There are many going up and many going down. There is a web site where you can check out trends in hundreds of locations in the USA. Temperature records that were started in small towns a hundred or so years ago are now in the heart of major cities where the reflect ambient urban heating. And of course wars and revolutions left holes in the record that are time consuming to account for and are thus often ignored. Yet the printed record (in bound books) still stands. The Dutch established a very large network for the times (1860s) in Indonesia, but later their meteorologists found the instruments were not recording properly.
I ran into this sort of thing elsewhere and am sure that it is much more common than one might expect. So half the day's record was not recorded. Some years ago I was involved in a recon of south Iran, and at the village of Jask, the weather tender informed me that he brought the instruments in at night so they would not be stolen. Mustafa, you are 1000% right on the reliability of the records. James, please allow us this minor excursion here (which started with a question on SWMM, anyway). There are hundreds of sites dealing with "global warming". Well I guess I have to chime in again here. Until more broad/fair agreement on the fundamentals (like a satellite photo would do for the round earth theory), I'll keep using the "scanty data and unreliable rain statistics".
The WSJ article has kept me in a rather neutral position on the topic. It may be that it is currently more political than scientific. Similar things happened when theorist started claiming the world was not flat. He had noticed this, not just in publishing, but in promotions, research funding, etc. His concern was that global warming has become such a trend, and was now so accepted, that those who speak contrary to it are "discriminated" against. Then, his comments to those letters were published later than normal, effectively loosing the overall focus of the discussion. In response, instead of comment letters showing up in the next issue, there were whole new articles (hastily prepared in his opinion) published rebutting his paper. If I recall correctly, he said his paper was printed later than normal, relative to when it was submitted. by a researcher who had views/data/conclusions contrary to the theory and submitted a paper to the AGU. I believe the NWS refrains from claiming Katrina and Rita and the current active hurricane outlook are evidence of the theory. A little lively hurricane weather may not either. I don't think our "scanty data and unreliable rain statistics" would support or be a broad enough base for the warming claims. I think the global warming support data comes from observed changes in deserts, deep polar ice borings and meltings, recent data on minor sea rise, etc. If you haven't seen NOAA Atlas 14 yet, it is an excellent reference for this topic:įor a sense of how rainfall stats can vary, see Figure 7.1 in the Volume 2 documentation. There are many jurisdictions that still dictate the use of outdated stats (e.g., TP-40 which is based on rainfall observations generally from 1940-1960). Rainfall statistics vary naturally due to climate change, but they also vary artificially due to the quality, accuracy, and period of record of the data used to derive the stats as well as the method of analysis and choice of statistical parameters/distributions. The stats I'm referring to are volume/duration/return period for sizing ponds and other storage facilities, and intensity/duration/return period for sizing pipes, culverts and other conveyance elements. So I think it's important for us SWMM-users to understand (and educate others on) the limitations of rain stats. Global warming and climate change issues aside, regulations everywhere still require the use of local rainfall statistics for sizing stormwater facilities.
0 kommentar(er)
