This page contains a list of blog-like posts. I do not allow comments on this site though due to limitations of the hosting service I use.  

  • Plausible upper limit of WAIS ice loss Ritz et al. (2015) have a recent model study of potential sea level rise from Antarctic marine ice sheet instability. In it they conclude:"Our assessment suggests that upper-bound ...
    Posted Dec 15, 2015, 3:09 PM by Aslak Grinsted
  • Digitizing pdf figures using inkscape I recommend using inkscape if you want to digitize a vector figure from a pdf file. Here's how you do that. Open Inkscape.In [inkscape preferences]-[svg output] disallow ...
    Posted Sep 30, 2015, 12:04 AM by Aslak Grinsted
  • More and Stronger Hurricane surges I thought I would share this quite illustration on how to interpret changes in return period/return magnitude plots. Data on hurricane surges along the US Atlantic and gulf coasts ...
    Posted Sep 30, 2015, 12:05 AM by Aslak Grinsted
  • Sea level, the moon, and Frankenstein Jens Morten Hansen (JMH) and co-authors have recently published a study where they use sine-regression to fit 5 oscillations plus a linear trend to a 160-year sea ...
    Posted Sep 25, 2015, 5:23 AM by Aslak Grinsted
  • Ice sheet pessimists are not outliers Bamber and Aspinall 2013 published a formal expert elicitation on the future of our two ice sheets, and found a large spread between individual expert answers. It has been argued ...
    Posted May 27, 2015, 7:03 AM by Aslak Grinsted
  • Loading MOLA PEDR files in matlab I have written a little matlab function to read the MOLA laser altimeter data from the Mars Global Surveyor.  More specifically the so called Precision Experiment Data Records (PEDR) records ...
    Posted May 19, 2015, 6:30 AM by Aslak Grinsted
  • Thoughts on the Pachauri harassment case Pachauri has been accused of sexual harassment. You can read about it here:http://indianexpress.com/article/india/india-others/delhi-police-fir-against-r-k-pachauri-on-charges-of ...
    Posted Sep 9, 2015, 1:21 AM by Aslak Grinsted
  • A better windows experience ChocolateyChocolatey is a package manager sort of like apt-get for windows, or a command-line version of ninite. You can do stuff like:choco install <packagename> Usually you ...
    Posted Mar 9, 2015, 4:11 AM by Aslak Grinsted
  • Bayesian exercises for Inverse problems Below is a pdf with some exercises for that i use in my course on inverse problems.Problem 0: Goal understand why it is attractive to use loglikelihoods over likelihoods ...
    Posted Oct 23, 2014, 4:18 AM by Aslak Grinsted
  • Tracking ice motion in Landsat 8 I have been attempting to track ice motion in landsat 8 files. I have only been able to find the L1T files. These are terrain corrected files. Unfortunately for my ...
    Posted Jun 11, 2014, 1:57 AM by Aslak Grinsted
  • West Antarctic collapse in the IPCC reports I have extracted some quotes from the IPCC reports since 1990 showing how West Antarctic Ice Sheet collapse has been discussed over time. It is not an exhaustive list.FAR ...
    Posted Jan 7, 2015, 11:36 PM by Aslak Grinsted
  • What does "likely" mean? It can be quite difficult to interpret what likely exactly means sometimes. For example in the AR5 sea level chapter they report a likely range of 21-33 cm for ...
    Posted May 14, 2014, 5:34 AM by Aslak Grinsted
  • Vulnerability of marine based sectors of Antarctica Should we take the risk of Antarctic collapse seriously?The IPCC AR5 sea level chapter considered instability of marine-based sectors of the ice sheets to be unlikely (Church et ...
    Posted Nov 3, 2014, 11:38 PM by Aslak Grinsted
  • EGU 2014 Me at EGU 2014:Convening the sea level session (Friday afternoon – you are welcome!)Surface velocities at Engabreen produced from time-lapse feature tracking (Alex)Sea level projections from FAR ...
