Talk:Noctilucent cloud/GA1

GA Review

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Hi, I'll be reviewing the article. All I know about noctilucent clouds I learned on Slashdot. The review should be posted within a couple of days. Wronkiew (talk) 16:21, 16 October 2008 (UTC)

Overview

GA review (see here for criteria)

1. It is reasonably well written.

   a (prose): b (MoS):

2. It is factually accurate and verifiable.

   a (references): b (citations to reliable sources): c (OR):

3. It is broad in its coverage.

   a (major aspects): b (focused):

4. It follows the neutral point of view policy.

   Fair representation without bias:

5. It is stable.

   No edit wars etc.:

6. It is illustrated by images, where possible and appropriate.

   a (images are tagged and non-free images have fair use rationales): b (appropriate use with suitable captions):

7. Overall:

   Pass/Fail:

Prose

• "Noctilucent clouds, also known as polar mesospheric clouds, are bright cloudlike phenomena in the upper atmosphere, visible in a deep twilight." Should be "cloud-like".
  • Done.
• "The exhaust from space shuttles, which is almost entirely water vapour, has been found to generate individual clouds." This should be capitalized.
  • Done.
• "Noctilucent clouds are composed of tiny crystals of water ice 40 to 100 nanometers in diameter and exist at a height of approximately 85 kilometres (53 mi),higher than any other clouds in Earth's atmosphere." Replace "approxmimately" with "about". Also, this is missing a space after "(53 mi),".
  • Done
• "As the mesosphere contains very little moisture, approximately one hundred millionth that of air from the Sahara desert, and is extremely thin, the ice crystals can only form at temperatures below about −120 °C (−184.0 °F)." Replace "approximately" with "about". Numbers above 10 should be written with numerals, but I'm not sure how to fix this case.
  • I've left this as it is for now. I'm not sure what to do about it either.
• "These showed for the first time that the occurence of the clouds coincided with very low temperatures in the mesosphere." Fix spelling.
  • Done.
• "Wegener correctly conjectured that they were composed of water ice." If "conjectured" is really a word, it's an uncommon one. Maybe replace with "Wegener's conjecture that...was later proven to be correct".
  • Conjectured is a word but I've changed it anyway because I think your version reads better.
• "On August 28, 2006, scientists with the Mars Express mission announced that they found clouds of carbon dioxide similar to noctilucent clouds over Mars that extended up to 100 km above the surface of the planet." This paragraph is too short. Either develop it further or combine it with another one. Also, the relationship between CO2 clouds on Mars and noctilucent clouds on Earth could use more explaining.
  • Done.
• "A classification scheme was developed by Fogle in 1970 that distinguished between five different forms." Generally, "between" distinguishes two different forms. Maybe replace with "differentiated five forms".
  • I've changed this to An identification scheme was developed by Fogle in 1970 that classified five different forms.
• "Climate models predict that increased greenhouse gas emissions cause a cooling of the mesosphere, which would lead to more frequent and widespread occurences of noctilucent clouds." Fix spelling.
  • Done.
• "There are also noctilucent clouds made of smaller crystals, 30nm or less, which are invisible to observers on the ground because they do not scatter enough light." In general, avoid the using "there" as a placeholder for a missing subject in a sentence. Start this one with "Also, some noctilucent clouds are".
  • Done
• Combine the last two paragraphs in the "Formation" section about sodium deposition and radar reflectivity.
  • Done.
• "His notes provide evidence that noctilucent clouds first appeared in 1885; he had been doing detailed observations of the unusual sunsets caused by the Krakatoa eruption the previous year and firmly believed that, if the clouds had been visible then, he would undoubtedly have noticed them." Break up this long sentence.
  • Changed the semicolon into a full stop.

MoS

• Lead section
  • Latin translation is explained in the lead but not later in the article
  • Altitude is given in the lead but not in a later section
• Layout
  • Some entries in the external links section need better descriptions, like "More pictures", and "BBC News Article on satellite mission".
• Words to avoid
  • "They are frequently regarded as being quite beautiful." Maybe a quote would work better here.
  • "It has been pointed out that the first sightings coincide with the Industrial Revolution and they have become more widespread and frequent throughout the 20th century." Even with the citation, this is not specific enough considering how controversial it is. Name the pointer.
  • "It has been suggested that a transition to a hydrogen economy could increase the number of noctilucent clouds through increased emissions of free hydrogen." Again, name the suggester.
    • These are all done. Reyk _YO! 03:06, 19 October 2008 (UTC)

