Wednesday, October 28, 2009

A challenge to the computer folks

Something I'd like to be able to do is to track the citation history backwards from a given paper.  But I want a couple of things that it looks like typical bibliographic sources don't do.  As matters of computer or library science, I don't think they're terribly difficult.  I've seen things done which strike me as much more complex.

Let's start with some paper, call it paper A.  It cites, say, 15 papers (papers B, second generation).  Each of those cites another, say 15, which at least temporarily means a list of 225 papers (C, third generation).  Easy to get the list of papers cited by paper A (the 15 papers B1..B15), but significant manual effort, it seems, to get the collected list of papers C1..C225.  One thing I would like, however, and which seems completely unsupported, is that I'd like a count of how many times each paper shows up in this tree.  Some of the papers in the second generation probably cite others in the second generation.  And it's near certainty that many of the third generation papers are cited by several of the second, and probably a good number of third generation cite each other.  This is pretty much just a simple social network kind of analysis -- some papers have lots of friends, and some not so much.  I'd like to see which papers are highly connected, and which aren't, working within the group established by papers cited by a paper of my interest (actually won't be one of my own in practice) and lines of reference descent from there.


The second sort of thing I'd like to see is for the chart to be continued through enough generations that sources like Newton's Principia start appearing on the list.  I'm curious how many generations, in terms of citation history, modern work is removed from some of the landmark sources.  Unfortunately, it seems that the bibliographic databases I have access to die out in the mid 1980s, which is a long time from when I want to be getting to.

Monday, October 26, 2009

Doing science, with sea ice

Every so often, I commit an act of science. Like most acts of science, you almost certainly never heard about it. Like many, however, life was eventually improved for some people somewhere. I'm rather pleased about that side of it.

What was at hand was, on one hand (it does help to have many hands if you're in science), a fairly straightforward piece of engineering. On the other hand, a bit of science. Remember that I think both engineering and science are good things, if different. Engineering is mainly aimed at 'apply what is known to achieve benefit for someone', while science is aimed at 'try to understand more about the universe'.

Back in 1993, I was at the National Meteorological Center (NMC), the part of the National Weather Service (in US -- NOAA) that develops the new weather forecast models or tries to make the old ones better. My area was sea ice. Now, one thing we sea ice, polar oceanography, polar meteorology people were entirely confident about was that sea ice mattered, a lot. For, well, everything, or at least enough. If we didn't think it mattered, we'd hardly be spending our time studying it. People outside our little community, including folks working on numerical weather prediction, didn't think sea ice mattered for much. And, if it did matter, surely it was only something that mattered for long time modeling -- climate scale forecasting. Surely the ice was already well enough represented to be good enough for weather prediction purposes.

Partisan as I was, and am, in favor of sea ice, I must confess that there were (and are) good reasons to believe that for short range forecasting, you didn't need very accurate representation of sea ice. It doesn't cover much of the surface area of the earth. And, while it might be very reflective, at the times that there is the most ice that is most reflective, there isn't much sun for the ice to reflect. I could have simply sat back in a wrangle with the weather folks, endlessly asserting that sea ice was important, and how much energy sea ice reflected was still important, and weather is chaotic so it had to matter, vs. endless repetitions of their counter-arguments. Perhaps you've seen that sort of thing happen a time or two on a blog or two.

Instead, time to do some science. Run the experiment and see what happens. This has the downsides that it requires my time, and I have to run the risk of the experiment showing that I was wrong -- that modest changes to how much of the sun's energy sea ice reflects really did not affect weather.

Wednesday, October 21, 2009

Antarctic Snow and Ice

The Antarctic has long been a favorite area of mine, going back to graduate school days.  This particular note, however, is prompted by a question over in the question place -- regarding Antarctic mass balance and snow.

The question at hand turns on just what is going on with Antarctic mass balance.  The apparent 'conflict' is between a study showing a recent decline in snow melt, and other studies that Antarctic ice mass is decreasing.  This is a particularly simple conflict to resolve, so I'll note that it really is taken as a serious conflict (per the questioner's link) over at WUWT (haven't we heard that name recently?)

The simple reality that the authors of the snowmelt paper are perfectly aware of, but WUWT ignored, is that there is more than one way for the Antarctic to lose mass.  I grant that melting the snow is the most obvious one.  But, when you're dealing with a continent as incredibly dry as the Antarctic is (the driest, and probably largest, desert in the world), you have to pay attention to more subtle processes.  One of them is not at all subtle -- huge icebergs break off of the Antarctic from time to time.  In these cases, you're talking about chunks of ice several hundred meters (call it 1000 feet for simplicity if you're non-metric) thick, and 50-100 km (30-60 miles) on a side.  Chunks large enough to be the size of entire US states and some countries.  (I have an ancient listing of some iceberg sizes and country, state, lake sizes for your comparisons -- additions welcome.)  There's also the very subtle process of evaporation straight from the surface of the ice sheet (sublimation) into the atmosphere.  And there's the not subtle but easy to forget about fact that Antarctica has ice shelves -- ice floating on the ocean that's fed by the continental (sitting on land) ice sheet -- and the bottoms of those ice shelves can and do melt.

