Wednesday, July 23, 2014

Data are ugly

Current news about whether there really is an increase in Antarctic sea ice cover is reinforcing my belief, shared by most people who deal with data, that data are ugly.  This work argues that the trend that some have seen in some trend analyses has more to do with the data processing than with nature.  I encourage you to read the article in full itself.  It is freely available.

From the abstract:
Although our analysis does not definitively identify whether this change introduced an error or removed one, the resulting difference in the trends suggests that a substantial error exists in either the current data set or the version that was used prior to the mid- 2000s, and numerous studies that have relied on these observations should be reexamined to determine the sensitivity of their results to this change in the data set.
One of the obnoxious things about data sources is that they don't remain the same forever.  This is not so much a problem for my concerns about weather prediction, since the atmosphere forgets what you said you observed in a few days.  But for a climate trend, the entire record is important.  For the data set being discussed, the Bootstrap Algorithm (Comiso) applied to passive microwave, we immediately run in to data obnoxing.  Since 1978, there have been several passive microwave instruments -- SMMR, SSMI F-8, SSMI-F11, SSMI-F13, 14, 15, AMSR-E, SSMI-S F16, 17, 18, and AMSR-2.  They didn't all fly at the same time, and they don't have exactly the same methods of observation.  And none of them exactly observe 'sea ice', which leads to a universal problem which we (people who want to use these instruments to say something about sea ice) all have to deal with.

So a few considerations of what all is behind the scenes of this paper and the earlier Screen, 2011.  The latter paper involved some of my work (read deep in to the acknowledgements).  This one doesn't, but the fundamental issues are the same ...

Tuesday, June 24, 2014

Ice Science Cafe

This Thursday (June 26th) I'll be talking about ice, and, better, yet, answering questions about ice at the Annapolis Cafe Scientifique.  The time will 6:30 PM.  Same location as usual -- Cafe 49 West.  Local folks are invited, and non-local are welcome to pose questions here. 
 
I'll also invite folks to suggest topics for me to prepare for.  My sources of information on sea ice are pretty different than my audience's, so it's hard for me to tell what people have been hearing about.

Our Sea Ice Outlook guesses this year are wildly different -- 4.8 million km^2 and 6.3 million km^2.  The former is above the median of contributions.  The latter is the highest of all, even higher than from Watts and company.  We have a third, unpublished, guess in between the two.  I need to check out a couple of things before writing it up.  Given the spread we're encountering ourselves, I think we're going to learn a lot this year.

Wednesday, May 21, 2014

A challenge and offer

The challenge is for a science teacher to incorporate Science and/or Nature in to their teaching.  The offer is that I'll pay for the subscription(s) for at least the first year.  US High School teachers only (sorry others, but I'll exercise provincialism here).  First come first served.

The prompting here is that I've been reading some of my backlogged Science and Nature issues.  Some articles are past almost all K-12 students (though not some I was talking to at Eleanor Roosevelt High School's Research Practicum celebration, so even the most rarefied will be useful in some institutions).  But there are research article summaries which don't require such a high level of background.  And I think a talented enough teacher can make good use of the wealth of material in each issue of Science and Nature.

The third leg of the tripod, so to speak, is that I'll invite some discussion as to exactly how a (US) grade 9-12 teacher can make use of professional journals like Science and Nature.  I know I have a teacher or two in the readership, and look forward to their ideas.

Update 5/27/2014: I've now got a taker, @ragbag01 on twitter.  But discussion of how to make use of the subscription is still very welcome (per anonymous1). 

Anonymous2 notes http://scienceintheclassroom.org/ has some free materials for the classroom on selected papers.

An article of mine on language and reading science may also be useful -- Science Jabberwocky

Tuesday, May 20, 2014

Agriculture in changing climate

If you're one of the people who thinks that food grows in grocery stores, all the talk about climate change affecting agriculture is passing you by.  You'd be wrong to think so, but most modern industrial country people are not involved in agriculture.  Having grown up in the corn belt I'm perhaps a little sensitized to the fact that farming is hard work.  And that farming is extremely sensitive to details of the weather.  Anything sensitive to weather is sensitive to climate.

Many foods depend on extremely specific climates.  Not just current climates, but the history of climate for thousands of years -- soils to grow a good crop in develop over that time span.  The corn belt is where it is not just because of current (well, 1950-1980) climate but because in the thousands of years before that, the soil improved and developed to the point of being able to support such farming.  For something like corn, which is grown across a huge area, climate change can be an issue.  But someone, somewhere, will probably be able to grow corn 30 years from now.

But many items grow in relatively small areas, subject to the whims of local change.  Some of these are:
Such specialized crops are sensitive, to the point of perhaps being eliminated, to climate changes.

I invite readers to check the sources linked to above.  And to contribute their own crop types that are either sensitive to climate change, those which are insensitive, and those which would even benefit from expected changes.  Please do include links to your examples.

