Aslak Grinsted
Associate Professor at the Niels Bohr Institute, University of Copenhagen. Interested in ice, climate, sea level, and extreme events. 🧪 ❄️ 🌊 🌀 🥼 🌡️
Dad of two teen girls, and one toddler boy.
Also on mastodon here: @agrinsted@fediscience.org
- Quite happy about this assignment for my inverse problems course (heavily based on material I inherited from Klaus Mosegaard). It is a gravity inversion problem using old IPY data.
- I just downloaded a textbook in epub format. It is actually possible to read it on my phone. (Unlike the pdf). I like it.
- Reposted by Aslak GrinstedThis is cool, 6 million year old ice from Antartica with inferred temperature ~12°C warmer than the late Pleistocene. No CO2 level yet! (That will be highly anticipated!) www.pnas.org/doi/10.1073/...
- Reposted by Aslak GrinstedOur traverse fieldwork had been accomplished www.green2ice.eu/2025/06/07/j...
- I have built a cool little prototype ML algo that can estimate population density in 20m resolution from S2 imagery. Here are 5 examples. Row1: Sentinel-2. (input data) Row2: population density from eurostat. (input data) Row3: ML model population density. (output data)
- Here's the code: github.com/grinsted/pop...
- A PhD fellowship in computational and mathematical modelling of flow and fracture in ice sheets. jobportal.ku.dk/phd/?show=16... Application deadline tomorrow
- Woodworth and Rowe 2018: The tidal measurements of James Cook during the voyage of the Endeavour (Cool paper and cool journal) hgss.copernicus.org/articles/9/8...
- Reposted by Aslak GrinstedWe lost a giant in polar and climate science this spring. Chet Langway, a man who was there at the start of ice core science and kept miles of cores frozen for decades of scientific study. ❄️🧪💙📚 #scicomm #climate #UVMresearch #science 🌎 🔬 ⚒️ #ClimateHealth www.buffalo.edu/ubnow/storie...
- Why do these 2 numpy lines not give the same result? Aaargh! data[range(1,3),range(1,3)].shape -> (2,) data[1:3,1:3].shape -> (2,2) I don't want the diagonal!
- Bedrock reached at the Ice coring on Müller ice cap (Axel Heiberg Island). I bet that we would reach at 611m --- pretty close to the final 613m. (Bo guessed 612m so i didn't win).
- They got the EGRIP camp weather data flowing out of camp. alice.egrip.camp
- Reposted by Aslak GrinstedThe resulting cataclysmic backsplash of water - a MEGATSUNAMI - was around 200 metres tall, and sent 100-metre-high waves racing across the fjord to smash against the other side of it. (This is still not the crazy bit!) 5/
- Crude estimate of the bicycle accident risk per km. (Sure to convince my teen girls to wear their helmets.) Numbers for denmark: Accidents: 15000 per year Trips: 2e6 per day Avg trip length: 3.2km =Approx: 1 accident per 150e3 km stormgmtpbie.z6.web.core.windows.net/cykelregnska...
- Greenland accumulation in terms of cucumbers. * Greenland acc = ~600Gt/yr. * global pop = ~9bn. So ~7.5 kg/person/hour * cucumber water content = ~166g So ~45 cucumbers/person/hour Unfortunately global cucumber production is only 95 Mt/yr = 1.2 cucumber/person/week 🥲
- An open position for a Global climate and ice sheet modelling scientist at DMI. candidate.hr-manager.net/ApplicationI...
- Reposted by Aslak GrinstedLarge fractures continue to open up at the grounding line of Thwaites Glacier Eastern Ice Shelf. Animation contains @copernicusland.bsky.social #Sentinel-1C data alongside 1A and 1B
- Alot of ML at EGU. Some of it good, but also some pretty random stuff.
