2012-12-29

Joseph Romm raves about Reagan, balks at Barrack: Figures of speech make and break communication


I have recently read Joseph Romm's new book, Language Intelligence,
which is really a brief review of rhetoric. It introduces modern readers to
the age-old topic of eloquent language intended to persuade
audiences. Romm uses just a few prime examples for each of the several
topics covered, from the ancient Greek greats to medieval masters who
wrote the King James Bible to modern practitioners such as Lady
Gaga. The point is to expose the principles of rhetorical discourse,
such as the various forms of repetition, irony, metaphor, and
seduction, and provide readers with some of the tools necessary to
build an effective argument as well as to erect a wall to defend
against the constant bombardment by advertisers, politicians, and
other persuaders.

The lessons are clear and well illustrated by examples. Especially
useful are the examples from recent political figures such as both
George Bushes, Bill Clinton, Barrack Obama, and Mitt Romney. Several
Republican strategists are pointed out for their cunning use of
rhetorical devices (Luntz and Rove, especially). Scientists (climate
scientists, especially) are singled out for their clumsy attempts to
communicate, usually avoiding rhetorical figures of speech. The
use of the figures being discussed occasionally becomes too blatant,
often in the final paragraphs of sections, but it is pleasing as a
reader to see such employment as sections close because it reinforces the
lesson. I am convinced that this brief introduction should be standard
reading for college students across disciplines, and those in the
sciences should pay careful attention to the lessons and employ more
intelligent language when describing their own work. Older readers
might pick up some new tricks, too, if they choose to read the book.

2012-08-28

American Meteorological Society Statement on Climate Chnage

Posting two days in a row!?!?

I just wanted to draw attention to the updated statement on climate change from the American Meteorological Society. Here's the link: [LINK]. It is just a 7 page statement that goes through the following sections:

  • Background 
  •  How is climate changing? 
  •  Why is climate changing? 
  •  How can climate change be projected into the future? 
  •  How is the climate expected to change in the future? 
  •  Final remarks
There is nothing surprising in the statement. The AMS supports the scientific consensus that the Earth's surface and lower atmosphere are warming due to the accumulation of greenhouse gases in the atmosphere from combustion of fossil fuels and deforestation. Overall, it is well-written and straight-forward, and I recommend taking a look at it no matter what your background is. My guess is that everyone will get the gist, and if you've got any background in climate science then you'll pick up on some of the details. I'd quibble over some of the word choices here and there, but the substance is fine. Maybe they over emphasize climate models in the future section, because many of the points they make there are not based solely on model projections, but also observations and basic theory. Anyway, go take a look.

2012-08-27

Smart meters and dumb people

As a regular listener of Coast to Coast AM, I have been aware of a conspiracy theory involving the transition from old-timey analog utility meters to internet-connected smart meters. Smart meters allow 2-way communication between a house's utility meter and the utility company. The idea is to monitor electricity use in real time (or near real time), which can allow more nimble management of the electric grid. The idea is to get electricity where it is needed when it is needed and allow better management of electricity generation. Both proponents and opponents cite the potential for tiered pricing, such as raising prices during peak energy use times. While some say this will help incentivize energy conservation, others say the tiered pricing could hurt lower income households disproportionately.

The consipracists, however, are not worried about low-income households or energy conservation.  There are really two flavors of the smart meter conspiracy. First is an irrational fear of technology that manifests as a concern about the radiation from smart meters being a health hazard. Yes, really [example]. This is not a legitimate concern, as the radiation levels are even below those of cell phones, and it is unlikely that many residents will spend significant time with their heads agains their electricity meter. The second version of the conspiracy is rooted in a deep distrust of government and an overly aggressive view of privacy. These are the people, like the ones cited in this Grist post [LINK] and the accompanying AP news article [LINK] about the smart meter opposition in Texas, who believe that the smart meters are ... well, let's just boil it down, they think that the smart meters allow the government to spy on them at home [great example, go ahead a browse this crazy site, I'll wait.]. There might be some actual privacy issues with smart meters (which that example kind of hits, but then goes to crazy), such as the potential for utilities to synthesize usage and sell the information to interested parties (who want to target their marketing efforts). This probably isn't much of a concern at this point, as it is unclear that utilities are savvy enough to profitably undertake such an analysis. Really, this comes down to some far-right-wing ideas that get mixed up by fear mongers into ridiculous conspiracy theories, encapsulated by this quote from the above cited blog, "This is all part of the radical green agenda that is being forced down the throats of people all over the world."

