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.
28 October 2009
26 October 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.
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.
21 October 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.
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.
19 October 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.
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.
18 October 2009
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