wolfie Posted February 10, 2012 Report Share Posted February 10, 2012 Yeah it was snowing a few minutes ago, well sort of I counted 14 good size flakes of snow as I looked out. Hardly a blizzard I know and it's stopped now but I thought I'd mention it First snow today then Diz. Well spotted. :roll: :lol: Quote Link to comment Share on other sites More sharing options...
Dizzy Posted February 10, 2012 Author Report Share Posted February 10, 2012 I was bored Wolfie. I don't suppose you happen to know any scienticic formula's or statistics associated with snow do you Quote Link to comment Share on other sites More sharing options...
Peter T Posted February 10, 2012 Report Share Posted February 10, 2012 I was bored Wolfie. I don't suppose you happen to know any scienticic formula's or statistics associated with snow do you H2O. Quote Link to comment Share on other sites More sharing options...
Evil Sid Posted February 10, 2012 Report Share Posted February 10, 2012 The average snowflake falls at a speed of 3.1 miles per hour. apparently Quote Link to comment Share on other sites More sharing options...
wolfie Posted February 10, 2012 Report Share Posted February 10, 2012 I was bored Wolfie. I don't suppose you happen to know any scienticic formula's or statistics associated with snow do you A systematic way to examine the origin of variety in falling snow. First, we define shape diversity as the logarithm of the number of possible distinguishable crystal forms for a given resolution and set of conditions, and then we examine three sources of diversity. Two sources are the range of initial-crystal sizes and variations in the trajectory variables. For a given set of variables, diversity is estimated using a model of a crystal falling in an updraft. The third source is temperature-updraft heterogeneities along each trajectory. To examine this source, centimeterscale data on cloud temperature and updraft speed are used to estimate the spatial frequency (m−1) of crystal feature changes. For air-temperature heterogeneity, this frequency decays as p−0.66, where p is a measure of the temperaturedeviation size. For updraft-speed heterogeneity, the decay is p−0.50. By using these frequencies, the fallpath needed per feature change is found to range from 0.8 m, for crystals near −15C, to 8m near −19C – lengths much less than total fallpath lengths. As a result, the third source dominates the diversity, with updraft heterogeneity contributing more than temperature heterogeneity. Plotted against the crystal’s initial temperature (−11 to −19C), the diversity curve is “mitten shaped”, having a broad peak near −15.4C and a sharp subpeak at −14.4C, both peaks arising from peaks in growth-rate sensitivity. The diversity is much less than previous estimates, yet large enough to explain observations. For example, of all snow crystals ever formed, those that began near −15C are predicted to all appear unique to 1-μm resolution, but those that began near −11C are not. The deposition of water vapor in air produces crystals with a surprising degree of variety, symmetry, and intricacy. Formation of various intricate features have been studied onand- off over the years (e.g. Nakaya, 1954; Yamashita, 1976; Frank, 1982; Hallett and Knight, 1994; Nelson, 2005), and the symmetry is now understood to arise from the growth mode (Frank, 1982), but the sources of snow crystal variety have not been examined systematically. The variety is generally equated to the number of possible crystal forms, a quantity that has been estimated through two approaches. The first approach is to estimate the number of possible distinct crystal forms for a given crystal radius (e.g. Knight and Knight, 1973). However, this approach yields no insights into the origin of the variety and it does not include limitations from the growth process; in particular, we neither learn the role of the crystal-growth response to the environment nor do we see how this response may limit the types of crystal forms. A different approach was suggested much earlier by Bentley (1901) when he wrote that the various crystal features originate from the various “atmospheric layers” the crystal falls through1. As a preliminary step in this direction, Hallett (1984) used knowledge of the crystal response to estimate the variety. His result, about 1030 000, is immense (and much less than the 103 000 000 of the first approach), but the method involved guessing the crystal’s environment. Now, we still do not know if crystals pass through enough “layers” (regions) to produce the observed variety, or even if those layers are the main source of variety. Of course this only applies if you are driving at 20mph. Quote Link to comment Share on other sites More sharing options...
Dizzy Posted February 10, 2012 Author Report Share Posted February 10, 2012 10/10 for effort Evils but alas only 1/10 for content as that is not a formula but was very interesting all the same. How do the figure that out though as every snowflake is unique and they break up and change all the time as they fall and reform Quote Link to comment Share on other sites More sharing options...
wolfie Posted February 10, 2012 Report Share Posted February 10, 2012 Damn, overlooked again. :angry: Quote Link to comment Share on other sites More sharing options...
Dizzy Posted February 10, 2012 Author Report Share Posted February 10, 2012 Damn, overlooked again. :angry: OMG Wolfie I am so sorry and I knew it was you and you were the one I was replying to hence my winks etc so god knows why I types Evils I can only imagine that it was because the previous post was by Peter and he made me think 'evil', or the fact that your wolf howling makeds me think 'evil; or perhaps my mind was still on the 20 theme I hope one day you will forgive me but hey poor Evils getting mistaken for you eh as that must be worse Quote Link to comment Share on other sites More sharing options...
Evil Sid Posted February 11, 2012 Report Share Posted February 11, 2012 about as bad as me being mistaken for bill bailey. Quote Link to comment Share on other sites More sharing options...
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