Maybe I over reacted in my previous post. Robert Chris professed ignorance whereas the people he cites do not to my knowledge profess ignorance.
I too am not an expert here, but my understanding is that the raw data are things like signal return times and phase shifts. There is no sea level that is raw data. There are tide gauges that measure local sea level. These same locations are observed by satellite and are used, to the best of my limited knowledge, to ground truth the satellites. So, the satellites can be thought of as a way to extrapolate from these local tide gauges out to the open ocean and other areas where there are no tide gauges and thus develop and estimate of global sea level. The satellites, as I understand it, are thus best thought of as spatial extrapolators and interpolators and not as the primary source of high confidence in sea level rise. Of course you also cannot naively interpret local tide gauge data either because factors like isostatic rebound from ice sheet removal can confound the global signal in a local record. Again, this is not my area of expertise so I may have some details wrong here. ------ Can I please ask that people not post statements attributed to unnamed people to this group even if that attribution was made in quoted text? This just propogates urban myths. If you have a question, please ask it, but try to avoid promoting a false premise. Ken Caldeira [email protected] +1 650 704 7212 http://dge.stanford.edu/labs/caldeiralab Sent from a limited-typing keyboard On Apr 30, 2012, at 11:43, Ken Caldeira <[email protected]> wrote: > I think it is incumbent on Robert Chris to provide the name of the person who > purportedly made the claimed statements so that we can verify the supposed > facts that Robert Chris is promulgating. > > This group should not be allowed to be used to make unattributed And > unsubstantiated defamatory comments. > > Robert, I think you should either provide support for your statements or > apologize to this group for making unsubstantiated defamatory remarks. > > Ken Caldeira > [email protected] > +1 650 704 7212 > http://dge.stanford.edu/labs/caldeiralab > > Sent from a limited-typing keyboard > > On Apr 29, 2012, at 22:45, Ken Caldeira <[email protected]> wrote: > >> http://sealevel.colorado.edu/ >> >> Mis-pasted link >> >> On Apr 29, 2012, at 22:43, Ken Caldeira <[email protected]> wrote: >> >>> I would be very suspicious of indirect quotes attributed to unnamed ipcc >>> authors. The truth of scientific statements depends on how they are >>> qualified. >>> >>> I am no expert in this area but my understanding is that satellites are >>> subject to decaying orbits, aliasing with respect to satellite orbits and >>> tides, and a myriad of other complicating factors. >>> >>> Often, people who claim they are showing 'raw' satellite data are just >>> displaying their ignorance of these complicating factors. >>> >>> My understanding is that satellites are often calibrated using tide gage >>> data. See for example. >>> >>> http://imos.org.au/srscalval.html >>> >>> http://imos.org.au/srscalval.html >>> >>> Ken Caldeira >>> [email protected] >>> +1 650 704 7212 >>> http://dge.stanford.edu/labs/caldeiralab >>> >>> Sent from a limited-typing keyboard >>> >>> On Apr 29, 2012, at 21:52, Robert Chris <[email protected]> wrote: >>> >>>> I have come across the work of Nils-Axel Morner who holds that IPCC >>>> reports that sea level is rising are inaccurate and alarmist. In his 2004 >>>> paper (http://www.sciencedirect.com/science/article/pii/S0921818103000973) >>>> he shows a graph of 'raw data' from the TOPEX/Poseidon satellite which >>>> shows that over the period from 1993 to 1999 there was no discernible >>>> change in global sea level. In IPCC AR4 Ch5 reference is made to a 2004 >>>> paper by Cazenave and Nerem which presents the same TOPEX/Poseidon data >>>> extended to 2003 but now shows a clear rising trend >>>> (http://www.eos.ubc.ca/~mjelline/453website/eosc453/E_prints/2003RG000139.pdf). >>>> In AR4 this series is further extended to 2006 and shows a continuing >>>> rising trend. It is very much based on this paper that the AR4 drew its >>>> conclusions about sea level rise. >>>> >>>> Can someone explain to me why, at least for the first 6 years, these two >>>> presentations of the same data show such divergent trends? >>>> >>>> Morner is also reported as saying: >>>> >>>> 'In 2003 the satellite altimetry record was mysteriously tilted upwards to >>>> imply a sudden sea level rise rate of 2.3mm per year. When I criticised >>>> this dishonest adjustment at a global warming conference in Moscow, a >>>> British member of the IPCC delegation admitted in public the reason for >>>> this new calibration: ‘We had to do so, otherwise there would be no >>>> trend.’ >>>> (http://iceagenow.info/2011/12/satellite-sea-level-data-tilted-distort-figures-sea-level-expert/) >>>> >>>> >>>> Robert Chris >>>> The Open University >>>> [email protected] >>>> -- >>>> You received this message because you are subscribed to the Google Groups >>>> "geoengineering" group. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msg/geoengineering/-/WuGgEKlDiLEJ. >>>> To post to this group, send email to [email protected]. >>>> To unsubscribe from this group, send email to >>>> [email protected]. >>>> For more options, visit this group at >>>> http://groups.google.com/group/geoengineering?hl=en. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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