Moisture in the Atmosphere and the Results of Energy Inputs Created By: Mr. Kreeger

Homework and Page References Review Book- Page 574, Review Book- Page 574, Textbook-Pages Textbook-Pages HW#1-1-3 on page 488 of textbook HW#1-1-3 on page 488 of textbook HW#2-1-4 on page 493 HW#2-1-4 on page 493 HW #3-Explain why condensation is a heating process and evaporation is a cooling process, how do these processes affect storm formation HW #3-Explain why condensation is a heating process and evaporation is a cooling process, how do these processes affect storm formation

Table of Contents 1. Moisture and Energy Input 2. Air movement a) Breezes and currents b) Winds 1. Pressure Gradients 2. Local Breezes 3. Planetary Convection Cells 4. Planetary Winds 5. Jet Streams 3. Clouds a) Formation/Rising and Subsiding air b) Why they form c) How are they classified 4. Precipitation

1. Moisture and Energy Input Moisture in atm depends on Moisture in atm depends on Evaporation-(L  G) Evaporation-(L  G) Transpiration- Water released by plants Transpiration- Water released by plants Evapotranspiration- All water vapor released, large amounts of energy (540cal/gm) Evapotranspiration- All water vapor released, large amounts of energy (540cal/gm)

2. Air Movement a) Breezes and Currents- A breeze is a small local movement of air while a current is a vertical movement of air (T-Storms)

2b. Winds A wind is a large horizontal movement of air near the Earth’s surface (named for direction from which it comes), Ex. SW wind means it came from SW and is moving NE. A wind is a large horizontal movement of air near the Earth’s surface (named for direction from which it comes), Ex. SW wind means it came from SW and is moving NE. 1. Pressure gradient-The rate of change in pressure between 2 locations (ESRT), closer the isobars, stronger gradient, stronger wind, further, less gradient, less wind.

Activity on Winds Determine which scenario world have greater winds. Determine which scenario world have greater winds. a. HP=1025mb, LP=990mb, Dist=5km b. HP=1030mb, LP=996mb, Dist=7.5km c. HP=1022mb, LP=998mb, Dist=10km

2b2. Local Breezes Day-Land heats faster than water (LP-Land, HP-Water)- Air flows from sea to land. (Sea breeze) Day-Land heats faster than water (LP-Land, HP-Water)- Air flows from sea to land. (Sea breeze) Night-Land cools faster than water (HP-Land, LP-Water)- Air flows from land to sea. (Land breeze) Night-Land cools faster than water (HP-Land, LP-Water)- Air flows from land to sea. (Land breeze)

2b3. Planetary Convection Cells (ESRT Page 14) Convection Cell- Cyclic movement due to density difference and effects of gravity. Convection Cell- Cyclic movement due to density difference and effects of gravity. Variations in insolation(Why?) result in unequal heating of earth’s surface and atm. Variations in insolation(Why?) result in unequal heating of earth’s surface and atm. Air moves vertically  pressure belts produced Air moves vertically  pressure belts produced Rising air (LP)-Zones of convergence (Moist) Rising air (LP)-Zones of convergence (Moist) Sinking air (HP)-Zones of divergence (Dry) Sinking air (HP)-Zones of divergence (Dry)

2b4. Planetary Winds (ESRT Page 14) If earth did not rotate and was equally heated  1 convection cell would be produced from NP to equator. If earth did not rotate and was equally heated  1 convection cell would be produced from NP to equator. BUT>>>>> it is modified by Corilois effect which aid in creating a planetary wind system. BUT>>>>> it is modified by Corilois effect which aid in creating a planetary wind system. At equator- Wind moves due to trade winds At equator- Wind moves due to trade winds At mid latitudes- move due to prevailing westerlies At mid latitudes- move due to prevailing westerlies At high latitudes- move due to polar easterlies At high latitudes- move due to polar easterlies

2b5. Jet Streams Winds at high altitudes that control movements of air masses. Winds at high altitudes that control movements of air masses. Travel at 7-8 miles high( travels at 200 kph, travels faster in winter) Travel at 7-8 miles high( travels at 200 kph, travels faster in winter) Migrates from 31N in winter to 50 N in summer Why? Migrates from 31N in winter to 50 N in summer Why?

