Geo - Atmosphere and Weather (2.1 - 2.4)

what is a diurnal energy budget?

the diurnal energy budget refers to the balance between incoming and outgoing energy over a 24-hour period (one day and night cycle)

what does the diurnal energy budget help explain?

it helps explain:

• daily temp changes

• how energy is distributed during the day and night

what are the 6 factors affecting the diurnal energy budget?

1) incoming solar radiation (insolation)

2) reflected solar radiation (albedo effect)

3) surface and sub-surface absorption

4) sensible heat transfer

5) latent heat transfer

6) longwave radiation

how does insolation (incoming solar radiation) work?

the sun emits shortwave radiation

• some is absorbed by the Earths surface warming it

• some is reflected back by clouds, water, and ice (albedo effect)

what are some factors affecting the amount of insolation received?

• time of day

• latitude

• season

• cloud cover

how does reflected solar radiation (Albedo effect) work?

some of the incoming solar radiation is reflected back into space?

• albedo is a measure of how much radiation is reflected by a surface

Light coloured surfaces (fresh snow, ice, and sand) have a high albedo (reflect more)

Dark Coloured surface (forests, oceans, asphalt) have a low albedo (absorb more)

what are some factors affecting albedo?

Thick clouds reflect more sunlight (cooling effect)

thin clouds trap heat at night (warming effect)

how does surface and sub-surface absorption work?

some solar energy is absorbed by land, water and vegetation

• land heats quickly, water heats slowly

• darker denser materials absorb more heat

• this stored energy is later released as heat

how does sensible heat transfer work?

heat change that is felt - heat is transferred between the surface and air via..

Conduction:

• direct heat transfer between the ground and air

Convection:

• warm air rises, cool air sinks, creating air movement (winds)

winds help redistribute heat, cooling some areas and warming others

how does latent heat transfer work? (evaporation)

heat change is not felt - but is when water changes state

evaporation: when water evaporates it absorbs heat (Cooling effect)

evaporation occurs when water absorbs heat and turns into vapour, cooling the surface.

• this happens more in oceans, lakes, and humid areas

• wind increase evaporation, removing heat faster

how does latent heat transfer work? (condensation)

when water condenses and forms clouds it releases heat

• releases heat into the air - slows down heat loss at night

• condensation happens when air cools, causing water vapour to form dew

• this releases latent heat into the atmosphere, slightly warming the air

how does latent heat transfer work on clear nights? (condensation)

on clear nights with no clouds to trap heat, temps drop quickly. but if condensation occurs, some heat is released, preventing extreme cooling

how does longwave radiation work?

the earth emits heat as long wave radiation (usually at night)

• some of this escapes into space, while some is trapped by greenhouse gases.

• Clear nights lose more heat, making them colder

which of the 6 factors affecting the diurnal energy budget occur in the day, night or both?

Day:

• incoming solar radiation

• reflected solar radiation (albedo)

• surface absorption

Night:

• Longwave Radiation

Day and Night:

• sensible heat transfer

• latent heat transfer - evap: day, condensation: night

what is the global energy budget?

the global energy budget is the balance of how much energy is received from the sun amd how much energy is radiated back to space

what does the global energy budget’s balance control?

it controls the earth climate and temperatures

what are the 4 differences between the global energy budget and the diurnal energy budget?

Timescale

scope (boundary range)

main factors

processes

what is the difference in the GEB and DEB in terms of timescale?

Global:

• Long-term (measured over years or decades)

Diurnal:

• short-term (daily cycle)

what is the difference in the GEB and DEB in terms of scope?

GEB:

• entire earths energy balance

DEB:

• energy balance at a specific location over a 24-hour period

what is the difference in the GEB and DEB in terms of their main factors?

GEB:

• insolation, albedo, greenhouse effect, outgoing radiation

DEB:

• day time heating and nighttime cooling, cloud cover, surface type

what is the difference in the GEB and DEB in terms of processes?

GEB:

• includes large-scale climate influences like GHG’s and long-term climate change

DEB:

• focuses on local effects like morning warming, peak afternoon temps, and night cooling

what is the Greenhouse effect and why is it so important?

It traps in the Earth’s atmosphere warming the surface and keeping it stable at and average of 15 degree’s. Without it, earths avg temp would be -18 degrees (very cold!)

what do greenhouse gases do?

absorb and re-radiate heat back to Earth

what are the 4 major GHG’s and what do they come from?

Carbon Dioxide - from burning fossil fuels, deforestation

Methane - from livestock, rice farming, and landfills

Water Vapour - natural but increases with warming

Nitrous Oxide - from agriculture, fertilizers

what is the enhanced Greenhouse effect?

caused by human activities - burning fossil fuels, farming etc) increase the concentration of GHG’s

• more heat is trapped rather than radiated out to space - warming the earth

• this leads to global warming and climate change

Projected warming:

1.5 degrees by 2050

2-4 degrees by 2100

what are the 3 factors affecting the Global Energy Budget?

