quiz 4 lab earth science

Which dune type forms when wind directions are highly variable, producing a multi-armed shape?

Star dune

Which statement about warm sectors in a mid-latitude cyclone is correct?

The warm sector is usually fair, warm, and humid due to southerly flow.

In the idealized three-cell model of atmospheric circulation, which cell occupies the latitudes between the equator and 30°?

Hadley cell

Which of the following best explains why tropical cyclones often weaken rapidly after making landfall?

Loss of the ocean heat and moisture source that fuels the storm

The Ferrell cell is driven primarily by:

Mid-latitude interactions between the Hadley and Polar cells and eddy-driven processes

On an infrared satellite image, a large area appearing black most likely indicates:

Cloud-free surface (warmer surface temperatures)

Using Table 2, if air temperature is 77°F and actual water vapor content corresponds to 10 g/kg capacity, what is the approximate RH %?

50% (because capacity at 77°F is 20 g/kg)

On a diurnal plot where temperature increases during daytime and dew point stays nearly constant, what happens to RH during the day?

RH decreases because warmer air increases water vapor capacity while water vapor content remains similar.

Barchan dunes are most likely to form where:

Sand supply is limited and there is a constant wind direction

In Figure 8, if a short period contains a very high liquid-equivalent precipitation rate simultaneous with sharp drops in temperature and increases in humidity, what mechanism most plausibly produced the precipitation?

Frontal passage or convective downdraft producing intense, short-duration rainfall and cooling (outflow).

How does increasing latitude generally affect the solar angle at local noon on an equinox?

Solar angle decreases with increasing latitude.

The primary driver that causes air to move from high-pressure areas toward low-pressure areas is best described as:

Pressure gradient force (Law of Least Resistance)

Surface convergence (C) at the Earth’s surface is most directly associated with which of the following?

Rising air and low pressure

A coastal desert is most likely to form when:

Prevailing winds from the interior prevent moisture from moving onto the coast

On the June (summer) solstice in the Northern Hemisphere, which statement is true for the Northern Hemisphere?

The Northern Hemisphere is tilted toward the Sun and has its longest day of the year.

Polar regions can be considered deserts primarily because they:

Receive very little precipitation annually

Dew point temperature is best described as:

The temperature at which air must be cooled for RH to reach 100%.

Which of the following best describes the relationship between length of daylight and seasonality?

Longer daylight increases the daily integrated solar radiation, contributing to warmer seasons.

Why are low latitudes generally warmer than high latitudes?

Low latitudes receive solar radiation at higher solar angles, concentrating energy on smaller surface areas.

On Figure 6 (a sunny winter day: temperature, dew point, RH over time), which pattern would indicate very dry air through the day?

Low latitudes receive solar radiation at higher solar angles, concentrating energy on smaller surface areas.

On Figure 6 (a sunny winter day: temperature, dew point, RH over time), which pattern would indicate very dry air through the day?

Temperature much higher than dew point and consistently low RH values.

A rain-shadow desert forms because:

Moist air loses precipitation on the windward side of mountains and the leeward side receives dry descending air

Which observation from Figures 6 and 7 would most clearly indicate that a precipitation event was driven by convective instability (i.e., thunderstorms) rather than large-scale frontal lifting?

Rapid daytime temperature increase followed by sharp cooling and sudden rise in RH coincident with brief intense precipitation totals.

Which scenario most likely produces cumulonimbus clouds and intense thunderstorms along a frontal boundary?

Warm air rapidly forced upward along a cold front

On an equinox, what is true globally about day and night?

Day and night are approximately equal (about 12 hours) at most locations.

Which circulation cell governs the mid-latitudes between roughly 30° and 60°?

Ferrell cell

Which of the following describes why air that rises cools as it ascends?

Rising air expands in lower pressure aloft and cools adiabatically, lowering its capacity for water vapor.

Which of the following best explains why coastal locations often have milder seasonal temperature ranges than inland locations at similar latitudes?

Ocean has high heat capacity, moderating temperature changes and influencing humidity.

Suppose Figure 7 shows dew point and air temperature nearly equal for several hours before rainfall. The most immediate implication is:

Relative humidity is near 100%, making condensation and precipitation likely.

In Figure 4 (daily record highs and lows for Laredo, TX), which seasonal pattern would you expect to find for extreme temperatures?

Highest record highs near mid-summer; lowest record lows near mid-winter.

Table 1 lists South Texas daylight lengths: Longest day 13.5 hr, shortest day 10.5 hr, equinoxes 12 hr. Which conclusion follows for South Texas?

The annual difference between longest and shortest day is 3.0 hours.

If Earth’s axial tilt were 0° (no tilt), which of these would be a direct consequence?

Each latitude would receive the same daily solar radiation year-round, eliminating seasons.

The same amount of incoming solar radiation at a lower solar angle is distributed over a larger surface area because:

Solar rays strike the surface more obliquely, spreading energy over more area.

