Climatology Flashcards
What is incoming solar radiation
Insolation
Name and briefly explain the two factors affecting the amount of insolation Earth receives
Latitude- The area around the equator receives more insolation because a) the distance the radiation travels is shorter, b) The angle the rays hit the surface is more direct and c) There is a smaller area to cover. As you move further North or South the angle becomes more oblique, the distance is longer and the area that must be heated is larger.
Seasons- The earth’s tilt on the axis and its revolution around the sun causes the seasons. It is hotter in summer and cooler in winter. The tilt of the axis means that one of the earth receives insolation for a longer period of time (more heating) and the other will have nighttime. The revolution around the sun the earth will have summer, fall. spring and winter. When a hemisphere has summer it receives more insolation.
How is the atmosphere heated
The insolation earth receives heats up the surface. when the surface has been heated, the earth then heats the atmosphere.
Two ways energy can be transferred
Ocean currents and Winds
Why does energy need to be transferred
Since the earth is unevenly heated parts of the world are very hot and others are very cold. To balance the heat energy on earth, warm temps must be moved to cooler places and cool temps must be moved to warm places.
Where do warm currents come from and how do we identify them?
Warm ocean currents come from the equator and move towards the tropical zones. All warm currents run on the eastern coastlines.
What is wind
The wind is moving air
What do winds do
Hint: Energy balance
the wind moves warm air to cooler regions and warms it up. It can also move from the poles to a warm area and cool it do.
what is atmospheric pressure
The weight of the atmosphere on the surface of the earth
what causes air movement
The difference in atmospheric pressure,
What is the relationship between atmospheric pressure and temperature
High temperatures result in low pressures as the air expands and rises. Air is drawn to low pressures so the area of converging air. Low temperatures result in high pressures as the air contracts and sinks. Air moves away from high pressures creating diverging air.
Name the low-pressure belts
Equatorial low-pressure belts, Subpolar low-pressure belts
What is the ITCZ
Intertropical Convergence Zone
Briefly explain how the cells work.
At the ITCZ the air expands and rises. When air reaches a temperature that is the same as the surroundings, the air will diverge. The air will begin to sink. when the air reaches the surface it will diverge and converge at low pressure.
Name the 3 air cells
The Hadley cell (0 to 30n/s), Ferrel cell(30 to 60n/s), Polar cell(60 to 90n/s)
Comment on the low and high-pressure rainfall
The low-pressure areas receive a lot of rainfall as the air rises here and condenses. In high-pressure areas, there is little to no rainfall as the air is subsiding
what is pressure gradient
The amount of change is atmospheric pressure.
What does PGF stand for
Pressure Gradient Force- forces air to move from high to low along the pressure gradient
What is subsiding air and its effects
This is the air that is descending. The cold air that converged in the upper atmosphere subsides. the air sinking warms up at the DALR. As it warms up, its ability to hold water vapour increases. It can’t condense as the ar is not saturated. Subsiding air causes warmer, drier conditions
Explain adiabatic warming
As air subsides, it becomes compressed and heat is released. The process where air warms as pressure increases is adiabatic warming
what is the opposite of adiabatic warming
Adiabatic cooling is the process of air cooling as pressure decreases.
What forms at the polar fronts
At the polar fronts, mid-latitude cyclones form. Cold fronts cause cyclonic/frontal rain in WC
How does the ocean influence the land temps
During the day and summer, the sea breeze will cool the land. Since the sea retains heat, the sea breeze will keep the land warm during winter and at night. This causes small seasonal temperature range and diurnal temperature range.
ocean currents influence on land temp
Air blowing over the ocean cause currents, and air above warm water becomes warm and prevailing winds blow this overland.
Ocean influence on land rainfall
Air over the ocean is saturated and when it blows over the land, it carries moisture. Warm currents have a high potential of rain while cold currents have less water vapour and bring drier conditions
Define desertification and drought
A drought is a long period with little or no rain.
Desertification is the process where fertile areas become increasing arider
What is the Sahel
This is a narrow strip of land that is at high risk of desertification.
Name and explain the 5 types of droughts
meteorological- Rainfall is below average for a long period of time
Hydrological- Little rain causes rivers, dams, reservoirs to decrease
Agricultural- Little rain and lack of soil moisture cause crop yields to decrease
Socioeconomic- Supply for crops, and water is lesser than the demand
Ecological- Natural vegetation duffers due to lack rain
Lists 4 causes of drought
- Irregularities in rain patterns
- Increased evaporation
- High Temperatures
- Climate change and global warming
List and explain causes of desertification
Climate change- Over an extended amount of time, lack of rain and high temps contribute to desertification
Human activity - Things like overgrazing strip the soil of vegetation. Deforestation is also a contributor. The overuse of natural resources due to growing growth also contributes to desertification.
Effects of drought and desertification on people
- Reduced crops and smaller harvests can lead to a shortage of food, famine, and malnutrition
- People die from malnutrition and heat stress
- People may lose their jobs if they work in the agricultural sector
- More people will move from rural areas to urban areas.
Effects of drought and desertification on environment
- Reduced water, increased evapotranspiration, and high temps which results in few plants
- Damages natural habitats and reduces diversity in ecosystems
- Dry vegetation, high temperatures, and low humidity can increase chance of veld fires
- Decline in river levels can results in dying fish.
How are authorities managing drought
- Monitoring vegetation cover. Satellites are able to show vegetation cover. The gov will then be able to tell if there is a decline in vegetation coverage.
- Building back up water facilities allows gov to be prepared for when drought occurs
- Water restrictions can be imposed in urban areas
how are authorities managing desertification
- United Nations Convention to Combat Desertification(UCCD). Govs are to create a strategy to fight land degradation and allocate funds to fight desertification
- Africa is developing and implementing National Action Plans
- 1 Afforestation programs
- 2 Proper soil management to reduce risk of soil erosion
- 3 Correction of land ownership to encourage sustainable management of resources
