Water Cycle and Climate Change Flashcards
(60 cards)
1
Q
The Water Cycle
A
Slide 15 of Lecture 2
2
Q
What are the 3 types of uplift of air?
A
Convective - caused by heating of moist air at the earth’s surface
Cyclonic - caused at by a warm air mass moving over a colder air mass
Orographic - caused by air moving over mountains
3
Q
What is precipitation
A
Water in liquid or frozen form that falls to the ground, i.e. rain, snow, sleet, hail
4
Q
What happens to water as it falls to the ground? Interception
A
Precipitation caught prior to reaching the ground, it may eventually reach the ground
5
Q
Amount of interception is dependent on?
A
- vegetation type
- land use
- season
- precipitation intensity
- precipitation magnitude
- initial conditions
6
Q
What happens to water as it falls to the ground? Storage
A
snow or ice
7
Q
What happens to water as it falls to the ground?
A
A) Interception B) Storage C) Runoff D) Infiltration E) Evapotranspiration
8
Q
What happens to water as it falls to the ground? Runoff
A
water that moves across the ground surface towards the stream
- gravity driven
9
Q
Amount of runoff is dependent on?
A
- slope angel; substrate material; rainfall characteristics (intensity, magnitude, type of precipitation)
- land-use type
10
Q
What happens to water as it falls to the ground? Infiltration
A
process through which water on the ground enters into the soil
11
Q
Amount of infiltration is dependent on?
A
- soil mositure; subtrate; slope; type of vegetation; intensity of precipitation
12
Q
What happens to water as it falls to the ground? Evapotranspiration
A
Combination of evaporation and transpiration
13
Q
Amount of evapotion is dependent on?
A
temperature; wind; area
14
Q
Amount of transpiration is dependent on?
A
type of vegetation; season; wind; soil moisture; humidity
15
Q
Water flux chart
A
slide 23 on lecture 2
16
Q
How long does water stay?
A
Ocean is the longest; atmosphere is the shortest
17
Q
what is residence time in relation to water?
A
how long on average water remains in each storage area (ocean = largest; atmosphere = shortest)
18
Q
What are the average residence times in major water stores? Oceans, glaciers, soil moisture, deep and shallow groundwater, lakes, rivers, atmosphere
A
Oceans = 1500 years; Glaciers = 1000 years Soil Moisture = 6 months deep groundwater = 10 000 years shallow groundwater = 200 yrs lakes = 50 yrs rivers = 14 days atmosphere = 9 days
19
Q
Global Energy Budget
A
Slide 25 on lecture 2
20
Q
Where is there more solar radiation than the poles?
A
Equator; more evaporation as well
21
Q
how is energy distributed?
A
oceanic and wind circulation through water cycle
22
Q
Water cycle is linked to the global energy balance. T/F
A
True = impacts where water is evaporated and precipitated
23
Q
warmer air cant hold more water vapor. T/F
A
F
24
Q
Air Tmeperature imact on water vapor
A
impacts the amount of water vapour that can be evaporate
25
what are the 3 distinct wind cells?
Hadley cells; ferrell cells (around the mid-latitudes in opposite direction) and polar cells (around the poles)
26
What is the Lake effect snowfall?
occurs in the great lakes region and other areas
| results in snowbelts with high precipitation
27
Why is the maj. of snowfall on south and east of the lakes?
predominant winds in this area come from the west
28
What causes lake effect?
1. cold air blows over the lakes,
2. air warms and gains moisture as it move over the lake
3. as it continues over the land it cools
4. cold air condense into clouds and snow
29
There is natural variability in the water cycle that varies on multiple timescales? T/F
True
30
What can variations in the water cycle cause?
Droughts and Floods
31
What are droughts?
Periods of abnormally low precipitation that can last for years or decades
32
What are floods caused by?
Periods of heavy rainfall where the waterbodies (rivers, lakes) overflow
33
Extreme events are made worse by?
environmental feedback --> soil moisture feedback
34
What happens with substantial cost with extreme events
human life can be lost; destruction of ecosystems (flooding, wildfires); destruction of infrastructures (costs billions/yr worldwide)
35
Soil moisture (oversaturated) caused
causes runoff and flooding
36
soil moisture (undersaturated)
can leave a dry layer that makes it impossible for the water to permeate
37
Dust Bowl Case Study
slide 40-41
38
What is El Nino?
El Nino southern oscillation (ENSCO) - modification of the ocean and atmospheric circulation which occurs every 3-6 years;
begins in the southern Pacific;
slowing of easterly winds which causes rainfall and warm ocean water to shift eastwards
39
What is La Nina?
stronger trade winds, resulting in warm water and heavy rainfall moving west
40
Are extremes assocaited with El nino or la nina?
