Transcript AE-Dimensions-Mod-3

CIVIL AIR PATROL
United States Air Force Auxiliary
Maxwell Air Force Base, Alabama
Aerospace Dimensions
Air Environment
Module 3
Presentation on 9 Jan 2014
by Col Richard F. Himebrook, CAP
Based on work by Patrick B. Smith, Washington Wg, CAP
Disclaimer: This presentation is for the exclusive use of Civil Air
Patrol and is not to be used for sale or profit.
Air Circulation
We’re going to talk about:
The Earth’s rotation and revolution, and its effect
on the Earth’s seasons.
• How the Sun heats the Earth.
• Various theories of circulation.
• Coriolis Force.
• Jet stream and the control surfaces that create that
motion.
Some Terms
• vernal (spring) equinox - when the sun’s direct rays strike
the equator resulting in a day and night of equal length,
usually on March 20 - 22.
• summer solstice - when the sun is at its northernmost
point from the equator in the Northern Hemisphere, the day
is the longest, usually on June 21st or 22nd.
• autumnal (fall) equinox - when the sun’s direct rays strike
the equator resulting in day and night of equal length,
usually on September 22nd or 23rd.
• Winter solstice - when the sun is the farthest south of the
equator and the Northern Hemisphere, the day is the
shortest, usually on December 21st or 22nd.
ROTATION AND
REVOLUTION
• The Earth revolves around the sun in about
365 1/4 days = one year.
• The Earth is rotating on its axis at an angle
of 23.5 degrees.
• The Earth’s rotation effects the length of
day = 24 hours.
• In the Northern Hemisphere, viewing from
space above the Earth, rotates in a
counterclockwise direction
SOLAR HEATING
• The sun heats the Earth unevenly – direct &
indirect angle.
• Some parts are hotter than others
• Unequal heating causes temperature and
pressure differences
• These differences create movement of air
• Cooler temperatures means air of higher
pressure
• Air of higher pressures flow to air of lower
pressure
CIRCULATION
• Refers to the global movement of air.
• Warm air rises from the Equator as it moves
towards the poles.
• Cold air sinks at the poles as it moves
towards the Equator
GLOBAL CIRCULATION
Cold arctic air to equator. But earth rotates – Coriolis Force
Terms
• rotation - the Earth rotates on its axis at an angle
of 23.5 degrees while it revolves around the sun.
• revolution - the movement of the Earth revolving
around the sun, it takes about 365 1/4 days.
• radiation - the method by which the sun heats the
Earth.
• coriolis force - deflects a freely moving object to
the right in the Northern Hemisphere due to
rotation of the Earth.
• jet stream - a strong wind that develops at 30,000
- 35,000 feet and moves as a winding road across
the United States, generally from west to the east.
Weather Elements
We’re going to talk about:
• Wind.
• Beaufort Scale.
• Heat.
• What temperature is and how it can be
expressed.
• What wind chill is and what it does.
• How a microburst can affect a plane.
A Tool You Can Use!
Admiral Sir Francis Beaufort,
K.C.B.
The Beaufort Scale has
been around since 1805.
It is not a scale for wind
speed but a measure of
force. The original
scale was intended for
ships at sea but was
“modified” for modern
meteorological uses
Heat: total energy of molecular motion within substance.
Temperature: molecular motion expressed in man-made scale.
Formula’s for
Temperature Conversion
Fahrenheit °F = 1.8°C + 32
Centigrade °C = (°F - 32) / 1.8
Some neat numbers to know:
68oF = 20oC
-40oF = -40oC
A Tool You Can Use!
Pressure of the Air
Measurement Devices
Aneroid Barometer
Mercury Barometer
(uses height)
Recording
Barograph
Terms - Weather Elements
• wind - a body of air in motion.
• Beaufort Scale - a scale for estimating wind
speed, on land or sea
• heat - the total energy of all molecules within a
substance.
• temperature - a measure of molecular motion
expressed on a man-made scale.
• atmospheric pressure - the weight of all the
atmosphere’s gases on the Earth’s surface
MICROBURSTS
A microburst is a
dangerous phenomenon
for aircraft. The
sudden updraft and
downdraft will
adversely affect the lift
of the plane and could
cause a pilot to overcorrect for these
changes.
Moisture and Clouds
We’re going to talk about:
• The condensation process.
• How saturation occurs.
• Dew point.
• What precipitation is and give some examples.
• Fog.
Important Terms
• condensation - the process of converting water
vapor to liquid.
• saturation - a parcel of air is holding as much water
vapor as it can.
• dew point - the temperature at which the air
becomes saturated.
• relative humidity - amount of water vapor in the air
compared to its water vapor capacity at a given
temperature.
• precipitation - general term given to various types of
condensed water vapor.
• fog - tiny droplets of liquid water in contact with the
surface
HAIL
FOG
Cloud Formation
• Clouds are a combination of tiny droplets of
water or ice crystals clinging to
condensation nuclei
• Condensation nuclei are tiny particles of
salt, soot and dust.
• There are three basic types of clouds:
Cumulus, Stratus, and Cirrus
Cumulus Clouds
Cumulus Clouds (under B-52)
Stratus Clouds
Stratus Clouds (B-2)
Cirrus Clouds
Weather Systems and Changes
We’re going to talk about:
• Air mass and air mass characteristics.
• Front and the types of fronts.
• Stages of a thunderstorm.
• Hurricanes, thunderstorms, and tornadoes.
• Safety precautions for thunderstorms and
tornadoes.
FRONTS (note lines of = air pressure)
About 600 miles
300 miles
OCCLUDED FRONTS
(green areas are precipitation, purple line is Occluded Front)
Cumulonimbus
Lightning
Cumulus Mamatus
Funnel Cloud
HURRICANES
Engine of a P-3 weather recon.
Important Terms - Weather Systems and Changes
• air mass - huge body of air with the same temperature
and moisture characteristics.
• front - a boundary between two air masses.
• thunderstorm - cumulonimbus cloud possessing thunder
and lightning; usually strong winds, rain and sometimes
hail.
• hurricane - a tropical cyclone of low pressure and very
strong winds; usually heavy rain with possible
thunderstorms and tornadoes.
• tornado - whirling funnel of air of very low pressure and
very strong winds; can suck up anything in its path and
must touch the ground to be called a tornado (otherwise a
funnel cloud).
Safety
• Many Lightening victims are struck in open spaces:
riding farm equipment, golfing, in small boat, in
vicinity isolated of trees.
• Get in building. If stuck on level ground keep head
as low as possible – but DO NOT lie down.
• If hair begins to stand on end, skin begins to tingle,
or hear ticking sounds BEWARE!
• For TORNADOS – Get underground, if can’t small
strong area (bathtub).
Are there any questions?