GRGAQS: Meteorological Modeling

1. GRGAQS:Meteorological Modeling Presentation to the SWCAA By ENVIRON International Corporation Alpine Geophysis, LLC August 8, 2006

2. Today’s Presentation • Further evaluation of MM5 performance • Analyses conducted for August and November modeling episodes: • 4-km surface wind fields in Gorge area • Cloud cover and fog on 4-km grid • Compare to satellite and Wishram camera • Wind, temperature, RH at Wishram

6. Wind Performance, August 2004 • Hi bscat 8/10-8/16, 8/19 • Poor performance at central sites 8/10-8/13 • Wind opposite direction • Good performance 8/14-8/22 • Maybe too light on some days

10. Wind Performance, November 2004 • Hi bscat 11/8-11/13 • Overall better performance than for August episode • Very good performance over 11/8-11/13 • Some stagnation leads to wind direction errors • Some windy periods are too light

11. August 2004 notes at Wishram camera: Cloud Cover 8/10 Scattered clouds < half of sky, No layered haze 8/11 No clouds, No layered haze 8/12 Scattered clouds < half of sky, No layered haze 8/13 No clouds, No layered haze 8/14 (high) Overcast > half of sky, No layered haze 8/15 Scattered clouds < half of sky, No layered haze 8/16 (high thin) Overcast > half of sky, No layered haze 8/17 (high thin) Overcast > half of sky, No layered haze 8/18 (high thin) Overcast > half of sky, No layered haze 8/19 Scattered clouds < half of sky, No layered haze 8/20 (high thin) Overcast > half of sky, No layered haze 8/21 (high) Overcast > half of sky, No layered haze 8/22 Overcast > half of sky, No layered haze

12. Wishram Camera August 13, noon Pristine

14. Wishram Camera August 14, noon Pristine

16. Wishram Camera August 19, noon Pristine

18. August 2004 Cloud Cover • Performance appears adequate • MM5 cannot replicate high thin/wispy cirrus • MM5 usually underperforms for scattered small-scale afternoon cumulus • These should not play significant role in regional PM chemistry

19. November 2004 notes at Wishram camera: Cloud Cover 11/3 Scattered clouds < half of sky, No layered haze 11/4 No clouds, Ground-based layered haze only 11/5 (high thin) Overcast > half of sky, No layered haze (hazy) 11/6 Scattered clouds < half of sky, Ground-based layered haze only 11/7 Overcast > half of sky, No layered haze (hazy) 11/8 Overcast > half of sky, Weather concealing scene (thick haze) 11/9 Overcast > half of sky, Weather concealing scene (thick haze) 11/10 Overcast > half of sky, Weather concealing scene (fog) 11/11 Overcast > half of sky, Weather concealing scene (thick haze) 11/12 Overcast > half of sky, Weather concealing scene (fog) 11/13 Overcast > half of sky, Weather concealing scene (thick haze) 11/14 Overcast > half of sky, Weather concealing scene (distant fog) 11/15 Overcast > half of sky, Weather concealing scene 11/16 Overcast > half of sky, No layered haze 11/17 Scattered clouds < half of sky, No layered haze 11/18 Overcast > half of sky, No layered haze

20. Wishram Camera November 6, noon Pristine

22. Wishram Camera November 8, noon Pristine

24. Wishram Camera November 10, noon Pristine

26. Wishram Camera November 15, noon Pristine

28. November 2004 Cloud Cover • Large-scale higher clouds appear well simulated • Low-level cloud/fog events are not • Especially on the high bscat days • This will impact aqueous PM chemistry • This would impact bscat reconstruction • If we use MM5-predicted humidity • EPA method: use measured humidity

29. Wishram Meteorology

30. Wishram Meteorology

31. Wishram Meteorology

32. Wishram Meteorology

33. August 2004 Meteorology • Wind speed/direction well simulated • Terrain channeling may be leading to higher observed speeds and direction bias • Temperatures on 4-km grid are highly suspect • RH performance follows poor temperature performance • Need to investigate further • Could use in some initial PM modeling

34. Wishram Meteorology

35. Wishram Meteorology

36. Wishram Meteorology

37. Wishram Meteorology

38. November 2004 Meteorology • Wind speed/direction performance appears acceptable • Temperature performance is poor • Need to investigate cause • RH is too low – no fog – not associated with temperature problem • This episode is currently not useable