Chapter 3 Study Guide

radiational cooling

The process by which Earth’s surface and adjacent air cool by emitting infrared radiation.

radiation inversion

An increase in temperature with height due to radiational cooling of Earth’s surface.

freeze

A condition occurring when the surface air temperature remains below freezing for a sufficient time to damage agricultural crops.

thermal belt

Horizontal zones of vegetation found along hillsides resulting from vertical temperature variations.

orchard heater

Oil heaters placed in orchards that generate heat and promote convective circulations to protect fruit trees.

wind machine

Fans placed in orchards for the purpose of mixing cold surface air with warmer air above.

daily (diurnal) range of temperature

The difference between the maximum and minimum temperatures for any given day.

mean (average) daily temperature

The average of the highest and lowest temperature for a 24-hour period.

controls of temperature

The main factors that cause variations in temperature from one place to another.

Isotherm

A line connecting points of equal temperature.

annual range of temperature

The difference between the warmest and coldest months at any given location.

mean (average) annual temperature

The average temperature at a given location for the entire year.

heating degree day

A form of the degree day used as an index for fuel consumption.

cooling degree day

A form of degree day used to estimate the amount of energy necessary to reduce the effective temperature of warm air.

growing degree day

A form of the degree day used as a guide for crop planting and estimating maturity dates.

sensible temperature

The sensation of temperature that the human body feels in contrast to the actual temperature.

wind-chill index

The cooling effect of temperature and wind, expressed as the loss of body heat.

Frostbite

The partial freezing of exposed parts of the body causing injury.

Hypothermia

The deterioration in one’s mental and physical condition due to rapid lowering of body temperature.

liquid-in-glass thermometer

An instrument for measuring temperature with a sealed glass tube attached to a glass bulb filled with liquid.

maximum thermometer

A thermometer designed to measure the maximum air temperature.

minimum thermometer

A thermometer designed to measure the minimum air temperature during a desired time period.

electrical thermometer

Thermometers using elements that convert energy from one form to another.

Radiometer

An instrument designed to measure the intensity of infrared radiation.

bimetallic thermometer

A temperature-measuring device consisting of two dissimilar metals that expand and contract differentially.

Thermograph

An instrument that measures and records air temperature.

instrument shelter

A boxlike structure designed to protect weather instruments from direct sunlight and precipitation.

perihelion

The point at which Earth is closest to the sun, occurring around January 3rd each year.

aphelion

The point at which Earth is farthest from the sun, occurring around July 4th.

solstice

Marks the longest and shortest days of the year.

equinox

Days when day and night are approximately equal in length.

temperature inversion

A layer of warm air that traps cooler air near the Earth's surface.

latitude

Affects the angle of sunlight received, influencing temperature and seasonal variations.

Proximity to Water

Coastal areas tend to have milder temperatures due to the moderating influence of large bodies of water.

Ocean Currents

Warm and cold currents significantly affect coastal climates.

Elevation

Higher altitudes generally experience cooler temperatures, leading to variations in climate.

heat index

A measure that combines air temperature and humidity to determine how hot it feels.

wind chill

The perceived decrease in temperature felt by the skin due to air flow.

alcohol thermometer

A thermometer using colored alcohol that expands in a glass tube to indicate temperature.

mercury thermometer

A thermometer containing mercury which expands with heat but poses toxicity risks.