Thale Damm-Johnsen

@thale.bsky.social

Postdoc with BIOCOD (CNRS/IPSL) modelling ocean palaeoproductivity across last deglaciations. Also passionate about the hidden wonders of snow petrel vomit (ANTSIE, Durham Uni)

🚨 Carbon dioxide (CO₂) levels set a new monthly *record high* in May 2025 - 430.51 ppm (seasonal maximum) This is the second largest May-May increase in this dataset (3.6 ppm higher than 2024). This is not good... 🫣 Data from gml.noaa.gov/ccgg/trends/

Red line graph time series of monthly carbon dioxide abundance from January 1959 through May 2025. There is a seasonal cycle and long-term increasing trend. Current levels of CO2 are at 431 ppm. This is the Keeling Curve graph. A line for CO2 10 years ago is also annotated.

This is horrible. I don't even know what to say. Some of our most key polar data. "As a result, the level of services for affected products below will be reduced to Basic—meaning they will remain accessible but may not be actively maintained, updated, or fully supported." nsidc.org/data/user-re...

Effective May 5, 2025, NOAA’s National Centers for Environmental Information (NCEI) will decommission its snow and ice data products from the Coasts, Oceans, and Geophysics Science Division (COGS). As a result, the level of services for affected products below will be reduced to Basic—meaning they will remain accessible but may not be actively maintained, updated, or fully supported. This includes Sea Ice Index, Snow Data Assimilation System (SNODAS) Data Products, Glacier Photograph Collection, U.S. National Ice Center Arctic Sea Ice Charts and Climatologies in Gridded Format Gridded Monthly Sea Ice Extent and Concentration, 1850 Onward World Glacier Inventory. If you rely on these products in your work, research, education, or planning, we invite you to share your story at nsidc@nsidc.org. Your input can help us demonstrate the importance of these data sets and advocate for future support.

Why is Antarctica so important? Antarctica might feel very remote - until you look at the planet from a different perspective. It's actually central to our world's ocean currents. 🎁 Check the alt text to dig into this diagram 🌊 This is from a new book by BAS' @oceanandice.bsky.social (et al.)

The image shows a map of the world's currents, but looking at a projection of the world from the bottom of the globe, with Antarctica at its centre. The diagram shows all of the world's currents cycling through major oceans, all linked together by a central circular current that goes around the outside of the Antarctic continent.

"The Southern Ocean around Antarctica is central to global ocean circulation. It enables connectivity across the whole planet by linking the Atlantic, Pacific and Indian Ocean basins, and is the key site where waters are returned to the surface from depth and then converted into new water masses. The clockwise circulation of waters around Antarctica is the Antarctic Circumpolar Current, the strongest ocean current system in the world."

(Figure 1.1 from "Antarctica and the Earth System", edited By Michael P. Meredith, Jess Melbourne-Thomas, Alberto C. Naveira Garabato, Marilyn Raphael)
British Antarctic Survey 🐧@bas.ac.uk · last yr.

🔗 To find out more and get your copy visit routledge.com/Antarctica-and-the-Earth-System/Meredith-Melbourne-Thomas-NaveiraGarabato-Raphael/p/book/9781032500867

🧪🌊 🧵 As the minimum in Antarctic sea-ice extent has now dipped below 2 million km² for the third year in a row, it is looking increasingly like this is the new normal. In the 10 years up to 2015 the minimum extent averaged more than 3 million km². Graph from @nsidc.bsky.social 1/n

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New paper out from our team! Satellite observations of subglacial lakes are much needed for improving knowledge of subglacial meltwater dynamics and evolution, and for improving simulating these processes in models. #glaciology #Antarctic #remotesensing #hydrology 🛰 💧

Jenny Arthur@antarcticjenny.bsky.social · 2y ago

*New evidence of active subglacial lakes under the East #Antarctic Ice Sheet!* We use #ICESat2 to show lakes fill and drain beneath slow-moving ice. Modelling likely meltwater routes suggests lakes discharge meltwater under ice shelves. tiny.cc/wsu7001 @npiglaciology.bsky.social