Maybe I should just list a couple of points that I think are relevant (in no particular order):

  1. Energy conservation is a good idea, and represents one of the "stabilization wedges" that we talk about as currently available solutions to global warming. [LINK]
  2. The radiation associated with electronics is not harmful.  [LINK]
  3. One of the criticisms that the opponents of smart meters seem to bring up often is that the FCC does not have strong enough restrictions on radiation [example]. Yet, as pointed out in Grist and the AP story above, these people tend to be on the far-right/libertarian/tea-party fringe of the political spectrum, meaning that philosophically they are opposed to government regulation (in favor of letting the "market" work out the appropriate solutions). This is completely inconsistent. I don't think this is an argument against the smart meter opposition, just a point that I wish would be discussed.
  4. The possibility of utilities selling the information aside, there seems to be a general fear of a degradation of privacy with smart meters, but I don't think there is any evidence that any personal information could be or is being collected by these meters.
  5. The transition to smart meters is being driven by the "market" as utilities try to reduce costs and maximize efficiency. This is a direct descendant of the deregulation of utilities in the USA, which right-leaning folks should be applauding (if they were being consistent with their purported economic philosophy).
  6. Because the utilities are deregulated, this information would be flowing to the utilities, and not the government. That means that there must be an extra layer of conspiracy in order to bring the government into the picture. Each additional layer of conspiracy makes the theory less and less plausible.
I think I can leave it there.

Note that in the links above that are cited as examples, I have used the "rel=nofollow" attribute which prevents search engines from following the links and improving those cites' search rankings. I decided to do that because those cites, while entertaining, do not present a useful view of the issue. The other links are normal, and represent appropriate source material. 

2012-07-20

Making mds and mdworker processes stop sucking CPU

I usually don't post computing tips, but I just learned how to get rid of a problem that has been bothering me off and on for over a year.

The problem: On multiple Macs running OSX 10.6 and/or 10.7, sometimes a large amount of CPU power (and also system memory) is being used by a process called mds. The problem persists over many hours, and on laptops causes the fans to spin and battery to drain.

Some relevant information: MDS and its friend mdworker are part of Apple's Spotlight software. Basically they troll your system looking for changes and recording them in an index. That index is used by Spotlight to help you find things like that email from four years ago describing how do some arcane thing that you couldn't possibly remember, except that it has the phrase "don't cry at this point". Anyway...

The fix: I've tried a number of things over the many months of having this problem. At home, I removed external drives from the Spotlight index and that fixed the problem. To do that, open System Preferences, go to Spotlight, click on the Privacy tab, and add the external drives to the list.

On my work computers I've done the same thing, but still have the problem sometimes. It has been especially bad on my new MacBook Air with no external drives connected.

Doing some searching, I found this very useful bit: LINK.

The crucial thing that post points out is that backup software that works in the background can cause files to be constantly changing. Constantly changing files need to be re-indexed in the view of Spotlight/mds.

For some reason, I'm not allowed to backup however I want at work (e.g, to a Time Machine drive that could be sitting right here in my office). Instead, my IT department installs some software that supposedly backs up my system. Going to /System/Library/Application\ Support and finding the name of that backup software (in this case it is Symantec) and adding that directory to the list of non-indexed places solves the problem. This is equivalent to the case in that link that uses some other backup software, and I bet that other backup systems also trigger the same behavior.

