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Quantifying the impact of the wind climate for Amsterdam Int. Airport Andrew Stepek Dirk Wolters Xueli Wang Ine Wijnant 11-09-2012. Andrew.Stepek@knmi.nl. Content. PROBLEM: Influence weather on take-off and landing Research question METHOD: Trends in wind climate?
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Quantifying the impact of the wind climate for Amsterdam Int. AirportAndrew StepekDirk WoltersXueli WangIne Wijnant11-09-2012 Andrew.Stepek@knmi.nl
EMS-ECAC 2012 Content PROBLEM: Influence weather on take-off and landing Research question METHOD: Trends in wind climate? Cross and tail wind frequencies RESULTS CONCLUSIONS
EMS-ECAC 2012 Influence weather on take-off and landing • Preference list • Minimum noise pollution: Take-off to / landing from North or South-Southwest • Preference 1 • Gordijn et al. 2007 • Limiting factors • Weather (safety first) • Runway maintenance • Time of day (Buitenveldert not at night)
EMS-ECAC 2012 Research question • ? 1971-present observations representative for climate in 2011/2018 ? • Is there a trend in wind climate (speed & direction)? • Are cross and tail wind frequencies changing? • Preference list + • Observations from 1971-present • (wind, cloud base, visibility) • Operational planning • (1 year ahead ≈ 2011) • Noise pollution forecasts • (5-10 years ahead ≈ 2018)
EMS-ECAC 2012 Content PROBLEM: Influence weather on take-off and landing Research question METHOD: Trends in wind climate? Cross and tail wind frequencies RESULTS CONCLUSIONS
EMS-ECAC 2012 Trends in wind climate? • Trend = Change geostrophic (upper) wind (1) + change in surface wind as a result of changes in local (2) and/or regional roughness (3)
EMS-ECAC 2012 Trends in wind climate? • Trend = Change geostrophic (upper) wind (1) + change in surface wind as a result of changes in local (2) and/or regional roughness (3) • Aberdeen • (Scotland) • Thyboron • (Denmark) • Armagh • (Ireland) • De Bilt • (Netherlands) • Aberdeen_Amargh_De Bilt: 1868-2000 • Aberdeen_Thyboron_De Bilt: 1874-2007
EMS-ECAC 2012 Trends in wind climate? • Trend = Change geostrophic (upper) wind (1) + change in surface wind as a result of changes in local (2) and/or regional roughness (3) • Aberdeen • (Scotland) • Thyboron • (Denmark) • Armagh • (Ireland) • De Bilt • (Netherlands) • Aberdeen_Amargh_De Bilt: 1868-2000 • Aberdeen_Thyboron_De Bilt: 1874-2007
EMS-ECAC 2012 Trends in wind climate? • Trend = Change geostrophic (upper) wind (1) + change in surface wind as a result of changes in local (2) and/or regional roughness (3) • Remove year to year variations of geostrophic wind fromyearly average potential wind to get trend as a result of changes in regional roughness
EMS-ECAC 2012 Trends in wind climate? • Two scenarios • no trend (Aber-Arm) • decreasing trend (Aber-Thy) of 0.8% per decade • Yearly average potential wind with year to year variations in geostrophic wind removed
EMS-ECAC 2012 Trends in wind climate? • Two scenarios • no trend (Aber-Arm) • decreasing trend (Aber-Thy) of 0.8% per decade So these trends are: • caused by change in regional roughness • used to extrapolate to the future • Yearly average potential wind with year to year variations in geostrophic wind removed
EMS-ECAC 2012 Cross and tail wind frequencies • Cross wind frequency = % of hours that component of average wind speed to runway > 20 kts • Tail wind frequency = % of hours that component of average wind speed // to runway from behind aircraft > 7 kts • Cross wind • Tail wind • 2007 Boeing E-3A Crosswind landing (Wikipedia) • Gust instead of average wind speed if gust > average + 10 kts
EMS-ECAC 2012 Cross/tail wind frequencies 2011 & 2018 (no trend) • We need hourly wind speed, wind direction and gust data to calculate cross and tail wind frequencies. • Available: hourly wind dataset 1971-1995 • Data before 1971 useless: only gusts > 25 kts stored • Data after 1995 useless: stored in whole m/s (1 m/s = 1.9439 kts) which leads to errors up to 10% in tailwind frequencies • Present climate (2011) • operational planning • Future climate (2018) • noise prediction • Hourly data • 1971-1995
EMS-ECAC 2012 Cross wind freq. 2011 & 2018 (decreasing trend) • Calculate 1969-2011 average wind speed which is representative for the wind climate around 1990 • Apply -0.8%/decade trend from 1990 to 2011/2018 • Use linear relationships in graph to determine corresponding 2011/2018 cross wind frequencies for all runways • Cross-wind: significant linear relationship could be found for all runways
EMS-ECAC 2012 Tail wind freq. 2011 & 2018 (decreasing trend) • Significant linear trend for runways 04, 06, 09, 36: determine tail wind frequencies assuming -0.8%/decade in annual average wind speed • No significant trend for runways 18,22,24,27: take average tail wind frequencies from hourly values 1971-1995 (should be treated as max freq)
EMS-ECAC 2012 Percentiles • 10%: • “calm” years • (low freq) • 50%: • common years • 90%: • “windy” years • (high freq) • Wind speeds vary significantly from year to year: use percentiles
EMS-ECAC 2012 Content PROBLEM: Influence weather on take-off and landing Research question METHOD: Trends in wind climate? Cross and tail wind frequencies RESULTS CONCLUSIONS
EMS-ECAC 2012 Noth-south runways (18/36): Common years (50% of years): cross wind frequency ≤ 7.6% Cross wind frequency varies from max 4.9% of the time in extremely low frequency years to max 8.9% in extremely high frequency years No trend: 1971-1995 represents 2011 & 2018 • Calm years (10%) • Interm. years (30%) • Common years (50%) • Interm. years (70%) • Windy years (90%)
EMS-ECAC 2012 Decreasing trend: future climate (2018) • Calm years (10%) • Year to year variation of cross and tail wind frequencies 5 times bigger than decrease of median frequencies caused by decreasing trend between 1971-1995 and 2011/2018 • Interm. years (30%) • Common years (50%) • Interm. years (70%) • Windy years (90%) • Calm years (10%) • Interm. years (30%) • Common years (50%) • Interm. years (70%) • Windy years (90%)
EMS-ECAC 2012 Conclusions The most likely scenario is a decreasing trend of cross and tail wind frequencies, but no change is also possible Compared to 1971-1995, decrease in median cross wind frequency is 5-13% (2011) and 7-16% (2018) depending on the runway Decrease in median tail wind frequency is 4-7% (2011/2018) Year to year variation of cross and tail wind frequencies 5 times bigger than decrease of median frequencies caused by decreasing trend between 1971-1995 and 2011/2018
EMS-ECAC 2012 24-8-2012 Cross wind 45 kts Lajes Azores (Paulo Santos, Daily mail) Dziękuję bardzo!