- Reposted by Aslak GrinstedIt's so sad to see that this incredible dataset, which has redefined how we approach many Arctic-related studies, may not be updated in the future 😞
- 📢 The final ArcticDEM & REMA release is here - and it might be the last. Funding cuts put vital polar data at risk. Help us rally support: take the survey! 🔗https://z.umn.edu/pgc-dem-survey #PolarScience #SavePolarData
- Reposted by Aslak GrinstedNorge vil lokke forskere til landet: 'Det handler især om situationen i USA'. I Norge har Forskningsrådet, der prioriterer og deler penge ud på vegne af staten, afsat 100 millioner norske kroner (cirka 63 millioner kroner) til at lokke udenlandske forskere til landet.
- Reposted by Aslak Grinsted#IPICS followers take note. The icecore subcategory is around 4GB and probably worth having at hand. #AlexandriaLibraryLuddites
- I need a new circular saw and would like the batteries to be compatible with my other DeWalt tools. But i am wondering if i should jump ship to some non-US brand. Also - they apparently have extra high exposure to the tariff situation.
- Reposted by Aslak GrinstedCome work with us PhD fellowship modelling flow and fracture in #ice sheets jobportal.ku.dk/phd/?show=16... (application deadline 3 June) @precise-project.bsky.social
- Reposted by Aslak GrinstedWho wants to work on the Arctic in Copenhagen? Super postdoc job going with our friends at Aarhus University* together with DMI on climate modelling and Arctic influences on the mid-latitudes: *at a campus not actually in Aarhus but just outside Copenhagen international.au.dk/about/profil...
- Reposted by Aslak GrinstedThis week is your last chance to apply for the Ice core Analysis and Techniques PhD school indico.nbi.ku.dk/event/2111/ #P2F #Icelink @precise-project.bsky.social
- Scandinavia in March vs April #modis
- I wrote up a tiny 2d shallow ice approximation python notebook for my continuum mechanics course. gist.github.com/grinsted/d5d...
- The background is that the students implemented a shallow water tsunami model immediately prior to me showing this, and the numerical scheme and code is so similar ... Hopefully makes it easy to understand.
- The Overleaf integrations with git and zotero is so great. New figures will appear in Overleaf when I commit and bib file sync also only takes a click.
- Reposted by Aslak GrinstedThe Danish Meteorological Institute (DMI) is offering a 3-year, full-time position as a Scientist for Modelling Ice Sheet–Climate Interaction. @precise-project.bsky.social candidate.hr-manager.net/ApplicationI...
- Reposted by Aslak GrinstedA three-year #postdoc in #machinelearning emulators of #ice-ocean processes is available at Northumbria University as part of our novo funded project PRECISE @precise-project.bsky.social
- Reposted by Aslak GrinstedIn case the existing news wasn't enough to put you in a funk 🧪⚒️
- Moomin=Kant? Tove Jansson made the first drawing of a moomin troll in an outhouse after an argument with her brother where one of them was quoting Immanuel Kant. I heard two different versions of that story. In one of them the Moomin troll was intended as a caricature of Kant.
- I think this article might be the original source of the story. But I don't have access... www.hs.fi/suomi/art-20...
- Fluid dynamics in an absolutely beautiful 64k computer demo. youtu.be/R-4wHUw_OdE?...
- I'm considering if my continuum mechanics course should cover some intro plasma physics too in the future. Any good books that span that space? Some keywords: (elastic solids, viscous fluids, to plasma physics).
- I am looking at different Lab/Lch colorspaces (OKLab/SR2Lab/...) - One issue they share is that the RGB color you get for very dark L-values becomes negative. Seems non-sensible to me.
- Any recommendations for a book on inverse problems covers both linear and Bayesian techniques - ideally with examples from earth science.
- Reposted by Aslak GrinstedFichtner et al present the results of seismic measurements from the EastGRIP borehole in Greenland. Earthquakes that were measured in the core reveal brittle deformation mechanisms that are not accounted for in the most commonly used ice flow law, Glen's Flow Law. doi.org/10.1126/scie...
- DR has now retracted the documentary. www.dr.dk/drtv/episode...
