Distribution of temperature and inversion of temperature

Toward the poles sun rays become more oblique and energy spreads out. In exams remember latitude with solar angle.

Low latitudes receive more direct sun rays. In exams link equatorial regions with higher temperature.

Temperature generally decreases with height and this is called lapse of temperature. In exams use it to explain mountain coolness.

Far from sea land heats and cools quickly. In exams link distance from sea with continentality.

Water has high heat capacity so coastal temperature remains moderate. In exams remember coastal areas by maritime influence.

In inland areas maritime control is weak so temperature range increases. In exams link continentality with higher temperature range.

The direct answer is C: isotherm. An isotherm is an imaginary line drawn on a map through places that have the same temperature at a specified time or during a specified period. The word can be understood as iso, meaning equal, and therm, meaning heat or temperature. Therefore C is correct. A, an isobar, joins places with equal atmospheric pressure, not equal temperature. B, an isohyet, joins places receiving equal rainfall. D, a coastline, marks the meeting area of land and sea; it does not show equal temperature. The exact identification is equal temperature → isotherm. The date or period matters in real maps because temperatures change, but the definition remains the same. Memory cue: therm means temperature, so isotherm means equal temperature.

Isotherms show spatial differences of temperature on maps. Link them with temperature maps in exams.

A warm current brings heat and can raise coastal temperature. In exams link warm current with warming.

A cold current can cool the air near the coast. In exams remember cold current by cooling effect.

Winds from sea carry maritime influence that moderates temperature. In exams link sea winds with moderate temperature.

Land winds have less maritime moderation so temperature can vary more. In exams check the source region.

Vegetation reduces solar heating and cools through transpiration. In exams treat vegetation as a local cooling factor.

Urban surfaces store heat by day and release it at night. In exams link city temperature with surface materials.

A sun facing slope can receive more solar energy. In exams link slope aspect with solar receipt.

In the Northern Hemisphere south facing slopes face the Sun more. In exams study slope direction with hemisphere.

Daily range is the difference between highest and lowest temperature of a day. Remember it as day night temperature difference.

The direct answer is A: the temperature difference between the hottest and coldest months. Annual temperature range measures the difference between the mean temperature of the hottest month and the mean temperature of the coldest month in a year. In calculation form, annual range = mean temperature of hottest month − mean temperature of coldest month. For example, if the hottest-month mean is 30°C and the coldest-month mean is 15°C, the annual range is \\(30-15=15^\\circ\\mathrm{C}\\). A is correct because it compares seasonal temperatures across a year. B is wrong because morning and evening wind is not the annual temperature range. C is wrong because river length is a distance, not temperature. D is wrong because mountain age is a time measurement unrelated to temperature. Memory cue: annual range means yearly high temperature minus yearly low temperature.

Water vapour and clouds can reduce day night temperature difference. In exams understand humidity as a temperature moderator.

With less moisture longwave heat escapes easily. In exams link deserts with strong night cooling.

Normally temperature decreases with height but in inversion it increases. Remember it as reverse of normal lapse in exams.

Temperature inversion is a condition in which the usual decrease of temperature with height is reversed near the ground. A layer of relatively warm air lies above a layer of colder, denser air. Because the colder air is trapped below, vertical mixing becomes weak. Smoke, dust, and pollution may therefore remain close to the surface, especially when winds are light and the sky is clear.

Option A is correct because the lower air is colder than the air above it during an inversion. Option B describes the opposite arrangement and is not the defining feature of inversion. Options C and D are unrelated: the lower air does not disappear and is not locked inside the sea. The essential pattern to remember is cold air below and warmer air above, which reverses the normal temperature arrangement.

On a clear calm night the surface cools by radiation and cools lower air. Link night cooling with radiation inversion in exams.

Clear sky allows heat escape and calm air reduces mixing. Treat clear calm night as main condition in exams.

The warm layer prevents cold lower air from rising. In exams link inversion with stable atmosphere.