Final Flashcards
human activity is a relatively new form of environmental manipulation that is _______ and _____________
very fast and intentional
what are examples of natural occurring stimuli that cause persistent change to local boundary level climate or surface conditions
fire, shifts in rain patterns, beetles (can kill trees and change forest)
small scale modification of surface by humans
albedo control
alternating geometry of the terrain/ soil
mulching
moisture control
small scale modification of the atmosphere by humans (frost control)
preventing heat loss
adding heat
redistributing heat within the system
Humans modify fog conditions by _________ and __________
adding and redistributing heat
humans modify wind speeds using ______
barriers
human modifications of surface and atmosphere change
radiative properties (K,L,Q)
moisture properties (water, QE)
thermal properties (conductivity, QH)
momentum
albedo control regulates ________. Therefore it affects ________ and __________.
K (shortwave radiation)
radiative and thermal energy balances
surface and atmospheric albedo affects an entire __________ and __________
environment and climate
low albedo means more or less absorbed ?
More absorbed
How does changing the color of a surface to be more white affect K up and Q*, and therefore QH
K up increases and Q* decreases, therefore less Q* means less QH and evapotranspiration rates
changing geometry can effect what kinds of radiation
shortwave (how much is absorbed), and long wave (how much is emitted)
how can humans modify soil surfaces in extra tropical latitudes to increase shortwave radiation and long wave radiation retention?
make it so that they receive insolation a more perpendicular angle of incidence
(sloped surface facing the sun)
what kind of surface do you want in the tropics to receive max solar heating ?
flat
sky view factor
% of the sky viewable from a specific vantage point, effected by roughness factors
4 ways that surface geometry influences radiative exchanges
insolation on a flat surface
insolation on a sloped surface - influence angle of incidence
insolation on a sloped surface - influences multiple reflection (effective albedo)
longwave emission from a sloped surface - sky view factors influences emission
more perpendicular angle means energy is spread out over a smaller or larger area?
smaller, more concentrated
more reflections means more or less L (longwave) radiation ?
more K (shortwave) absorbed so more L (longwave) emitted
How do furrows work
More solar radiation incidence because perpendicular angle, shortwave gets emitted back and forth between the two sides
When the sun is low in winter a solar collector should be more
When the sun is high in the summer, a solar collector should be more
Upright, Horizontal
What is mulching?
Putting something on the surface to create a barrier, exchanges are greatly reduced, evapotranspiration reduced
Four techniques for mulching
- Aerating the surface with hay, wood chips, gravel or other material with airspace because air has a lower conductivity than bare soil, passes less energy to other objects
- Lowering surface albedo with dark material (black plastic), increases surface absorptivity, increase in QH
- covering surface with material that has lower energy conductivity, such as paper
When is mulch laid down?
Autumn to trap in heat throughout the winter,must be removed at spring to allow input of insulation during the warm season
What are examples of moisture control
Irrigation
Increasing soil moisture = increase in thermal diffusivity, spreads out energy at higher rate (no single area overheats)
High heat capacity and latent heat properties, water creates lower temp in soil environments, flooding sometimes practiced to ensure these events
Two types of frost
Radiative frost - due to radiative divergence (energy leaving something)
Advective frost - cold airmass horizontally transporting cold air into the environment
boundary layer extends
1km above surface and first meter under ground
multiple reflection greatly increases what?
energy absorbed in a system
what does it look like to intentionally redistribute heat in a system?
“push it back down” (eg with a fan)
why is adding moisture a good technique for controlling temp
- increases latent heat use with no change in the amount of Q it will decrease the use of QH (sensible heat)
windmills are useful to bring _________ by_________
warm air to the surface by increasing turbulent mixing
tree and buildings effect wind patterns by
what is QF?
anthropogenic heat flux
what is QS ?
net change of energy storage by building and enclosed air
+ heat from our body and machines and wires (anything that humans create)
What is QG?
soil heat flux, energy exchanged between the building and the underlying ground
Characteristics of the forest floor environment
cool, dark, moist, low wind, diffuse energy
Methods from the mediterranean to moderate temp
building materials that insulate, while colored exterior for high albedo
sloped surfaces have _________ effects
advective
if greenhouses get too hot it means a buildup of too much what?
longwave emission
indoors, we don’t want it to be too humid inside so what can we do?
pass air through water to cool it, using moisture to control QH
indoor non greenhouse environment characteristics *know this
low transmissivity to K
(except through windows)
High absorption of L
Other things I missed!
describe effects of the urban heat island
- multiple reflections increase the amount of K* and therefore Q*
- low effective albedo (what’s leftover after everything else is absorbed)
- high QF = extra energy source of having a lot of people
- high pollution
- heat accumulates between buildings due to lack of airflow
Inadvertent consequences of climate modification
vegetation removal
irrigation
buildings
removal of vegetation
altered albedo (vegetation to bare soil) and geometry (zero-plane displacement to ground surface wind)
- therefore changes radiation budget
changes energy budget
- add more info
Consequences of irrigation
creates runoff
- new moisture conditions downhill may influence temp in that new location
flooding (creation of a reservoir)
- alters temp and moisture
increases evaporation, atmospheric moisture and surface energy absorption
- decreases local surface and air temp
consequences of buildings
create shadows, decrease direct solar radiation
increase long. wave radiation by changing sky view factor
introduce new heating sources by emitting QH and L
change thee water budget
change air flow
one other ?