Physical Environment of the Boreal-Arctic Region Part 2

Question 1

What are 2 implications of northern areas having long, cold winters and short summers in regards to productivity?

Answer 1

• no primary production in winter –> energy stores need to remain in the area
• huge productivity burst in summer –> migrants can capitalize on summer productivity

Question 2

Insolation=

Answer 2

total amount of solar radiation per unit of time and area

Question 3

The tilt of the earth’s rotational axis and its spherical shape make the __ ___ ____ of sunlight uneven at diff latitudes

Answer 3

angle of incidence

Question 4

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?

Answer 4

5
100

where oceanic climates prevail (eg eastern canada) b/c the water moderates climate

Question 5

Temperatures vary __(more/less) in the northern hemisphere where the moderating influence of ___ is less

Answer 5

more

water

more land mass in N hemisphere

Question 6

___% of incoming sunlight is absorbed by the surface, and most of that is absorbed by ___

Answer 6

45

plants

Question 7

The amount of solar radiation absorbed by the surface depends on what’s on the surface– ___ absorb the most

Answer 7

plants

Question 8

amount of solar radiation absorbed by air follows a ___ proportion of the incoming radiation

Answer 8

fixed

Question 9

light reflected by clouds is ___ in the temperate regions due to dense

Answer 9

higher
clouds

Question 10

Reflection by the surface s highest at ____, but more in ___ than in ___ because of ___

Answer 10

poles

Antarctica
Arctic
snow

Question 11

why is snow blindness more of a concern at higher latitudes?

Answer 11

because the sun is coming at you horizontally! due to tilt/ angle of incidence

Question 12

Historic UV radiation was low in arctic– it is rising b/c of ___
How could this destabilize communities?

Answer 12

ozone depleting

warming
UV can damage DNA & retinas

Question 13

How does ozone loss differ in Antarctic vs arctic?

Answer 13

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

Question 14

The ozone layer protects us from ___

___ is important for photosynthesis, and ___ is damaging

Answer 14

UVb

UVa (good)
UVb (bad)

Question 15

The climate pattern on earth ultimately depends on __ received from the ___ which warms the land and seas

Answer 15

energy
sun

Question 16

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

Answer 16

prevailing winds
currents
rotation

precipitation

Question 17

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

Answer 17

angle
surface

atmosphere
reflected

Question 18

at high latitudes, more energy is ___ than ___, resulting in a net ___.

Near the equator, more energy is ____ than ___, resulting in a net ___

Answer 18

more emitted than gained
cooling

more gained than emitted
warming

Question 19

climate conditions are divided into 2 subtypes:
1.
2

Answer 19

1. maritime: coastal areas where ocean moderates climate= less variation
2. continental: much lower precipitation and greater contrast b/w summer and winter

Question 20

Why would somewhere on Norway’s coast have milder winters than a town in NWT? Note they’re at the same latitude

Answer 20

more ocean warming in Norway than in canada= moderates temps

Question 21

summer temp in Norway vs NWT is very similar compared to their different winters. Why?

Answer 21

b/c ocean doesn’t have as much of an influence in moderating climates in the summer
- summer temps influenced more by sunlight

Question 22

Hadley cell is from __ deg to __ deg

Ferrell cell is from ___ deg to ___ deg

Polar cell is from ___ deg to ___ deg

Answer 22

Hadley: 0 to 30

Ferrell: 30 to 60

Polar: 60 to 90

Question 23

What is the North Atlantic Oscillation (NAO)?

Answer 23

index defined as the anomalous difference b/w the polar low and the subtropical high
- dominant mode of winter climate variability in N Atlantic
- large seesaw in atmospheric mass b/w the subtropical high and polar low

Question 24

t/f
NAO varies from year to year and does not remain in one phase for longer than a couple of years

Answer 24

false

varies from year to year
tends to remain in one phase for up to several years, which has consequences

Question 25

A positive NAO system has:

Answer 25

very low L pressure system and a very high H pressure system (greater difference)

Question 26

a negative NAO system has:

Answer 26

now very low L pressure and not very high H pressure (less difference)

Question 27

NAO has been mostly ___ recently, which is a major driver of ___ ____ Also, NAO is often linked to ____ dynamics of terrestrial species

Answer 27

positive climate change population

Question 28

Primary productivity on land and water is ___ at high latitudes and ___ with longitude

Answer 28

low varies

Question 29

Why are many arctic areas foggy?

Answer 29

Cold air moving over warmer oceanic waters creates fog

Question 30

Cloud cover is more abundant in northern systems because of the ____ Cloud cover: __-__% in summer __-__% in winter

Answer 30

cold 70-90% summer 4-60% winter

Question 31

Cloud cover: There's persistent and extensive ___ cloud layer over the polar ____ - Large scale transportation of relatively mild, __ air into the arctic

Answer 31

stratus oceans humid

Question 32

northern ecosystems receive __-__cm of precipitation per year, which is __ than southern areas

Answer 32

40-100cm less

Question 33

Winters are ___in the north, and more than ___ of the annual precipitation falls in the summer

Answer 33

dry half

Question 34

How do mountains impact moisture in northern areas of North America and Eurasia?

Answer 34

warm air rises over mtn air cools as it rises and drops all its moisture on one side

Question 35

How does winter precipitation impact reindeer?

Answer 35

more moisture in the winter= more deaths because they can't reach food (lichen covered by too much snow)

Question 36

Polar vortex= an area of __ pressure located in ___ (almost always present)

Answer 36

low the arctic

Question 37

What happens when the polar vortex is strong?

Answer 37

the cold air remains in the north (1 very low L pressure system)

Question 38

What happens when the polar vortex weakens?

Answer 38

changes the jet stream- it becomes wavier (waves because of relaxation/ destabilization of the system_ and the cold arctic air moves south

Question 39

The Arctic Oscillation (AO) is linked to the ___ and is driven by similar ___ differences

Answer 39

NAO pressure

Question 40

t/f AO effects are limited just to the arctic

Answer 40

false represents an important source of variability for the entire N hemisphere

Question 41

Describe the positive phase of the AO

Answer 41

stable cold air builds up in north Low pressure in north- jet stream is consistent with lots of very small waves

Question 42

describe the negative phase of the AO

Answer 42

destabilized high pressure in the north warm air moves north and cold air moves south - jet stream has a couple of huge waves (reach far south and north)

Question 43

Impacts of negative phase of AO:

Answer 43

- warm and loss of sea ice in Canada/ greenland - cold and dry in Norway/ Northern europe

Question 44

Impacts of positive phase of AO:

Answer 44

cold and more sea ice in N Canada/ Greenland - warm and wet in N europe

Question 45

What are the impacts of a positive NAO?

Answer 45

takes warm, moist air from east coast of N America to N Europe - N Europe gets hot and wet - drought in S Europe - warm, moist water over Arctic circle= bad for sea ice

Question 46

Positive NAO has a __ than usual subtropical high-pressure center and a ___ than normal Icelandic low

Answer 46

stronger deeper

Question 47

Negative NAO shows a ___ subtropical high and a ___ icelandic low What does this mean for the arctic circle?

Answer 47

weak weak not as much warm water moving into arctic circle, and more moisture= more ice formation