Social Studies -Weathering the storm Macleans

Latitiude

Distance north/south of Equator. Controls temperature because sunlight hits more directly at low latitudes and more angled at high latitudes, making higher latitudes cooler.

Alitiude

Height above sea level. Temperature drops about 1°C every 100m because air becomes thinner, expands, and cannot hold heat well.

Distance from sea

Coastal areas have small temperature range because ocean heats/cools slowly. Inland areas heat/cool quickly, causing extreme temperatures and lower rainfall.

Maritime Climate

Mild temps, high rainfall, small temperature range. Caused by ocean moderating temperature and providing moisture.

Continental Climate

Large temperature range, hot summers, cold winters, low rainfall. Caused by land heating/cooling quickly and being far from moisture sources.

Relief/Topography

Mountains force air to rise (uplift). Rising air cools, condenses, forms clouds → rain. Land shape controls where rain falls and where dry areas form.

Southern Alps affect

Moist westerlies from Tasman Sea hit Alps → forced upward → cool → condense → heavy orographic rain on West Coast. After crossing, air sinks on east side → warms → dries → creates rain shadow. Explains why Hokitika is extremely wet and Christchurch/Alexandra are dry.

Rain shadow

Dry region on leeward side of mountains. Air descends, warms, and increases its ability to hold moisture, so almost no rain falls.

Akl climate

Maritime: mild temps, high rainfall, coastal, low altitude. Influenced by warm ocean currents and moist air.

hokitika climate

Very wet due to strong westerlies hitting Southern Alps. Classic orographic rainfall zone.

christchurch climate

Dry, in rain shadow. Westerly winds lose moisture before reaching east coast. Larger temperature range.

Alexandra climate

Extreme continental climate. Surrounded by mountains blocking moist air. Hot summers, freezing winters, very low rainfall.

Orographic rainfall

Air forced up mountains → cools → condenses → rain on windward side. Creates wet west, dry east in NZ.

Frontal rainfall

Warm air mass meets cold air mass. Warm air rises over cold, cools, condenses → steady rain along front boundary.

Convectional rainfall

Sun heats ground → ground heats air → air rises quickly → cools → thunderstorms. Common in tropics and hot summer days.

tropical zone

Near Equator. Hot all year, high rainfall, strong convection, low temperature range.

temperate zone

Mid‑latitudes (NZ). Moderate temps, four seasons, variable weather due to changing air masses.

Polar zone

High latitudes. Very cold, low sun angle, long winters, little precipitation.

Green house effect

Natural process where gases trap heat in atmosphere. Essential for life. Human emissions increase greenhouse gases → enhanced greenhouse effect → global warming.

thermometer

Measures air temperature in °C.

barometer

Measures air pressure in millibars. High pressure = settled weather; low pressure = stormy.

rain gauge

Measures rainfall in mm.

Anemometer

Measures wind speed in km/h or m/s.

Wind vane

Shows wind direction (where wind is coming FROM).

hygrometer

Measures humidity (amount of water vapour in air).

Isobars

Lines of equal air pressure. Close together = strong winds; far apart = light winds.

Milibars

Units for air pressure. Typical NZ pressure ranges 980–1030mb.

High pressure (anticyclone)

Air sinks, warms, and dries. Clear skies, calm winds, stable weather.

low pressure (depression)

Air rises, cools, condenses. Clouds, rain, strong winds, storms.

cold front

Cold air pushes under warm air. Causes heavy rain, thunderstorms, sudden temperature drop.

warm front

Warm air slides over cold air. Causes steady, long‑lasting rain and gradual warming.

El Nino

Pacific pattern causing stronger westerlies, cooler temps, and drier conditions in eastern NZ. West Coast becomes wetter.

Cyclone Gabrielle

Intense low‑pressure system. Warm ocean water fueled strong winds and extreme rainfall. Caused flooding, slips, storm surges, widespread damage.