vince <vinceska...@gmail.com> writes: > Greg - > does https://www.usna.edu/Users/oceano/pguth/md_help/html/vert_datum.htm > help any ?
No, but it's a great short introduction for people not familiar with the subtleties of height meaurement. (There are a few minor errors, too: chart datum is not always MLLW - some US regions use MLW. And I've never heard of orthometric heights from geoid models called geodetic before.) While the various datums are described, it doesn't answer: Which elevation and which vertical datum does NWS mean when they say say "sea level". I am guessing it is "0m NAVD88", but I am just guessing. My second guess is "0m WGS84 Orthometric Height as defined by EGM2008", to align with what WMO might want. > There are some links at the bottom of the article to NOAA info as well... One of those says It should be noted that due to effects such as atmospheric pressure, temperature, prevailing winds and currents, and salinity variations, MSL can depart from an equipotential surface by a meter or more. which is what I was getting at in saying that mean sea level, without qualifications, is a fuzzy concept. -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/rmisfor8cb8.fsf%40s1.lexort.com.
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