Talk:Earth's atmosphere

This article was ported here from Wikipedia

I have taken it apart and rebuilt with major reformatting, major deletions, majors additions, new tables and a new image. It is now a full-fledged CZ article. Milton Beychok 18:48, 18 August 2009 (UTC)

My first venture outside my field of expertise

This is my first venture outside my field of expertise. CZ needed this article, so I ported it here from WP and re-did it (see just above).

I would very much appreciate it if someone with atmospheric science expertise would offer comments and/or edits. Milton Beychok 18:59, 18 August 2009 (UTC)

Some initial thoughts, which may or may not fit.

Let's be sure to have some redlinks for radio propagation, which isn't restricted to the ionosphere (e.g., troposcatter). I'll try to fill them in.

I'm not sure if it's worth mentioning the issue of microclimatology vs. climatology/meteorology, and how terrain features can have surprising effects. This is something I learned to appreciate when working on the Vietnam-era "People Sniffer" (an ammonia detector), and also in chemical warfare.

Will spend some more time later -- I am getting some notes out of an overdue book I need to return to the library before it closes.Howard C. Berkowitz 19:29, 18 August 2009 (UTC)

Milton, in reply to your post on my talk, I think the article is excellent. As a general rule I'm against ex-wikipedia content appearing on CZ, not out of any dislike for WP (I'm a member of both) but just because I want to see CZ stand on its own feet. But putting that aside this time, I think it's excellent. CZ needs more like you. My knowledge is more extra-terrestrial, but I'll see if there's anything I can add at some point. Tom F Walker 20:30, 18 August 2009 (UTC)

Milton, it looks good to me, very readable (except for "lapse rate"). I have the following very minor comments: Maybe you should explicitly mention that the inversion layer is not shown in the figures? I was looking for it. Further you write 101,325 Pascals. I'm somewhat pedantic about this, but the accepted (counterintuitive) rule is: if name of person is in full then lowercase, if abbreviated then uppercase, e.g., 1 N = 1 newton. And one should not use plural, hence 101,325 Pascals ---> 101,325 pascal or 101,325 Pa. (Also 26,437 Pascals -->26,437 pascal). As I said, I don't know what a "lapse rate" is and its link is red. Equation 2 is the Boltzmann distribution, known from thermodynamics; maybe it is useful to mention this name? The table below --> the table on the right (or is this my browser?). That's it, cheerio, --Paul Wormer 07:05, 19 August 2009 (UTC)

(no indent) Paul, thanks for the comments:

• I will change the Pascals to pascals.
• As for lapse rate, I am currently gathering information in preparation for that being the next article I plan to write. Lapse rates are covered in my book about air pollution dispersion modeling ... so writng an article about lapse rates will give me a chance to cite my book.
• I'll try to work in mention of inversion layers ... although they are not always present, only under certain conditions. So I didn't consider them to be a bona fide atmospheric layer.
• Nothing wrong with your browser. The table was below at first. When I moved it to the right, I forgot to change the text ... which I will do now.
• I haven't the faintest notion what the Boltzmann distribution is. Did you mean that Equation 2 "is" the Boltzmann distribution or did you mean Equation 2 can be derived from it? Can you (I hope) provide some wording that could be used in mentioning it? The two equations were obtained from the U.S. Standard Atmosphere, 1976 cited as a reference in the article.Milton Beychok 08:13, 19 August 2009 (UTC)

Paul, as of last night and this morning, I have revised the article on the points above except that I have yet to write an article on "lapse rate" (which I hope to do in a few days). However, I did add a note/reference with a very brief definition of "lapse rate". Inversion layers are now included in the discussion of the "atmospheric boundary layer" as are two referenced books that cover inversion layers. Thanks again for your comments. Milton Beychok 19:00, 19 August 2009 (UTC)

Suggestions for additional content

Milton, nicely done.

Would like to learn something about how the Earth's atmosphere evolved over the 4.6 billion year history of the Earth. Enjoyed reading about some aspects of that topic in:

• Lane N. (2002) Oxygen: The Molecule That Made the World. Oxford University Press. ISBN 978-0-19-860783-0.
  • Publisher's website, contains description of book, table of contents, reviews
  • Author's website, contains extensive extracts from four chapters
  • Author CV

Also, would like to know something about the history of our learning about the Earth's atmosphere, the pioneers and major players. I know John Dalton as a pioneer meterologist, but not much more. Anthony.Sebastian 03:03, 21 August 2009 (UTC)

Hi, Anthony. Its midnight and I was headed for bed when I saw your comment. After I've had an opportunity tomorrow to read your references to that book about "Oxygen: The Molecule That Made the World", I will respond. Milton Beychok 07:02, 21 August 2009 (UTC)

Anthony, I agree with you that this article could use a section devoted to the history of our knowledge about the Earth's atmosphere. Perhaps, some knowledgeable atmospheric scientist or meteorologist in CZ might add such a section. If some such member of CZ does not do so in the coming 3-4 weeks, I'll try to do it myself.