REPEAT: Exclude your backup software's /System/Library/Application\ Support directory from Spotlight indexing in System Preferences -> Spotlight -> Privacy and mds CPU usage should drop to 1% or less.

Sigh of relief.

2012-05-01

Wind turbines and warming

The Christian Science Monitor [LINK] does a decent job in smacking the media coverage of a new Nature Climate Change paper by Zhou et al. [LINK]. It is no surprise to see another example of the media making hay of a superficially surprising study. Most of the articles apparently get the story mostly right, but the headline writers once again have their heads up their asses... but actually not, as their job is to get people to read the headline and then click to get to the article in order for the ads on that page to load. One particularly horrible story comes from, wait for it, FoxNews.com; the story is titled "Wind farms are warming the earth, researchers say" and it is written poorly by Eric Niiler (of Discovery News?). I'm clearly not going to post a link to that story, but just say that it does not present a very fair assessment of the paper (which I did link to above and which I did actually read).

The science of the study is nothing terribly exciting, but could provide observational evidence for the scale and magnitude of a simple mixing effect. The idea is that big wind turbines in Texas are mixing air in their vicinity, and at nighttime that means mixing air in two distinct layers. On clear nights, as the ground cools, cool air settles in contact with the ground. Cool air is more dense than warm air, so this situation creates a stable vertical structure of colder, denser air below warmer, lighter air. Usually temperature decreases as you go up, so we call this stable configuration an inversion. Just to throw some more jargon at you, this very common situation is a nocturnal stable boundary layer. The study finds trends during 2003-2011 in both daytime and nighttime surface temperature, but the larger and convincing trend is the nighttime trend, especially during summer. 

These stable layers are usually quite thin, maybe 100 meters deep. Just above the inversion, the air retains the heat from the daytime (sometimes called the residual layer). There is also a slightly less common meteorological phenomenon called a nocturnal low-level jet that is a layer of relatively fast wind that can form in or above this residual layer. (see my skillfully drawn cartoon)

If you want to put wind turbines up, one attractive feature would be thin nighttime inversions and frequent low level jets. As it happens, Texas has a lot of places like that. Note, however, that you would not want very strong winds on the top of the turbine compared to the bottom because strong torque is structurally undesirable. 

Let's imagine a turbine spinning in a low level jet above a stable layer (as in my awesome cartoon). The motion of the blades creates a turbulent wake just downstream, which mixes approximately isotropically. Let's say this means that the air is mixed up from the surface to a little above the turbine height. The result of this mixing is the same as if you stir a cup that has some warm liquid on top and cold liquid on bottom: the temperature is mixed and the resulting temperature is the mass-weighted average of the warm fluid and the cool fluid. This is exactly what the paper finds in western Texas, though they don't include a calculation of the efficiency of the mixing because their satellite data does not include profiles of temperature with height. The authors take the data in close proximity to the turbines, average it, and subtract the average from the data that is farther away from turbines. In the residual, they find this warming trend. This means that very close to the turbines, there is a nighttime warming trend, which the authors attribute to the mixing by the turbines. 

The consequences of this finding are not some kind of cautionary tale about trying to use renewable energy sources. In terms of climate change, this means almost nothing. First, as is pointed out in even that FoxNews.com article, these turbines produce 10,000 megawatts of electricity (that's enough for about three million American homes); that is a substantial amount of CO2 not being emitted to the atmosphere. Second, the effects being reported are small. Third, but most important, the warming effects of the turbines are confined to the immediate vicinity of the turbines themselves. The entire study area in western Texas is about 100km across, and the warming from the turbines is warming that is enhanced in a fraction of this small area. Related to this, the effects are not additive. Once a region has enough turbines to create this effect, that's it, the "trend" can not continue into the future because there won't be more turbines added to the area. (In fact, as turbine design gets more efficient, you'd expect to see the trend reversed eventually because there would be less downstream turbulence.)

