Newsgroups: lter.ced Path: LTERnet!daniel From: "Bruce P. Hayden" Subject: CED 2.4b Message-ID: <1993Apr29.193320.27171@lternet.washington.edu> Sender: daniel@lternet.washington.edu (Daniel Pommert) Organization: Long Term Ecological Research Date: Thu, 29 Apr 1993 19:02:39 GMT ***************************************************************** ***************************************************************** *** *** *** *** *** MR. FRANCIS BEAUFORT'S SCALE *** *** *** *** *** ***************************************************************** ***************************************************************** Mr. (SIR) Francis Beaufort was a square-rig-ship driver in His or Her Majesty's Royal Navy, a Rear Admiral and Hydrographer to the Royal Navy. In 1805, he developed a scale of wind forces (dynamic pressures) in terms of the behavior of the sails on his ship. Zero on his scale was a wind inadequate to move his frigate or a man-of-war. His scale went to 12 where winds were so strong 120 kmh that no canvas could be carried. His wind scale was inherently non-linear. A seaman can look at the sea, e.g., the local waves, as contrasted with the swell produced elsewhere, and could tell what Beaufort wind force was blowing. He could then look at the sails and confirm his eye-test. Well, all things that have cross-sectional area have a gradation of response to dynamic wind pressure. Below is a table with connections between Mr. Beaufort's scale and the behavior of the selected members of the biosphere. An E-mailable Beaufort Table in Two Parts: if you have to rework a messed up e-mail disturbed version of the table, you will find that I have put a period before each entry in the table. CUT & PASTE AND RESPACE. SORRY *********************************************************************** Force Human Whole Seed & Leaf Activity Plants *********************************************************************** 0 .Smoke Rises .Still .Plumed Seeds Fall 1 .Smoke Drifts .Still .Plumed Seeds Sail 2 .Feel Wind on .Face Leaves Rustle .Salix Seed Clouds 3 .Dust Raised .Twigs Move Winged .Seeds Sail 4 .Hair Disturbed .Small Branches Move .All Plumed Sail 5 .Eye Discomfort .Tumbleweed Rolls . Leaves Airborne 6 .Arms Blow from Sides .Large Branches Move .All Leave in Air B I O L O G I C A L W I N D T H R E S H O L D 7 .Walking Difficult .Whole Trees Move .Loose Matter Up 8 .Progress Impeded .Twigs Break .Remains So 9 .Children Blown Over .Branches Break .Remains So 10 .Adults Blown Over .Trees Uprooted .Remains So *********************************************************************** (The Table Continues) BIRDS INVERTEBRATES *********************************************************************** 0 .All Active .Gossamer Seen in Air 1 .Soarers Up .Aphids Fly, Spiders Take Off 2 .Few Thermals .All Species Active 3 .No Thermals .Hoppers, Aphids & Spiders Grounded 4 .Peak Soaring .Beetles Grounded, No Mosquitos Biting 5 .No Night Migrations .Flies (except Horse & Deer) Grounded 6 .Few Small Birds Aloft .Moths and Bees Grounded B I O L O G I C A L W I N D T H R E S H O L D 7 .Perchers Grounded .Butterflies and Deerflies Grounded 8 .Swifts, Ducks, Raptors .Only Dragonflies Still Airborne .and Swallows Flying 9 .Only Swifts Flying .All Insects Grounded 10 . All Birds Grounded .Same *********************************************************************** [Source L. Watson (1984). Heaven's Breath: A Natural History of the Wind. Wm. Morrow.] The biological wind threshold, between Force 6 and Force 7 winds is the trouble zone for living things. **************************************************************************** Dynamic pressures on a 1 square meter cross-section person in kg per square meter for various force winds and the ratio of dynamic pressures using the dynamic pressure for force 1 wind as the standard. **************************************************************************** Force: 1 2 3 4 5 6 7 8 9 10 11 12 Pressure .05 0.4 1.3 3.2 6.3 11 18 26 36 50 68 85 Ratio: Pressure to Pressure at 1 8 27 64 125 216 343 512 720 1000 1331 1728 Force 1 **************************************************************************** The little table above shows how dynamic wind pressure grows as wind force increases. Wind of force 2 has an 8 times greater dynamic pressure than a force 1 wind. Force 3 wind has a 27 times dynamic pressure than a force 1 winds. Inspection of the table indicates that the number is the cube of the wind force number. It was a force 4 wind that gave the shrew so much trouble. To blow down a child takes a force 9 wind and 720 times the dynamic pressure of a force 1 wind. DYNAMIC WIND PRESSURE IS THE CUBE OF THE BEAUFORT FORCE ***************************************************************** ***************************************************************** *** *** *** *** *** APHIDS UPDATE *** *** *** *** *** ***************************************************************** ***************************************************************** Dust is often small stuff. It doesn't take much of a wind to get it into the air. All it has to do is show its cross-section to the wind and it is off. Add a pair of winds or two and off you go even if you didn't want to. In the air, between 4,300 meters and the surface, over an average square Louisiana-kilometer you would normally find about 14,000,000 insects. Sort and classify it and you might find different 700 species. Flies, mosquitoes, beetles, wasps, bees, hoppers and aphids is the typical order of abundance. Do your harvesting by night and beetles lead the pack. [Glick, P. A. (1960). Collecting