Transcript Earth`s atmosphere - Bakersfield College

The Atmosphere
Atmospheric Objectives:
• Students will learn how the Earth’s atmosphere is structured
by observing its layers, temperature variations, and
distribution of atmospheric pressure.
• Students will learn how air parcels circulate within the
Earth’s atmosphere, creating wind
• Students will understand the nature of insolation entering
the Earth’s atmosphere, specifically the impact of ultraviolet
radiation on various types of material.
• Students will gain insight regarding the global warming
debate.
Thermosphere
• Begins at 80 km (50 miles)
• Temperatures as high as
12000C
Mesosphere
T
• 50-80 km (31-50 miles)
• atmosphere thins rapidly
• coldest layer  - 900C
Stratosphere
• 11 km – 50 km (7-31 miles)
• 20% of the atmospheric
weight
• Contains the ozone layer
(lower stratosphere)
• Temperatures increase with
altitude
T
T
Troposphere
T
• 11 km thick (7 miles)
• 80% of the atmospheric
weight
• All storm activity takes
place
• environmental lapse rate
6.50C/1000 m
Atmospheric Pressure
Low
Pressure
• Force/unit area exerted against
a surface
• Represents the weight of the
atmosphere
Decreasing Pressure
Thinning Air
Molecules
• Uniformly decreases with altitude
• However --NOT uniform
across the entire earth
• Analogous to boiling water
Air masses rise and
fall within the
atmosphere.
High
Pressure
14.7 psi (1013 mb)
Dependant on the
cooling/heating of
the Earth’s surface
Cooling air sinking air
Warming air rising air
High Pressure
Low Pressure
What causes high and low pressure zones ??
High Pressure
• Cold sinking air
Anticyclone
Low Pressure
• Warm rising air
Cyclone
Wind - What is it?
• Unbalanced air pressures
• High air pressure moves into low
pressure systems
Rising ascending
air parcel
Cooling descending
air parcel
Low
Pressure
High
Pressure
Warm
Land
High pressure air rushes
to fill the “void” left by rising
the rising air parcel
Cooler
Water
isobar
Pressure Gradient Force
• primary force that causes wind
• always drawn perpendicular to isobar lines.
Isobars – equal points of pressure
Producing an
Isobar map
What is light?
(insolation)
Light is a form of electromagnetic radiation, vibrating electric and
magnetic fields moving through space.
wavelength
Insolation (light from the sun) is measured using wavelength
What is incoming solar radiation? (insolation)
• energy the earth receives from the sun
• travels 300,000 km/sec (186,000 mi/sec)
• travels in “wave motion”
• Sun rays comprise the electromagnetic spectrum.
Electromagnetic Spectrum (EM scale)
Wavelengths the human eye can see
R
O
Y
Not harmful
Long Waves
G
B
I
V
Very harmful
Short Waves
Visible light spectrum
Is separated into the various
ROYGBIV wavelengths
Visible light spectrum
passing through a glass
prism
Glass Prism
insolation
Thermosphere
most short waves
are absorbed
Mesosphere
OZONE
UV waves are absorbed
and make ozone (O3)
Most EM is longwave
before hitting the surface
(visible and IR)
Stratosphere
Troposphere
UV
97% of UV radiation absorbed
3% of UV radiation makes to
the Earth’s surface.
Today’s Lab– take a deep breath
• Complete part A
• definitions – definitions can be found in the
lab text –READ IT
• Complete part B
• Complete the diagram by illustrating the layers of the
atmosphere – use colored pencils
• Complete the US isobar map (USE PENCIL!
• Complete part C
• Acquire the UV detecting beads and follow the instructions
outlined in part C
• Complete part D
• Read the lab text and answer questions regarding
the greenhouse effect and the relation to global warming.