Laserfiche WebLink
<br /> <br /> <br />positions of tnlt:rest are Ihe liAS seeding location. the <br />TAR instrumented weather station. the four larget <br />gauges GSc. GTR. GSO and GDl'O listed in order of <br />increasing dov.nwind dislance. and the: Gl'OO <br /> <br />, <br /> <br />crosswind control gauge. Figure 2 shows tht: <br />inslrumenled TAR station ins[nJme:nts atop a <br />platfonn at about 25 n above ground level. <br /> <br />, <br /> <br />'" <br /> <br />\ <br /> <br />:t: <br />.,~, ~'" <br />~ 1 ',.*: - I~' , . <br />--~,...~, ,. <br />~-' ,...t~.,.-~. <br />, '~" <br />_ ......;,..."t <br />:'~-',:!., ~ <br />..... <br /> <br />, <br /> <br />'" <br /> <br />- <br /> <br />" <br /> <br />I.~"- <br /> <br />. <br /> <br />. -. <br /> <br />Figure 2. The TAR instrumented target facilities in early winter lookmg towan! the west-southwesl. The IlOwer generator and <br />satellite dish for Internet l"1>nnection are on the far right. The instrumentation platform wa, immediately west of the he.lled trdiler <br />whIch hou'i.L'(\ comput<.'rs, electronics and othe-r equipment. <br /> <br />mOlar)" measurements for stalislical evaluation <br />\'o'ere from high resolulion precipitalion gauges <br />protecled trom the wind in small natural clearings in <br />e\'ergreen fores!. They were equipped wilh Alter- <br />type wind shields to further reduce wind-caused <br />undercalch, a serious problem lor snowfall <br />observalions, Gauge: tin~ resolution was about I <br />minute and data logger lime:s we:re quite slabk. <br />fre:qm:ntly checked against a standard time signal. <br />Each of Ihe: highly sensitive load cell gauges was <br />carefully calibrated and the individual codlicients <br />were used in Ihat gauge's data logger program which <br />converted the weight of the antifreeze and melted <br />snow WaleI' solution into recorded I minute averages. <br />The gauges proved to be \'el')' reliable, resulling in no <br />missing data for any experimenlal period. Figure 3 <br />show the control gauge with data from the dala <br />logger being dO....'llloade:d into a Palm Pilot device as <br />was done during approximately we:ekly service visits. <br />These data we:re transmmed to project scientists \-ia <br />the Internet. Running means of fiw were filled to all <br />I minute gauge samples. cenlered on the middle <br /> <br />minute, before: making calculations ofSWE <br />accumulations mer time:. Examinalion of resulling <br />smooth time: history plots suggested that gauge <br />resolution was between 0.002 and 0.003 inch SWE. <br /> <br />Three propane dispensers were used at the liAS <br />seeding site. located about 100 feet apart on an axis <br />across the prevailing southwest wind III reduce <br />aggregation losse:s of the high initial concentrations <br />of seeded ice cryslals. Two nozzles were use:d with <br />each dispenser al the ends ofa 10 foot horizontal <br />rube. again to reduce aggregation. All dispenser <br />\'al\'e controlkrs. propane flowmeters and <br />tempera lure sensors near each propane nozzle were <br />hard-\nred into a d:lta logge:r at the central dispenser. <br />Figure"; shows Ihe central propane dispenser and <br />instru~nted tower at liAS .....ith the view toward the <br />south.soUlheast. The propane controller and data <br />logger were in the box at the: base of the tower. A <br />propane dispenser is a relatively simple and <br />ine_llpensiw device, consisting: ofa propane supply. <br />readily 3\'ailable from commercial sources, an <br /> <br />~ <br />