Climate Dynamics and Milankovitch Cycles

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Questions and Answers

What does the eccentricity of the Earth's orbit primarily influence?

The distance between the Earth and Sun

The length of the seasons (correct)

The intensity of solar radiation

The tilt of the Earth's axis

How often does the axial tilt of the Earth complete a full cycle?

100,000 years

26,000 years

41,000 years (correct)

10,000 years

What aspect of the Earth’s movement is responsible for the timing of the seasons?

Axial tilt

Precession (correct)

Eccentricity of the orbit

Orbital speed

What is a primary reason for differential heating between high and low latitudes?

Albedo effects from ice Signup and view all the answers

What process maintains the balance of heat distribution on Earth?

Global circulation of the atmosphere and oceans Signup and view all the answers

What occurs on the windward side of a mountain range?

Air rises, cools, and releases moisture. Signup and view all the answers

What happens during the daytime sea breeze effect?

Air over land heats up and rises, causing cool ocean air to replace it. Signup and view all the answers

Which process drives the global ocean conveyor belt circulation?

Thermohaline differences in temperature and salinity. Signup and view all the answers

Why is the global ocean conveyor belt important?

It redistributes heat and distributes nutrients. Signup and view all the answers

What is the average global sea surface temperature as of February 2024?

21.06°C Signup and view all the answers

How long does it take for 1 m³ of water to complete a full cycle around the global ocean conveyor belt?

Roughly 1000 years. Signup and view all the answers

What is a characteristic of ocean currents created by differences in water density?

They include both warm and cold currents. Signup and view all the answers

What effect do fronts have on weather patterns?

They lead to the development of storms when different air masses meet. Signup and view all the answers

What primarily measures Sea Surface Temperature (SST)?

Satellite instruments detecting infrared radiation Signup and view all the answers

What indicates a warmer sea surface temperature?

More infrared radiation detected Signup and view all the answers

Which phenomenon is characterized by warmer-than-average sea surface temperatures in the equatorial Pacific?

El Niño Signup and view all the answers

What is the expected duration of an El Niño phase?

9-12 months Signup and view all the answers

What condition is associated with stronger east winds and cooler ocean temperatures?

La Niña Signup and view all the answers

Why is predicting El Niño and La Niña important?

They can increase the likelihood of extreme weather events. Signup and view all the answers

What is the expected chance of La Niña conditions during July to September 2024?

60% Signup and view all the answers

Which two locations are compared to understand the fluctuations in air pressure for ENSO?

Tahiti and Darwin, Australia Signup and view all the answers

What is the main distinction between weather and climate?

Weather encompasses short-term atmospheric conditions, while climate refers to long-term patterns. Signup and view all the answers

What does a global warming potential (GWP) of 310 for nitrous oxide signify?

Nitrous oxide has the potential to warm the atmosphere 310 times more than carbon dioxide over a period of 100 years. Signup and view all the answers

Which atmospheric circulation cells are located between the equator and 30° latitude?

Hadley cells Signup and view all the answers

What is the effect of the Coriolis effect on wind patterns?

Winds in the Northern Hemisphere deflect to the right. Signup and view all the answers

What phenomenon is responsible for the formation of ocean gyres?

Winds and the Coriolis effect Signup and view all the answers

What is radiative forcing?

It measures the ability of a greenhouse gas to trap heat in the atmosphere. Signup and view all the answers

Why is predicting El Niño significant?

It influences global ocean currents and weather patterns. Signup and view all the answers

How does the ice-albedo feedback contribute to global warming?

Melting ice reduces reflectivity, leading to more absorption of heat. Signup and view all the answers

What is the primary role of radiative forcing in climate change?

To quantify the change in energy balance due to forcing agents Signup and view all the answers

What is adjusted radiative forcing?

The change in net radiation that includes stratospheric temperature adjustments Signup and view all the answers

What is the effect of radiative damping in the Earth's atmosphere when positive radiative forcing is imposed?

It limits the increase in surface temperature as the balance restores Signup and view all the answers

Which feedback mechanism is considered a positive feedback due to increased climate temperatures?

