Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!uniwa!cc.curtin.edu.au!tlijy From: tlijy@cc.curtin.edu.au Newsgroups: sci.space.shuttle Subject: Re: Ozone and the shuttle Message-ID: <1991Apr13.131337.7755@cc.curtin.edu.au> Date: 13 Apr 91 05:13:37 GMT References: <1991Apr12.163103.11472@welch.jhu.edu> Organization: Curtin University of Technology Lines: 55 In article <1991Apr12.163103.11472@welch.jhu.edu>, jimh@welch.jhu.edu (Jim Hoffman) writes: > I have heard some rumors that the shuttle has caused more damage to the ozone > layer than all of the CFCs combined. How valid is this claim???? If it is > valid, what is being done about it????? While on the topic, is the shuttle > being considered as a tool in fighting the ozone problem????? > I did a literature review on ozone issue last year. I have come across some articles addressing the potential damage to ozone layer caused by space shuttle and supersonic jet fuel. But I think it is unfair to say that shuttle has caused more damage to the ozone layer than all of the CFCs combined. How many tones of CFC released to the atmosphere a year? How many space shuttle flights a year? Shuttle can be used as a tool in fighting the ozone problem, mainly because it can and has carried remote sensing device on board, such as BUV or SBUV type of sensor. Before you start assessing the damage to the ozone layer, you must have done some quatitative work on it. Ironically, we have doubts in different types of ozone measurements. This is actually two fold problem. First, you need to extract anomaly from its long term natural variability. It is not an easy task, you should have kept long term ozone record and perform a complicated time series analysis. Second, different types (satellite based or ground based, sensing in IR or UV) of ozone measurement are affected by different factors. For instances, ground based measurement (mainly Dobson spectrometer) is annoied by aerosol in the atmosphere and it only gives the ozone reading direct over your head. Satellite based measurements (9.6 miron in IR or in UV region) only give you an area averaged total ozone number because of poor resolution. Physical retrieval model used in satellite data processing is not near perfect yet. Previous work and my own work reveal systematic and non-systematic differences between satellite and ground based measurements. There is no absolute truth in this type of comparison. I am wondering which total ozone measurement can be trusted. -- _Jason Y. Li =============================================================================== Satellite & Remote Sensing Res. Group |1) PSImail: psi%050529452300070::TLIJY Dept. of Applied Physics __________|2) Internet: TLIJY@cc.curtin.edu.au Curtin Univ. of Tech. |3) Bitnet: TLIJY%cc.curtin.edu.au@cunyvm.bitnet Perth, West. Australia |4) UUCP : uunet!munnari.oz!cc.curtin.edu.au!TLIJY <<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> People who have nothing to say are quickly tired of their own company. [Collier]