From: email@example.com (Larry Stone) Organization: InterServe Communications, Inc. Date: 27 May 96 13:35:37 References: 1 2 3 4 Followups: 1 2
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In article <airliners.1996.805@ohare.Chicago.COM>, felton@phoenix.Princeton.EDU (phil. Felton) wrote: >This is incorrect, the altitudes that are flown by commercial airlines are ><40000 feet. The atmosphere up to the tropopause is well mixed and therefore >the altitude of emission is irrelevant, SSTs on the other hand fly higher and >NOx emissions there are of more concern. However, note that the main source >of NOx in the stratosphere is from agricultural fertilizers! To illustrate the >degree of mixedness note that Mauna Loa where the classical set of data on >CO2 is taken (at an altitude of about 13,000 ft) shows a ~2% annual fluctuation >due to the seasonal growth and die back of vegetation. Two problems: 1) As Karl has already stated, many modern jets do go above 40,000. A week ago, I was on a 767 that cruised at 43,000. 2) I believe at certain times of the year, the tropopasue can be down as low as the low-30's putting a large percentage of jets cruising above the tropopause. -- -- Larry Stone --- firstname.lastname@example.org Belmont, CA, USA My opinions, not United's.