Decreasing albedo of ice and snow Signup and view all the answers

How do clouds generally affect climate change?

By varying in effect, either warming or cooling based on cloud type and altitude Signup and view all the answers

In what manner does an increase in water vapor concentration function as a feedback mechanism?

It serves as a positive feedback by amplifying the initial warming effect Signup and view all the answers

What characterizes high clouds in terms of their effect on climate?

They tend to contribute to warming by trapping infrared radiation Signup and view all the answers

What is the primary role of aerosols in climate systems?

They serve as nucleating agents for cloud formation and can alter radiation Signup and view all the answers

Which factor primarily determines the cooling effect of clouds?

The difference between cloud and surface albedos and incoming solar radiation Signup and view all the answers

What is the primary consequence of a downward shift in water vapor distribution as a climate warms?

It would constitute a negative feedback Signup and view all the answers

Study Notes

Milankovitch Cycles

Eccentricity cycle: 100,000 years; influences the length of seasons and seasonal solar radiation received.
Axial tilt cycle: 41,000 years; affects the percentage of Earth's surface receiving direct sunlight.
Precession cycle: 26,000 years; shifts the timing of seasons due to the rotation axis's wobble.

Solar Energy and Global Air Circulation

Global air circulation regulates temperature and precipitation through uneven solar energy distribution.
High latitudes lose more heat than they gain due to low angles of solar incidence and ice albedo.
Low latitudes gain more heat, creating a balance that drives atmosphere and ocean circulation.

Rain Shadow Effect

Windward side of mountains receives precipitation as rising air cools and condenses.
Leeward side experiences dry conditions as descending air warms and retains moisture.

Sea Breeze Front

Daytime: Land heats up faster; warm air rises, creating onshore breezes as cool ocean air moves in.
Nighttime: Land cools faster; warm air over water rises, causing offshore breezes as cool land air replaces it.

Fronts and Storms

Fronts are interfaces where differing air masses meet, leading to storm development.

Global Ocean Currents

Wind-driven upper ocean currents and density-driven deep currents (thermocline circulation) interact.
Currents are influenced by temperature and salinity, distributing heat and nutrients globally.

Global Ocean Conveyor Belt

Series of thermohaline currents circulates water over roughly 1,000 years.
Critical for moving large water volumes, regulating climate, and supporting aquatic ecosystems.

Sea Surface Temperature (SST) Measurement

Average SST around 20°C; February 2024 recorded a peak at 21.06°C.
Measured mainly via satellite detecting infrared radiation, supplemented by ship and buoy data.

ENSO – El Niño Southern Oscillation

ENSO is a global ocean-atmosphere cycle affecting weather patterns, especially in the Pacific.
El Niño occurs when east-central Pacific waters warm, altering currents and weather globally.
La Niña involves cooler waters and stronger east winds; typically lasts longer than El Niño.
ENSO events influence fisheries, agriculture, and are critical for predicting extreme weather occurrences.

Radiative Forcing

Measures the energy imbalance as a result of altered energy inputs (e.g., greenhouse gases, aerosols).
Important for quantifying climate change effects; expressed in watts per square meter (W/m²).

Climate Feedbacks

Feedback mechanisms, like water vapor and cloud presence, directly impact climate stability.
High altitude water vapor amplifies warming; clouds can reflect sunlight (cooling) or trap infrared radiation (warming).

Aerosols

Small particles affecting climate through altering radiation absorption and reflection properties.

Exam Preparation Tips

Review differences between weather and climate, methods of detecting climate changes, and causes of climate change.
Understand concepts like radiative forcing, radiative damping, and the relationship to temperature stabilization.
Be familiar with oceanic and atmospheric phenomena, such as El Niño and La Niña, and their effects on global weather patterns.

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Description

This quiz explores key concepts in climate dynamics, including Milankovitch cycles, global air circulation, the rain shadow effect, and sea breeze fronts. Understand how these phenomena impact temperature, precipitation, and seasonal variations across the globe.