insects by airplane ... U. S. Department of Ag. Tech. Bul. No. 1222.] Charles Lindberg did some bug catching [It must have veen boring up t If you want to nab a dragonfly in your biplane, take her up with your nets out on the passage of cold front. Dragonflies apparently become long distance fliers with the help of the squall lines ahead of the cold front. If you really get into this stuff you can get hold of a radar that can track aphids at 500 meters and determine its wing-beat frequency. The aphids regularly rise to over 1500 meters and travel widely. A single, potted-alfalfa plant as bait set out in the desert has been shown to attract aphids from as far away as 135 km. They fly day and night. [Dickson (1959). Aphis dispersal over southern California deserts. Ann. of the Ent. Soc. of Am. 52:368-372.] Sailing ships with insect collectors run by Bishop Museum in Hawaii collected 13,000 specimens. Most were Asian. They apparently ride the mid-latitude westerlies out of Asia to the Pacific islands. Gobi Desert Dust takes the same route and is added to the volcanic soils of Hawaii. Winds facilitate exchanges between ecosystems. African insect fauna populate the Caribbean just as African dust takes the same path. Hurricanes in 1947 and 1950 moved Puerto Rican water striders (Rheumatobates minutus) to temporary fresh-water ponds in the Florida Keys. [Herring (1958), Evidence for hurricane transport and dispersal ... Pan-Pacific Entomologist 34:174-175.] ***************************************************************** ***************************************************************** *** *** *** *** *** CED MAIL *** *** *** *** *** ***************************************************************** ***************************************************************** Rick Boyce, a new CED reader from Dartmouth, is working on the fate of red spruce in a scenario-world of global climate change and had some lingering questions he forwarded to CED. RICK may be known to some of you for his work on "tree flagging and fir waving!" [Can. J. Forest Res. 18-461 (1988)] and more recent work on red spruce and winter climate [For. Sci. 37:1567-1580 (1991) & Tree Phys. 11: 341-355]. He has been sticking met stations near his red spruce to get at the role of winter desiccation and freezing in the red spruce decline. Winter damage to current-year foliage is generally agreed to be responsible for spruce decline, with air pollution apparently predisposing trees for more frequent injury episodes. Red spruce tops-out about about 1220 meters up the White Mountains of New Hampshire. Boyce's model predicted that the foliage dries out and that low cuticular resistance to water vapor loss and low relative humidity are the most important variables limiting spruce distribution. However, he found winter freezing was the cause of damage. But, with the skill to pull interesting results form a rejected hypothesis, he found that his model was pretty good at predicting winter water relations. He thinks it explains why red spruce are found below 1220 meters elevation. Cuticular resistence, the best predictor of tissue desiccation, was a function of summer temperature. Rick wanted to know what would this mean for the time when the world warms up? Just what do those GCM juggernauts tell us about our summers of the future? Well, as a general rule the GCMs say warmer and wetter air. They usually don't say partition warmer into maximum or minimum temperatures and when they say wetter they usually mean higher average vapor pressure, specific humidity or water vapor mixing ratio. Since relative humidity is a function of both temperature and water vapor content of the air one should sort of stay away from fooling around much with relative humidity! Relative humidity change in a 2XCO2, warmed world is a slippery beast. Rick laments, "nobody seems interested in relative humidity changes, or at least not interested enough to publish anything!" The GCM workers usually publish a mean temperature and so if you got a relative humidity from that it would be some mean relative humidity that happen twice a day -- once during the warm-up of the daylight hours and once during the cool-down when the sun is on the other side of Earth. Rick wants to know "how summer temperatures will increase." My answer is mostly night time temperatures. Because -- 1) Greenhouse gases work to retard outgoing long wave radiation and thus limit nocturnal cooling. Daytime maximum temperatures are driven by the sun. 2) Wetter air would mean higher dewpoint temperatures and thus higher minimum temperatures. 3) Wetter air would mean more cloudiness (the GCMs are spit on this prediction) and more cloudiness would mean suppressed daytime high temperatures and higher minimum temperatures. RICK also wanted to know about humidity and VPD in winter. My guess is that with higher water vapor content to the atmosphere that VPDs would narrow some. ***************************************************************** ***************************************************************** *** *** *** *** *** VERTICAL EVACUATION FOR P. rubens *** *** *** *** *** ***************************************************************** ***************************************************************** Rick also notes that red spruce abundance drops off below 760 meters altitude, which is, as Richard points out, the cloud base elevation that Tom Siccama identified 30 years ago. And, red spruce does just great along the foggy coast of Maine. All this led Rick to turn his attention to Coweeta-land. What if, he asks, the cloud elevation in the