(Interpretation of Figure 8 – precipitation) Liquid equivalent precipitation measures:

The total amount of water (liquid) resulting from melting all solid precipitation plus liquid precipitation, standardized for comparison.

Which of the following best explains why Earth experiences seasons?

Earth’s axis is tilted relative to its orbital plane, changing the hemisphere’s exposure to the Sun.

Relative humidity (RH %) is defined by which formula?

RH % = 100% [(Water Vapor Content) / (Water Vapor Capacity)]

Subtropical deserts commonly form at about which latitudes?

30° North and South

Flash floods in deserts occur primarily because:

Heavy precipitation over short periods produces high-velocity flows that cannot infiltrate compacted or hydrophobic soils

Dust from large deserts can travel long distances. Which example from the passage illustrates this global transport?

Dust from the Sahara reaching the United States and being found in Atlantic Ocean sediment cores

A mid-latitude cyclone typically includes which three major components?

Central low-pressure area, cold front, and warm front

When surface air is forced to sink beneath a high-pressure center, what is the typical thermodynamic response?

Sinking air compresses and warms, decreasing RH and suppressing cloud formation.

Which condition would most likely produce condensation (cloud formation or dew)?

Air temperature cooled to dew point so RH reaches 100%.

If a weather map shows a large high-pressure center over a region, the most likely near-term weather is:

Sinking air, warming, lower RH, and generally fair, clear conditions.

Which of these best describes the typical movement of mid-latitude cyclones across the continental United States?

West to east, steered by westerlies and associated upper-level flow

Which factor most directly causes the apparent height of the Sun above the horizon (solar angle) to change over the year at a fixed location?

Earth’s axial tilt combined with Earth’s position in its orbit.

Which combination of surface temperature and dew point typically feels most humid to humans?

75°F temperature and 72°F dew point.

If an air parcel at the surface has RH = 40% and temperature increases during the day while water vapor content remains constant, which statement is true?

RH will decrease because water vapor capacity increases with temperature.

Deserts often show extreme temperature swings between day and night mainly because:

Lack of atmospheric moisture and scarce cloud cover reduce heat retention at night

Which of the following best defines an erg?

A broad sand-sea covered by a sheet of fine sand forming dunes

Which statement about desert dunes is true?

The leeward (slip) face of a dune develops when sand pours over the crest and reaches the angle of repose

Which human activity is commonly linked to accelerating desertification?

Overgrazing by livestock and unsustainable farming practices

If air at 59°F has a water vapor capacity of 10 g/kg, and measured water vapor content is 5 g/kg, the RH % is:

50%

Desertification refers to:

Human-caused degradation of once-productive land into arid conditions

In the Northern Hemisphere, winds around a surface high-pressure system near the ground will:

Spiral outward clockwise away from the center

Which worst-case hazard can a relatively weak tropical storm still produce after landfall?

Widespread, slow-moving heavy rainfall causing inland flooding

When a tropical disturbance organizes into a system with sustained winds of 40 mph, it is classified as:

Tropical storm

Which statement correctly contrasts cold fronts and warm fronts in terms of precipitation intensity and duration?

Cold fronts produce intense, short-lived precipitation; warm fronts produce lighter, longer-lasting precipitation.

Which of these deserts is a classic example of a coastal desert?

Namib

A tropical depression differs from a tropical storm primarily by which criterion?

Maximum sustained wind speed threshold (less than 39 mph for depression)

In the Northern Hemisphere, which steering flow initially carries developing tropical cyclones westward from the coast of Africa?

Northeast trade winds within the Hadley cell

During a summer precipitation event (Figure 7), which of the following typical changes would you expect near the onset of rainfall?

Dew point and air temperature converge and RH approaches 100%.

A hurricane’s characteristic “eye” indicates:

A well-developed, intense tropical cyclone with a calm center

The Racetrack Playa experiments concluded that the movement of “sailing rocks” was due to:

Thin ice sheets combined with wind-driven forces allowing rocks to slide

Low-pressure systems are associated with which sequence of processes?

Rising air → cooling → increasing RH → cloud formation and precipitation.

Isobars on a weather map are analogous to which other map feature, and what do tightly packed isobars indicate?

They are analogous to contour lines of elevation; tightly packed isobars indicate a strong pressure gradient and stronger winds.

Desert pavement forms primarily by:

Removal of fine particles by wind leaving behind closely packed pebbles and cobbles

Which of the following is the most widely used quantitative criterion for classifying a region as a desert?

Average annual precipitation fewer than 10 inches

Which statement about dew point is correct?

A higher dew point means a greater absolute amount of water vapor present.

Yardangs and ventifacts are landforms shaped mainly by:

Wind abrasion and saltating sandblasting of rock surfaces

Infrared satellite imagery shows colder cloud tops as white and warmer surfaces as black. Which feature would appear white on an IR image?

High cumulonimbus cloud tops

An arroyo is best described as:

A dry wash or ephemeral stream channel that fills quickly after rain

Which process describes wind-driven short hops of sand grains that dislodge others on impact?

Saltation