Persistent warming and reduced freshening of the abyssal Southern Ocean. - Kathy Gunn

Add to your list(s) Download to your calendar using vCal

• Kathryn Gunn (University of Southampton)
• Wednesday 24 September 2025, 15:30-16:30
• BAS Seminar Room 1 (http://bit.ly/4pDlm6l).

If you have a question about this talk, please contact Katherine Turner.

Recent observations reveal that Antarctic Bottom Water is thinning, warming, freshening, and spreading more slowly  northward into the abyssal ocean. Using the most-up-to-date historical data (1985-2024) alongside simulations out to 2050, I review and assess abyssal ocean changes that are ongoing and projected. Between 1985-2024, isopycnals below 3000 m have descended at a rate of -95±5 m/decade, and have been replaced by warmer water, resulting in warming of 0.02±0.02 °C/decade. Freshening of -0.002±0.003 g/kg/decade also occurred, due to meltwater-driven changes in the continental shelf waters.  Projections, in line with the latest observations, suggest thinning and warming will persist in response to continued glacial melt. However, freshening slows and even reverses. Meltwater makes shelf waters too light to reach the deep ocean, weakens the shelf-to-abyss connection, alters long-standing trends, and doubles the deep ocean contribution to Southern Ocean sea level rise.

This talk is part of the British Antarctic Survey - Polar Oceans seminar series series.

This talk is included in these lists:

• All Talks (aka the CURE list)
• BAS Seminar Room 1 (http://bit.ly/4pDlm6l)
• Biology
• British Antarctic Survey
• Cambridge Environment
• Climate Science Seminars within Cambridge
• Featured lists
• Life Sciences
• Life Sciences
• ME Seminar
• Queens' College Politics Society
• School of Physical Sciences
• Talks related to atmosphere and ocean dynamics and climate science
• my_list
• ob366-ai4er
• other talks

Note that ex-directory lists are not shown.