• Latitude (excesses and deficits)

• atmospheric transfers: (wind belts and ocean currents)

• seasonality

what is latitude?

latitude is the measurement of a locations distance, north or south of the equator

• expressed in degrees

• the equator is 0 degrees latitude

• the north pole is 90 degrees North

• the south pole 90 degrees South

what is the importance of latitude in terms of energy balance?

areas near the equator receive more direct insolation while high latitudes receive less due to the angle of sunlight

what is the importance of latitude in terms of climate patterns?

different latitude zones have distinct climates (e.g tropical, temperate and polar)

what is the importance of latitude in terms of seasons and daylight?

higher latitudes experience more variation in daylight hours throughout the year

what are the three main ways that latitude impacts the global energy budget?

1) unequal solar energy distribution

2) excess (surplus) and deficit zones

3) heat redistribution

explain how latitude impact the GEB by its unequal solar energy distribution

the earth is curved, so different latitudes receive different amounts of solar energy

• Low Latitudes get more direct sunlight = high angle of sunstrike = high insolation = energy surplus

• High Latitudes get more spread out sunlight = low angle of sunstrike = spreads energy over a larger surface area = deficit

finish the sentence..

“the equator receives about……as much solar energy per unit area as ……….”

“the equator receives about twice as much solar energy per unit area as the poles

what is the tilt of the earth?

23.5 degrees

what is the latitude or areas where there is an energy surplus

Energy Surplus: (Between 35⁰N and 35⁰S)

what is the latitude or areas where there is an energy deficit

Energy Deficit: (Above 35⁰N and Below 35⁰S)

what do high latitudes rely on heat transport from (Between 35⁰N and 35⁰S)

from lower latitudes through winds and ocean currents

what does the latitudes (Between 35⁰N and 35⁰S) drive?

the Hadley cell circulation which redistributes heat

what redistributes heat energy from the equator?

Winds and ocean currents

what do cells in atmospheric circulation do?

Hadley, Ferrel and Polar cells move warm air poleward and cold air equatorward

what do ocean currents do (warm and cold)?

warm currents (Gulf Stream) transfer heat from the tropics to higher latitudes

while cold currents (Peru Current) bring cold water toward the equator

what is a perfect sentence to explain how latitude affects the global energy budget?

Latitude controls the distribution of solar energy, creating a global pattern of energy surpluses at low latitudes and energy deficits at high latitudes. This imbalance drives global atmospheric and oceanic circulation. helping to regulate Earth’s climate

what are the differences between warm and cold air?

warm air expands - cold air contracts

warm air is less dense - cold air is denser

the warm air rises - the cold air sinks

warmer places have low air pressure - colder places have high air pressure

what are the three cells that make up the tri-cellular model

Hadley cell

Ferrel cell

Polar cell

what latitude is the Hadley cell and what circulation is it?

the latitude is (0^o - 30^o)

and its a tropical circulation

what is the largest and powerful cell

the Hadley cell

How does the Hadley cell work?

1) intense solar heating at the equator causes air to rise

2) the rising air cools and condenses forming clouds and heavy rain

3) the air moves toward the poles at high latitudes and sinks at 30^o

4) the sinking air moves back toward the equator as the “Trade Winds”

what latitude is the Ferrel cell and what circulation is it?

the latitude is (30^o - 60^o)

Mid-Latitude Circulation

what is the Ferrel cell and what is it driven by?

The Ferrel Cell is an indirect cell, driven by the Hadley and Polar cells

how does the Ferrel cell work?

1) Air at 30^o latitude sinks (from the hadley cell) creating the high pressure

2) some of this air moves toward the poles rising again at 60^o latitude

3) This rising air fuels storm systems and wet climates at mid-latitudes

what winds does the Ferrel cell drive?

The Ferrel cell drives the Westerlies (West to East)

what latitude is the Polar cell and what circulation is it?

the latitude is (60^o - 90^o)

Cold Air circulation

what is the smallest and weakest of all the cells?

Polar cell

how does the polar cell work?

1) cold dense air sinks at the poles

2) this air moves toward 60^o latitude, where it meets the warm air from the ferrel cell

3) the warm air rises, creating low pressure and stormy conditions

what are wind belts?

large scale patterns of wind circulation caused by the Earths rotation and uneven heating.

what is the coriolis effect?

caused by the Earths rotation it deflects winds to the right in the Northern hemisphere and to the left in the southern hemisphere

how are winds formed?

1) unequal heating of the Earth’s surface

• warm air rises, creating a low-pressure area

• cool air sinks, creating a high pressure area

2)) air moves from high to low pressure - needs to balance

• air moves horizontally from high pressure areas to low-pressure areas: this movement is wind

3) The coriolis effect changes wind direction

• because the earth rotates, moving air does not travel in a straight line

• so the CE deflects wind

4) near the ground obstacles like mountains forest etc slow down windspeed and change its direction slightly.