As for the book "Oxygen: The Molecule That Made the World", from what I read in the references you provided, it strikes me as primarily being about the origins of life and death, the evolutionary past and future of life on Earth, killer diseases and aging. Some quotes from the publisher's promotional material and from the author's website:

• ... he unravels the unexpected ways in which oxygen spurred the evolution of life and death. He shows how oxygen underpins the origin of biological complexity, the birth of photosynthesis, the sudden evolution of animals, the need for two sexes, the accelerated aging of cloned animals like Dolly the sheep, and the surprisingly long lives of bats and birds.
• Drawing on this grand evolutionary canvas, "Oxygen" (the book) offers fresh perspectives on our own lives and deaths, explaining modern killer diseases, why we age, and what we can do about it.
• This book is about life, death and oxygen: about how and why life produced and adapted to oxygen; about the evolutionary past and future of life on Earth; about energy and health, disease and death, sex and regeneration; and about ourselves. Oxygen is important in ways that most of us hardly even begin to imagine, ways that are far more fascinating than the loud claims of health features.
• The identity of LUCA, or the Last Universal Common Ancestor of all life on Earth, can be pieced together by comparing the genes of different organisms, especially from the domains of bacteria and archaea.
• The exact sequence of our genes is less important in human ageing than the changes in their activity imposed by oxygen. The double-agent theory, introduced later in this chapter, argues that there is an evolutionary tradeoff between our vulnerability to infectious diseases in youth and the diseases of old age later in life.

If I had to define the book in a few words, I would say it is about environmental biochemistry and evolution. I think a stand-alone article about the book would be interesting. Perhaps you or someone in the biochemistry subgroup would undertake the writing of such a stand-alone article.

To sum up my my response to your above suggestion, I don't believe the book is about atmospheric science and I don't believe it should be a part of this article which is about the structure and composition of the Earth's atmosphere as it now exists. Milton Beychok 18:03, 21 August 2009 (UTC)

I have no problems with your above assessments and conclusions. I will re-read Nick Lane's book both for relevance to the evolution of our present atmosphere, changing as it does through industrial activity and other anthropogenic effects, and for consideration of a separate CZ article on the book. Thanks for considering my suggestions. Anthony.Sebastian 21:04, 24 August 2009 (UTC)

Boltzmann distribution

Milton, in answer to your question I wrote Boltzmann distribution, where I give (almost) your formula and use the term lapse rate. --Paul Wormer 11:26, 22 August 2009 (UTC)

Paul, I read your article Boltzmann distribution and it is way above my head. I think I understand perhaps 5 percent of it. But I do see that your equation resembles the equations given in the "U.S. Standard Atmosphere" document in reference 12 of this article. You continue to amaze me, Paul.

I really don't see any virtue in adding anything about the Boltzmann equation to this article, because probably few readers will understand what the Boltzmann distribution is (just as I didn't).

By the way, I started on the lapse rate article and hope to complete it within the next 2-3 days. Regards, Milton Beychok 15:05, 22 August 2009 (UTC)

[unindent]

Just for the fun of it, I will show you the last few steps needed to come from my equation to yours. I have:

${\frac {n(h_{1})}{n(h_{2})}}=\exp {\Big [}-{\frac {mg(h_{1}-h_{2})}{kT}}{\Big ]}=\exp {\Big [}-{\frac {N_{\mathrm {A} }mg(h_{1}-h_{2})}{N_{\mathrm {A} }kT}}{\Big ]}=\exp {\Big [}-{\frac {Mg(h_{1}-h_{2})}{RT}}{\Big ]}$

where N_A is Avogadro's constant, M = N_A m is the molecular weight of air and R = N_A k is the universal gas constant.

Further the ideal gas law states

$p(h_{1})={\frac {n(h_{1})}{V}}kT\quad {\hbox{and}}\quad p(h_{2})={\frac {n(h_{2})}{V}}kT$

so that

${\frac {n(h_{1})}{n(h_{2})}}={\frac {Vp(h_{1})}{kT}}\times {\frac {kT}{Vp(h_{2})}}={\frac {p(h_{1})}{p(h_{2})}}$

Taken together

${\frac {p(h_{1})}{p(h_{2})}}=\exp {\Big [}-{\frac {Mg(h_{1}-h_{2})}{RT}}{\Big ]}$

Say, level h₂ is the base level and h₁ is the "running" level, then

${\frac {p}{p_{b}}}=\exp {\Big [}-{\frac {Mg(h-h_{b})}{RT}}{\Big ]}$

The temperature is constant (temperature at base level). Change lowercase p to uppercase (we had this discussion before), then

$P=P_{b}\exp {\Big [}-{\frac {gM(h-h_{b})}{RT_{b}}}{\Big ]}$

You see? I'm sure that you learned about Boltzmann in your sophomore or junior year, you must have forgotten it. After all it is a few years ago that you went to college ;-) . --Paul Wormer 15:57, 22 August 2009 (UTC)

Paul, my sophmore year was 66 years ago and I am positive that my physics professor never took us that far. The physics he taught us must have been "unclassical" statistical physics :>) .... and you still continue to amaze me! But then again, maybe I am easily amazed? Regards, Milton Beychok 18:26, 22 August 2009 (UTC)

Paul,I have added a footnote (reference 13) acknowledging that Equation 2 can be obtained from the Boltzmann distribution and linked it to the article you wrote on the Boltzmann distribution. Milton Beychok 16:53, 23 August 2009 (UTC)

A few remarks

The article is a nice description of the atmosphere and good to read.

