26 June 2013

2013 Sea Ice Estimates

Our June guesses for 2013 are 3.9, 4.1, and 4.4 million km^2 for September monthly average sea ice extent as computed by NSIDC.  See the ARCUS SEARCH Outlook for the full current collection of estimates.

Again, I'll put our estimates in context of some other estimation methods. 

  • Climatology 1979-2000: 7.03 million km^2
  • Climatology 1979-2008: 6.67 million km^2
  • Linear Trend Climatology 1979-2008: 5.15 million km^2
  • Wang, Wu, Grumbine model: 4.4 million km^2
  • Wu, Grumbine, Wang model: 4.1 million km^2
  • Grumbine, Wu, Wang statistical ensemble: 3.9 million km^2
All three of our estimates are well below what they were last year -- 4.9, 4.8, and 4.4 million km^2, respectively.  For the two model-based estimates, this is because the model has continued to thin its ice cover, and that ice cover is less extensive.  Then the model (which is coupled air-sea-ice) is not seeing any reason for the ice to be getting markedly thicker or more extensive.

The statistical ensemble reflects two items.  One is, last year being a new record, well below the estimate (by 0.8 million km^2), pulled down the best curves that can be fit through the data.  The second is, the curve itself shows a zone of steep decline.  This is where the feedback of more open water -> warmer ocean -> thinner ice -> easier to melt ice -> more open water in summer is starting to take off rapidly.  (If the basis for my using this curve is reasonably correct, that is.)

The linear 'climatology' estimate last year was 5.23 million km^2, versus the observed 3.61.  Too high that year, and every year 2007-2012, and very likely many more to come.  Merely points to a straight line not being a good representation of how the ice pack is changing, which is no surprise.  But it is also a reminder that talk of sea ice 'recovery', which will no doubt occur in some corners when (if) 2013's extent is greater than 2012's, is nonsense. 

25 June 2013

2012 Sea Ice Prediction Evaluations

Before launching in to my estimates for this year, I have to evaluate last year's estimates.  Not much point in making estimates if you don't re-examine how well the previous ones were.

Last year's observed (NSIDC) September monthly average sea ice extent was 3.6 million km^2.  That blew away the old record set in 2007.

Our June 2012 Estimates were:
4.9 Wang, Grumbine, Wu -- statistical correction of CFS
4.8 Wu, Grumbine, Wang -- semi-physical correction of CFS
4.4 Grumbine, Wu, Wang -- Purely statistical from prior Septembers

4.9 Wang, Grumbine, Wu -- statistical correction of CFS
4.7 Wu, Grumbine, Wang -- semi-physical correction of CFS

3.9 Wang, Grumbine, Wu -- statistical correction of CFS

No updates in August for the semi-physical CFS correction as it hadn't looked like it was coming out any different than the prior months.

The Wang et al. was the best of all August estimates, and was still too conservative by 300,000 km^2 (the approximate land area of Poland, the Philippines, Norway, or Ecuador).  The observed mean extent, of 3.6 million km^2 was about 20% larger than India.  The 1979-2000 average was 7.0 million km^2 -- almost double what we just saw, and about the 10% smaller than Australia.

24 June 2013

Question place

Have at it -- questions welcome.  Answers probably of higher quality (from me, at least) if they're about ice, sea surface temperature, and related parts of the climate, or about running. 

Also suggestions welcome.

17 June 2013


Last week was hiatus because I was working on things that didn't quite make it to completion.  This includes evaluating last year's sea ice estimates (Alastair won both his bets with me so is now even), and writing up this year's estimates (all our estimates are lower than last year this time, but not as low as last year's observations).

This week, it is that I away from home and had a hard computer failure.  I don' like long typing on a touch screen, which is what I'm doing at the moment, so twitter is about it this week.  @rgrumbine.

See you next Monday, when I'll hang out the 'question place' shingle.

07 June 2013

Science's Spock Problem

XKCD captured perfectly where scientists start from in terms of relating to others about their subject:
What we do, the part of the universe we study, is wonderful, fascinating, and we want to run around sharing our wonderful discoveries with everybody.  Including when it's dog vomit slime molds.  See also my niece's write up from jr. high about knight anoles.