Finally, there is the rather bizarre fact that ice is not a solid.  Once you build up to having an ice sheet, the pressure of the ice above a point near the ground is so enormous that the ice flows.  Ok, it's a really, really, thick fluid (think very cold molasses).  But it flows.  This means that the ice sheet move mass out to the edges -- out to the ice shelves where there can be snow melt, ice evaporation, or ice shelf melting, or massive icebergs can break off.

So, just on a fairly cursory consideration -- there's more than one way to skin a cat, or, rather, there's more than one way for an ice sheet to lose mass -- we already know there's a problem with the WUWT article.  In the science, no real conflict.  More below the fold.

Monday, October 19, 2009

Sound and Fury at WUWT

From the question place, where a reader noted a high traffic item at Watt's Up With That  and asked for a science response.  Where to begin?  First, I guess I'll note that most of the post is bluster and personal attack.  Once you cross out those parts, it's a much shorter article.

Second, as always, go back to the original source.  In this case, it is a Mann et al. 2008 paper Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia, with supplementary material.

Then, consider exactly what the claims (in this case, at WUWT) are, and just what evidence is produced for it. 

The fundamental claim at WUWT is that the entire reconstruction is upside down.  (We're treated to pictures of other things that are upside down.)  Right off, we know WUWT is wrong. 

Sunday, October 18, 2009

Question Place

About time again for one of these. Questions, suggestions, ideas, and so forth.

Saturday, October 17, 2009

Barb Didrichsen's Blog

I've been remiss about mentioning a friend, Barb Didrichsen, who has been blogging for a while. Her latest note is A Conversation on Climate Change. It was also a contribution to Blog Action Day, where an attempt was made to have climate be the topic of the day on as many blogs as possible.

As you'll see in reading her article, Barb is not a scientist. She's an interested and interesting person and a writer. Take a look.

Tuesday, October 13, 2009

Holding place

Not much going on by way of things that I'm writing up. Or at least not that I'm finishing for blog purposes. The better news is that I'm doing more reading, of various sorts. That includes some fun -- Terry Pratchett's _Unseen Academicals_, _The Callendar Effect_ by James Rodger Fleming (biography of Guy S. Callendar, arguably the inventor of the CO2-induced climate change theory) and _Species: A History of the Idea_ by John S. Wilkins (which I've mentioned here before; I should be meeting up with John at the National Museum of Natural History on the 24th). And some also fun, but also more serious, in some respects, reading, including some books on amateur scientist and amateur engineer experiments, and my too-large backlog of Science and Nature (and EOS, Bulletin of the American Meteorological Society, Association for Computing Machinery, ...).

Reading, learning what other people are doing or have found out about the universe, is almost always the start of my own creative activities. At the very worst it is like when I volunteered at the mile 21 water stop for a marathon. At that point, my longest race was 10 miles (16.1 km), and my longest run was a half marathon (13.1 miles, 21.1 km). After seeing the people coming past me, who were still perfectly able to chat, thank us volunteers, ask where to toss their empties, and such, there was just no excuse left for me about finishing my own marathon. Some, I wouldn't have bet a quatloo could run 2 miles from looking at them, much less be cheerfully passing mile 21. They proved to me that if you do the training, you can do the race.

For writing, if I see some very poor stuff, or some stuff that is not all that 'brilliant' (more than one paper has been published on things that I never bothered to write up), then it's a bit of a kick to get up and start my own writing. If it's great stuff, then it's energizing -- look at all that great stuff people are doing out there. Time for me to add a good thought or two. Win-win.

Also to be coming, and in keeping with my aim for educational content, is that I'll be visiting a school at the end of this month. Still working out some details on the what and how for my visit. I want, always, for my visits to classrooms to add to what the teacher was trying to do, and support learning by the students. Plus, obviously, there are some messages of my own I want to get across at the same time -- science is interesting, the universe around us is interesting, and it is understandable, and the students can indeed do some of that understanding and figuring out. Related to that, I'll probably be putting up a note or two. Looks like it's time for something about clouds and hurricanes.

Along with doing my reading, I'll be writing up some thoughts about some of the books. A pair I'll definitely be mentioning shortly are Danica McKellar's Kiss My Math and Math Doesn't Suck. If you are, or know someone who is, in what I take to be the target audience -- teenage girls who are struggling with math, and/or are having boy-induced problems about math -- go ahead and get the books.

Plus the usual odds and ends. Clearly there's a lot more to say about evaluating forecasts, and I'll be doing so. And much more to the world of sea ice, and climate. And ... well, the universe is a very interesting place. Suggestions always welcome too. Several of the notes I've liked most have been from reader suggestions.

