Semester 1 all lectures. Flashcards
(371 cards)
1
Q
What is the hydrological cycle?
A
This describes the movement of all forms of water on, in and above the earths surface.
2
Q
Why is the hydrological cycle important?
A
It is an unlimited resource on a global scale, the largest circulation of matter in the earth-atmosphere system, primary biological production, major transporter of heat and key in the greenhouse effect.
3
Q
Is the hydrological cycle open or closed? What does this mean?
A
It is an open system, changing in response to astronomical, geological and biotic factors.
4
Q
What is the hydrosphere?
A
A series of reservoirs interconnected by water cycling in various phases, e.g. the ocean, the cryosphere, terrestrial water, water in the biosphere and the atmosphere.
5
Q
What is the cryosphere?
A
Ice sheets, glaciers and seasonal snow/ice.
6
Q
What is terrestrial water?
A
Rivers, soil moisture, lakes and ground water.
7
Q
What is water in biota/in the biosphere?
A
Water in the plants/animals.
8
Q
The volume of water is … but the supply of water is …
A
The volume of water in finite, but the supply of water is infintie.
9
Q
Some water is broken down or created by volcanic eruption, is this a large amount?
A
No, its negligible.
10
Q
By what volume has water increased over billions of years?
A
1 km3 a-1 dues to degassing of the earths mantle as water is chemically bound in rocks.
11
Q
How is water cycling accomplished?
A
Evapouration, transport in the atmosphere, condensation, precipitaion and terrestrial runoff.
12
Q
What is the largest store of water in the hydrosphere?
A
The oceans.
13
Q
What are the two smallest stores in the hydrosphere?
A
Man-made reservoirs and irrigated soils.
14
Q
There is more evapouration from the oceans than is precipitated back into the oceans, by how much?
A
40,000 km3.
15
Q
What is the total volume of water in the hydrosphere?
A
Roughly 1500 billion km3.
16
Q
What % of all water is in the oceans? How long does it stay there?
A
95-98% - 3.6 ka
17
Q
What % of water is in the atmosphere? How long does it stay there?
A
0.001% - 10 days
18
Q
80% of fresh water is where? How long does it stay there?
A
Ice. it stays here for 15 ka
19
Q
How long does water stay in ground water stores?
A
10 ka
20
Q
How long does water stay in rivers?
A
Day-weeks
21
Q
How much faster do freshwater stores turnover than saline? (excluding ice) And why?
A
3-5 times faster. Terrestrial waters get more exposure.
22
Q
What factors effect water turnover?
A
The amount of energy available, how efficient this energy is and the case of exchange.
23
Q
How much moisture does evapouration put into the atmosphere from the oceans and from land.
A
Oceans - 87% - 150cm over tropical oceans a year.
Land - 13%
24
Q
Water losses from plants are called?
A
Transpiration
25
Evapouration and transpiration are hard to seperate so what term is used?
Evapotranspiration.
26
Define precipitation.
The deposition of water from the atmosphere in liquid and solid form.
27
Moisture in the atmosphere 'cascades' what does this mean and what are the proportions?
25% condenses to rain, 75% forms ice and snow, then 70% melts to rain, the remaining 5% snow and ice crystals.
28
Humans are dependent on what stores?
The smallest, terrestrial stores. Only freshwater.
29
What are factors the effect the earths radiation balance?
Sun-earth relations (milankovitvh cycles),
the suns emissions,
the earth-atmosphere propertites (shape of the globe, greenhouse effect)
30
What are the 3 milankovitch cycles?
Eccentricity - 100,000 year cycle. Stretch.
Obliquity - 40,000 year cycle. Tilt,
Precession of the equinox - 20,000 year cycle. Wobble.
31
What can our eyes see on the electromagnetic spectrum?
The visible light. The peak of solar radiation.
32
What is the wavelength?
Distance from one peak or trough to the other.
33
What is the Stefan-Boltzmann law?
e = σT^4
| Radiation emitted increases very much faster as temperature of emitter rises.
34
What is Wien's law?
λ = 1/T or T-^1
Hotter objects emit shorter wavelengths of radiation,
E.g.
Red hot to white hot
35
The sun emits short or longwave radiation?
Short
36
The earth emits long or short wave radiation?
Long wave reflections of the suns radiation.
37
What are the two sunspot minimums and when were they?
The maunder minimum - 1659 to 1700.
| Dalton minimum - 1800 ish
38
What was the sunspot maximum and when was it?
Modern maximum, 1950 ish
39
Are rainfall and sunspot numbers linked?
Yes, rainfall increases with sunspots.
40
Do all solar beams reach the earth?
No, gamma rays, x rays and ultra violet are stopped by the atmosphere.
41
What is the albedo of water bodies?
10-60%
42
What is the albedo of the moon?
6-8%
43
What is the albedo of fresh snow?
80-95%
44
What is the albedo of forests?
10-20%
45
What is the albedo of crops/grassland?
10-25%
46
What is the albedo of grass?
25-30%
47
What is the albedo of asphalt (blacktop)?
5-10%
48
What is the albedo of concrete?
17-27%
49
What is the earths average albedo?
