15 - Climate and Climate Variability Flashcards

This deck focuses on the factors and processes that influence climate and climate zones, including latitude, atmospheric and ocean circulation, and natural climate drivers such as volcanic eruptions and Milankovitch cycles. It also delves into the evidence used to reconstruct past climate variability, including ice cores and sediment cores. (39 cards)

1
Q

Define:

climate

A

The long-term average of weather patterns in a region.

Climate represents the sustained atmospheric conditions in a region over many years, rather than short-term variations.

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2
Q

Explain:

How does climate differ from weather?

A
  • Climate is long-term weather patterns.
  • Weather is short-term weather patterns.

Weather can change in minutes or days, but climate takes years to shift.

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3
Q

Define:

climate zone

A

Region classified by temperature, precipitation, and vegetation.

Image Source

These zones help describe how climate varies across different regions of the Earth.

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4
Q

Explain:

What are the three major climate zones on Earth?

A
  1. Tropical
  2. Temperate
  3. Polar

Tropical: Warm, humid, near the equator.

Temperate: Moderate, distinct seasons.

Polar: Cold, ice-covered, near the poles.

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5
Q

Define:

climate variability

A

Natural fluctuations in climate over short and long periods.

Unlike climate change, which refers to long-term trends, climate variability includes short-term patterns like El Niño or volcanic cooling.

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6
Q

True or False:

The polar climate zone receives the most solar radiation.

A

False

The polar regions receive the least solar radiation, leading to extreme cold.

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7
Q

Identify:

What is the layer of the atmosphere where weather occurs?

A

troposphere

The troposphere is the lowest layer of the atmosphere, where most of Earth’s air mass and water vapor are found, driving weather patterns.

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8
Q

True or False:

Climate change only affects temperature.

A

False

It also affects precipitation, sea levels, and extreme weather events worldwide

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9
Q

Define:

latitude

A

A geographic coordinate that measures distance from the equator.

Latitude affects solar radiation intensity, influencing climate zones such as tropical, temperate, and polar regions.

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10
Q

Identify:

What cycle drives long-term climate change from orbital shifts?

A

Milankovitch Cycle

These changes affect how much solar energy Earth receives, leading to natural climate variations over thousands of years.

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11
Q

Explain:

What are the components of the Milankovitch Cycle?

A
  • Eccentricity
  • Axial Tilt
  • Precession

Eccentricity: Changes in Earth’s orbit shape.

Axial Tilt: Variations in Earth’s tilt angle.

Precession: The wobbling motion of Earth’s axis.

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12
Q

Explain:

How does axial tilt influence climate?

A

Greater tilt increases seasonal contrasts.

A higher tilt angle leads to more extreme summers and winters, while a lower tilt reduces seasonal differences.

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13
Q

Identify:

What is eccentricity in Milankovitch cycles?

A

The change in Earth’s orbit from circular to elliptical.

This affects the amount of solar energy Earth receives, contributing to glacial and interglacial periods.

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14
Q

True or False:

Milankovitch cycles operate over short time periods.

A

False

These cycles take thousands to hundreds of thousands of years to complete, driving long-term climate change.

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15
Q

Describe:

How do Milankovitch cycles contribute to ice ages?

A

They regulate solar energy reaching Earth.

Periods of reduced solar energy lead to glacial expansion, while increased energy triggers ice melting.

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16
Q

Define:

atmospheric circulation

A

The movement of air across the planet that distributes heat.

Wind patterns such as Hadley, Ferrel, and Polar cells help regulate climate.

17
Q

Explain:

Why is atmospheric circulation important for climate?

A

It redistributes heat and moisture, affecting regional climates.

Wind currents move warm air toward the poles and cold air toward the equator, shaping climate patterns.

18
Q

Identify:

What drives the large-scale movement of seawater?

A

Ocean currents

Ocean currents regulate climate by transferring heat across the globe.

19
Q

Define:

El Niño

A

A periodic warming of the central and eastern Pacific Ocean.

It disrupts global weather patterns, causing droughts, floods, and storms.

20
Q

Explain:

How does El Niño impact global climate?

A

It alters precipitation and temperature patterns worldwide.

It weakens trade winds, leading to extreme weather events in many regions.

21
Q

Explain:

What are the main natural climate drivers?

