Physical Environment of the Boreal-Arctic Region Part 2 Flashcards
What are 2 implications of northern areas having long, cold winters and short summers in regards to productivity?
- no primary production in winter –> energy stores need to remain in the area
- huge productivity burst in summer –> migrants can capitalize on summer productivity
Insolation=
total amount of solar radiation per unit of time and area
The tilt of the earth’s rotational axis and its spherical shape make the __ ___ ____ of sunlight uneven at diff latitudes
angle of incidence
The average annual temp of northern boreal forests is below __C, and there’s a range of up to __C in seasonal temp extremes.
What results in less extreme variation?
5
100
where oceanic climates prevail (eg eastern canada) b/c the water moderates climate
Temperatures vary __(more/less) in the northern hemisphere where the moderating influence of ___ is less
more
water
more land mass in N hemisphere
___% of incoming sunlight is absorbed by the surface, and most of that is absorbed by ___
45
plants
The amount of solar radiation absorbed by the surface depends on what’s on the surface– ___ absorb the most
plants
amount of solar radiation absorbed by air follows a ___ proportion of the incoming radiation
fixed
light reflected by clouds is ___ in the temperate regions due to dense
higher
clouds
Reflection by the surface s highest at ____, but more in ___ than in ___ because of ___
poles
Antarctica
Arctic
snow
why is snow blindness more of a concern at higher latitudes?
because the sun is coming at you horizontally! due to tilt/ angle of incidence
Historic UV radiation was low in arctic– it is rising b/c of ___
How could this destabilize communities?
ozone depleting
warming
UV can damage DNA & retinas
How does ozone loss differ in Antarctic vs arctic?
Antarctic: almost complete removal of lower-stratospheric ozone currently results in an ozone hole every year
Arctic: ozone loss is highly variable and has until now been much more limited
The ozone layer protects us from ___
___ is important for photosynthesis, and ___ is damaging
UVb
UVa (good)
UVb (bad)
The climate pattern on earth ultimately depends on __ received from the ___ which warms the land and seas
energy
sun
Redistribution of solar energy depends mainly on ____ ____ and ocean ____, which is driven by the ____ of the earth and the position of the continents.
This in turn influences ___ patterns
prevailing winds
currents
rotation
precipitation
Light energy coming in at high latitudes:
- hits earth at an ___, so energy spreads over a large ___
- hit ____ at an angle, so more energy is ___ back to space
angle
surface
atmosphere
reflected
at high latitudes, more energy is ___ than ___, resulting in a net ___.
Near the equator, more energy is ____ than ___, resulting in a net ___
more emitted than gained
cooling
more gained than emitted
warming