31%
50
What is the albedo of brick/stone?
20-40%
51
What is the albedo of a light roof?
35-50%
52
What is the albedo of a dark roof?
8-18%
53
Clouds tend to trap and reflect what radiation
Trap longwave and reflect shortwave
54
Difference between high and low clouds at reflection and trapping radiation is?
High clouds reflect less solar radiation but still trap the earths radiation.
Low clouds are better at reflection radiation.
55
Conduction definition
Transfer of thermal energy between neighbouring molecules due to temperature gradient to equalize temperature.
56
Convection definition
Fluid motion in which warm air rises or cold air sinks.
57
Advection definition
The transfer of a property of the atmosphere such as heat, cold or humidity by horizontal movement of air mass.
58
Radiation definition
The transfer of energy between two bodies without the aid of an intervening medium at the speed of light.
59
Latent heat definition
The thermal energy involved in a change of state i.e. energy used when water changes from a liquid to vapour during evapouration and released when water vapour condenses to liquid.
60
Balance equation for surface heat budget simplified to what?
Qnet + Qs + Ql = Qresidual
61
What is net radiation?
The resultant flux of solar and terrestrial radiation through a horizontal surface - the balance of radiation between input and output.
62
Do the poles have a postitive or negative net radiation?
Negative.
63
Does the equator have a positive or negative net radiation?
>80 net radiation.
64
What is the difference between direct and oblique radiation?
Direct radiation arrives parallel to the earths sureface and is more concentrated, oblique is more diffuse.
65
The equator recieves what surplus of incoming energy? What does this cause?
Surplus 30 degrees north to 30 degrees south.
| This fuels the circulation of the atmosphere.
66
Does land/sea make a difference to radiation absorbed?
Yes, different albedos.
67
Net radiation decreases more than solar radiation does as you move towards the poles, why is this?
There is an increased albedo as you move towards the poles and oceanic absorption is higher in the tropics.
68
What is the speed of land and oceans cooling?
Land warms and cools much faster the bodies of water. There is no mixing in land, water is transparent so deeper warming can occur.
69
What has a higher range in temperatures generally, land or sea?
Land, especially in northern latitudes.
70
What is sensible heat?
Heat transfer by convection or conduction where heat is transferred by the rising and mixing of warm air.
71
Sensible heat increases pole wards at sea but decreases pole wards on land, why is this?
This is because water warms air more than land because of its heat capacity in higher latitudes.
Ocean circulation brings warm water to higher latitudes so there is more sensible heat to be released.
72
There is more latent heat over the oceans, why is this?
There is no limits to evaporation and the sea absorbs more radiation.
73
When does evaporation occur? What happens?
When energy is transported to an evaporating surface where the air pressure above is below saturation value. It requires energy to overcome the inter molecular attraction. Energy is acquired by heat from immediate surroundings, latent heat lost and temperatures drop.
Wind speed above creates air turnover for evaporation to occur.
74
Molecular evaporation definition is?
The addition of kinetic energy makes the molecules velocity increase, more likely for an individual molecule to escape the surface of the water. Fastest escape first.
75
What is the formula for evaporation rate?
Evaporation rate = f(u) (e,saturated–e,actual).
| U = wind speed and (e,saturated–e,actual) = the saturation deficit. Saturated being the max.
76
What is Dalton's law.
e = vapour pressure – standard measure of water vapour content
77
Warmer air can hold more water vapour, what is this relationship called?
The Clausius-clapeyron relationship.
78
What is a Lysimeter?
This measures evapotranspiration by the change in soil weight.
79
Where globally is the most evaporation?
Mostly from the oceans, subtropical oceans away from the equator, or in the equator when there is cloud cover. Most evaporation on land occurs from tropical rain forests.
80
What are the three parts of the oceans vertical structure?
```
Ocean surface (thermally mixed 10m-400m)
Thermocline (lower temp, higher density, stratified with little mixing 200m-1000m)
Deep layer of cold, dense water, movement driven by density variations due to change in salinity.
```
81
How is the ocean effected vertically?
Effected by atmospheric circulations.
82
Example of a warm water current and how it effects evaporation.
The gulf stream/north Atlantic drift, increase in evaporation so more rain in Europe.
83
Example of a cold surface current and how it effects evaporation.
The west coast of south america and south Africa, reduced evaporation and the cause of deserts.
84
Why do surface currents head pole wards on the western side of oceans?
Due to the coriolis effect/the spin of the earth.
85
Hurricane belts are fueled by what over warm waters?
High evaporation.
86
What occurs with sea breezes at night?
Cool air is drawn inland as the land is warmed quicker (the air inland is rising)
87
What occurs with sea breezes during the day?
As the land is cooling faster the cool air is drown out to sea and the air above the sea is warmer so rising.
88
Differences in the thermal properties of land and sea are responsible for what events?
Monsoons.
89
What is El Nino?
A short term fluctuation, 2-7 years, a reversal in the winds in the equatorial Pacific. Opposed to the normal conditions where winds blow from south America to Indonesia. High pressure over Indonesia reverses this wind.
90
Impacts of El Nino are?
