1. Nowcasting Airport Winter Weather – AVISA Tests During AIRS II Presentation by George A. Isaac Cloud Physics and Severe Weather Research Division Environment Canada AVISA – Airport Vicinity Icing and Snow Advisor AIRS – Alliance Icing Research Study

2. Co-Authors & Funding Agencies Monika Bailey, Stewart Cober, Norman Donaldson, Ismail Gultepe, Norbert Driedger, David Hudak, Anna Glazer, Janti Reid, Peter Rodriguez, and J. Walter Strapp Environment Canada, Toronto Alexei Korolev Skytech Research Inc, Richmond Hill Frederic Fabry McGill University, Montreal Funds from Transport Canada, FAA, SAR/NIF, NRC/IAR, CRC, McGill, CFCAS, NSERC

3. Problems Associated with Airport Winter Weather Ice forming on wings of aircraft requiring de-icing Reduced visibility Low ceilings Runway icing and snow removal In-flight icing during takeoff and landing Extreme cold temperatures

4. Hazardous Hours at Canadian Airports Stuart and Isaac, 1994: ICAO Journal

5. Alliance Icing Research Study II A large international research program (participants from 25 organizations from N.A. and Europe, gov’t and university sectors) Lead by MSC Conducted in the Ottawa-Mirabel region 3 Nov 2003 to 13 Feb 2004 Focus on aviation meteorology research, nowcasting, aircraft icing, cloud processes Web site http://airs-icing.org/ (Science Plan, Data access, publications, etc)http://airs-icing.org/ Endorsed by Aircraft Icing Research Alliance (AIRA) and WWRP Aircraft In-Flight Icing Project (AIFI) Five (5) research aircraft involved Three (3) different Nowcasting systems (MSC, NASA, NCAR/NOAA) Data currently being quality controlled and archived Project Workshop was conducted at Mt. Tremblant, 9-10 November Special Session at AIAA in Reno in January/05

6. IOP1 IOP2 AIRS II Precipitation & Flight Summary over Mirabel

7. AVISA Input Parameters GOES Satellite POSS, HP & Met Station Vertically Pointing Radar (VPR) RadiometersHIMAP & GEM Models

8. MSC-AVISA Airport Vicinity Icing and Snow Advisor

9. ARE SKIES CLEAR? SLW IS ASSUMED FALSE FOR ALL HEIGHTS SLW IS INCONCLUSIVE SLW IS ASSUMED FALSE AT THAT HEIGHT DERIVE BEST GUESS CTH DERIVE BEST GUESS CBH IS THERE LIQUID PRECIPITATION? IS THE RADIOMETER LWP > 0C AND GEM MODEL TEMP < 0C? SLW IS ASSUMED TRUE FOR THAT HEIGHT YES NO YES Supercooled Liquid Water (SLW) METHOD 1 FOR HEIGHTS BETWEEN BEST GUESS CT & CB

10. Case Study: February 6, 2004 1900-2210 UTC Temperature [deg C] LWC [g/m 3 ] and Sphere Particle Fraction Altitude [km] LWC [g/m 3 ] or [g/kg] for HIMAP M+S Icing

11. YMX February 6, 2004 - 19 UTC in the vicinity of YMX HIMAP Supercooled LWP & GOES Icing 0.03 cm 0.04 cm YMX GOES ICING @ 1902 Precipitation Observations & Forecast at YMX LWP Observations & Forecast at YMX HIMAP Total Precipitation Rate and Radar 0.5 mm/hr 0.9 mm/hr > 0.5 mm/hr 20 km HIMAP Total Precipitation Rate and Radar 0.5 mm/hr 0.9 mm/hr > 0.5 mm/hr 20 km HIMAP Supercooled LWP & GOES Icing 0.03 cm 0.04 cm YMX GOES ICING @ 1902

14. Model/Radiometer Comparison Liquid Water PathsWater Vapour Paths Profiling Radiometer LWP [cm]Profiling Radiometer WVP [cm] HIMAP LWP [cm] HIMAP WVP [cm]

15. Comparison with HIMAP During AIRS II ParameterInstrumentHit RateFARTSS Liquid Water Path Profiling Radiometer HIMAP0.540.110.43 Cloud Occurrence CeilometerHIMAP0.960.690.27 Precipitation > 0 mm/hr Hot Plate 1HIMAP0.780.170.61 Precipitation > 2 mm/hr Hot Plate 1HIMAP0.420.010.41

16. Orange marks when the YMX observer reported ZR November 4-5, 2003: Freezing Rain Event Time series data contain a change in model runs at 00 Z POSS reports mainly rain type Wx

17. Conclusions AIRS II produced an excellent data set to develop and test airport systems to detect winter weather, with emphasis on icing and snow. Although weaknesses in some sensors and models were documented, a good system will use the strengths from various potential input components to produce reliable and accurate detection and forecast methods. Other aspects such as SLD formation, aircraft response to icing, and cloud characterization measurements also studied but not reported here.

18. TAMDAR Data  GLFE (Great Lakes Fleet Experiment) is a 12-month project started in Jan 2005 that is testing tropospheric AMDAR systems aboard 64 aircraft in the Great Lakes region  TAMDARs also measure RH, icing and turbulence  Graph shows TAMDAR icing and temperature data collected in the vicinity of Pearson on Aug 31 2005

19. Questions?