In the mean time, for new content I'll suggest again to my adult readers my wife's blog Vickie's Prostitution Blog. Current is a 2 (maybe more, part 1 is up now) part look at How much money do prostitutes make. I give away little indeed in observing that the answer is very, very little. That contrasts starkly with the impression you might have from media, or some economists' write ups (one of which Vickie addresses more directly).

Saturday, October 10, 2009

Sea Ice Finals 2009

The final September figures are in from the NSIDC. In terms of the Connolley-Grumbine bet, William lost. So 50 quatloos will find their way to me. Or, given how close it was (5.38 was our dividing line, and 5.36 was the observation), we could go double or nothing on next year's ice.

I'll also mention a few other predictions, or methods:


MethodPredictionError
Climatology-15a7.231.87
Climatology-306.631.17
Climatology-15b6.160.8
Connolley Line5.840.48
Grumbine Curve4.920.44
Persistence4.680.68



Climatology 15a is the average of the first 15 years. 15b is the average for the last 15 years (not counting 2009!). Climatology 30 is the average of the first 30 years of the satellite record.

Persistence is to say that this year's ice will be the same as last year's. For atmospheric temperatures, persistence is a pretty good forecaster for the first two days (at least in the sense that it is closer to what you see than climatology). For sea ice, it is not so good, beating climatology only 17 of 30 years. It's interesting, however, that its losses are strongly clumped. In the 14 years from 1990-2003, persistence won 2 and lost 12 versus climatology-30. In the remaining 16 years, it went 15-1.

Update: Per William's request, I'll add the ARCUS estimates (as given in the full report) for June's report. I believe the values all were rounded to the nearest 0.1 million km^2, so for consistency will list mine at 4.9 here.
MethodPredictionError
Canadian Ice Service5.00.36
Hori, Naoki, Imaoka5.00.36
Nguyen, Kwok, Menemenlis4.90.46
Lindsay, Zhang, Stern, Rigor4.90.46
Kaleschke and Halfmann4.90.46
Grumbine4.90.46
Fowler, Drobot, Maslanik4.90.46
Stern4.70.66
Arbetter, Helfrich, Clemente-Colon4.70.66
Pokrovsky4.60.76
Stroeve, Meier, Serreze, Scambos4.60.76
Kauker, Gerdes, Karcher, Kaminski, Giering, Vossbeck4.3, 4.61.06, 0.76
Zhang4.21.16

To judge from the graphic that accompanied, however, the bar chart was done with figures that had more precision, as Kaleschke and Halfmann's 4.9 is clearly higher than Fowler and company's.

Thursday, October 8, 2009

Saving lives

A while back, I mentioned the fact I'm still walking around and able to write to you is due to modern science.

I've not going to write often about it (this being only the second post in over a year), but, the truth remains that a lot of us are still walking around because of modern science. The single biggest contributor to that is vaccination. There's a very nice video here, from a pediatrician, Joseph Albeitz (h/t Phil Plait) that outlines some of the magnitude of good that vaccination has done:




In looking at vaccination, as he discusses, you're looking at saving hundreds of millions of lives. The list of things that could contend for saving more is awfully short.

One thing he mentions in passing, which I'll spend a little more time on, is herd immunity. There's a feeling out there, a false sense of security, that as long as 'everyone else' is vaccinated, it doesn't matter if your kids are. If your kids were the only unvaccinated kids, that might be true. But, in reality, you're not the only person who might think that way. Your kids interact with many other children. Once the number of unvaccinated children is high enough (depending on the disease it's in the range 10-30%), the disease can establish itself and spread. The 'herd' is immune only if enough people are immune. Once enough fail to vaccinate, you're a breeding ground for the disease. Worse, you're a breeding ground to infect people who did get vaccinated -- vaccines aren't 100% effective in all people. If enough of you are carriers, then the disease can spread to other kids and kill them.

I know that measles is commonly considered a trivial disease. But that 'trivial' disease kills over a million per year (listen to the video). I'm thinking that not killing off a million children each year would be a good thing. Similarly for the numbers of polio victims -- with vaccination, the number who would get it goes to zero. Both of these diseases are like smallpox in an important way -- they only spread between people. If we reached a point where nobody had the disease, as was the case for smallpox, then nobody would ever again need to be vaccinated against it. It would be gone. As the Dr. mentions, they're about 99% of the way there for polio. Measles have farther to go. Both, amazingly, can be eradicated.

Digressing a second, but not really, is my genealogy. One of my direct ancestors died from smallpox. Lived long enough to have kids, obviously. But died 20-30 years early because of the smallpox. As many a person who looks in to genealogy has observed, you see a lot of very short lives when you look back then (1700s - mid 1800s), many of them children who were never even named. Much of the reason for that change is vaccination. That ancestor (Zeboeth Brittain, how's that for a name?) died before the vaccine was discovered -- 1790, vs. 1796 for Edward Jenner's discovery. But I think he'd be amazed at the idea that the disease that killed him could be erased from the face of the planet -- and it now has been. Measles and polio can be as well.