Flooding in Peru and Ecuador,
reduced cool water from deep down so fishing and birds suffer and south america.
North America warms.
91
Define rain
Falling water drops with a diameter of >0.5mm and typically 2mm.
92
Define snow
Ice crystals falling in branched clusters of snowflakes.
93
Define hail
Hard pellets, balls or irregular lumps of ice, at least 5 mm across.
94
Define graupel
Snow pellets of opaque conical or rounded ice particles, 2-5mm in diameter formed by aggregation.
95
Define sleet
Rain-snow mixture (uk)
| Small, translucent ice pellets (us).
96
Define dew
Condensation droplets on the ground surface or grass, deposited when surface temperature is below the airs dewpoint temperature.
97
Define rime
Clear crystalline/granular ice deposited when supercooled fog encounter vertical structures.
98
What are causes of precipitation?
Convergence of air (uplift) orography/relief (adiabatic cooling) and ocean circulation.
99
What is adiabatic cooling?
When air rises, it expands as there is less air above, this cools without more or less heat added.
100
What is the dry adiabatic lapse rate?
That rising air cools and sinking air warms, 0.98 degrees per 100m rise.
101
What is the saturated adiabatic lapse rate?
This is when dew point has been reached in the air, heat is being released during condensation so the rate is 0.5 to 0.9 degrees per 100m rise.
102
Latent heat does what to the cooling and heating process in air?
Complicates it.
103
What are lifting mechanisms that create clouds?
Low pressure, plowed fields, orographic, and frontal.
104
What is a typical warm front?
The cold air mass is passive, the warm air gentle rises and creates clouds and drizzly rain as the warm front moves towards the cold.
105
What is a typical cold front?
Dense cold front forces warm air up abruptly, large clounds, raindrops and heavy showers/thunder and lightning occur.
106
What is a cumulonimbus thunder head?
A large cloud with circulation within it, tall and creates thunder and lightning.
107
How do droplets grow big enough to fall?
In clean air supersaturation is needed for condensation to occur, normal air is dirty and the dirt acts as condensation nuclei. This can be dust or sea spray directly or coagulation of small particles etc.
108
What are the three types of condensation aerosol?
Nonwettable and insoluble nuclei (useless).
Wettable but insoluble.
Hygroscopic nuclei - most efficient, they absorb water vapour below 100% humidity.
109
What are the different sizes of nuclei?
Giant nuclei 1-10 micro meters - useless unless hydroscopic.
Large nuclei 0.1-1 micro meter. more effective.
Aitken Nuclei 0.01-0.1 micro meter. Most effective. Any less is useless,
110
What is Coalesence and what is its relationship with condensation?
Happens after condensation, increases as condensation becomes less effective.
111
What is the Bergeron process?
Water prefers to stick to ice, so the water pressure around this is lowered, causing water off other droplets to evaporate of that due to the lower pressure and on to the ice crystal too.
112
Are all snow crystals the same?
No, they form differently at different temperatures and therefore different altitudes.
113
What are global precipitation patterns?
Equatorial maximum (slightly to north), west coast maxima, dry areas of subtropical high pressure cells (create major desserts) Low over high latitudes.
114
What is atmospheric pressure?
The pressing of the air in the atmosphere down on the earths surface. The molecules in the air are impacted by gravity.
Atmospheric pressure decreases with altitude, rapidly at first then more gradual.
115
What are Pascals (Pa)
Pressure as a force per unit area.
116
How do bars, millibars, pascals and mmHg compare?
1 bar = 1000mb = 10,000 Pa = 75 mmHg.
117
What is the Pa at 15 degrees at sea level?
101,320.
118
What does a Barometer measure?
Atmospheric pressure.
119
What is the key principle of pressure gradient?
Air, acting under gravity will always move to result in equal pressure.
120
What do isobars represent?
Areas of similar atmospheric pressure.
121
Wind definition.
The motion of air flow around the earths surface between areas of differing pressure, the greater the gradient, the stronger the win. Predominantly horizontal, vertical called updrafts or down drafts.
122
What are wind speeds measured by, and on what scale?
Anemometer on the Beaufort scale.
123
Who first describe the coriolis effect and when?
Gustave-Gaspard Coriolis 1835,
124
What is the coriolis effect?
Results from the rotation of the earth, deflects the path of an object e.g. parcel of air.
Northern hemisphere - deflects to the right.
Southern hemisphere -
deflects to the left.
125
What is deflected by the coriolis effect more, strong winds or weak winds?
Strong winds are deflected more.
126
What is the coriolis effect at the equator?
Zero.
127
Where is the coriolis effect strongest?
The poles.
128
What are frictional forces on wind?
The earths surface causes the wind to slow down and move in irregular ways.
129
How is global circulation divided?
The lower atmosphere and the upper atmosphere.
130
What is the jet stream?
Fast traveling wind where the pressure gradient is strong, stronger in the winter than the summer.
131
What are the two jet streams?
Polar which can go as far south as 35 degrees (Texas) and the subtropical jet stream which is between 20-50 degrees. There is also two in the other hemisphere. Move to the west and found in the tropopause.
132
What is the rossby wave?
