10.1088/1748-9326/acc2d5.

——, ——, and Y. Shao, 2024: Enhancement of carbon sink in the main marginal sea ice zone by cold season Arctic cyclones. Sci. Total Environ., 918, 170637, https://doi.org/10.1016/j.scitotenv.2024.170637.

McErlich, C., A. McDonald, J. Renwick, and A. Schuddeboom, 2023a: An Assessment of Extra‐Tropical Cyclone Precipitation Extremes Over the Southern Hemisphere Using ERA5. Geophys. Res. Lett., 50, https://doi.org/10.1029/2023gl104130.

——, ——, ——, and ——, 2023b: An Assessment of Southern Hemisphere Extratropical Cyclones in ERA5 Using WindSat. J. Geophys. Res.: Atmos., 128, https://doi.org/10.1029/2023jd038554.

Moreno‐Ibáñez, M., J. J. Cassano, S. L. Gray, and M. Seefeldt, 2025: Sensitivity of the Representation of Polar Lows to Typical Climate Model Resolutions. Atmos. Sci. Lett., 26, https://doi.org/10.1002/asl.1319.

Rinke, A., J. J. Cassano, E. N. Cassano, R. Jaiser, and D. Handorf, 2021: Meteorological conditions during the MOSAiC expedition. Elem.: Sci. Anthr., 9, https://doi.org/10.1525/elementa.2021.00023.

Schreiber, E. A. P., and M. C. Serreze, 2020: Impacts of synoptic-scale cyclones on Arctic sea-ice concentration: a systematic analysis. Annals of Glaciology, 149, 1–15, https://doi.org/10.1017/aog.2020.23.

Song, J., Y. Xu, Z. Han, and J. Wu, 2025: CMIP6 projected trend of winter and summer variation in Arctic cyclones over the 21st century. Clim. Dyn., 63, 82, https://doi.org/10.1007/s00382-024-07531-5.

Song, J.-N., G. Fu, Y. Xu, Z.-Y. Han, Q.-Z. Sun, and H. Wang, 2021: Assessment of the capability of CMIP6 global climate models to simulate Arctic cyclones. Adv Clim Change Res, 12, 660–676, https://doi.org/10.1016/j.accre.2021.07.007.

Tomkins, L. M., S. E. Yuter, M. A. Miller, M. Oue, and C. N. Helms, 2025: Synthesis of surface snowfall rates and radar-observed storm structures in 10+ years of northeastern US winter storms. Atmos. Chem. Phys., 25, 9999–10026, https://doi.org/10.5194/acp-25-9999-2025.

Valkonen, E., J. Cassano, and E. Cassano, 2021: Arctic cyclones and their interactions with declining sea ice: A recent climatology. Journal of Geophysical Research: Atmospheres, https://doi.org/10.1029/2020jd034366.

Valkonen, E., J. Cassano, E. Cassano, M. Seefeldt, and C. Parker, 2025: CMIP6 Representation of Declining Sea Ice and Arctic Cyclones in the Current Climate. J. Geophys. Res.: Atmos., 130, https://doi.org/10.1029/2024jd042388.

Wang, Z., M. Yang, J. E. Walsh, R. M. Rauber, and M. Peng, 2024: A Diagnostic Analysis of the Mechanisms for Arctic Cyclone Intensity Evolution. J. Atmos. Sci., 81, 1383–1399, https://doi.org/10.1175/jas-d-23-0130.1.

Yang, M., Z. Wang, R. M. Rauber, and J. E. Walsh, 2024: Seasonality, Latitudinal Dependence, and Structural Evolution of Arctic Cyclones. J. Clim., 37, 1937–1950, https://doi.org/10.1175/jcli-d-23-0445.1.

Zhang, M., J.-J. Luo, T. Xie, J. Song, and J. Fu, 2024: The impact of IPOD on boreal midsummer extratropical cyclones accompanied by torrential rains in Central and Eastern China. Environ. Res. Lett., 19, 114081, https://doi.org/10.1088/1748-9326/ad8365.

Page updated

Google Sites

Report abuse