BAMOS Vol 30 No. 4 2017 - Page 31

BAMOS Dec 2017
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Table 1 . Australian Bureau of Meteorology weather station site information and years of wind speed data collection ( Bureau of Meteorology , 2016a ).
Site name
Bureau station number
Years of wind speed data
Latitude (° S )
Longitude (° E )
Bicheno - Council Depot 92003 1965 – 2010 41.87 148.30 Burnie - Round Hill 91009 1965 – 2010 41.07 145.94 Bushy Park - Bushy Park Estates 95003 1957 – 2010 42.71 146.90 Butlers Gorge 96003 1957 – 1993 42.28 146.28 Cape Bruny Lighthouse 94010 1957 – 2010 43.49 147.15 Dover 94020 1990 – 2010 43.33 147.00 Erriba - Craddle Mountain Road 91119 1962 – 2000 41.45 146.11 Flinders Island Airport 99005 1962 – 2010 40.09 148.00 Hobart - Ellerslie Road 94029 1893 – 2010 42.89 147.33 Hobart Airport 94008 1958 – 2010 42.83 147.50 Lake Leake - Elizabeth River 92019 1990 – 2000 42.01 147.80 Larapuna - Eddystone Point 92045 1961 – 2010 40.99 148.35 Launceston - City 91049 1884 – 1959 41.43 147.13 Launceston Airport - Comparison 91104 1939 – 2009 41.54 147.20 Low Head - Comparison 91057 1895 – 1997 41.06 146.79 Marrawah 91223 1971 – 2010 40.91 144.71 Orford - Aubin Court 92027 1968 – 2010 42.55 147.88 St Helens Post Office 92033 1957 – 2001 41.32 148.25 Strathgordon Village 97053 1971 – 2010 42.77 146.05 Swan Island Lighthouse 92037 1983 – 2001 40.73 148.13 Swansea Post Office 92038 1957 – 2008 42.12 148.07 Tarraleah Village 95018 1981 – 2010 42.30 146.45
Figure 1 consists of data from sites that had a minimum of three data-points ( three decades worth of thirty-year mean annual wind speeds ). To establish a relatively recent overview of Tasmanian wind speed trends , some data-points were removed ( pared ) ( Figure 2 ). Data lines that failed to attain the most recent thirty-year mean data-point ( ie : 1981 – 2010 ) were removed from Figure 2 . Data displaying changes in mean wind speed propensity ( from negative to positive , or visa-versa ), were pared at the inflection point . To highlight potential trends , though not commonly performed due to a potential lack of statistical significance , Figure 2 included data from sites with only two data-points ( two decades worth of thirty-year mean annual wind speeds ). All data omissions and additions can be easily seen by comparing Figures 1 and 2 .
Using data from Figure 2 , a mean decadal percentage change ( per every 10 years ) between the first and last thirty-year mean wind speed data-point , was calculated and included in Figure 3 . A zonal area of positive wind speed changes over time ( the zone ) was geographically highlighted ( Figure 3 ). Although the exact boundary position of the zone was somewhat arbitrarily determined , the region of the zone was systematically determined by including all positive decadal wind speed changes while excluding all negative decadal wind speed changes .
Historical data of recorded Tasmanian tornado sightings dating back as far as 1928 were obtained from the Bureau of Meteorology website ( Bureau of Meteorology , 2016b ). Individual tornado sightings were each geographically plotted on a map of Tasmania ( Figure 3 ). A 30-year period histogram , and trend line of tornado sightings was produced ( Figure 4 ).
BAMOS Dec 2017 Table 1. Australian Bureau of Meteorology weather station site information and years of wind speed data collection (Bureau of Meteorology, 2016a). Site name Bureau station number Years of wind speed data Latitude (°S) Longitude (°E) Bicheno - Council Depot 92003 1965–2010 41.87 148.30 Burnie - Round Hill 91009 1965–2010 41.07 145.94 Bushy Park - Bushy Park Estates 95003 1957–2010 42.71 146.90 Butlers Gorge 96003 1957–1993 42.28 146.28 Cape Bruny Lighthouse 94010 1957–2010 43.49 147.15 Dover 94020 1990–2010 43.33 147.00 Erriba - Craddle Mountain Road 91119 1962–2000 41.45 146.11 Flinders Is [Z\ܝNL H NM$̌ L H M ؘ\ H[\YHYM H NL$̌ L H M ˌ’ؘ\Z\ܝM  NMN8$̌ L M ˍLZHXZH H[^X]]\L NH NNL8$̌  H M ˎ \\[H HY\ۙH[L H NMx$̌ L NH M B][\ۈ H]HLL H N 8$NMNH K M ˌL“][\ۈZ\ܝ H\\\ۈLLL  NLx$̌ H KM M ˌXY H\\\ۈLL M NMx$NNM K M BX\]ZLL NMx$̌ L LH M Bܙܙ H]X[\L NM8$̌ L MH M ˎ[[ٙXHL NMM$̌ H K̈ M B]ܙۈ[YHM L NMx$̌ L M B[\[Y\HL NN $̌ H M L”[XHٙXHL  NMM$̌  L M •\[XZ[YHML N NN x$̌ L  M BY\H Hۜ\و]HH]\]YHZ[[][HقYH]K\[ YHXY\ܝو\K^YX\YX[[X[[YYK\X\H[]][HX[ݙ\Y]ق\X[X[[YY[YH]K\[\H[[ݙY\Y H Y\H K]H[\]Z[Y]Z[H[X[\K^YX\YX[]K\[ YN NN x$̌ L H\H[[ݙYHY\H ]H\^Z[[\[YX[[YY[]H HY]]H]]K܈\K]\JK\H\Y]H[X[ۈ[ YY[X[[Y[[ۛH\ܛYYYHH[X[Xو]\X[YۚYX[KY\H [YY]HH]\]ۛH™]K\[ XY\ܝو\K^YX\YX[[X[[YYK[]HZ\[ۜ[Y][ۜ[HX\[BY[H\\[Y\\ H[ \[]HHY\H HYX[XY[\[YH[B\]\H LYX\H]Y[H\[\\K^YX\YX[[YY]K\[ \[[]Y[[YY[Y\BˈHۘ[\XHو]]H[YY[\ݙ\[YH BۙJH\[ܘ\X[HYYY Y\H K[YB^X[\H][ۈوHۙH\Y]]\]\[B]\Z[Y HY[ۈوHۙH\\[X]X[B]\Z[YH[Y[[]]HXY[[YY[\[H^Y[[Y]]HXY[[YY[\˂\ܚX[]HوXܙY\X[X[ܛYY[™][X\\\ NL\H؝Z[YHH\X]BوY][ܛHX]H \X]HوY][ܛK MK[]YX[ܛYY[\HXX[ܘ\X[HYۈHX\و\X[XH Y\H KH ^YX\\[\ܘ[K[[[HوܛYY[\XY Y\H K