The westward flow of the upper-air frequently forms undulations (flows in a "circle" to the west and has waves)
Sometimes smooth but warm air can move upwards causing the ripples and the cold air will poke out and eventually be cut off leaving a pocket of cold air further south than usual.
133
How do rossby wave influence the ocean?
Displace the thermocline and influence currents.
134
Who is the Hadley cell named after and when was it first discussed?
George Hadley in 1735.
135
What are Hadley cells?
A convection loop caused by heating at the equator due to the suns strength here. One per hemisphere, deflected eastwards due to coriolis.
136
What are the NE and SE trade winds?
Hadley cell air cools at 30 degrees, this air coming back to the equator is the trade winds.
137
What are the 3 cells that make up global circulation?
Hadley, ferrel and polar cells.
138
What is the polar cell?
Vertically smallest, one in each hemisphere, cold dense air slows flows from high pressure out south to roughly 60 degrees.
139
What is the ferrel cell?
Driven by the other two cells, surface winds move from south to north, and cause westerly winds. Between 60 and 30 degrees.
140
What are horse latitudes?
Areas of general subsidence in the zone between 20 and 35 degrees.
141
The flow from horse latitude to the equator is called what?
Trade winds. (there are others)
142
When trade winds from both hemispheres converge what is this light wind called?
Doldrums.
143
The three cells in the atmosphere mix the air how?
The Hadley cell is the tropical convection loop, the ferrel cell mixes cold and warm air, and the polar cell is the circulatory loop for polar regions.
144
What does ITCZ stand for?
Inter Tropical Convergence Zone.
145
What is the ITCZ?
Air that flows into the low pressure left by the hadly cell converges (joining of two trade winds) and brings heavy precipitation. Same as Doldrums.
146
At 30 degrees where the hadley cell descends there is high pressure, what is this area called?
The sub-tropical high pressure belts. They have clear skies and low precipitation. Deserts found in these areas,
147
The Hadley cells strength changes seasonally, what does this cause? And why does it change?
The ITCZ to move, and monsoons occur. It changes due to the suns position.
148
Does the ITCZ move more on land or on sea?
On land.
149
When the ITCZ moves North, what occurs over Asia and Africa?
Monsoons due to the moist air being brought over the continent.
150
What does the IPCC predict will happen to the monsoon season?
Its likely to become longer.
151
What is the ITCZ moves too far north?
Drought brought to the Sahel region of Africa.
152
What is climate?
The average weather over 30 years, includes temperature, precipitation and wind.
153
What is the Koppen-Geiger system of classification?
Av monthly temp, av monthly precipitation and total precipitation.
154
What are the 5 climates?
```
A -Tropical moist climate >18 degrees.
B - Dry climates
C - Moist mid latitude - Mild winters
D - Moist mid latitudes - cold winters
E -Polar climates
H -Highlands
```
155
Mid latitudes can also be describes as what?
Mesothermal/middle temperature. C category. 55% of the worlds population in these areas.
156
What are the two major characteristics of air mass?
Moisture content/source:
c = continental (dry)
m = maritime (moist)
```
Latitude source:
A = Arctic/antarctic
P = Polar
T = Tropical
E = Equatorial
```
157
What are the three sub-groups of mid latitude?
C groups.
Humid subtropical (Hot summers with thunderstorms and mild winters)
Marine (West coast of continents, heavy precipitation due to cyclones)
Mediterranean (extreme summer aridity, rainfall mostly in winter)
158
High latitude and polar climates are?
D and E
Greater seasonality, warm to cool summers, cold winters and year round cold in the higher latitudes.
159
Microthermal climates are?
Associated to large land masses. Not enough land in the southern hemisphere for these.
160
3 sub-groups of microthermal climates are?
Moist continental with warm summers
Moist continental with mild summers.
Subarctic climates with cool summers and very cold winters.
161
What is an anticyclone?
During winter cold continental interiors can develop stable high pressure.
162
What direction do anticyclones rotate in the northern hemisphere?
Clockwise.
163
What direction do cyclones rotate in the northern hemisphere?
Anti-clockwise.
164
What is an ocean current?
Any persistent, dominantly horizontal flow of ocean water.
165
What are ocean currents driven by?
Pressure and density differences. Influenced by the coriolis effect.
166
What are surface currents?
Top 400m, 10% of the oceans.
167
Heating of water at the equator causes expansion, what does this result in?
A slight slope. Water wants to flow with gravity.
168
How much doe the corolis effect deflect ocean currents from the direction of prevailing winds?
Roughly 45 degrees.
169
What are Gyres?
Mounds of warmed water.
170
Increased salinity does what to density?
Increases it.
171
How are deep currents created?
Where there is low pressure and high salinity waters slowly sink to the bottom, e.g. N Atlantic where gulf stream has brought saline water. Sea ice creation leads to brine rejection and then more saline in the water.
172
What is thermohaline circulation? What is it also known as?
How deep waters interact with surface water. Or the ocean conveyor system. Crucial for heat transfer.
173
What is a storm?
Any disturbed state of the atmosphere, especially effecting the earths surface. Usually implies severe weather which may be destructive.
