Chapter 26Section II, III and IVPoints of Emphasis

Energy Transfer, Lapse Rate, Inversions, Temperature Scales

and Isotherms

26-II Energy in the AtmosphereThe 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

(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?

HW: Draw diagrams 26.6 and 26.7 pg 485 & 486 (Ch. 26 Section II)

How energy (heat) moves

• Conduction (contact)• Convection (movement of fluid)

Medium: Particles of Matter

• Radiation (electro-magnetic)

Medium: Electric and Magnetic Fields

Heat Balance and Greenhouse Effect

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 InversionTropospheric 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 factorsthat 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)PsychrometersSoil thermometerInsolation thermometersWell scoop thermometersTank thermometersThermocouplesThermistors 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