Chapter 26
Section II, III and IV
Points of Emphasis
Energy Transfer, Lapse Rate,
Inversions, Temperature Scales
and Isotherms
26-II Energy in the Atmosphere
How energy (heat) moves
• Conduction (contact)
• Convection (movement of fluid)
Heat Balance and Greenhouse Effect
The Sun – cont’d
A. Solar constant
the average solar radiation arriving at the top of the Earth's
atmosphere is 1355 watts per square meter (joule/m2∙s).
1. Distribution of Incoming Energy
a) Energy in the atmosphere
– See figure 26.6 pg 485 for Electromagnetic Radiation
not hitting surface
(1) Reflected by Air, dust, clouds
(2) Absorbed by…
(a) Ozone and Dust
(b) Clouds
b) Energy making it to the surface
(1) Heats the Earth = ↑temp land
Medium: Particles of Matter
• Radiation (electro-magnetic)
(2) Heats the Ocean = ↑temp ocean
(3) Evaporation of water = energy used to break bonds
between molecules
(4) Absorbed and re-radiated (Greenhouse Effect)
What do these
squiggly lines mean?
Medium: Electric and Magnetic Fields
HW: Draw diagrams 26.6 and 26.7 pg 485 & 486 (Ch. 26 Section II)
26-III Topic 11: Lapse Rate*
Diabatic vs. Adiabatic Changes in Temperature
– Diabatic - Energy is added to a parcel of air from an external source
•
•
•
Radiation – energy added to the parcel from the Sun  USUALLY THE MOST IMPORTANT
Convection – air currents rising up into a parcel
Conduction – air molecules contacting the parcel
– Adiabatic – Parcel expands or is compressed
•
•
•
The total amount of energy in the parcel remains constant
Expansion is a form of “work” that decreases the motion of particles
Compression is a form of “work” that increases the motion of particles
Lapse Rate
– Change in temperature with change in altitude
•
•
•
Dry lapse rate: 5.5 per 1000 feet
Moist (saturated) lapse rate: 2 to 3 per 1000 feet
Normal lapse rate (for air of typical humidity): 3.3 per 1,000 feet
*http://meteorologytraining.tpub.com/14312/css/14312_47.htm
26-III Topic 11: Inversions
Inversions in atmospheric layers
Permanent Inversion
Tropospheric air is “capped” by
(won’t rise through) the warmer
air of the stratosphere
Topic 13: Hottest and Coldest Hours
• Mid afternoon and just after dawn
Topic 14: Hottest and Coldest Months
(Review)
• Energy Budget
(incoming vs. Leaving)
• Heat Balance
(equilibrium temperature)
based on many factors
Quick Write:
what are some of the factors
that affect our Heat Balance?
Topic 15: Land Heats Faster than Water
Water heats and cools more slowly than
land because…
1. Light Penetration (more mass)
2. Fluid (ability to convect)
3. Heat Capacity
(distribute energy in molecules)
4. Phase Change
• evaporation – molecules absorb energy
• Condensation – molecules release energy
26-IV Topic 16: Temperature
• Temperature is a measure of the average kinetic energy of air
molecules
Topic 17: Temperature Scales
• Temperature Scales are always relative to something…
– Freezing Water Sea (0) vs. Freezing Pure (30) – Fahrenheit
• Room temp is 75 °F
• Increments adjusted so pure water boils at 180 degrees above freezing
(180 is divisible by 2,3,4,5,& 6 – like a circle)
– Freezing (0) and Boiling (100) of pure water – Celsius
• Room temp is 25 °C
• Increments raise temp of 1g pure water 1 degree
– All motion stops (0) – Kelvin
• Absolute zero – absence of all motion
• Room temp is 298 °K
• increments raise temp of 1g pure water 1 degree
Types of Thermometers
Meteorological extreme thermometers (min/max)
Psychrometers
Soil thermometer
Insolation thermometers
Well scoop thermometers
Tank thermometers
Thermocouples
Thermistors
Liquid-In-Glass Thermometers
Resistance Temperature Detectors (RTDs)
Bimetallic Thermometers
Semiconductor Temperature Sensors
Labels, Crayons, Paints, Tabs (Phase Change Devices)
Topic 18: Drawing Isotherms
https://courseware.e-education.psu.edu/public/meteo/meteo101demo/Examples/Images/Section2/contour_tool_t0203.swf
Instruction for this activity: https://courseware.e-education.psu.edu/public/meteo/meteo101demo/Examples/Section2p03.html
accessed 9-2008