Finally, some of the blow-hards (ha ha, get it?) are saying that this warming could be bad for crops. It is plausible that crops are being grown within the small regions that could be affected by this nighttime mixing. If these people were so worried about warming affecting crops, I think they'd note that the local impact in western Texas is about the same amount of warming as the ENTIRE GLOBE has seen from greenhouse gases. A nearby weather station [LINK] shows a pretty clear warming trend (note there must be a site change or instrument change around 1959) and I'd guess that the overall 20th Century warming for western Texas is greater than the wind farm effect. The 1979-2005 trend looks like it is about the same size in summer [LINK], and note that is average temperature, not nighttime temperature which is the notable value for these wind farms. I'm not sure what 0.5C warming at nighttime does to crops, but I'm guessing that the greenhouse warming is more important (even within this study area) than the wind farm "warming." 


LINKS:

http://www.csmonitor.com/Science/2012/0430/Don-t-believe-the-headlines.-Wind-farms-do-not-cause-global-warming


http://www.wunderground.com/climate/local.html?id=42572266000&var=TAVG

2012-04-24

ENVISAT likely dead in the sky

More bad satellite news: ENVISAT seems to have stopped phoning home. ENVISAT is a giant satellite managed by the European Space Agency, and has been collecting a ton of environmental data since 2002. It has 10 different instruments, and has been used extensively in climate research over the past decade.

Sometime on 8 April, ENVISAT stopped communicating with controllers at the ESA. There has been a concerted effort to determine the cause of the failure and re-establish communication of the satellite. This effort is impressive, with the French satellite Pleiades even being turned away from Earth to try to capture images of ENVISAT to determine the state of the solar panels. Other observations of the satellite are also being used to make sure that ENVISAT is -- and is staying -- in a stable orbit. There is some hope that a connection can be reestablished if ENVISAT has gone into -- or could be cajoled into switching to --  "safe mode." Otherwise, it is likely that there has been catastrophic failure of the main computer or power source on board, and there's no hope of recovery. 

ENVISAT's estimated lifetime was just 5 years, so again over-engineering paid off (like the Mars rovers, SeaWiFS, etc). Unfortunately, the Sentinel satellites that are planned to replace ENVISAT have not been put into orbit yet, so there is likely to be a gap in the data record for some of the quantities that ENVISAT monitors. These even include CO2; the launch failure of the Orbiting Carbon Observatory (NASA) in 2009 left just ENVISAT and a Japanese satellite with capabilities to monitor CO2 from space. Now there is just the Japanese satellite, the Greenhouse Gases Observing Satellite. Apparently there is a lot of controversy and arguing about how to pay for the Sentinels, making the ESA's commitment to climate monitoring just as shaky as NASA and NOAA's in the USA.

SOURCES:
Geoff Brumfiel, 
Nature
 
484,
 
423–424
 
()
 
doi:10.1038/484423a

ESA [link]

2012-03-02

What's the difference between the Maunder Minimum and the late twentieth century?

Somehow I became distracted by an online "discussion" in which someone was confused about the connections between solar variability and climate variability. The result of that distraction was that I made a plot, shown here, that compares the Maunder Minimum (1645 - 1715 CE) to the last 60ish years (1945-present). Below is the text I wrote to present this figure, along with data sources and citations. 