174
Causes of tornadoes?
Rapid cloud formation due to rapid ground heating or frontal collision.
175
Tornadoes form thunder storms, what is needed for this?
Air instability, warm and humid. Wind shear is needed, difference in wind direction and speed which increases with height. Up and down drafts for example create supercells, creates intense spinning.
176
What are some tornado hotspots?
Brazil, S Africa, Australia and Japan. US and Canada.
177
When is peak tornado season in USA?
April and July.
178
What is Tornado Ally in USA?
Central USA has flat terrain.
179
Where in Wales gets tornadoes?
Mid-Wales.
180
What is the Fujita scale?
Tornado classification scale. 40-318 mph wind speed.
181
What are details of the Greensburg Tornado?
Kansas 2007. >200 mph winds. 95% of the town destroyed. 50.6% population decrease.
182
Explain the generation of mid-latitude cyclones.
Large areas of low atmospheric pressure,
form along the polar front due to warm and cold air meeting. Generation of a high pressure gradient.
Can move 1200 km a day. Long durations of precipitation.
183
What are flood generation mechanisms?
Weather patterns, local topography and geomorphology, nature of anthropogenic activity.
184
Describe the generation of tropical cyclones.
A hurricane like storm that generates over tropical oceans, between 23.5 degrees north and south.
Also called cyclones and typhoons.
No fronts, sea temps of over 26 degrees needed. Convergence of warm air masses, condensation creates latent heat.
185
What is the seasonality of tropical cyclones?
Specific in different parts of the world.
186
Why is there seasonality of tropical cyclones?
They originate in western Africa driven west by easterly trade winds. Diverted by northeast westerlies.
187
Cyclone naming follows what system?
Male and female alternating, then alphabetically.
188
What scale is hurricane damage potential measured on?
Saffir-Simpson hurricane damage potential scale.
189
Hurricane Katrina details are?
Storm surge of >20 ft. 1800 lives.
190
Hurricane Dorian details are?
Storm surge 23 ft. sea surface temps <30 degrees. 70 lives lost.
191
What does intra mean?
Within.
192
What does inter mean?
Between.
193
What is El nino?
Inter-annual oscillation
3-7 cycle
Reversal or ceasing of Walker circulation
Impacts around the globe.
194
What is pressure like when there isn't an ENSO year?
Low pressure over west Pacific and high over east - creates easterly trade winds.
195
What does SOI stand for?
Southern Oscillation Index.
196
What is SOI?
The pressure difference between Tahiti and Darwin.
Negative SOI in EL Nino years
Positive SOI in La Nina years
197
Water circulation in the Pacific is what in normal, el nino and la nina years?
Normal = upwelling of cool water in the east (S America) that travels to the west and creates a warm pool.
La Nina = Strengthening of the normal conditions.
EL Nino = Weakening of circulation.
198
Where and what is the Humboldt current?
A cool current equator-wards, along S America.
199
How does the Humboldt current get subdued?
The easterly trade winds get weakened, allowing warm west Pacific water to flow back over and subdue it, poor for fisheries.
200
What effects are there to weather in El Nino years?
Low pressure in Australia is replaced by high pressure, this reduces rain and causes drought.
S America has unusual low pressure, this increases rain and leads to floods in Peru/Ecuador/Bolivia.
201
Does El Nino effects vary seasonally?
Yes.
202
How does El Nino effect the Gulf stream?
It becomes cool and wet, bringing floods.
203
Where does EL Nino effect?
Climates in middle and high latitudes, has cost $80 billion.
204
How does global warming effect ENSO?
Weakening of easterly trade winds, warmer equatorial sea surface temps.
205
What does NAO stand for?
North Atlantic Oscillation.
206
What is the NAO?
Pressure difference between the Icelandic low and the Bermuda-Azores high
207
What are the effects of NAO in the UK?
Dominant impacts Dec-Mar
High index = UK wet and mild
Low index = UK cold and dry
208
A low index in 2010 causes what in the UK?
25 deaths, coldest winter since 1978.
209
What does AO stand for?
Arctic Oscillation
210
What effect does a low index in the AO have on the NAO?
Also causes this to be low.
211
What are some other climate oscillations?
Madden Julian Oscillation - Intra-seasonal.
Pacific North American Oscillation - Intra-seasonal.
Pacific Decadal Oscillation - Multi-decadal.
212
Define the Cryosphere.
The portion of the earths surface covered in water in its solid form. A component of the hydrosphere.
Includes ice caps, glaciers, river/lake ice, permafrost, snow, sea ice, icebergs and ice sheets/shelves, also atmospheric ice.
213
Ice is ranked where on the list of biggest water stores?
Second.
214
Ice is what % of fresh water stores?
85%.
215
The Antarctic ice sheet holds what % of the cryosphere?
89.7%
216
How much water does the cryosphere hold?
27.5m km^3.
217
What has the lowest turnover rate in the hydrological cycle?
The cryosphere.
218
What is the snow and ice portion of the precipitation cascade?
5% of all precipitation, 76% melts and 24% goes into permanent or semi-permanent surface ice.
219
Melting ice is 2% of global surface runoff, is this reliable?
