Download Chapter 1 - Stanford University

Presentation Slides
for
Chapter 1
of
Fundamentals of Atmospheric Modeling
2nd Edition
Mark Z. Jacobson
Department of Civil & Environmental Engineering
Stanford University
Stanford, CA 94305-4020
[email protected]
March 10, 2005
Brief History of Meteorology
• 340 B.C.
•
– Meteorologica - Aristotle
• 1400's
– Hygrometer - Cryfts (1450)
– Anemometer - Alberti (1450)
• 1500's
– Thermoscope - Galileo
• 1600's
– Barometer - Torricelli (1643)
– Les Meteores - Descarte (1637)
• 1700's
– Trade winds - Hadley (1730)
•
1800's
– Three-cell model - Ferrel (1855)
– Weather maps of surface pressure
1900's
– Weather prediction from maps Bjerknes (1903)
– Polar front theory - Bjerknes
(1921)
– Numerical weather prediction Richardson (1922)
– First computer forecast - Charney
/ von Neumann (1948)
– Daily balloon observations
(1940's)
– Weather satellites (Tiros I, 1960)
Excerpts from Aristotle’s
Meteorologica
• There are two reasons for there being more winds from the northerly than
the southerly regions. First, our inhabited region lies toward the north;
second, far more rain and snow is pushed up into this region because the
other lies beneath the sun and its course. These melt and are absorbed by
the earth and when subsequently heated by the sun and the earth’s own
heat cause a greater and more extensive exhalation.
• Let us now explain lightning and thunder, and then whirlwinds, firewinds
and thunderbolts; for the cause of all of them must be assumed to be the
same. As we have said, there are two kinds of exhalation, moist and dry;
and their combination (air) contains both potentially. It condenses into
cloud, as we have explained before, and the condensation of clouds is
thicker toward their farther limit. Heat when radiated disperses into the
upper region. But any of the dry exhalation that gets trapped when the air
is in process of cooling is forcibly ejected as the clouds condense and in its
course strikes the surrounding clouds, and the noise caused by the impact
is what we call thunder.
Scales of Motion (Table 1.1)
Molecular scale (<< 2 mm)
Molecular diffusion
Molecular viscosity
Microscale (2 mm- 2 km)
Eddies
Small plumes
Car exhaust
Cumulus clouds
Mesoscale (2 - 2000 km)
Gravity waves
Thunderstorms
Tornados
Local winds
Urban air pollution
Synoptic scale 500-10,000 km)
Pressure systems
Weather fronts
Tropical storms
Hurricanes
Antarctic ozone hole
Planetary scale (>10,000 km)
Global wind systems
Rossby waves
Stratospheric ozone loss
Global warming
Atmospheric Model
•
•
•
Gas processes
•
– Emission
– Photochemistry
– Gas-to-particle conversion
– Cloud removal
Aerosol processes
•
– Emission
– Nucleation/condensation
– Aerosol, cloud coagulation
– Dissolution/chemistry/crystallization
– Dry deposition/sedimentation
•
– Rainout/washout
Cloud processes
– Activation on aerosol
– Conden./evap./deposition/sublim.
– Hom./het./contact/evap. freezing
– Cloud, aerosol coagulation
– Precipitation/lightning
– Dissolution/chemistry
Radiative transfer
– UV/visible/near-IR/thermal-IR
– Scattering/absorption
Gas
Aerosol
Hydrometeor
– Snow, ice, water albedos
Meteorological processes
– Velocity
Geopotential
– Pressure
Water vapor
– Temperature Density
– Turbulence
Surface processes
– Temperatures and water content of
• Soil
Water
Snow
• Sea ice Vegetation Roads
• Roofs
– Surface energy/moisture fluxes
– Ocean-atmosphere exchange
– Ocean dynamics, chemistry
Fig. 1.1