3. Clouds a) Formation-Condensation, need a surface called cloud condensation nuclei (CCN), can only occur when saturation happens (Dewpoint=Air Temp) and a CCN is present i.e. dust, salt Condensation is a heating process- fuel for storms (540 cal) Condensation is a heating process- fuel for storms (540 cal)

Rising and Subsiding Air 1. RISING AIR EXPANDS AND COOLS Higher P Lower P High P 2. SUBSIDING AIR IS COMPRESSED AND WARMS Lower P Higher P (surface) Low P

3b. Why do clouds form Lifting Cloud Type Localized convective lifting Cumulus Topography (orographic lifting) Nimbostratus / lenticular Convergence Cumulus / cumulonimbus Uplift along weather fronts (frontal wedging) Nimbostratus/stratus, cumulonimbus

3b. Why do clouds form Cont..

3c. How are clouds classified Divided into groups based on the height in which they form. Divided into groups based on the height in which they form.

High Clouds > 6000 m > 6000 m Cold and “dry” - thin Cold and “dry” - thin Almost exclusively ice crystals Almost exclusively ice crystals mares’ tails mackerel sky halo Cirrocumulus

Middle Clouds 2000 – 7000 m 2000 – 7000 m Mostly water droplets, some ice crystals Mostly water droplets, some ice crystals No halo, associated with warm fronts, form before storms Morning Ac means afternoon thunderstorms in summer

Low Clouds <2000 m <2000 m Almost always water droplets (ice and snow in winter) Almost always water droplets (ice and snow in winter) Light-moderate rain For long duration High pressure, Stabile weather Fog that doesn’t reach the ground, drizzle

Clouds with Vertical Development Cumulonimbus – unstable atmosphere Cumulonimbus – unstable atmosphere Rapid convection brings tops to 12 km Rapid convection brings tops to 12 km Form thunderstorms / lightning Form thunderstorms / lightning Fair weather  Thunderstorms

Summary of cloud types

4. Precipitation When water droplets or ice crystals grow large enough to fall. When water droplets or ice crystals grow large enough to fall. Types Types Rain Rain Snow Snow Sleet Sleet Freezing rain Freezing rain Hail Hail

Diagrams explaining precipitation Type Diameter (mm) Fall Velocity (km/hr) Small cloud droplets Typical cloud droplets Large cloud droplets Drizzle drops 0.57 Typical rain drops Large rain drops 5.033

Rain Drops of water that fall from a cloud with a diameter of >0.5mm Drops of water that fall from a cloud with a diameter of >0.5mm Originates from nimbostratus or cumulonimbus clouds Originates from nimbostratus or cumulonimbus clouds Begins often as snow crystals, but also as raindrops Begins often as snow crystals, but also as raindrops

Snow Packets of ice crystals Packets of ice crystals Low temps  light fluffly snow or “powder” Low temps  light fluffly snow or “powder” Warm temps (-5C)  heavy moist snow Warm temps (-5C)  heavy moist snow

Sleet Sleet = small, translucent particles of ice Sleet = small, translucent particles of ice Formed as ice, melted, refrozen as ice pellets Formed as ice, melted, refrozen as ice pellets

Freezing Rain Subfreezing air near ground is not thick enough to allow raindrops to freeze Subfreezing air near ground is not thick enough to allow raindrops to freeze Raindrops supercooled Raindrops supercooled

Summary of Precipitation

Hail Hard round pellets Hard round pellets Concentric shells of ice from traveling up and down a convective cloud Concentric shells of ice from traveling up and down a convective cloud Produced in large cumulonimbus clouds, speeds = 160km/hr Produced in large cumulonimbus clouds, speeds = 160km/hr