Yes lots still depend on it, release water at the beginning of the growing season.
220
What helps snow to produce better runoff than rainfall?
Frozen ground, less vaporization due to temperature and rapid saturation due to the fast melting.
221
Polar ice sheet facts are?
Slow turnover rate
low surface:volume ratio
little internal/basal melting
222
Valley glacier facts are?
Meltwater at the bed year round due to pressure melting.
Sub glacier meltwater important for glacier flow.
Low latitudes mean their important for freshwater source.
223
Define accumulation in glaciers.
Mass gain.
224
Define Ablation in glaciers
Mass loss.
225
What is the equilibrium line of a glacier?
Boundary between zone of net accumulation and the zone of net loss.
226
Permafrost facts are?
Temperatures below 0 degrees for at least 2 winters in soil and rock.
Underlies 20-25% of the earths land.
Mostly in Siberia, Canada, Alaska and China.
227
How does river ice increase flooding?
The ice blocks meltwater from elsewhere, this causes flooding.
228
What is the significance of lake ice?
Can contain metamorphosed snow and can push water out of the lake as it grows. This increases winter river flow and reduces the lake storage ready for snowmelt floods.
229
Ice cover has high albedo, it also has high emissivity which is what?
Efficient radiator of longwave radiation.
230
What is a snow board?
A small board used to measure the thickness of snow, normal rain gauges are useless for snow.
231
Drawbacks of snow boards?
Wind can blow the snow away.
232
What is a Wyoming snow gauge?
A snow measurement system that blocks wind.
233
Ways of measuring snow are?
Snow plate, ablation stake networks, dGPS, repeat photography, satellite imagery.
234
What can snow and ice be used for?
Irrigation, natural river flows and hydropower.
235
Who is John Tyndall?
In 1859 proved heat absorbing capacity of CO2 and water vapour.
236
Who is Svante Arrhenius?
1896 estimated that CO2 would warm the earths atmosphere.
237
Who is Guy Callendar?
Demonstrated the link between temperature increase and greenhouse gases.
238
What evidence have we gained from ice cores?
CO2 and CH4 are higher than they've been in the last 800,000 years.
239
Why is the UKs weather so variable?
It is impacted by lots of different winds, Continental and marine, polar and tropical.
240
Where were there large floods in Aberystwyth?
January 2014
241
What is expected for Wales as climate change happens?
Hotter, drier summers, increased storms, more intense rain and less severe winters.
242
Who suffers when Wales has heat waves?
Farmers, droughts are not studied well here as they are so rare.
243
How do we get historical information on climate/weather?
Meteorological observations, documentary records, proxy records for annual variations (tree rings, ice cores and varved lake sediments) and non-annual proxy records (Lake and marine sediment, peat bogs)
244
What are the different scales of climatic change?
Decade, century, millennia, tens of millennia, hundreds of millennia.
245
When did the central England temperature record begin?
Daily record 1777
| Monthly record 1659
246
When did the rainfall records begin in England and Wales? And sub regions?
1766
| Sub regions 1873
247
What is #showyourstripes?
Global temperatures show by colour from 1850-2018 by Ed Hawkins.
248
What is the 'old weather' project?
This gathers old documentary evidence from ship logs.
249
When was the medieval climate anomaly?
The medieval warm period was AD 800-1300
250
When was the little ice age?
AD 1400-1850
251
Explain the viking settlement of Greenland.
Settled with 3,000 by 1000 AD.
| Likely effected by little ice age. Lots of crop failure and population reduction in southern Greenland.
252
What were frost fairs in the little ice age?
The Thames and other rivers would freeze and people would have stalls on them (painting in museum)
253
What do historical records tell us?
Local climate/weather, extreme events, perceptions of risk, responses to events, coping strategies and how things are remembered.
254
When and what was the 'night of the big wind'?
A great storm that swept through Ireland and has stuck in peoples memories.
1839.
255
Where else did the night of the big wind effect other than Ireland?
Wales, historical records here too.
256
What is the Diary of a Welsh Swagman?
1849-61. In the national library of Wales.
257
UK climate projections come from?
A collaboration between the met office and governments and agencies. Use historical extremes for scenario testing.
258
When is the Quaternary period?
Last 2.6 million years.
259
The Quaternary is in a ice age, with what oscillations?
Glacial and interglacials.
260
What are the two parts of the Quaternary?
Pleistocene - 2.6 ma - 11.7 ma
| Holocene - 11.7 to now.
261
When did Genus Homo appear?
Last 3 million years.
262
When did anatomically modern humans appear?
Last 200-300 kyr
263
How far do ocean sediments date back?
Millions of years
264
What organism is used for telling global ice levels in the past?
Foraminifera - calcium carbonate shells show oxygen isotopes.
265
There is a marine sediment record called what and when?
The LR-04 Benthic Stack in 2005.
266
Ice core in Greenland showed what about previous climate?
There have been abrupt changes in climate through the last glacial cycle.
267
What is the younger Dryas?
A 10 degree warming in occurred in 50 years, after this the younger dryas was a 1,000 year cooling period - 12,500-11,700 years ago.