And that's what makes the Spock problem such a problem.  What I mean by this is that there is heavy cultural (in the US at least) expectation that scientists _are_, or at least _should_ be, like Mr. Spock -- emotionless, heartless, 'rational', and fundamentally not human.  Humans, and scientists are human, do generally respond to society's expectations.  One common response being to present a public appearance of conforming to those societal expectations.  In private, it can be a different matter.  But, per yesterday's comment, scientists do tend to play in to this expectation in public and it doesn't, I think, work well in the larger society.  So public gets the wildly wrong idea in that case that scientists don't criticize each other, among other wildly wrong ideas.

06 June 2013

Scientist mutual criticism

I've been active on twitter lately (@rgrumbine).  The 140 character limit poses the problems to me that regular readers would expect.  140 words is pretty short for me.  Still, there are some good things out there (I'll be posting a raft of links from my twitter feeds Real Soon Now).  And sometimes a short comment is sufficient, but reminds me of things worth more than 140 characters.

One short comment, bizarre to me, was that scientists don't criticize each other's work.  On one narrow aspect, there's some truth to this.  That aspect being that, for example, pretty much all the people studying sea ice think that sea ice is something worth studying.  Within any given niche of science, occupants of the niche think it's important.  The thing is, each niche is very, very, small.  Occupants of every other niche are more than happy to tell the sea ice people that sea ice isn't nearly as important as their own niche.  At length and volume.  Of course the sea ice people argue back.  And so it goes.  Every multidisciplinary meeting I'm at, this is routine conversation.  Partly it's just a game.  Partly it can lead to something interesting -- say when the sea ice person (finally :-) persuades the ... let's say boundary layer theorist ... that there really is something interesting -- to a boundary layer theorist -- about sea ice.  It's for this latter prospect that I play the game (sometimes being the persuaded rather than persuader).

Yet, even within a relatively small niche like sea ice, there are sub-niches, and sub-sub-niches.  Each of these divisions, even while agreeing that sea ice is important and important to study, is in disagreement about the how, why, what about studying sea ice.  One has in any natural science a certain amount of division between observation/modeling/theory.  The observers think what's really needed is more and better observations, modellers think you need bigger and better models, theorists think we need better theories.  All are right, to some degree.  All are wrong, to some other degree.  But one thing this guarantees is that the sub-niches are ready to criticize each other.  And do so.

05 June 2013

We're still all related

Carl Zimmer, whose work I've enjoyed for years, recently had an article on how we're all (those of us with any European ancestry at all, which is more than you might think) related to Charlemagne (Carolus Magnus, Very great grandpa Chuck) and each other.  I contributed a few comments, and the scientist author of the article 'cousin' Carl was writing about entered the discussion.  I took the chance to grill, er, ask a couple of questions. 

I've read many a book on historical geography -- the activity of trying to construct what the boundaries of the Roman Empire, Holy Roman Empire, Burgundian States, Tang Dynasty, Inca culture, and so forth through many an example through all of time.  One of the few conclusions I can reach (and related to the above research) is that anyone who talks of being 'pure' anything, is ferociously ignorant of history. 

My English ancestors probably include some Vikings, Normans, and others in their history.  The Germanics probably had, well, pretty much anything from Spain through Russia, including the Balkans.  The Romanians probably included anything west to Spain, and east to Mongolia.  The Jewish ancestors probably tie me to anything from the Middle East through to the parts of the Holy Roman Empire that they emigrated to the US from.  And that's all just within the last 1000 years, from the parts I know about.  As I know less than 40% of my ancestry, I lay claim to the rest of the world from the 60% I don't know.

In any case, take a look at the Charlemagne article for some insight to why it is we're probably all related to each other from not more than about 3400 years back, and far less than that if you have some European ancestors.