A few points I noticed:
Meteors are mentioned later, but I think they should be also added in the intro together with the radiation.
Since the height of the space station is mentioned, I would also like to read where airplanes travel (and possibly how high weather baloons go). And also the heights where clouds live.
Probably the infamous hole in the ozone layer should also be mentioned.
And I wonder about the caps in "Troposphere" etc. (and with "Earth"?).
Peter Schmitt 18:29, 22 August 2009 (UTC)

Peter, I have incorporated meteors into the intro as you suggested. I also added commercial airliner cruise altitudes (in the troposphere section) and weather balloon maximum altitudes (in the stratosphere section) as you suggested.

As for capitalization, I only used caps and bolding for Troposphere, Stratosphere, etc. in the lead-in sentences of the Structure section for emphasis (to introduce them and make them stand out). After that, I used caps for them only when they were subsection headings. They are not capitalized anywhere else in the text (unless they start a sentence). As for Earth, in English the uncapitalized word "earth" usually denotes the soil at the surface of the land. The capitalized word "Earth" is the name for our planet just as Mars and Jupiter are names of other planets in the solar system.

As for the ozone hole, I think that should be covered in an article on ozone (yet to be written by someone) which should explain what it is and why it was formed as well as why it is harmful. That is why I red-linked it to that yet not written article. Milton Beychok 19:55, 22 August 2009 (UTC)

Earth vs. earth: I realized this distinction, but my Collins doesn't make it -- therefore the question mark.ataaaaaaaa

Caps: It was the bolded list that made me wonder. Therefore I mentioned it.

And I just noticed another minor point that makes me wonder: is "kilometre" compatible with AE?

Peter Schmitt 23:18, 22 August 2009 (UTC)

Peter, just ask yourself whether you would write "the atmospheres on mars and jupiter are different than earth's atmosphere ..." or would you write "the atmospheres on Mars and Jupiter are different than Earth's atmosphere ...".

Your comment about the compatability of American English and kilometre is a good one. In the 19-20 months since I joined CZ, I have worked on and written over 100 technical articles (engineering, chemistry, etc.) and a great many of them include the use of SI units. Early on, I gave a good amount of thought as to whether to use "kilometres" or "kilometers". Since most science and engineering students in the U.S. universities have been increasingly taught to use SI units for some years now and many of our technical journals now require the use SI units, I decided to use the SI system as much as I could. The average non-technical person in the U.S. probably still uses miles instead of either kilometers or kilometres, but many of them would probably understand what is meant by a kilometre. A good example is that in all of my 100 or more articles, I selected AE in the metadata templates and a good many CZ members are Americans ... yet you are the first person to comment on my use of kilometre rather than kilometer. So I hope that you will forgive my transgression of choosing to use kilometre rather than kilometer. (:>) Milton Beychok 06:55, 23 August 2009 (UTC)

Just out of curiosity: Peter have you heard of a thermal Boltzmann distribution? You must surely have heard of your fellow countryman Boltzmann (wasn't his picture on an Austrian banknote once?). --Paul Wormer 07:56, 23 August 2009 (UTC)

Paul, of course I know Boltzmann. For more than twenty years my office's address was in Boltzmanngasse. And I know about his kinetic gas theory, and Boltzmann equation, though I'm not sure if I ever came across the term "Boltzmann distribution" (certainly not in school). Regarding his picture on a banknote: You probably think of Schrödinger who was on the last 1000 schilling banknotes before the euro.

Milton, I never intended to critisize your English (whether American or British:-). I am a non-native speaker bound to make mistakes. And additionally, it is difficult to speak or write "pure" AE or BE. At school I learned what is called "Oxford English", but I read much American literature, and see more American than British films. (And I read material in "the common language of science: bad or broken English".) This certainly influences my usage of English. But I am interested in language and therefore I try to notice differences (and use - what I think is - BE myself).

It's interesting that you use "kilometre" because it is SI -- I think the average Brit also prefers miles, etc.

Concerning "Earth": I understand that you use it as proper name, and it is quite logical to do so. But, I thought that it is only rarely used. Therefore I was surprised. Getting curious I used Google and cannot tell what is more frequent. There is even (inconsistently) "distance between sun and Earth"

Peter Schmitt 15:00, 24 August 2009 (UTC)

I'd go for the (extremes or average) distance between Sol and Earth, for consistency. Not sure how I'd compute the 'averge', though. Sweep area (m²) divided by circumference of revoltion (m)? Anthony.Sebastian 21:16, 24 August 2009 (UTC)