268
What is the Younger Dryas known as in the UK?
The Loch Lomond Stadial.
269
What is the difference between a stadial and an interstadial?
```
Stadial = Cold
Interstadial = Warm
```
270
What is the Holocene defined by?
11,700 years ago there was an abrupt warming and rapid north ward moving of the treeline.
271
What are the three periods of the Holocene?
Greenlandian, Northgrippian and Meghalayan.
272
How have Africa lakes changed from 9,000 years ago?
Almost all are much higher.
273
Runoff = ?
Runoff = precipitation - evaporation +/- storage.
274
Where is the greatest runoff in the global pattern?
Rain forests - especially tropical
275
Aside from rain forests, where are there peaks in runoff?
Down wind or around oceanic warm currents.
Orographic precipitation in mountains.
Areas with mid latitude depressions.
276
What is a river regime?
The average annual discharge of a river.
277
What is the velocity- area method for measure river discharge?
```
Q = V x A
Discharge = Velocity x Area
```
278
What are the ways of measuring area of a river?
Weirs, flumes and flow gauges. All tend to be useless in extreme flows.
279
What is a rating curve used for?
To convert depth of water to discharge on a weir.
280
When did flow gauging stations begin to increase in the UK
1960 when spike began.
281
What are problems with discharge measurements?
Lack of well-established gauging stations, rivers with none, difficult to estimate precipitation and evaporation.
282
What are some major rivers with poor gauging?
Amazon, Ganges and Congo.
283
Where has virtually no river measurements?
South East Asia.
284
What is runout?
Water that drains directly to the ocean through groundwater.
285
What are 4 trends in riverflows in the world?
2 year cycle in Russian rivers - possible link to Quasi-biennial oscillation.
11-year cycle - linked to sunspot cycle (can be 9-17 years)
NAO causes depressions (low pressure and rain)
7 year El Nino cycle.
286
Recent climate change data shows the increasing severity of what weather events?
Drought and flooding.
287
What is water sustainability?
Activities that ensure a given water resource will satisfy current objective of a society without compromising the resource.
288
What are water resources from terrestrial stores?
Deep ground water, shallow groundwater, soil moisture (drains into rivers) and river channels.
289
Why are rivers our primary water source?
Large quantities pass through, easily accessible, rapid turnover so less pollution and easily dammed.
290
Where are there critical scarcities in water resources?
Middle east
West USA
Southern Africa
Australia
291
What fraction of humanity live in dryland areas?
2/3
292
What fraction of water comes as stormflow?
2/3, less frequent so needs regulation from reservoirs.
293
Per capita resources vary how?
Asia and Europe have high population so lower per capita.
| Australia has low population so per capita is quite high.
294
What % is per capita water resources likely to decrease by 2080 dues to global warming?
48%
295
Is more water consumed than withdrawn?
No, less is consumed.
296
Irrigated land uses water, is this land increasing?
Yes.
297
What does increased irrigation cause in rivers?
Increased salinity in the case of the Rio Ebro.
298
Nitrate levels increased almost to the world health organisations limit where?
The UKs 4 main rivers.
299
There is global acidification in surface waters, where is this highest?
Middle of Europe and East of USA.
300
Where are there major hydropolitics?
The Nile basin - conflict over large dam building.
Israel and the west bank (Aquifers) and Jordan (River).
The Mekong Basin
The Tigris and Euphrates basins.
301
What drive Hydropolitics in Israel?
Increase in population rapidly and 90% of its water comes from the river. Major dams built.
302
How can we control water supply?
Water meters, improve recycling and reduce pollution.
303
Where else can we get freshwater from other than terrestrial sources?
The ocean, the cryosphere (dangerous), the atmosphere (rainmaking).
304
How do we make fresh water from the ocean?
Desalination, important for drylands and islands.
305
How does rain making occur?
Using silver iodide or more recently potassium chloride.
306
Examples of local/national modification of the water balance are?
Reservoirs, deforestation, land use and urbanisation.
307
Examples of how the global water balance has be modified?
Irrigation (increases vapour flow from land by 4%)
Deforestation (decreases vapour flows from land)
Combined this is almost zero, there are spatial distributions creating variations regionally.
308
How has Australia effected its crop production by deforestation?
The salinity has increased so crop production has decreased.
309
How has Colorado effected its weather with irrigation?
Evaporation increased by 120% producing more precipitation, reducing temperatures and increasing thunderstorms.
310
What effects do soil moisture have?
It acts as a buffer to water being released and sustains plant life.
311
What is deforestation?
Replacement of trees with grassland and crops.
312
What does deforestation do to soil moisture?
Reduces it.
313
How much water do rainforests store?
1350 tonnes of water per ha
314
What do artificial water surfaces increase?
Soil moisture, evaporation and albedo.
315
Where is the Aral sea?
Kazakstan.
316
When was the Aral sea the 4th largest sea?
1961
317
What rivers fed the Aral sea?
Amudar’ya and Syrdra’ya Rivers.
318
What has happened to the rivers feeding the Aral sea since 1930s?
Channels made to irrigate land.
319
What happened to the river channels feeding the Aral sea since 1960s?