    Posted Apr 16, 2014, 5:23 AM by Aslak Grinsted
  • Comparison of sea level projections I have been making a nice figure which compares the 21stC sea level projections from the AR5, with previous IPCC reports, Semi empirical models, and an expert elicitation ... I hope ...
    Posted Oct 23, 2014, 5:10 AM by Aslak Grinsted
  • Optimistic & over-confident ice sheet projections in AR5 Take away message: The graph on the right shows that AR5 process based ice sheet projections are optimistic and over confident when compared to views of ice sheet experts. To ...
    Posted Oct 8, 2015, 5:01 AM by Aslak Grinsted
  • AR5 sea level rise uncertainty communication failure I am disappointed in how the sea level rise projection uncertainties are presented in the IPCC AR5. The way the numbers are presented makes people believe 98 cm by 2100 ...
    Posted Oct 23, 2014, 5:05 AM by Aslak Grinsted
  • Can process models close the sea level budget? Before we can trust the projected models of sea level rise then it is reasonable to demand that these models can match the record of global mean sea level rise ...
    Posted Nov 20, 2013, 1:33 AM by Aslak Grinsted
  • Return period of Boulder 2013 extreme rain Several media stories on the Colorado floods talk of it as a 1000-year flood. However, the original source of this claim was talking about a 1000-year precip event ...
    Posted Nov 20, 2013, 1:30 AM by Aslak Grinsted
  • Trends in extreme hurricane damage I have downloaded the ICAT damage estimates of normalized hurricane damages(/losses) and looked at the trends in the data. This series is often used to argue that there is ...
    Posted Nov 20, 2013, 1:34 AM by Aslak Grinsted
  • WAIS collapse during the last interglacial? There are several lines of evidence pointing to a WAIS collapse during the last interglacial (MIS 5 / Eemian).Evidence for a WAIS collapse.Oldest ice in WAIS-divide ice core ...
    Posted Oct 17, 2013, 2:11 AM by Aslak Grinsted
  • The units of ACE are simply wrong Definition of Accumulated Cyclone Energy as is lifted from wikipedias entry:"The ACE of a season is calculated by summing the squares of the estimated maximum sustained velocity of every ...
    Posted Sep 11, 2013, 12:39 AM by Aslak Grinsted
  • A quick look at El Niño in CMIP5 TeleconnectionsEl Nino is not well represented by many climate models. In Nature there is a very high anti correlation between SOI and NINO3.4 in the order of -0 ...
    Posted Feb 27, 2014, 6:54 AM by Aslak Grinsted
  • Humanity eats 1 Hiroshima per minute! Global average calorie intake is: 2940 kCal/capita/day.We are 7 billion people on Earth.That adds up to 8.6 * 1016 Joule per dayThat is equivalent ...
    Posted Dec 2, 2013, 4:02 AM by Aslak Grinsted
  • Changing Sea level budget and Semi-Empirical models A flawed argument against SEMsIt is expected that the balance of the sea level budget will change in the future as the slow giants of the ice sheets awaken ...
    Posted Nov 20, 2013, 1:39 AM by Aslak Grinsted
  • GDEMv2 geotiff compression There is no good way to download the entire GDEM dataset. It is just lots of manual work. I assume it is because of datavolume that they put artificial restrictions ...
    Posted Aug 10, 2013, 2:51 PM by Aslak Grinsted
  • Ice sheet contributions to SLR from Bamber & Aspinall Bamber and Aspinall (2013) carried out an expert elicitation of ice sheet experts. From this they could derive uncertainty ranges of the rate of mass loss from each ice sheet ...
    Posted May 6, 2015, 2:16 AM by Aslak Grinsted
  • Linear response of ice sheets? Bamber & Aspinall 2012 made an expert elicitation of ice sheet experts. They shows this table in their supplementary information:This table shows that on average then most experts expect that ...
    Posted Nov 20, 2013, 1:38 AM by Aslak Grinsted
  • Citing CMIP data It would be nice to have a simple doi-like way of citing CMIP6 datasets and this is being discussed today on twitter. I have not been involved in the ...
