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Alexandra Jahn

@seaiceclimate.bsky.social

Climate scientist with focus on the Arctic Ocean and Professor at CU Boulder. Opinions my own. New here

323 Followers  |  456 Following  |  10 Posts  |  Joined: 07.10.2023  |  1.7305

Latest posts by seaiceclimate.bsky.social on Bluesky


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A walk across Alaska’s Arctic sea ice brings to life the losses that appear in climate data A polar scientist explains the changes hunters who rely on the ice are seeing off Utqiagvik, and how those shifts are echoed in satellite data and climate models.

INSTAAR fellow Alexandra Jahn @seaiceclimate.bsky.social has spent more than a decade studying sea ice and how it's changing in the 21st century. Last year, she visited an arctic community that is feeling those changes first hand. theconversation.com/a-walk-acros...

24.09.2025 19:39 — 👍 4    🔁 2    💬 0    📌 0
A group of people stand together in a field surrounded by pine trees

A group of people stand together in a field surrounded by pine trees

RECCS is a paid summer research internship program open to community college students in Colorado, Nebraska, Wyoming, Utah, New Mexico, and Kansas. Applications for Summer 2025 are due by Feb. 9, 2025: https://buff.ly/3DOY0Y7

@ciresceee.bsky.social @colorado.edu

13.01.2025 16:00 — 👍 8    🔁 7    💬 0    📌 2
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An ice-free day on the Arctic Ocean? It’s coming sooner than we realized, a CU researcher says The Arctic Ocean is one of the coldest regions on the globe. But a CU researcher says that some day soon, the Arctic will see its first day in which all of the sea ice has melted due to rising global ...

🔊 ALEXANDRA JAHN @seaiceclimate.bsky.social speaks with KUNC's Erin O'Toole about predicting when the 1st ice-free *day* on the Arctic Ocean might occur. Jahn & @clnhz.bsky.social found it could happen within 3-20 yrs, an ominous milestone

Listen to 9 min interview: www.kunc.org/podcast/inth...

17.12.2024 21:12 — 👍 9    🔁 8    💬 0    📌 0

Can you add me to the climate scientist starter pack too please? Thanks.

05.12.2024 18:16 — 👍 1    🔁 0    💬 0    📌 0
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The first ice-free day in the Arctic Ocean could occur before 2030 - Nature Communications The first day with no sea ice in the Arctic will be a visible sign of climate change. This work reveals that this could occur before 2030 already and becomes more likely as the world warms. As the ice...

Published open access as „The first ice-free day in the Arctic Ocean could occur before 2030“ www.nature.com/articles/s41...

03.12.2024 16:02 — 👍 9    🔁 5    💬 0    📌 0
Graph of model output showing a projection of a first ice free day within 4 years

Graph of model output showing a projection of a first ice free day within 4 years

How could this look like? One example of a #CMIP6 model simulation shown below, with the first occurrence of an ice free (less than 1 million km2) day within 4 years

03.12.2024 14:59 — 👍 1    🔁 0    💬 1    📌 0

This article in @naturecomms.bsky.social was written jointly with @clnhz.bsky.social from @naturvetenskap.bsky.social

03.12.2024 13:49 — 👍 3    🔁 0    💬 1    📌 0
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Countdown to an ice-free Arctic: New research warns of accelerated timelines The first summer on record that melts practically all of the Arctic’s sea ice, an ominous milestone for the planet, could occur as early as 2027.For the first

www.colorado.edu/today/2024/1...

03.12.2024 13:48 — 👍 3    🔁 0    💬 1    📌 0

Only if global warming can be limited to below 1.5°C could ice-free days potentially be avoided. Under all emission scenarios with more than 1.5°C warming, the Arctic sea ice will reach ice-free conditions in the next decades. This is most likely to occur for the first time within 7-30 years.

03.12.2024 13:48 — 👍 3    🔁 2    💬 2    📌 0
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The first ice-free day in the Arctic Ocean could occur before 2030 Nature Communications - The first day with no sea ice in the Arctic will be a visible sign of climate change. This work reveals that this could occur before 2030 already and becomes more likely as...

There is a small chance that the first sea ice free day in the Arctic Ocean could occur before 2030 if the right sequence of weather events occur, based on #CMIP6 models. rdcu.be/d2gBK www.colorado.edu/today/2024/1... @clnhz.bsky.social @naturvetenskap.bsky.social @colorado.edu @instaar.bsky.social

03.12.2024 13:48 — 👍 31    🔁 21    💬 1    📌 5

Congratulations Céline! As far as obsessions go, a #CMIP one is a useful one 🤣

03.12.2024 13:19 — 👍 0    🔁 0    💬 0    📌 0

This article was written with my co-authors Marika Holland (NCAR CGD) and Jennifer Kay (CU, ATOC & CIRES)

CU story: colorado.edu/today/2024/03/…

05.03.2024 18:46 — 👍 2    🔁 0    💬 0    📌 0

New paper alert: While ice-free conditions in September are now likely unavoidable, with first ice-free days possible within the next decade & likely before 2050, future emissions will determine how frequently & for how long the Arctic will be ice-free. rdcu.be/dApgx

05.03.2024 18:46 — 👍 10    🔁 3    💬 2    📌 0

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