Two major dams built and human population grew x3.
320
What did damming the Aral sea cause?
The river flow got less and less till it ceased completely from Sydra'ya 1974-1986.
321
How much did the Aral sea shrink in the 80s?
80-90 cm a year.
322
How far did the coastline of the Aral sea retreat?
100km
323
How much did the water volume decrease in the Aral sea?
80%
324
What happened to the shoreline of the Aral sea?
Desertification and soil erosion.
325
How much did the salinity increase in the Aral sea?
10 g l^-1 to 45 g l^-1
326
How many fishing jobs were lost in the Aral sea?
60,000.
327
What is the name of the desert created in the shoreline of the Aral sea?
Aral Kum.
328
What effects did the Aral sea reduction have on farm land?
Salinity was blown onto the farmland, this decreased it.
329
How can the Aral sea be saved?
Withdraw from irrigation
Improve irrigation efficiency
Use water from Caspian sea
Use ground water
Regulate rivers
330
How is the North of the Aral sea being saved?
But sectioning it off and letting the Syrdra'ya sill it, fish species are already returning.
331
What is the Soviet Arctic river reversal?
USSR wanted to ease agricultural drought in Ukraine, idea was shelved for socio-economic reasons.
332
Rural areas have what kind of flood hydrograph?
A delayed response in discharge from when rainfall occurs.
333
What effect has urbanization has on infiltration and runoff?
Decreased infiltration and increased runoff.
334
What is the precipitation increase in urban areas?
5-10% increase in precipitation in and around urban areas.
335
What mitigation is being done to reduce the runoff in cities?
Plants around and on top of buildings, opening up rivers to daylight again.
336
What is a drought?
The deficiency of precipitation over a region for a period of time or season,
337
What is the US drought monitor for?
To aid agriculture in being careful with water.
338
What is a meteorological drought?
When there is less than 75% of normal rainfall based on a 30 year record.
339
What impacts are meteorological droughts linked to?
Agricultural impacts. Susceptibility varies between crop species.
340
The US defines an agricultural drought as what?
At least partial crop damage.
341
What is a famous drought in the US?
Oklahoma 1930s.
342
What are hydrological droughts focused on?
How it influences the hydrological system. May be linked to lack of precipitation or subsurface groundwater - indicated by river or reservoir levels.
343
How does land use effect hydrological drought?
How the basin is managed changes recovery time for a drought, regions and different countries manage basins so it is important.
344
What is the sequence of drought impacts?
The first indication is usually with crops
Agriculture quickly recovers while stores may take months.
345
What are socio-economic droughts?
Link droughts to human impacts, occur because demand exceeds supply, can lead to new infrastructure and desalination.
346
Where is most at risk of drought?
South Africa. East of North America.
347
What are drought prevention and water resource management?
Dam building (pros and cons)
Large scale projects globally:
Southeastern Anatolian project - building of large hydroelectric stations, 22 dams and 19 power stations all to aid irrigation in Turkey. This leads to drought downstream.
348
How many children under the age of five are killed by unsafe water a year?
1.6 million.
349
What % and number of people do not use a toilet?
2.6 billion or 40%
350
When was the great plague?
1665
351
Where did the plague come from?
A water pump in London.
352
What are major infectious agents transmitted by water?
Norovirus, Salmonella spp (tyohid), cryptosporidium and Giardia.
353
What do cryptosporidium and Giardia have in common?
Both protozoan parasites of cattle, sheep and humans.
Widespread in environment.
Both cause gastroenteritis.
Both resistant to chlorine.
354
Sources of Giardia and cryptosporidium?
Cattle, beef, raw vegetables, apple cider, salami, humans and water.
355
Examples of outbreaks of cryptosporidium in the UK in what years?
1983-1997 - 80 outbreaks in total. 7 outbreaks from private water supplies.
356
Symptoms of crypto are?
10-15 day illness.
| Life threatening to the immunocompromised.
357
How well monitored are private water supplies?
Not very well, tanks for monitoring can be easily accessed by people or animals.
358
Sources of private water are?
Shallow throughflow, surface waters, shallow wells and boreholes.
359
What are risks for private water sources?
Animal feces on nearby land, can be spread as fertilizer.
Hotspots for animal standing and roof drainage.
Septic tanks.
360
How are risks spread to private water supplies?
Rainfall moves dangerous microbes, if the supply system has been irrigated by something.
361
What is water treated with?
Chlorine.
362
Is the Kuroshio current warm or cold?
Warm.
363
Which law states hotter objects emit shorter wavelengths of radiation?
Wiens law.
364
What does perpendicular mean?
An angle of 90 degrees.
365
The thermocline is effected by what?
Frictional drag of the surface layer.
366
What ocean layers are effected by the coriolis effect?
All of them.
367
The period of low sunspot activity in 1800 AD is called what?
The Dalton minimum.
368
What are the three layers of the atmposhpere?
Thermosphere
Mesosphere
Stratosphere
369
The spectrum of radiant energy is called?
Electromagnetic spectrum.
370
What is the main process of precipitation formation in clouds?
The Bergeron process
371
What is the first law of evaporation?
Daltons law.