- Anybody has access to recent very high resolution satellite imagery of Greenland. We want to know if a Ø22cm pipe is still sticking out of the ice at this location: 75.09714423N, 42.31992755W (5m uncertainty) Please help - it could save a lot of fuel (It is the NGRIP borehole casing)
- Colonial mining profits... Denmark has made huge profits from a cryolite mine in Greenland. A new explosive documentary has sparked debate in DK. I think the criticism of the documentary is a bit unfair - the caveats regarding the 400bn are clearly highlighted IMHO.
- I just wish it had come out a long time ago, and not right in an election. It is not a time for nuance.
- This is a nice article in science about EastGRIP. Love the photos. www.science.org/content/arti...
- Reposted by Aslak GrinstedA new paper about the Antarctic Ice Sheet in a special issue of @science.org reviews critical knowledge gaps in our understanding of how Antarctica responds to variations in global climate. Antarctica in 2025: Drivers of deep uncertainty in projected ice loss www.science.org/doi/10.1126/...
- Reposted by Aslak Grinstedde Wit et al present a new database of Holocene sea level indicators and proxies for the Netherlands. This could be one of the best vetted datasets of this kind ever published, and it contains over 700 data points! doi.org/10.5194/essd...
- Loewe 1936: "... there is a strong evidence that the Greenlandic ice cap is not quickly decreasing today but in a nearly stationary condition". Pretty impressive statement considering the sparse data at the time. I'd love a pdf of that paper. Anybody? www.buchfreund.de/de/d/p/79453...
- Reposted by Aslak GrinstedNEW: What extreme weather or climate change disaster sensors could you use in your home to give you an early warning, and time to respond? I spoke to one climate scientist who found flood sensors indispensable recently! www.thereengineer.pro/p/climate-ha...
- Reposted by Aslak GrinstedAfter #Trump used a Sharpie to alter the projected path of #HurricaneDorian on a map to show #AL in its path, #NeilJacobs helped draft a #NOAA statement backing Trump’s projection. An internal NOAA report determined Jacobs violated the agency’s scientific integrity policy by issuing the statement.
- Details from @thehill.com
- End of an era. The final Symposium of the EastGRIP project.
- I have moved the entire family to immich instead of Google Photos and it is great. Open Source appreciation day.
- I wish that VS Code would remember which environment i last used for a python notebook. -Or maybe if i could add an annotation clue to the first cell with the name of an environment. Just like i can add "#!/usr/bin/env bash" to a shell script.
- Reposted by Aslak GrinstedIn case all the interest in #Greenland has raised your interest, our ace collaborators in #Asiaq, the logistics and survey organisation are currently recruiting a #climate + cryosphere position. This is a *permanent* position and a super opportunity asiaq.career.emply.com/en/ad/climat...
- Many electrical wood working tools work great on ice. I've used band saws, circular saws, chainsaws, hand drills, router, and planer. Here's me 20years ago. Cutting a blue ice sample with a chainsaw.
- Blue ice areas are a source of ancient ice. So, you can potentially use them to get a horizontal ice core. Here's a photo of a very clear layer that i interpret as an isochrone. Maybe this layer was caused by volcanic eruption. The challenge is how to date the ice.
- Here, I've exaggerated the contrast of a Sentinel-2 median image from the same region (Sharffenbergbotnen). Notice the clear layering. The youngest blue-ice appear more brownish. I wonder why? We believe this valley to be mostly holocene ice.
- Reposted by Aslak GrinstedClosing 19 Jan 2024! 👇
- Stressful morning. Blocked sewers outside our house - they could not keep up with the melting snow & rain. But we avoided getting flooded - Yay! I had just bought and installed some flood sensor alarms (SNZB-05B), and got an early warning from home assistant.
- I had also just got an annual subscription to a sewer service company and they responded rapidly. Happy about that too.
- I can recommend that flood sensor. Home assistant is great too, but it is a commitment, so only if you want to nerd out on it. I started that journey because of my new solar setup. I wanted to control power usage in a more clever way.
- Organizing some old fieldwork photos using immich. Here's a nice black "dragon" shaped stripe in Scharffenbergbotnen, Heimefrontfjella, Antarctica.