    Posted Aug 10, 2013, 4:26 AM by Aslak Grinsted
  • Slicing up our Earth I have been experimenting with different methods of slicing up Earth. My motivation is that I want to divide the Earth into an equal area grid because this is critical ...
    Posted Aug 9, 2013, 2:37 AM by Aslak Grinsted
  • Lets move Earth! ... away from the sun. I believe that there is a real risk/possibility that at some point humans will attempt some form of geo-engineering to deal with climate change ...
    Posted Aug 1, 2013, 2:00 AM by Aslak Grinsted
  • Three views on sea level commitment Three recent papers on long term sea level commitment:ModelsLevermann, Clark, Marzeion, Milne, Pollard, Radic, Robinson (2013). The multimillennial sea-level commitment of global warming. Proceedings of the National ...
    Posted Aug 26, 2015, 11:43 PM by Aslak Grinsted
  • Hurricane surges in tide gauges The hurricane surge index was constructed by extracting the hurricane surge signal from tide gauge records. This involved some pre-filtering of the tide gauge data. This page illustrates a ...
    Posted Nov 20, 2013, 1:47 AM by Aslak Grinsted
  • Aslak, that is me Just became aware of a cartoon with my name "Aslak" (h/t PiM). It looks awesome.I'd love to use that as my signature or as a logo on ...
    Posted Jul 8, 2013, 4:36 AM by Aslak Grinsted
  • Scholarfy I very often want to make a google scholar search using exactly the same search terms that i just had in google. For that i have used the Scholarfy bookmarklet ...
    Posted Jun 10, 2013, 2:17 AM by Aslak Grinsted
  • Review of global glacier volume estimates This is an updated version of the regularized global glacier volume estimates from Cogley (2012). I have included 2 new estimates: one by myself (G13) and another from Huss and ...
    Posted Nov 10, 2014, 4:20 AM by Aslak Grinsted
  • Glacier projections Regularizing glacier projectionsGraham Cogley (2012) regularized a number of projections of glacier wastage in a recent book (so that all numbers include the glaciers peripheral to the ice sheets ...
    Posted Nov 21, 2013, 6:46 AM by Aslak Grinsted
  • Did AGW increase the odds of that extreme weather yesterday? - Well, it is more likely than it decreased the odds.All weather will be influenced by the background changes in climate. Climate change (and AGW) will increase the odds of ...
    Posted Jul 30, 2013, 2:59 PM by Aslak Grinsted
  • Python? I am seriously considering swapping to Python as my primary language. There are several things which hold me back.Multiple concurrent versions of the official Python is symptom of something ...
    Posted May 31, 2013, 6:51 AM by Aslak Grinsted
  • Ice sheets and Semi-empirical models Here I demonstrate that a very simple Semi-empirical model (SEM) can approximate the historical contribution to sea level rise from Greenland as estimated by Box and Colgan (2013). I ...
    Posted Nov 20, 2013, 1:50 AM by Aslak Grinsted
  • Cyclones and Societies in the Mascarene Islands 17th-20th Centuries A new paper is out in AJCC which finds a long-term increase of cyclones of the Mascarene Islands based on historical records (Garnier and Desarthe, 2013). It looks pretty ...
    Posted Jul 30, 2013, 3:01 PM by Aslak Grinsted
  • A rebuttal to Pielke Jr's 18ft critique. We show in our paper that the surge index correlates with major land falling hurricanes with a correlation coefficient of 0.6. As expected this correlation improves with smoothing (see ...
    Posted Sep 13, 2013, 3:03 AM by Aslak Grinsted
  • Estimating global glacier volume 35 cmI have recently written a paper where I estimate global glacier volume to be 35 cm using a statistical approach . The statistical approach i use is a refinement ...
