the impact of orographic precipitation on the form of mountain ranges alison anders earth and space...
TRANSCRIPT
![Page 1: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/1.jpg)
The Impact of Orographic Precipitation on the Form of
Mountain Ranges
Alison Anders Earth and Space Sciences
Dale Durran Atmospheric Sciences
Gerard Roe Earth and Space Sciences
University of Washington, Seattle, WA, USA
![Page 2: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/2.jpg)
Do mountains and mountain weather co-evolve?
Gyala Peri (7150 m) from the Po-TsangPo River, TibetThanks to Noah Finnegan
![Page 3: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/3.jpg)
Erosion by Rivers Shapes Mountain Landscapes
Queets basin,Olympic Mountains
Washington, USA
• Channel network sets landscape relief
Elwha River, Olympic Mountains, Washington, USA
• Hills are at the critical slope and fail as rivers erode
![Page 4: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/4.jpg)
Stream Power Model of River Incision
• Erosion balances uplift
![Page 5: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/5.jpg)
Stream Power Model of River Incision
Typical River Channel Profile
0
100
200
300
400
500
0 20 40 60 80 100Distance (km)
Ele
vati
on (
m)
Steep Upper SectionLow Discharge
Gentle Lower SectionHigh Discharge
![Page 6: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/6.jpg)
Stream Power Model of River Incision
0
100
200
300
400
500
0 20 40 60 80 100Distance (km)
Ele
vati
on (
m)
Q*S
Erosion Rate is Proportional to Discharge times Slope
![Page 7: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/7.jpg)
Precipitation Patterns Can Influence Topography
• Patterns persist for the response time of the system; at the scale of ~10 km, this is ~100,000 years
Q/Q S/S
![Page 8: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/8.jpg)
Range-Scale Impacts: Olympic Mountains, Washington, USA
Elevation ~ 0 – 2400m Precipitation ~850 – 5000 mm
Low S, High Q
![Page 9: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/9.jpg)
Range-Scale Impacts: Olympic Mountains, Washington, USA
Elevation ~ 0 – 2400m Precipitation ~850 – 5000 mm
High S, Low Q
![Page 10: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/10.jpg)
Sub-Range Scale Variability
• How do precipitation patterns and topography compare at small scales (~10 km)?
• MM5 run by UW researchers for forecasting precipitation at a 4km resolution
• 2 years of archived precipitation forecasts
• Simple Ice Scheme (Dudhia, 1989)
![Page 11: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/11.jpg)
MM5 Annual Precipitation
![Page 12: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/12.jpg)
MM5 Intense Storm Precipitation
![Page 13: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/13.jpg)
Conclusions
• Storm Events
• Seasonal Totals
• Annual Totals
In the Olympics, MM5 precipitation is consistently modulated by topography
![Page 14: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/14.jpg)
Conclusions
• Simulated Precipitation is Greater on Ridges than in Valleys
• Simple Model Predicts Ridges are Lower and More Gently Sloping than with Uniform Precipitation
![Page 15: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/15.jpg)
Further Work
• Field validation of precipitation pattern
![Page 16: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/16.jpg)
Further Work
• Landscape evolution modeling
CASCADE landscape evolution model, courtesy of Jean Braun
Tectonic Uplift
![Page 17: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/17.jpg)
Atmospheric Issues
• High spatial resolution precipitation patterns
• Interactions between topography and precipitation
• Stability of precipitation patterns through glacial-interglacial climate cycles
![Page 18: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/18.jpg)
Mountain Weather and Mountains Co-evolve
![Page 19: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/19.jpg)
Further Work• Other Mountain Ranges
European Alps
Precipitation Gauge ClimatologyFrei and Schär, 1998
![Page 20: The Impact of Orographic Precipitation on the Form of Mountain Ranges Alison Anders Earth and Space Sciences Dale Durran Atmospheric Sciences Gerard Roe](https://reader035.vdocuments.mx/reader035/viewer/2022062804/56649f045503460f94c1784b/html5/thumbnails/20.jpg)
Further Work• Other Mountain Ranges
Himalaya
TRMM Satellite PR Climatology1998-2001