References

• Usage of "Notes" and "References" sections should be consistent, or at least logical. Why are some references listed in the notes section?
  • Most of the references are single-page websites which can be directly referenced within the in-line citation, and I can quite easily cite them several times if I have to (such as the first Phillips reference). But there are a few instances where I've cited specific pages of a longer document (Gadsden & Parviainen, and Schroeder). There it would be cumbersome and untidy to constantly have to include the full information of the document for each inline citation so I've abbreviated it to, say, "Gadsden & Parviainen (2006), p. 13" and stated the full document information just once, in the References section. This is how other good articles, such as The Hobbit, organize things.
• Web site citations should have either authors or publishers named. For example, http://www.albany.edu/faculty/rgk/atm101/nlc.htm was written by Robert G. Keesee and was published by University at Albany.
• Some of the journal abstracts and books need much better citations so interested readers can easily find them. Examples:
  • Karlsson, B.; Gumbel, J.; Stegman, J.; Lautier, N.; Murtagh, D. P.; The Odin Team (2004). "Studies of Noctilucent Clouds by the Odin Satellite" (PDF). 35th COSPAR Scientific Assembly: 1921. Bibcode:2004cosp...35.1921K. Retrieved 2008-10-16.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  • Hervig, Mark; Thompson, Robert E.; McHugh, Martin; Gordley, Larry L.; Russel, James M.; Summers, Michael E. (2001). "First Confirmation that Water Ice is the Primary Component of Polar Mesospheric Clouds". Geophysical Research Letters. 28 (6): 971–974. Bibcode:2001GeoRL..28..971H. doi:10.1029/2000GL012104. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  • Gadsen, M. (1975). "Observations of the colour and polarization of noctilucent clouds". Annales de Geophysique. 31: 507–516. Bibcode:1975AnG....31..507G. {{cite journal}}: Unknown parameter |month= ignored (help)
  • Gadsden, M. (1995). Observing Noctilucent Clouds (PDF). International Association of Geomagnetism & Aeronomy. ISBN 0965068609. Retrieved 2008-10-16. {{cite book}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)

Attribution

• Apparent contradiction: "are bright cloudlike phenomena" vs. "normally too faint to be seen".
  • Removed the word "bright". I guess the clouds are bright compared to the night sky but faint compared to a daylight sky, but anyway...
• "they are too high to be reached by weather balloons" Needs a reference.
  • Removed that bit.
• "located in the mesosphere at altitudes of around 75 to 85 kilometers (47 to 53 mi)" Needs a reference.
  • Found one. :)
• "The dust is believed to come from micrometeors although volcanoes and dust lifted upwards from the troposphere are also possibilities." Needs references and a comma.
  • Added the comma. The sentence is supported by reference #5.
• "About half of the vapor is injected in the thermosphere, typically at altitudes of 103 to 114 kilometers (64 to 71 mi)." Needs a reference. You'll find it in the US Navy press release in the external links section. Also, this sentence is lifted directly from the press release.
  • Done. That sentence was one of the few bits left over from how the article was before I stared on it.
• "Studies have shown that this exhaust can be transported to the Arctic region in little over a day, although the exact mechanism of this very high-speed transport is unknown." Best to just name one study and then cite it. This article has a noticeably high number of ambiguous references to studies, measurements, and experiments. Also, in uncontroversial cases you can delete the "studies have shown" phrase and just state the results, as long as you have appropriate citations.
  • Done.
• A duplicate citation closer to Bellan's name would be nice.
  • Done.
• "Study was limited to ground-based observations and scientists had very little knowledge of the mesosphere until the 1960s, when direct rocket measurements began." Needs a reference for the lack of knowledge and a comma somewhere.
  • Done.
• "Noctilucent clouds were first detected from space by an instrument on the OGO-6 satellite in 1972." This definitely needs a reference.
  • Done.

Images

• Image:Northpoleclouds AIMData c.jpg may not be a NASA image, and therefore would not be PD. I sent an email to the University of Colorado asking for clarification.
  • I've taken the image out for the time being. Reyk _YO! 04:05, 19 October 2008 (UTC)

Comments

Nice work, I'm sure you'll have this fixed up in no time. I tried to be specific, but if you have any questions, just let me know. Wronkiew (talk) 03:43, 18 October 2008 (UTC)

Article is GA quality. Nice work. Wronkiew (talk) 04:49, 19 October 2008 (UTC)

• Thanks. That was some really thorough auditing you did, very much appreciated. Reyk _YO! 05:00, 19 October 2008 (UTC)