Download Weather & Climate Chapter 1

Chapter 1
Introduction to
the Atmosphere
Ecclesiastes 1:14-16
A generation goes, and a generation
comes,
But, the Earth remains forever.
The Sun rises, and the Sun goes down,
And hastens to the place where it
rises.
The wind blows to the south,
and goes around to the north.
Round and round goes the wind,
and on its circuits the wind returns.
“A Big Blue Marble”
Seen from space, the Earth looks
like no other planet that we
know
Its most conspicuous features are
its atmosphere and hydrosphere
From pre-history Man has been
directly and indirectly affected
by environment
--- nothing as much as weather
--- Sun God; Rain God; omens;
reward/punishment; etc
--- SAD
Seasonal Affective
Disorder (SAD)
Prolonged, but seasonal depression
coinciding with shortening days and
decreasing angle of insolation
Recognized by National Institute of
Mental Health; the AMA; the APA
Variable: geographically [Fig 1-3];
demographically; physiologically
Weather: the state of the Earth’s
atmosphere with respect to heat or
cold; wetness or dryness; clearness
or cloudiness (Webster)
--- atmospheric extent is conceptual
--- manifest in wind; temperature
and precipitation patterns;
storms; etc
Climate: weather of a location
over an extended period of time,
including its extremes
[I do not like terming climate as “average
weather” – look at variability in NYC
temperature hidden in Average Daily
Highs/Lows (Fig 1-4)]
Meteorology
Study of the atmosphere and processes
that create weather and climate
Atmospheric elements of:
(1) temperature of the air
(2) humidity of the air
(3) type and amount of
cloudiness
(4) type and amount of precipitation
(5) pressure exerted by the air
(6) speed and direction of wind
Atmospheric Hazards:
Assault by the Elements
“Natural hazards are a part of living on
Earth” [understatement]
They effect millions worldwide and
cause billions of dollars damage
--- Earth geologic hazards grab
the press
--- atmospheric hazards total more
more lives; damage; dollars
… unfortunately human lifestyles continue to
make hazards worse
The Atmosphere: A Part
of the Earth System
From the human perspective the Earth is
huge
[surface area – 500 mill sq. km /103 mill sq mi]
It is a single global system of interrelated
components operating as a single entity
This Earth system is defined by four
subsystems
The Atmosphere: A Part
of the Earth System, cont
(1) Lithosphere – the outer, rigid
portion of the “solid” Earth
(upper mantle; crust)
(2) Atmosphere – gaseous
envelope surrounding the
Earth; provides air we breath;
protects from radiation;
provides energy exchange
The Atmosphere: A Part
of the Earth System, cont
(3) Hydrosphere – dynamic water
and energy exchange processes
that make Earth unique; 97% of
Earth water is tied up in oceans
(4) Biosphere – life portion of the
Earth; a narrow band--- the
interface of the other three
zones
Composition of the
Atmosphere
variant vs non-variant gases
nitrogen
oxygen
water vapor
trace elements (CO2; O3)
dust
industrial exhaust (NOx; SOx)
insolation vs terrestrial radiation
Ozone (O3)
Stratospheric
Tropospheric
--- VOCs and NOx
--- Corrosive
--- Biological irritant
(a secondary pollutant)
--- compliance measured as
hourly average (0.085ppm)
Ozone (O3), cont
Factors affecting O3
--- human/economic
… industrial mix
… transportation
--- Physical
… wind
… atmospheric stability and
inversions
… topography
… severe air pollution potential
Origin of Atmosphere
- First atmosphere of light gases
disappear to space
- “degassing” and “dissolving”
- plants absorb CO2, release O2
Vertical Structure of the
Atmosphere
Atmosphere structure is based on:
(1) pressure
(2) temperature
(3) vertical variation in
composition
--- Homosphere
--- Heterosphere
Vertical Structure of the
Atmosphere, cont
Earth atmosphere weight approx.
5.6 X 1018
Structure based on:
(1) pressure
(2) temperature
(3) vertical variation in
composition
Vertical Structure of the
Atmosphere, cont
Homosphere
Troposphere
Tropopause
normal lapse rate / inversions
Stratosphere
Mesosphere
Heterosphere
Thermosphere
Ionosphere
Exosphere
Heating of the
Atmosphere
Radiation
Conduction
Convection / Advection
Latent Heat of Condensation
Controls on Weather and
Climate
(1) Latitude
(2) Land-Water
(3) Ocean
Currents
(4) Altitude
(5) Physical Barriers
(6) Human Activities
(7) Pressure systems and storms
Average Breakdown of
Insolation
Absorbed by atmosphere –
19%-22%
Reflected into space –
34%
Absorbed Earth surface –
43%-47%
Heat Energy Budget

Insolation to the Ground
47% of incoming solar radiation
reaches the surface of the Earth
… ultimately returned to the
atmosphere
terrestrial radiation – 14%
conduction/convection – 10%
latent heat – 23%
Variation in the Heat
Energy Balance
Regions of Energy Surplus
--- tropical zones
--- seasonal
Regions of Energy Deficit
--- polar zones
--- seasonal
Air Temperature
Temperature and Heat
sensible temperature
Temperature-Humidity Index
[THI=T- 0.55(1-RH)(T-14)]
wind chill
Temperature Measure
liquid-in-glass
bi-metal
electronic
Scales
Fahrenheit
Celsius
Kelvin
Short Term Variations in
Temperature
Daily affects of insolation
Cloud cover
Differential heating (land/water)
Reflection
Horizontal Air Movement