A
  • Volcanic eruptions
  • Solar radiation changes
  • Milankovitch cycles

Volcanic eruptions – Release particles that block sunlight, causing cooling.

Solar radiation changes – Variations in the Sun’s energy that can warm or cool the Earth.

Milankovitch cycles – Long-term changes in Earth’s orbit that affect climate.

22
Q

Identify:

What is the main climate effect of volcanic eruptions?

A

Short-term cooling

Volcanic eruptions release sulfur dioxide, forming aerosols that reflect sunlight and lower global temperatures.

23
Q

Explain:

What was the climate impact of the 1815 Mount Tambora eruption?

A

It caused the Year Without a Summer.

Global temperatures dropped due to volcanic aerosols, leading to widespread crop failures and extreme weather.

24
Q

True or False:

Asteroid impacts cause rapid cooling and ecosystem collapse.

A

True

Large asteroid impacts eject dust and aerosols into the atmosphere, blocking sunlight, lowering temperatures, and disrupting climate systems, leading to mass extinctions.

25
# Explain: What was the significance of the **Chicxulub impact**?
* Caused the K-Pg **extinction event**, eliminating roughly 75% of species, including non-avian dinosaurs, and drastically altering Earth's climate. * This mass extinction event **allowed for the diversification and rise of mammals**, fundamentally changing the trajectory of life on Earth.
26
# True or False: The effects of **asteroid impacts** on climate are **short-lived**.
False ## Footnote Large impacts can disrupt climate for **decades**, with long-term consequences for ecosystems.
27
# Explain: How do **plate tectonics** influence **climate**?
By changing **landmass positions** and **ocean circulation**. ## Footnote Continental drift alters atmospheric and oceanic patterns, affecting global climate.
28
# True or False: Plate tectonics have **no impact** on greenhouse gas levels.
False ## Footnote Tectonic activity **releases CO₂** from volcanoes and influences carbon storage in the ocean.
29
# Define: paleoclimatology
The **study of past climates** using natural records. ## Footnote Scientists use evidence from *ice cores*, *sediment cores*, *tree rings*, and other *natural sources* to reconstruct Earth's climate history.
30
# Identify: What are **natural indicators** that record past climate conditions?
Climate proxies ## Footnote Examples include ice cores, sediment cores, tree rings, corals, and historical records.
31
# Define: speleothems
Cave formations like **stalactites** and **stalagmites** used as climate records. ## Footnote Their chemical composition reflects past *rainfall* and *temperature changes*.
32
# Identify: What are **cylindrical samples** of ice drilled from glaciers or ice sheets?
Ice cores ## Footnote They contain *trapped air bubbles* and *isotopic data*, revealing past temperatures and atmospheric composition.
33
# True or False: Ice cores can provide **climate records** going back **millions** of years.
False ## Footnote While ice cores provide valuable climate records, the oldest known cores date back approximately **800,000 years**, not millions.
34
# Identify: Where are ice cores **mainly collected** from?
Antarctica and Greenland. ## Footnote These regions have *thick ice sheets* that preserve long-term climate records.
35
# Fill in the blank: The **ratio** of \_\_\_\_\_\_\_ isotopes in ice cores helps determine past temperatures.
oxygen ## Footnote Different *oxygen isotopes* (O-16 and O-18) vary with temperature, providing a record of past climate conditions.
36
# Explain: Why are **deep-sea sediment cores** valuable for **climate research**?
They **preserve continuous climate records** for millions of years. ## Footnote Unlike ice cores, which are limited to high-latitude regions, sediment cores cover *longer timescales* and *global locations*.
37
# Define: sediment cores
Layers of **accumulated sediments** from lakes or oceans. ## Footnote These cores contain *biological*, *chemical*, and *physical clues* about past climates, including pollen and microfossils.
38
# Explain: What are **three key components** analyzed in sediment cores?
1. Pollen grains 2. Microfossils 3. Chemical isotopes ## Footnote **Pollen grains** – Indicate past vegetation and climate. **Microfossils** – Show past ocean conditions. **Chemical isotopes** – Reveal temperature and ice volume changes.
39
# Explain: What role do **microfossils** in sediment cores play in climate studies?
They indicate **past ocean temperatures** and **conditions**. ## Footnote The chemical composition of microfossils, like *foraminifera*, reflects past sea surface temperatures and ocean chemistry.