Weather & Climate: Key Concepts and Sample Questions for Geography 130

What distinguishes supercell thunderstorms from simple air mass thunderstorms?

Supercell thunderstorms rotate, usually last much longer, and are more intense, potentially including hail and tornadoes.

What are the characteristics of air mass thunderstorms?

They usually last less than an hour, are less than a few kilometers in diameter, and rarely produce hail or tornadoes.

What is the precipitation that forms when ice particles are repeatedly carried upward in a thunderstorm cloud?

Hail.

Why can thunderstorm activity along a squall line last for several hours or days?

Squall lines advance into warm air, which fuels updrafts, while downdrafts occur in the cold air sector.

With which type of thunderstorms are tornadoes often associated?

Supercell thunderstorms.

Which U.S. state has the highest frequency of tornadoes per square mile?

Oklahoma.

What is true about lightning?

Lightning is the result of charge separation in thunderstorm clouds and does not always travel from a cloud to the ground.

What are microbursts?

Microbursts are strong downdrafts that may form beneath thunderstorms and can cause serious aviation hazards.

What are the characteristics of tornadoes?

Tornadoes have the highest surface wind speeds of any storm type and can completely destroy city blocks while leaving adjacent areas intact.

What is an example of a multicell thunderstorm?

A mesoscale convective complex or a squall line.

What type of storm occurs when mT air meets cT air in Texas?

A dryline thunderstorm.

What describes a moderate rain shower lasting 45 minutes on a summer afternoon?

An air mass thunderstorm.

What is a powerful wind that poses a serious aviation hazard?

A microburst.

What describes an isolated cluster of thunderstorms occurring in Indiana in July?

A mesoscale convective complex.

What is a cyclonic storm off the coast of Florida with a wind speed of 45 mph?

A tropical storm.

What is a rotating storm in Lincoln, Nebraska producing lightning and golf-ball sized hail?

A supercell thunderstorm.

What is a rotating storm with a wind speed of 212 mph moving northeast across Oklahoma?

A tornado.

What is a wintertime storm bringing strong winds and 1.2 inches of rain to Southern California?

A mid-latitude cyclone.

What is a Category 5 storm named Michael moving north in the Gulf of Mexico?

A hurricane.

What are the characteristics of tropical climates in the Köppen Classification?

They are classified as 'A'.

What are the characteristics of polar climates in the Köppen Classification?

They are classified as 'E'.

What are humid moderate (mesothermal) climates classified as in the Köppen system?

They are classified as 'C'.

What are mountain (highland) climates classified as in the Köppen system?

They are classified as 'H'.

What factors might be associated with a wet climate?

Persistent low pressure, maritime air masses, and frequent frontal passages.

What is true about monsoon climates?

They are characterized by distinct wet and dry seasons.

What is the dominant summertime influence on climates in Southern California and Mediterranean Europe?

Subtropical high pressure.

How does latitude influence temperature as one moves from the Equator toward the Poles?

Temperature decreases and seasonal variation increases.

How do mountain ranges influence precipitation?

Precipitation is usually highest on windward slopes facing the prevailing winds.

What are air masses?

Large bodies of air that have fairly uniform characteristics, classified by temperature, moisture, and source region.

What does the Köppen climate classification system classify?

Climate based on temperature and precipitation.

What characterizes Ice Cap Climates?

Average monthly temperatures are above freezing only during the summer.

What are the characteristics of a Mediterranean climate?

Dry summers, winter rainfall, and moderate year-round temperatures.

What characterizes the Earth's Equatorial zone?

Year-round rainfall.

What defines areas where potential evapotranspiration exceeds actual precipitation?

They are known as deserts.

What causes precipitation in Moist Subtropical Climates?

Mid-latitude cyclones in winter and maritime tropical air masses in summer.

How does weather generally move in mid-latitude zones?

From West to East.

What is true about mid-latitude continental climates?

They usually have greater seasonal temperature variation than mid-latitude marine climates.

What characterizes highland climates in the Köppen classification?

They are highly variable and can occur at almost any latitude.

What is true about areas located midway between the Equator and 30°N or S?

They often have distinct wet and dry seasons due to the migration of the ITCZ.

What are the reasons for using multiple techniques in climate reconstruction?

Different techniques are better suited to different lengths of time, different climatic variables, and allow for correlation and cross-checking of results.

What is true of the Earth's overall annual temperature?

It is higher than it was during the mid-1800s.

How can Earth's climate over the past 540 million years be described?

It has long warm ice-free periods separated by colder intervals known as ice ages.

What can cause changes in overall energy output of the sun?

Changes may occur as a result of sunspots.

What is associated with a change in the tilt of the Earth's axis over 41,000 years?

It is associated with Milankovitch Cycles, which affect the intensity of the seasons and the volume and geographical extent of ice sheets.

What happens during periods of increased seasonality caused by changes in the Earth's orbit?

Ice sheets usually retreat and greenhouse gas concentrations increase.

What are airborne particulates and aerosols in the atmosphere?

