Climate Controls

What are the main factors (controls) that influence climate?

Latitude, altitude, relief, size of landform and proximity to oceans, sea temperatures and currents, and wind and pressure systems.

How does latitude affect temperature?

The closer to the equator, the warmer the temperature. The further from the equator, the colder. This is because the sun's rays hit the equator at less of an angle and are more concentrated. Temperature decreasing with distance from the equator is called the temperature gradient.

How does altitude affect temperature?

The higher the altitude, the colder the temperature. You lose approximately 1°C for every 100 metres gained in altitude. This is because there is less atmosphere at higher altitudes to retain the sun's heat — like a thinner duvet keeping less warmth in.

How does relief affect climate?

Mountains influence rainfall by producing orographic (relief) rainfall. Example: Westland (NZ) receives over 3,000mm of rain per year while Central Otago (in the rain shadow of the Southern Alps) receives only 600mm. Relief can also cause wind funnelling through gaps in mountain ranges — e.g. Cook Strait, which explains why Wellington is very windy.

How does proximity to the ocean affect climate?

Oceans heat and cool more slowly than land, so they moderate nearby temperatures — warming coastal areas in winter and cooling them in summer. Most of NZ is close to the ocean, keeping its climate relatively mild. Sea breezes cool the land in summer and warm it in winter.

What is a continental climate?

A continental climate occurs in the interiors of large landmasses (e.g. Eurasia) far from the ocean. These areas cannot be cooled by ocean breezes in summer or warmed in winter, so they experience much greater extremes of temperature (very hot summers and very cold winters).

Give an example comparing oceanic vs continental climate.

London and Moscow are on similar latitudes, but London has milder winters and cooler summers than Moscow because London is closer to the sea, which moderates its temperature.

How do ocean currents affect climate?

Ocean currents transport heat from the equator toward the poles. Warm currents warm the air above them, bringing warm breezes and wet conditions to nearby coasts. Cold currents cool the air above them, bringing cool breezes and dry conditions. This helps keep coastal temperatures consistent.

What are the effects of warm vs cold ocean currents on a coastline?

Warm currents = wet conditions with warm breezes, warming the coast. Cold currents = dry conditions with cool breezes, cooling the coast.

How do wind and pressure systems affect climate?

The world is divided into pressure belts. Wind generally moves from high pressure to low pressure areas. These systems determine rainfall and temperature patterns globally and in New Zealand.

What are the pressure and weather conditions at the equator?

Low pressure at the equator because the air is very hot and rises. Warm rising air contains evaporated moisture — it cools, condenses and forms clouds, producing heavy rainfall (e.g. tropical rainforests).

What are the pressure conditions at the poles?

High pressure at the polar regions because the air is very cold and sinks.

What pressure systems are near New Zealand and where are they?

Subtropical high-pressure belt is to the north of New Zealand. Sub-polar low-pressure belt is to the south of New Zealand (roughly 40–60°S of the equator).

What is the general direction of wind movement?

Wind moves from areas of high pressure to areas of low pressure.