    Posted Jun 7, 2013, 3:42 AM by Aslak Grinsted
  • Structure from Motion - link collection Here's some links to different software packages that i plan to try:Bundler: A blog postVisualSFM: Sift+Bundler+PMVS/CMVSmicmac+apero (I might have to give up ...
    Posted Oct 12, 2012, 5:08 AM by Aslak Grinsted
  • Building GAMIT/GLOBK under ubuntu (in a virtualbox) Here's what i did (so far): Install linux in a virtualbox. This is where i want to have my GAMIT installation. Install virtualboxGet an xubuntu/kubuntu/ubuntu image ...
    Posted Apr 19, 2013, 4:05 AM by Aslak Grinsted
  • Glacier mass balance models Excellent stuff in this paper... This is what i should look at.MacDougall et al (2011) "A preliminary assessment of glacier melt-model parameter sensitivity and transferability in a dry ...
    Posted Sep 24, 2012, 3:33 AM by Aslak Grinsted
  • Cold and Warm Extremes in a warmer world Greenhouse gases is warming the world and this will lead to more frequent heat waves all else being equal. You might naively think that this increase in extreme warm spells ...
    Posted Jun 24, 2012, 8:41 PM by Aslak Grinsted
  • Model validation Here is a finite element simulation of strong winds in the Scharffenbergbotnen blue ice area. Simulations made by Torsten Malm (Aalto Univ.) and Thomas Zwinger (CSC - IT Center for Science ...
    Posted Jun 7, 2013, 3:43 AM by Aslak Grinsted
  • Math apps for Android I've put some links to the best android math apps i've found so far.A good calculator, A mini matlab, and a Mathematica. A truly great calculator: handycalc ...
    Posted Nov 17, 2011, 12:15 AM by Aslak Grinsted
  • Space station time-lapse I just love this time-lapse video. [from: http://infinity-imagined.tumblr.com/]
    Posted Sep 21, 2011, 5:32 AM by Aslak Grinsted
  • Times Atlas PR mistake, and the story of an excellent press response. A new version of the Times Atlas has been made and with it there ofcourse was a press release (see below). Between the old and new editions large changes were ...
    Posted Sep 21, 2011, 3:20 AM by Aslak Grinsted
  • Climate and extreme weather Nature has a nice news feature here about linking extreme weather to climate change (author: Quirin Schiermeier). This is something I have been working on, and so I thought I ...
    Posted Sep 9, 2011, 5:29 AM by Aslak Grinsted
  • Video from the bottom of the NEEM borehole On July 1st. 2011 scientists at NEEM managed to film the journey of the drill down through the 2538m deep ice core borehole. The 20 sec. video clip that was ...
    Posted Sep 5, 2011, 1:17 AM by Aslak Grinsted
  • Projected warming under RCP 4.5 This a quick look at a run from the CMIP5 archive. This is a model with low sensitivity.It shows pentadal averages of temperature from 1850-2100 relative to a ...
    Posted Jul 30, 2013, 3:03 PM by Aslak Grinsted
  • Statistics of extreme events This is a short link collection to some free online resources on extreme events.A nice short and readable introduction of some key concepts. http://www.edwardomey.com/nonsave/MallorNualartOmeyExtremeWindSpeeds ...
    Posted Sep 13, 2010, 12:59 AM by Aslak Grinsted
  • Ice conditions in the Danish waters 690-1860 A.D. In 1915 C. J. H. Speerschneider from DMI compiled alot of evidence regarding past ice conditions in Danish waters. My colleague J.P. Steffensen found it in a pile of ...
    Posted Jun 7, 2013, 3:45 AM by Aslak Grinsted
  • A Shallow Ice Glacier Model I have experiemented with using matlabs built-in ode solvers to integrate a Shallow ice . Surprisingly the ode solvers are able to take much greater timesteps than what theoretical stability ...
    Posted Feb 8, 2010, 2:32 AM by Aslak Grinsted
  • Game of Life Here's a very short version of Conways Game of Life for Matlab. In fact it is so short that it would fit in a tweet:a=rand(128)>0 ...