• higher in the atm, winds are faster because there is less friction

what are the 4 main winds

• Trade Winds

• Westerlies

• Polar Easterlies

• Jet Streams

what is an ocean current?

a continuous of seawater in a specific direction, typically caused by factors like wind, temperature differences, salinity, and the Earths rotation

how does the land and sea absorb heat differently

• oceans heat up 5 times slower than land

• oceans have a higher heat capacity

• oceans absorb more radiation from the sun

• oceans lose more heat slowly

what do warm surface currents do?

they move warm water from the equator towards the poles by convection

as they flow, they transfer heat to the atm warming nearby costal regions

what is an example of a warm ocean current?

The Gulf stream in the Atlantic

• keeps Europe milder in the winter compared to N. America on the same latitude

where is the gulf stream?

North Atlantic Ocean - orginates in the Gulf of Meixco and flows along the eastern coast of NA into NW Europe

what does the Gulf Stream do and what is it caused by?

redistributes heat and influences climate patterns on both sides of the Atlantic

its caused by the earths rotation and the Westerlies

the Gulf Stream has an impact on three continents what are they?

North America

Europe

Africa

what is the impact of the Gulf Stream on North America’s climate

• warm air and moisture, increasing humidity

• hurricanes along the East Coast

• Keeps winters along the SE US milder compared to inland areas

what is the impact of the Gulf Stream on Europe’s climate

• warm waters to northwestern Europe, moderating winter temps

• without it, Europe would have a much colder climate, similar to parts of Canada at the same latitude

what is the impact of the Gulf Stream on Africa’s climate

influences West African monsoons, affecting rainfall patterns

what do cold ocean currents do?

they move cold water from polar regions toward the tropics (convection)

• these currents help cool the air above them, influencing local climates and reducing evaporation rates

what is an example of a Cold Ocean current

the Humboldt Current

where is the Humboldt current located?

South Pacific Ocean

• flows Northwards from Chile, along the west coast of South America towards Peru

what is the purpose of the Humboldt current

it redistributes heat globally, but also allows nutrient rich water to rise to the surface, supporting large ecosystems

what is the Humboldt current caused by?

Southeast trade winds pushing surface water westward, allowing cold water to rise

what are the impacts of the Humboldt on climate?

• the cold water lowers temps along the west coast of America making it cooler and drier than other costal areas at the same latitude

• it reduces rainfall by preventing warm air from rising contributing to desert conditions

what are the impacts of the Humboldt on climate, in terms of El Nino?

the Humboldt current affects global climate through its role in El Nino and La Nina events

what does el nino do?

it weakens the humboldt current, causing warmer water, heavy rainfall and droughts

what does la nina do?

la nina strengthens the current, bringing cooler temps and drier conditions

what is the thermohaline circulation (conveyor belt)

this moves warm and cold water between the surface and deep ocean layers

what is the process of thermohaline circulation (conveyor belt)

• warm water from surface currents cools as it moves poleward - becomes denser and skinks forming deep cold currents

• these cold currents slowly circulate back toward the equator

• rising again through upwelling, completing the cycle

what is ocean upwelling?

a process where cold, deep, nutrient-rich water rises to the surface to replace warm surface water that has been pushed away.

what is the process of ocean upwelling?

1) wind driven movement

• upwelling occurs when strong winds blow surface water away from a coastline or the open ocean

2) replacement by deep water

• as surface water moves, cold, nutrient rich- water from deeper layers rises to replace it

3) Nutrient boost

• this deep water is rich in nutrients like nitrates and phosphrates, which fuel plankton growth, supporting rich marine ecosystems

what effect does ocean upwelling have?

a cooling effect: upwelling brings cooler water to the surface, lowering regional sea surface temps and influencing atmospheric circulation

what is ocean upwellings impact on climates?

upwelling regions experience:

• cooler sea surface temps leading to drier conditions because of reduced eaporation

what is seasonality?

seasonality is the yearly change in weather, temperature and daylight. It happens because the Earth tilts at a 23.5-degree angle as it moves around the sun.

when does summer occur

when a hemisphere is tilted toward the sun

when does winter occur

when a hemisphere is tilted away from the sun

are days longer in summer or winter

summer

when is summer and winter in the southern hemisphere

Summer:

December to February

winter:

June to August

when is summer and winter in the northern hemisphere

Summer

June to August

Winter

December to February

what does the ITCZ stand for

intertropical convergence zone

what happens with the ITCZ and wind belts during seasons

they shift north in July and South in Decmber

this brings intense solar heating to their areas

what are monsoons?

seasonal wind patterns that result from the differential heating of the land and sea

what is the case study for monsoons

The indian Summer Monsoon

what are the causes of the Indian summer monsoons

• april - may: intense heating of the Thar Desert (40 - 50 degrees) due to differential heating and latitude

• The ITCZ moves northwards: this strengthens the winds blowing in and brings heavy rains due to the low pressure belt acompanying it