04 June 2013

Science as a method rather than conclusion

Some of us carry science with us throughout our life.  I'm one, and think we tend to have more fun in our lives.  That's the method aspect.  To my mind, the absolutely central aspect of science is "try to learn more about how the universe works".  All of us can do this, in almost any circumstance.  Some don't choose to do it, but even if you're not doing it at a professional level, you can do it.  Learning things about the world _you_ didn't know before is, still, science.

A side effect of this view is that I 'stray' from my alleged focus.  This includes field glaciology, planetary astronomy, observing atmospheric carbon dioxide levels, and, well, many topics that show up on my blogroll and points farther afield.

Really, though, my view is described best by one of my students.  I was teaching college physical geology (a story in its own right, but one I'll neglect here) and late in the class, after the field trip, one of my students mentioned that the class had changed how he looked at the world. 

The world is a fascinating place.  Look anywhere and amazing things are happening, or in progress, or about to happen.  To quote a different person, my niece; she went for _adventures_, not merely walks.  Just look at those ants.  What are they doing?!  Why this, and not that?!  In the case of physical geology, you can look at the river meanders that are in process of getting more (or less) extreme, the hillside that is in the process of slumping because the roadcut was too steep, and ... just amazingly many different things we can all see if we look.  The countryside is an _active_ place, always evolving to different conditions.

Related point is that my wife and I went traveling to Alaska with a pair of field biologists.  I know from nothing about biology, especially field biology.  But my wife and I had a lot of fun walking around Denali National Park with the field biologists.  She and I would see "a bunch of mossy-kind-of-stuff", being un-knowledgeable.  Our friends were seeing all kinds of amazing things.  "You don't get moss like _this_ back east!!", "Just _look_ at how thick that moss is!!".

We have tools for doing science, making more things observable, or testing ideas.  But the ground zero of being a scientist and doing science is that we realize that the universe is an incredibly interesting place.  The tools are aids, not requirements.  Figuring out the universe, the fascinating and stranger-than-we-_can_-suppose universe, is the requirement and excitement.

so say I :-)

03 June 2013

Building a climate model

Last Friday I mentioned a model, and will be getting to how it connects to Saturn's hurricane.  But some interesting to you, I hope, byways occurred to me. 

Let's start with the notion of a model.  Sometimes people quote sarcastically George Box's observation "All models are wrong.  Some models are useful."  Often they omit the second half.  And often they ignore the fact, well-known to any observationalist, that the same applies to observations. 

Models are idealizations of the real thing.  As an idealization, they don't represent reality fully.  This is mandatory for my kind of models.  Suppose you want to model ice ages, which span 100,000s of years.  A complete, non-idealized, model would be exactly an entire duplicate Earth, in a duplicate solar system, that we could control for our experiments.  Which might be fine as far as that goes, but would also mean we'd have to wait 100,000 years to see the result of 1 ice age experiment.  'Real time' modeling doesn't cut it for climate.  Or for weather -- if it takes 24 hours to make a 24 hour forecast of the weather, you really can't get much use from the model.

Being able to get an approximate answer much faster than real time is crucial to weather and climate modeling.  I backed in to this by way of some computer sciency experimentation I was doing.  Consider the important element being how much faster that you can get an answer than in real time -- how much 'lead' you can get.  One figure of merit, for instance, is to get a 24 hour model forecast or 'run' in only 1 hour.  This gives you 23 hours to make use of the model before the weather hits.  Obviously the more powerful the computer, the more computing you can do in 1 hour.  But this runs in to some other issues.

01 June 2013

Atlantic Hurricane Season opens in US

Today is the official opening of hurricane season in the US, at least for Atlantic hurricanes.  NOAA's seasonal outlook (note that the term is 'outlook', not 'forecast') is for more hurricanes than usual.  But do read down in to the discussion of the science behind the outlook.

Also, of course be prepared if you live anywhere in the Caribbean, Central America, Mexico (east or west coast), Gulf Coast, or US East Coast.  As folks got reminded last fall with Sandy, this means all the way up the coast, not just southerly places.

Do read through the full information there, and follow up for more information.  If you've got kids, perhaps ready.gov/kids will be helpful.