atmospheric moisture chapter 6 - geographer to gogeographertogo.com/geog1/moisture.pdfthe impact of...
TRANSCRIPT
![Page 1: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/1.jpg)
Atmospheric Moisture Chapter 6
![Page 2: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/2.jpg)
The Impact of Atmospheric Moisture on the Landscape
• Forms haze, fog, clouds, rain, sleet, hail and snow • Streams and rivers flood • Causes weathering and erosion • Plant and animal life
![Page 3: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/3.jpg)
3
Water’s Unique Properties
• Exists in 3 states • Pure water is
colorless, odorless and tasteless
• Changes states as energy is absorbed or released
• Drives daily weather patterns
![Page 4: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/4.jpg)
The Nature of Water
• 70% of the surface of the Earth • Solid below 32o F and expands when freezing
• Density decreases with freezing • Liquid from 32o F to 212o F • Boils at 212o F and becomes water vapor
![Page 5: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/5.jpg)
Latent Heat• To change states, water must expend or absorb
energy • Expending energy creates heat • Absorbing energy removes heat • Sublimation
![Page 6: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/6.jpg)
Evaporation
• The escape of water molecules from a liquid into the air as water vapor – Warm water evaporates more than
cold – Warm air promotes evaporation
• Water cannot keep vaporizing and entering the air without limit – At any given temperature there is a
maximum amount of vapor – The higher the temperature, the
higher the maximum amount of water vapor
![Page 7: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/7.jpg)
7
Humidity• Refers to water vapor in the air • The capacity of air to hold water is dependent on
temperature • Warmer air can hold more water vapor • Cooler air can hold less water vapor
![Page 8: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/8.jpg)
• Relative Humidity - a ratio that compares the actual amount of water vapor in the air to the water vapor capacity of the air • Expressed as a percentage • 0 to 100% • Weather forecasts
• Saturation is the point where air reaches 100% relative humidity • Any additional water vapor or decrease in temperature
results in condensation
![Page 9: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/9.jpg)
Condensation
• Opposite of evaporation • In order for condensation
to occur the air must be saturated
• Surface for condensation to occur is required
• Condensation molecule bumps into each other and combine into larger droplet
![Page 10: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/10.jpg)
• Dew Point – When air is cooled, water vapor
capacity decreases and relative humidity increases.
– Cooling can bring unsaturated air to saturation point
– The temperature at which saturation is reached is called the dew point.
![Page 11: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/11.jpg)
11
Atmospheric Stability• Parcel is used to describe a body of air that has
specific temperature and humidity characteristic • Two opposing forces
• Buoyancy • Gravity
• Warm air is less dense than cold air • Warm air rises and expands • Cool air descends and compresses
• Stability refers to the tendency of an air parcel to either remain in place, rise or descend. • Stable = resist upward movement • Unstable = continues to rise
![Page 12: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/12.jpg)
Adiabatic Processes
• Only way for large air masses to be cooled to the dew point is for it to gain altitude
• Only way to develop clouds and produce rain is by adiabatic cooling
• As air rises it cools • As air descends it warms
![Page 13: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/13.jpg)
• Dry Adiabatic Rate(DAR) - the rate at which unsaturated air cools – As unsaturated air rises, it cools at 5.5o F per 1000 feet – As air cools it’s capacity to hold water vapor decreases – Descending air warms at the DAR
• Lifting Condensation Level (LCL) – Altitude at which air cools to the dew point – Air reaches 100% saturation – Clouds form – Normally visible
![Page 14: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/14.jpg)
• Saturated Adiabatic Rate (SAR) - the rate at which saturated air cools – Release of latent heat slows the cooling of air – As saturated air rises, it cools at 3.3o F per 1000 feet
• Dry Adiabatic Rate - Rate at which unsaturated air cools • Lifting Condensation Level - point that air becomes saturated
![Page 15: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/15.jpg)
Clouds
•Tiny droplets of water or ice crystals •Covers 50% of earth •Creates all precipitation •Influences solar energy
![Page 16: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/16.jpg)
Fog• Minor form of condensation
• Cloud layer on the ground • Visibility less than 3300 feet • Difference between cloud and fog = how it forms • Impacts human life
![Page 17: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/17.jpg)
17
• Advection Fog • Surface air migrating to another place • Warm moist air over cooler ocean, lake or snow • Moist air flowing to higher elevation along a hill or
mountain
![Page 18: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/18.jpg)
18
• Radiation fog • Cooling of a surface chills the air directly above it to
the dew point, creating saturation • Occurs over moist ground
![Page 19: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/19.jpg)
Precipitation• All precipitation originates in clouds • Most clouds do not yield precipitation • How does precipitation form?
– Collision and coalescence – Ice crystal formation
• Types – Rain – Sleet – Snow – Hail
![Page 20: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/20.jpg)
![Page 21: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/21.jpg)
Convective lifting• Air heated and becomes unstable, rising above the Lifting condensation level • Covers a small area, but multiple cells can form close by • Warm parts of the world and warm seasons • Common in the mid-west United States
![Page 22: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/22.jpg)
Orographic Lifting
• Topographic barrier that blocks air movement • Precipitation on windward side • Rain shadow on leeward side of barrier
![Page 23: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/23.jpg)
![Page 24: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/24.jpg)
Frontal Lifting• Point where two air masses of different pressure
meet • Warm air is forced to rise, cool and possible
cloud formation and precipitation • Cool polar air meeting warm tropical air • Midlatitudes
![Page 25: Atmospheric Moisture Chapter 6 - Geographer To Gogeographertogo.com/geog1/moisture.pdfThe Impact of Atmospheric Moisture on the Landscape • Forms haze, fog, clouds, rain, sleet,](https://reader030.vdocuments.site/reader030/viewer/2022020214/5b1a60387f8b9a3c258d9564/html5/thumbnails/25.jpg)
Convergent Lifting
• Least common type of lifting • Uplift because of crowding of air masses • Associated with cyclonic storm systems
(hurricanes, tropical storms, etc) • Low latitudes