ES1 Wind and Clouds

What is latent heat?

Latent heat is "hidden heat" that is absorbed or released during a phase change, but the temperature does not change.

Which processes absorb heat (endothermic)?

1. Melting (solid extharr liquid)

2. 2. Evaporation / boiling (liquid extharr gas)

3. 3. Sublimation (solid extharr gas)

Which processes release heat (exothermic)?

1. Freezing (liquid extharr solid)2. Condensation (gas extharr liquid)3. Deposition (gas extharr solid)

What happens to temperature during phase changes?

During melting or boiling, temperature stays the same even though heat is added. All energy goes into breaking or forming bonds, not heating it.

What is the formula to calculate relative humidity (RH)?

RH = 100 \times (\text{actual water vapor} \div \text{capacity})

How do you use humidity charts to find relative humidity, dew point, or capacity?

1. Find the dry bulb temperature.2. Subtract wet bulb to get the wet bulb depression.3. Use the chart to read RH or dew point.4. Use the temperature to read capacity from the graph.

How is humidity measured with a psychrometer?

A psychrometer has a dry bulb thermometer and a wet bulb thermometer wrapped in wet cloth. The wet bulb evaporates water, causing cooling. The more it cools, the lower the humidity.

How does a hair hygrometer work?

A hair hygrometer uses human or horse hair. Hair lengthens when humidity rises and shortens when humidity drops. The machine measures this change to give humidity.

Differentiate between Relative Humidity and Absolute/Specific Humidity.

1. Relative humidity: How full the air is compared to what it can hold (percentage).2. Absolute/Specific humidity: Actual amount of water vapor in the air (g/kg).

Why does a drop in temperature increase Relative Humidity (RH)?

Cooler air holds less water vapor (capacity goes down), which causes the relative humidity (RH) to go up.

Which processes cool air to form clouds?

1. Orographic lifting extharr air rises over mountains2. Convection extharr warm air rises3. Frontal wedging extharr warm air rises over cold front4. Adiabatic cooling extharr rising air expands and cools5. Convergence extharr air piles up and rises

What are the three ingredients needed to form clouds?

1. Water vapor2. Cooling air3. Condensation nuclei (dust, salt, smoke)

Define Dew point.

Dew point is the temperature where air is saturated.

Define Saturated air.

Saturated air is air with 100% relative humidity (RH).

Define Adiabatic cooling.

Adiabatic cooling is when air cools as it rises and expands.

Define Condensation nuclei.

Condensation nuclei are tiny particles water condenses on.

What are the conditions associated with Cloudy weather?

1. Temp decreases2. Pressure decreases3. Air rises4. Air expands5. Condensation happens

What are the conditions associated with Clear weather?

1. Temp increases2. Pressure increases3. Air sinks4. Air compresses5. Evaporation happens

What causes wind?

Wind is caused by uneven heating due to:1. Earth’s tilt2. Earth’s curved shape (equator gets more energy)3. Land heats faster than water.Wind blows from high (cold air) to low (warm air) pressure.

How does convection cause wind?

Warm air rises and cold air sinks. The sideways movement of air as a result of this convection is wind.

What is the Coriolis Effect?

The Coriolis Effect is caused by Earth’s rotation, deflecting winds:1. Northern Hemisphere: winds curve right2. Southern Hemisphere: winds curve left

Describe the global wind patterns and pressure belts.

1. 90°N Polar Easterlies

What are the pressure belts at 0°, 30°, 60°, and 90° latitudes?

1. 90°N – High (sinking air)2. 60°N – Low (rising air)3. 30°N – High (sinking) – Horse Latitudes4. 0° – Low (rising) – Doldrums5. 30°S – High (sinking) – Horse Latitudes6. 60°S – Low (rising)7. 90°S – High (sinking)

How do High and Low Pressure relate to air movement?

1. High pressure: sinking air2. Low pressure: rising air

Fill in the blanks: Wind travels from to pressure.

Wind travels from high to low pressure.

Fill in the blanks: Wind travels from to temperatures.

Wind travels from cold to warm temperatures.

Describe a Sea Breeze (during the day).

During the day, wind blows from the sea (cool, high pressure) to the land (warm, low pressure).

Describe a Land Breeze (during the night).

During the night, wind blows from the land (cool, high pressure) to the sea (warm, low pressure).

Differentiate between Valley and Mountain Breezes.

1. Valley breeze (day): Warm air rises up slopes.2. Mountain breeze (night): Cold air sinks into valleys.