El nino
droughts can occur in southern africa, indonesia, australia, and other regions;
floodings occurs in western and southern usa, peru;
climate impacts o la nina are opposite to those of el nino
41
when is precipitation over land anomalously high?
during la nina; low during el nino;
| mild winters in the northern usa and canada
42
Ho would changing the climate impact the water cyle?
intrinsic link between th water cycle and energy balance controls climate;
model climate change to estimate potential changes to the water cycle (many different models can be used);
current climate models predict increasing temperature;
scientists use computer models to predict potential changes to the water cyle based on climate change -- with a prediction in increasing temperatures
43
What are conributors to climate change?
generally agreed that human caused increase in greenhouse gases is resulting in climate change (increasing the natural greenhouse effect);
greenhouse gases include (carbon dioxide, water vapour, methane, nitrous oxide, chloroflurocarbons (CFCs)); aerosols can also contribute to climate change (natural aerosols (salt, dust, ash)) (90% of aerosols are natural); (man-made aerosols (sulfate aerosols common))
44
Mount Pinatubo
located in the phillipines; erupted on june 12, 1991 (Second largest volanic eruption in the 20th century);
launched large amount of ash into the atmosphere (natural aerosol);
suface cooling occurs from reflection of solar radiation (less evaporation at the surface and less air moisture) (ash blocks out solar radiation and causes it bounce back thus colling overall planet);
reduction in precipitation and streamflow for th year after the eruption (largest decrease in precipitation over land in records)
45
Sahal Region
in africa that lies south of the sahara;
abundeunt agriculture in the region (95% of land used for agriculture);
dependent on the movement of the intertropical convergence zone (ITCZ) for precipitation;
severe drought hit the area in the 70s and 80s;
its a band under sahara;
mostly used for agriculture
46
What caused drought in sahel region?
overgrazing of the land increased albedo reducing surface temperature and evaporation;
natural variation in rainfall patterns;
cooling of the northern hemisphere by sulfate minerals which strengthedn the northern hadley cell shifting hte itcz southward
47
As air temperature increases...
there will be an increase in evaporation at the surface
48
impacts of icnreasing temperature
water vapour is a significant contriutor to the natural greenhouse effect (accounts for 60% of this effect);
warmer air can contain more water vapour than colder aie (creaters a positive feedback loop (most important feedback loop in the climate system))
49
What happens if the glaciers melt?
warming climate will cause an increase in the rate of glacier melt;
potential issues with rapid glacier ice loss (less water resources for many communities; increase the sea level; change the oceanic circulation (impacts atmospheric circulation climate));
change in glacier ice into running water means that the water will return to lower elevations (remember it follows gravity); wont stay up in the mountains giving freshwater to higher elevation communities; increases sea level and also then impacts those normal cyclical water current patterns in the ocean
50
what happens to precipitation?
with changes in the temperature and circulation is precited that there will be changes to precipitation patterns (difficult to predict precipitation changes due to the complex interactions of factors);
already observing changes in precipitation with current warning temperatures (decreases in precipitation in subtropics and tropics; increases in land precipitation at higher latitudes)
51
Intensification of the water cycle
The increase in water vapour in the atmosphere provides more moisture for storms to feed on (Results in intensifying the cycle);
Predicted that there will be more heavy rainfall events
(Moisture to feed large events is gathered from long distances which will cause less moderate rainfall events;
Increase in rainfall in one area means a decrease in other regions);
Climate change will amplify the regional differences in precipitation and evaporation
(Dry areas get drier, wet areas get wetter);
Drought and flooding have generally increased in the 20th century;
Found that some regions do not experience increased heavy rainfall with warming
(Region of Arizona has experienced 2°C increase in temperature with no substantial increase in rainfall and instead changed to less intense and longer lasting storms;
May be true for other regions);
Water cycle is a complex system that works on multiple scales
52
Climate change and el nino
Based on historical data the warming climate may impact the duration and severity of El Nino;
Based on the last 478 years, scientists found that:
(43% of the most severe El Nino events occurred in the 20th century --> 30% of them since 1940;
28% of the longest events have been in the 20th century)
53
Reduced snowpack can result in?
A reduction in water resources available in the summer;
Greater loss of water to evaporation and ablation;
Lower soil moisture
54
What is ablation?
melting of snow or ice and then evaporates
55
Let it snow?
As the temperature continues to increase it is more likely that precipitation will fall as rain rather than snow
(Especially at the end and beginning of the snow season);
May have more snow in some regions as the climate changes
56
Changes in lake effect snow
There has been an increase in lake effect snowfall in the great lakes region even as there is a decrease in snowfall in surrounding areas
57
What are causes of increased lake effect snow?
Less ice cover in the winter;
| Warmer water in the lakes
58
As climate countines to change, there are positive and negative feedback loops
true
59
what is the snow-ice albedo feedback
Albedo is the amount of solar radiation reflected back into space (Snow has high albedo, soil has lower albedo);
Warmer temperature and earlier spring thaw results in less snow accumulation;
Less snow means that more radiation will be absorbed at the surface causing it to warm faster which consequently results in less snow;
This feedback loop is one of the reasons that warming is expected to be greater at higher latitudes
60
what are some potential changes to water resources?
Areas dependent on snow melt will have a decrease water resources;
More heavy rainfalls will result in more runoff, less infiltration of the water;
Drought prone areas may have more severe drought episodes
