Mountain climate Mountain Geography, term A, 2007
Major climatic controls ALTITUDE LATITUDE CONTINENTALITY TOPOGRAPHY
Climate factors/elements Pressure, oxygen, water vapour Temperature Precipitation Winds Radiation clouds
3. CONTINENTALITY
4. TOPOGRAPHY Barrier effects –DAMMING –DEFLECTION –BLOCKING Depends on topography (mtn. range vs. isolated peak)
Pressure
Temperature a measure of the average kinetic energy of the molecules in that substance. how fast the air molecules are moving.
Effect of altitude on temperature
Wind Wind results from a horizontal difference in air pressure sun heats different parts of the Earth differently, causing pressure differences Sun is the driving force for most winds.
Wind direction Winds are directed towards low pressure, which results in: Lifting of air "Bad" Weather Winds are directed away from high pressure, which results in: Sinking of air "Good" Weather
Types of winds Large-scale –Standing waves –roters Regional scale –Chinook winds; –Monsoon winds Small scale: –Slope winds –Mountain/Valley winds –Glacier wind
Large-scale standing waves
Rotor clouds
Lenticular clouds
Orographic precipitation occurs where mountains and hills force moist air to rise
Chinook winds Warm, dry winds coming off the leeward side of the mountains Explain why they occur Also called Foehn (Germany); Mistral (French Alps) Santa Ana (California)
Monsoon winds regional scale wind systems created by the temperature contrasts between land and ocean Land heats up/cools faster than oceans warmer
Direction of the monsoon
Valley breeze (Anabatic) - upslope Daytime warmer LOW P colder HIGH P Temperature inversion
Mountain breeze - Katabatic (downslope) Night time colder HIGH P warmer LOW P
Mountain/Valley breeze Mountain breathes IN Mountain breathes OUT IN OUT
Glacier winds
Cloud Formation In order to make a cloud we need: Moisture Nuclei on which to condense (cloud condensation nuclei, or ice nuclei) A method of cooling the air to saturation
What about if the air temperature is below 0°C? It is possible for liquid water to remain liquid below temperatures of 0°C if there are no Ice Nuclei (IN). Liquid water below 0°C is called "supercooled" or "subcooled" water.
Types of clouds
Need: Plenty of moisture. A mass of warm unstable air. A source of energy to lift the warm, moist air mass rapidly upward.
Cumulo-nimbus clouds
Home exercise (X-credit): Watch for clouds over the Boulder area Take a picture, identify the clouds Write about how the clouds was formed Submit to Abby
Composition of Solar Radiation