Let's compare the Maunder Minimum with the second half of the 20th Century. Since there isn't really that much data, we are limited to a few quantities. I have chosen two, one is the total solar irradiance (TSI), which is the energy received by the Earth from the sun (per time per area, expressed in Watts per square meter). This data comes from a reconstruction by Wang et al. (2005) as modified by Kopp & Lean (2011), and was obtained at the link below. This data is very similar to other reconstructions (Lean et al. 2004, 2000, 1995), but is basically shifted downward by about 5 W/m2 as a recalibration. The updated data covers 1610 to 2011. The second quantity we can investigate is the northern hemisphere temperature anomaly (degrees C). There are not direct observations (of sufficient quality) reaching back to the Maunder Minimum, so we will use the temperature reconstruction of Moberg et al. (2005). That data actually stops at 1979, but we can visually extend the data to near present day by including the observed northern hemisphere temperature anomaly from Smith et al. (2008) which reaches to January 2012. For the Smith et al. data, I chose to use the land plus ocean values. There is an issue with baselines, the Moberg et al. data are anomalies with respect to the 1961-1990 average temperature while the Smith et al. data are with respect to the 1901-2000 average temperature (which is cooler than the shorter, later average). I have not adjusted for this offset, and the result is that the pink dots in the figure should actually all be slightly upward compared to the red line. The agreement between the overlapping interval is quite good, but would be a little worse if the shift were included. There are other reconstructions available, and I have no reason to choose Moberg's over the others except that it is perhaps the most recent. The TSI and temperature reconstruction data are both annual, and I've made sure the data are centered within each year. The Smith et al. data are monthly (which is why I need to center the annual records). 

Finally, just for completeness, I define the Maunder Minimum using the definition on the Wikipedia page, which is 1645 to 1715. This is in line with the TSI data. For the more recent climate, I chose to simply shift 300 years into the future. So the plots cover 1945 to 2015, but the data sets stop at whatever their last times are. The Maunder Minimum times and data are shown in blue, while the 20th/21st Century data are shown in red and pink with the time labeled along the top of each panel. 

To try to head off any misinterpretation of this plot, let me simply state what it shows. During the Maunder Minimum, there was reduced solar activity and the average northern hemisphere temperature was about 0.6 C cooler than the the 1961-1990 average value. During the period covering 1945 to the 1960s/1970s, the northern hemisphere temperatures were relatively flat and near their 20th Century average. Over those years, the sun was active, showing "normal" sunspot and TSI 11-year cycles. From some time in the 1970s until present, shown in the pink circles, the northern hemisphere average temperature shows a clear upward trend. All the monthly average values after 1996 are warmer than the 20th Century average. During this rapid and clear warming, the solar activity was typical, and quite similar to the 1945-1975 period, showing clear quasi-periodic activity. There appears to be little connection between variation in solar activity and variation in northern hemisphere average temperature during the late 20th Century. 

REFERENCES

Kopp & Lean (Geophysical Research Letters, 38, L01706, doi:10.1029/2010GL045777, 2011)

Lean, J.. 2004: Solar Irradiance Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology. Data Contribution Series # 2004-035. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA.

Lean, J. 2000: Evolution of the Sun's Spectral Irradiance Since the Maunder Minimum. Geophysical Research Letters, Vol. 27, No. 16, pp. 2425-2428, Aug. 15, 2000. 

Lean, J., J. Beer, and R. Bradley. 1995: Reconstruction of Solar Irradiance Since 1610: Implications for Climate Change. Geophysical Research Letters, v.22, No. 23, pp 3195-3198, December 1, 1995.

Moberg, A., D.M. Sonechkin, K. Holmgren, N.M. Datsenko and W. KarlĂ©n. 2005: Highly variable Northern Hemisphere temperatures reconstructed from low-and high-resolution proxy data. Nature, Vol. 433, No. 7026, pp. 613-617, 10 February 2005. 

Wang, Lean, and Sheeley (The Astrophysical Journal, 625:522-538, 2005 May 20)

DATA SOURCES
TSI: http://lasp.colorado.edu/sorce/data/tsi_data.htm
TSI: http://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/solar_variability/lean2000_irradiance.txt
NH T Reconstruction: http://www.ncdc.noaa.gov/paleo/pubs/moberg2005/moberg2005.html
NH T Observations: http://www.ncdc.noaa.gov/cmb-faq/anomalies.php