They are produced by human activities and natural processes, can serve as condensation nuclei in clouds, and can cause global temperature to cool.

What are the main causes of glacial ice advances during the past two million years?

Changes in seasonality associated with variations in Earth's orbit are a primary cause.

How do changes in continental position affect climate?

They can lead to changes in the Earth's albedo, global rainfall patterns, and global temperature.

What are possible sources of data to reconstruct climates from more than twenty million years ago?

Ocean sediments are a possible source.

What was the most likely cause of Cenozoic cooling between 55 and 2.6 million years ago?

The uplift of the Himalayas and increased chemical weathering.

What is El Niño most closely associated with?

A warming of the waters in the Eastern Pacific off the South American coast.

What was the Polar Vortex in 2014 associated with?

A southerly shift of the Polar Jet Stream.

What is the eastward shift in low pressure along the Equator during El Niño called?

The Southern Oscillation.

What is El Niño generally associated with in Southern California?

A higher than normal incidence of winter storms and higher than average rainfall.

How do ocean currents affect climate?

They give Western Europe a much warmer climate than similar latitudes in North America and transport heat from the Tropics toward the Poles.

What is the Little Ice Age?

It occurred between approximately 1350 and 1850 AD and may have been linked with decreased sunspot activity.

What is an example of positive feedback in the climate system?

An increase in low cloud growth and planetary albedo as a result of initial warming.

What is an example of negative feedback in the climate system?

An increase in chemical weathering and a reduction in carbon dioxide as a result of initial warming.

What is true of the Earth's energy budget?

The Earth receives shortwave radiation from the sun and emits longwave radiation.

What is the time scale associated with changes in continental positions?

More than 1 million years.

What is the time scale associated with changes in atmospheric particulate levels?

Less than 100 years.

What is the time scale associated with El Niño - La Niña?

Less than 100 years.

What is the time scale associated with variations in Earth's orbit?

10,000-1,000,000 years.

What is the effect of an increase in carbon dioxide in the atmosphere?

It is likely to cause global temperature to increase due to increased absorption of longwave radiation.

What may result from a reduction in the Gulf Stream current?

It may cause Europe to experience a period of cooling.

What do Global Circulation Models (GCMs) indicate as the most significant cause of climate change in the past 100 years?

An increase in atmospheric greenhouse gas concentration.

What are realistic strategies to decrease global greenhouse gas emissions?

Shifting towards renewable sources of energy, such as solar and wind power.

What is the influence of global temperature increase on ecosystems?

It can lead to a poleward migration of some species, such as the spruce bark beetle.

What has happened to greenhouse gas concentrations since the 19th Century?

Greenhouse gas concentrations have increased sharply since the 19th Century.

How is precipitation expected to change as the Earth's climate warms?

Precipitation is likely to increase overall in some locations, decrease in others, and become more variable, possibly increasing both droughts and floods.

Why is agricultural productivity likely to decline as the climate warms?

Due to decreased soil moisture, decreased solar radiation, and a decreased length of the growing season.

What are the likely consequences of a warming climate?

Consequences include extinction of some species, a rise in sea level, and changes in agricultural productivity in many regions.

Which geographical areas may become uninhabitable due to global temperature increase?

Low-lying island nations of the South Pacific are likely to become uninhabitable.

What do most climate models predict for global climate in 2100?

They predict increased temperature over land surfaces.

How does burning fossil fuels contribute to climate change?

It releases carbon dioxide into the atmosphere.

What is the most likely scenario for Earth's climate in the future?

Earth's temperature will fluctuate, but it will be warmer in 50 years than it is today.

What characterized the first four billion years of Earth's history?

They likely had larger temperature changes than currently experienced and included at least three severe ice ages.

What does the BLAG hypothesis suggest about Earth's temperature?

It suggests that Earth's temperature over millions of years is controlled by the rate of release of carbon dioxide from sea floor spreading.

What can a large blizzard in January indicate about global climate?

It would not necessarily indicate very much about global climate on its own.

What are fronts in meteorology?

Fronts may be associated with precipitation, wind shifts, and changes in temperature.

What is true about the Earth's energy budget?

The Earth receives shortwave radiation from the sun and emits longwave radiation.

What is the atmospheric layer immediately above the troposphere?

It is known as the stratosphere, which contains ozone that absorbs harmful ultraviolet radiation.

What happens to atmospheric pressure as elevation increases?

Atmospheric pressure decreases.

What is the Coriolis Force?

It is the result of the Earth's rotation and affects wind and ocean currents.

What primarily causes the seasons on Earth?

The tilt of the Earth on its axis.

Where do persistent high-pressure systems tend to form?

Over the Poles, where air is sinking.

What is likely to occur if atmospheric pressure is dropping?

Increasing cloudiness is likely.

What is chemical weathering?

It increases as temperature, precipitation, and vegetation cover increase, and can remove carbon dioxide from the atmosphere.

What type of weather is likely when a cold front is approaching?

Rainfall is most likely to occur.