Friday, May 2, 2014

Learning

"Kids are born learners.  Job of parents and teachers is to avoid killing that drive." @rgrumbine

That tweet from yesterday has gotten picked up more, and by wider group, than usual.  No doubt this was aided by the fact that it was in midst of tweets between @louisck (I'm a fan) and @alexnazaryan.  The twitter-storm is driven by 'common core', whatever that is these days, Alex making some surprising-to-me defenses, and Louis being peeved about the cc (by way of his daughters).  I have some biases I'll discuss at the bottom

Alex replied to my tweet: "Yes.  But learning is a hungry beast.  You have to supply it with good material daily."  I agree with that, too, though we may not agree about what constitutes good material.

I'm going to start very much smaller than writing my own comprehensive national program for education.  Start with a tweet I made earlier today, answering @dougmcneal about how I got in to science -- "Permanent interest in learning, and being better at that than applying it practically (i.e. engineering)."

As a permanent learner, what do I do? Well, let's start with one end result: it means I know a lot of stuff*.  That's probably not the end to emphasize in design and testing of schooling, though.  Two of the things I know, for instance, are that the atomic mass of hydrogen is right about 1, and the atomic mass of helium is a bit less than 4 times hydrogen's.  It would be easy to write a test that asked students for the name and atomic mass of every element (#117 was recently confirmed).  This would be worse than useless, though this approach is common.  Also common to be asking whether the atomic mass of Helium is 4.00, or 3.98, or 3.998, etc.

Wednesday, March 26, 2014

AABW in the news!

It only took 25 years, but my thesis topic is now becoming newsworthy!  Gluttons for punishment can see at least the abstract at A model of the formation of high-salinity shelf water on polar continental shelves.  Which is aimed at one of the important ingredients for AABW (Antarctic Bottom Water).

I've been reluctant to blog about the topic because it is, after all, my baby and I'm sorely tempted to post at excruciating length and detail.  (Not that there aren't other people who have studied the topic before or since, but I'm one of the people who has.)

I'll take this note as opportunity to get in to some detail about the weirdness that is sea water, and come to the climate change, carbon dioxide burial, and heat burial, aspects later.  The story of AABW turns on some odd facts about how sea water behaves in Antarctic conditions.  Not least, it can go below freezing.

Monday, March 24, 2014

Harry Bulkeley: A few questions about global warming -- Answered

An opinion writer (a retired judge) asked a few questions in his Galesburg, IL local paper, and I'll provide some answers here.  As always, I encourage you to read the original.

The good judge, like the usually informative Mr. Krauthammer, starts off on a very wrong foot, with bad philosophy of science.  There are many facts in science -- the earth is round, the sun is hot, there is a greenhouse effect, and CO2 is a greenhouse gas.  All can be questioned -- but not in the trivial way that Bulkeley and Krauthammer seem to think.  'I question it' is trivial, and pointless.  If you have a _scientific_ question about these things, or any other, it is because, and only because, you have scientific evidence that the 'fact' is false.

Climate change, as even commenters in agreement with Bulkeley note, is indeed a fact.  Climate changes, that's a fact.  One of the tasks of science is to try to understand the hows and whys of that fact.

Let's see about the questions:
1) Average temperature has indeed gone up the past 15 years.  This is a question, apparently, because the author didn't bother to look at the data. One can experiment with time periods and trends at NOAA/NCDC.
http://www.ncdc.noaa.gov/cag/time-series/global/globe/land_ocean/1/2/1880-2014  
It's worth paying attention to the fact that climate trends are defined on 30 year periods, not 15.  Some discussion of why this is the case is at
http://moregrumbinescience.blogspot.com/2009/01/results-on-deciding-trends.html

Wednesday, March 5, 2014

Science Fair Participants

First: Congratulations to Elliott Rebello, winning his category in the Eleanor Roosevelt HS Science Fair.  (The reason I single him out -- he's my intern.  Be sure, though: the work he presented was his.  And it was his presentation and understanding that earned him his place.  Yay Elliott!)

Having judged another year's science fair at ERHS, I'll share some thoughts for participants.  I'm a little emboldened that maybe I know something since Elliott did well.  On the other hand, maybe he did well in spite of me.  Use your own judgement on what ideas to make use of, and how to make use of them.

One note: I never did very well in science fairs when I was growing up.  You don't have to do well in science fairs to do well in science, even more true than you don't have to be good at math to do well in science.  One failing in most of my projects: I was setting about learning what was already known, rather than striking out my own path.  This is an excellent way to learn more, but not to get science fair points.

My base suggestion for any age: try to learn more about the universe, know what you did and why you did it.  Maybe there are points in it, maybe not.  But you'll definitely learn something, which is always good.

For science fairs, the major categories on the official judge's score sheet are: 'Scientific Thought', 'Creative Ability', 'Thoroughness/Clarity', and 'Exhibit Presentation'.  They have some connection to usual professional proposal or paper review criteria (except, mostly, for exhibit presentation).
But we all, and it's interesting that it's all of us given that we come from different backgrounds, even judges in my rather small niche, think differently than this.  We start more like journalists:
  • What did you do?
  • Why did you do it?
  • Why did you do it this way?
  • What did you learn?
  • How would you do it differently?  (given what you've learned)