Great Smokies and a few peaks in Virginia, in a global warming world, crept up the mountain! "They can't retreat very much higher." Well, what of 2XCO2 global warming and red spruce? The standard global warming model is surface warming (in the troposphere) up to about 15,000 feet or so and cooling above that. This all means that dT/dz (the vertical temperature lapse rate) is steeper in a warmed world. And warmer air means that it can hold more water and with warmer oceans there is the means to get more water into this air that can hold more! Dewpoint temperatures, absolute humidity, specific humidity, and mixing ratios should all be a bit higher. Now with a steeper dT/dz and a wetter air, cloud base should be lower. Vertical evacuation for the red spruce might mean heading for the basement! Clouds mean cooler afternoon temperatures had higher morning temperatures. This should not hurt the red spruce. One of the reasons the coast of the Gulf of Maine is so foggy and so friendly to red spruce is that there is ample cool moist air that can flow over a colder land surface and presto ground fog is generated. With a warmed-world, wetter air of slightly higher temperatures fog in places with colder surfaces should be easier to come by. So, if Boyce's desiccation model for red spruce survival is on target we might well see red spruce expand its range southward along the coastal margins. Even in a warmed-world the seas in the high latitudes will be warmer than the land in winter and cooler than the land in summer! ***************************************************************** ***************************************************************** *** *** *** *** *** LIGHTNING UPDATE *** *** *** *** *** ***************************************************************** ***************************************************************** Well, I have more data on trees at risk of electrocution of by Mother Nature. I am interested in the why question but I am still short on explanations why your genes should make any difference in this matter. CED readers are welcome to have a go at it. Count by Dr. Hess in Lippe-Detmold Forest [Royal Meteo. Soc. Quart. Journal 33:255. 1907] **************************************************** # of strikes % forest % of all (1874-1890) by species Strikes **************************************************** Oaks 310 11% 58% Scots Pine 108 6% 20% Spruce 39 13% 7% Beech 33 69% 6% Larch 11 >1% 2% Birch 10 >1% 2% Poplars 6 >1% 1% Ash 4 >1% .7% Willow 2 >1% .3% Austrian Pine 1 >1% .2% Weymouth Pine 1 >1% .2% Other 13 >1% 2% **************************************************** Total 538 ***************************************************************** ***************************************************************** *** *** *** *** *** OZONE UPDATE *** *** *** *** *** ***************************************************************** ***************************************************************** >From time to time I have kept CED readers up-to-date on the latest good stuff on the repeating news-story #2241: The Demise of the Ozone Layer. This is from NASA by way of the usual pre-scientific paper news release and their mouthpiece this time is the Washington Post. The Washington Post got a new religion on this one [April 15, 1993]. Here is an assortment newsy headers in their two-page feature: "For Eons, Nature Has Created, Destroyed Ozone above Earth," "Ultraviolet Fluctuates Naturally," "Amount of Ozone in Any Area Location Varies," "In the Debate About Ozone, No Depletion in Rhetoric." NASA-Goddard scientist Richard Stolarski weighs in with this little gem, "I happen not to be of the disaster school. It's a serious concern but we can't show that anything really catastrophic has happened yet, or that anything catastrophic will happen in the future." Greener than thou Michael Oppenheimer (EDF) adds, "The current and projected levels of ozone depletion do not appear to represent a catastrophe. But I'm flabbergasted that we let it go this far before taking action." The Post notes that "If there has been any increase in UV, researchers say, it is too small to measure against a background of normal ultraviolet levels that rise and fall by large amounts for entirely natural reasons on time scales from hours to decades. It is noted that late winter ozone has decreased say 8 to 10% in the high latitudes but with the low sun angle the path length of ozone it has to pass through is 40 times as much ozone as when the UV rays are perpendicular to the atmosphere like over the equator at the times of the equinoxes . John Frederick, atmospheric physics University of Chicago, contributes this one to the Post's new view, "People get all excited about a few-percent change in UV, but it's nothing to get a 20 % increase naturally. If an increase of 20 % were going to be so damaging, there should be no life in Florida." Florida UV always exceeds the allegedly dangerous levels once forecast for more northerly latitudes. So, this may be my last Ozone Update for CED readers. Don't count on it. There may be a die-hard out there who does not read the Washington Post. ----------------+--------------------------------+------------------------- Bruce P. Hayden | Dept. Environmental Sciences | bph@virginia.EDU (804) 924-0545 | Clark Hall, Univ. of Virginia | bph@virginia.BITNET (804) 924-7761 | Charlottesville, VA 22903 | (804) 982-2137(fax) ----------------+--------------------------------+------------------------- -- -- Daniel Pommert Long Term Ecological Research Network Office dPommert@LTERnet.Washington.edu (206)543-1135 -or- 685-8292