1. What Happens When Air Moves Over A Mountain? How do Mountain Ranges Influence Climate? Mr. Walter – Earth Science

2. What Do We Know About Air Masses? They Cool Down When They Expand They Warm Up When They Are Compressed How do Air Masses Expand in Nature? When they rise there is less air pressure - they expand

3. Do We Know How Much Air Cools as it Rises? Yes, but it depends on if the air is saturated or NOT saturated Adiabatic Heating means a change in temperature without adding or subtracting heat! Dry Adiabatic = 5.5˚F per 1,000’ rise in elevation Wet Adiabatic = 3.5˚F per 1,000’ rise in elevation Dew Point Adiabatic = 1.0˚F per 1,000’ rise in elevation

4. USE Dry Adiabatic = 5.5˚F per 1,000’ When The Air Is NOT Saturated USE Dew Point Adiabatic = 1.0˚F per 1,000’ When The Air Is NOT Saturated USE Wet Adiabatic = 3.5˚F per 1,000’ When The Air Is Saturated

5. Mt. Walter 2,000 Feet 4,000 Feet 6,000 Feet 8,000 Feet at Peak 6648 55 46 44 37 30 4132 5234 3663 3874 -11-2 -11-2 -7 WEST SIDE EAST SIDE The Air Just Became Saturated!

6. Mt. Walter 2,000 Feet 4,000 Feet 6,000 Feet 8,000 Feet at Peak 6648 55 46 44 37 30 4132 5234 3663 3874 Look at the results Why are the Temperatures Different? Why are the Dew Points Different? WEST SIDE EAST SIDE

7. The Air Coming Down the Mountain is being compressed So it Heats Up! But … It Went Up The Mountain By The Same Elevation Change (Cooled) Hint – What Happened When the Air Became Saturated?

8. Latent Heat Was Given Off When The Air Was Cooled After It Became Saturated! A Cloud Will Form That is Why the Air Temperature Only Dropped by 7 Degrees Each Level It Rose

9. Mt. Walter 2,000 Feet 4,000 Feet 6,000 Feet 8,000 Feet at Peak 6648 55 46 44 37 30 4132 5234 3663 3874 Latent Heat Was Added To The Air! WEST SIDE EAST SIDE

10. What Happened To The Difference Between The Air Temperatures and The Dew Points? There Is A Greater Difference on the East Side Of The Mountain

11. Mt. Walter 2,000 Feet 4,000 Feet 6,000 Feet 8,000 Feet at Peak 6648 55 46 44 37 30 4132 5234 3663 3874 66-48 = 18 74-38 = 36 WEST SIDE EAST SIDE

12. The Air On The West Side Is Drier! Water Vapor Was Lost When The Water Vapor Condensed And Made A Cloud!

13. Mt. Walter 2,000 Feet 4,000 Feet 6,000 Feet 8,000 Feet at Peak 6648 55 46 44 37 30 32 5234 3663 3874 WEST SIDE EAST SIDE -11 -2 -11 -2 -7 +11 +2 +11 +2 41 66 48 -=18 7438 - 36 =