    Posted Feb 8, 2010, 1:55 AM by Aslak Grinsted
  • Non-Optimal interpolation of global sea level. The best data set for reconstructing global mean sea level over the last century is the Tide gauge records archived at the Permanent Service for Mean Sea Level. There are ...
    Posted Apr 14, 2011, 12:40 AM by Aslak Grinsted
  • Relationship between sea level rise and global temperature More recent workThis page may be a bit outdated. Look here for my comments on three more recent papers.One graph that is often put forward to illustrate the ...
    Posted Jul 19, 2013, 3:21 AM by Aslak Grinsted
  • A sanity check for RCS There has been a lot of blogging about yamal. Some of it concerns if RCS introduces spurious signals. It is clear that it is very important to try to get ...
    Posted Jul 30, 2013, 3:05 PM by Aslak Grinsted
  • Recent work on Atlantic tropical cyclones I really like this page (I've copied the contents here - just in case it gets deleted.): http://www.edf.org/page.cfm?tagid=654 It should be updated with ...
    Posted Jun 17, 2009, 5:13 AM by Aslak Grinsted
  • Hindcasts using the Rahmstorf 2007 model On realclimate.org Rahmstorf critizes our model (Grinsted et al., 2009) on the basis that it has too low sensitivity (m/ºC) when extrapolated to a 65 m rise in ...
    Posted Jun 7, 2013, 3:46 AM by Aslak Grinsted
  • Recent papers on sea level I've recently published a paper where we predict a ~1 m sea level rise by 2100. This is quite compatible with other recent studies. Here's a summary i ...
    Posted Sep 10, 2010, 3:56 AM by Aslak Grinsted
  • Codex of Chemical Engineering Great idea for a game: http://www.kongregate.com/games/krispykrem/the-codex-of-alchemical-engineering
    Posted Jan 12, 2009, 1:59 AM by Aslak Grinsted
  • An infinite supply of carbon free energy. Sounds really nice, right? But there are apparently some pitfalls with that... I remember reading a science fiction book where global warming drove the government into the ground. Interrestingly, it ...
    Posted Jan 5, 2009, 4:28 AM by Aslak Grinsted
  • Guide to inserting iframes or flash in Google Sites I receive so many email requests on how to insert flash or iframes in Google Sites. I do not have time to answering them as I should also be working ...
    Posted May 25, 2010, 2:44 AM by Aslak Grinsted
  • Centre for Ice and Climate I have started my new post at the Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Denmark. More details coming....   Thanks alot to all my old friends ...
    Posted Sep 1, 2008, 12:25 AM by Aslak Grinsted
  • Inserting custom gadgets in Google Sites. Google Sites does not allow you to insert javascript, iframes, *** in your html. That makes it very difficult to insert custom media players, flash objects and other widgets in a ...
    Posted Aug 6, 2008, 11:58 PM by Aslak Grinsted
  • How would the world look if Greenland melts? On this page you can see the effect of Global sea level rise on your local coastline. An alternative google mapplet can be found here. You can also do the ...
    Posted Sep 22, 2011, 1:49 AM by Aslak Grinsted
  • Finnish Antarctic expedition 2006-2007 blog In the austral summer 2006/07 i was part of an ~100 day expedition to Scharffenbergbotnen, Heimefrontfjella, Antarctica with FINNARP. There we collected a ~2.5km long horizontal ice core ...
    Posted Jun 24, 2015, 3:02 AM by Aslak Grinsted
  • Wavelet Coherence FAQ I have written a new FAQ for the Crosswavelet and Wavelet Coherence matlab package. At the moment the questions answered are: How do I know whether AR1 noise is an ...
    Posted Mar 18, 2008, 1:59 AM by Aslak Grinsted
  • Visualize the impact of sea level rise in google earth. I found this great layer for google earth which allows you to visualize the impact of sea level rise on your coast line in google earth. It is limited by ...
    Posted Jan 8, 2009, 6:38 AM by Aslak Grinsted
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