Ocean-atmosphere interactions

A continuous, directed flow of seawater (e.g. the warm Gulf Stream, the cold Humboldt Current).

A large, roughly circular system of surface currents driven by winds and the Coriolis effect (clockwise in the northern hemisphere).

The slow, global deep-ocean circulation driven by differences in **temperature** (thermo) and **salinity** (haline).

Cold, **nutrient-rich** deep water rising to the surface (e.g. off Peru), feeding plankton and large fisheries.

The warm ENSO phase: trade winds weaken, warm water spreads east, and upwelling off South America is **suppressed**.

The cold ENSO phase: trade winds strengthen, the eastern Pacific **cools**, and upwelling **intensifies**.

El Nino = eastern Pacific warms + upwelling off Peru collapses; La Nina = eastern Pacific cools + upwelling strengthens.

Warm water shuts down the Humboldt upwelling, so nutrients fall, anchovy stocks collapse, and fishing income drops.

Fewer Atlantic hurricanes (more wind shear), so the US Gulf and Caribbean coasts suffer fewer tropical storms.

Heavy rain and flooding in eastern Australia/SE Asia, and worse drought and wildfire in California.

Subtract the lowest reading from the highest reading (e.g. +2.25 - (-1.50) = 3.75), then quote the units.

A developed benefit AND harm in different regions, named places, a weighing of which outweighs, and a balanced judgement.

A large, rotating **low-pressure** system with very strong winds and heavy rain, fuelled by a **warm ocean**.

The same hazard in different regions: **hurricane** (Atlantic/E Pacific), **typhoon** (W Pacific/Asia), **cyclone** (Indian Ocean/Australia).

About **26.5 °C or warmer**, and warm to roughly 50 m depth, to supply enough energy.

The **energy released when water vapour condenses** into cloud — the storm's fuel.

The Earth's spin makes the storm **rotate**; it also stops storms forming right on the Equator.

The wall of seawater the winds push ashore — usually the **deadliest** part of the hazard.

Warm sea → **evaporation** → vapour rises and condenses, releasing **latent heat** → air rises faster, pressure falls, storm intensifies.

Its **fuel is cut off** — no warm-water evaporation, so it loses energy and the winds drop.

More energy (stronger winds), more rain, and a **higher storm surge** — and they widen where storms can form.

**State** = read a direction/region straight off; **Estimate** = the **time gap** between two points (or distance ÷ speed).

**Vulnerability** matters too — low, crowded, poor coasts (e.g. the **Sundarbans**) suffer most for a given storm.

Two+ developed points (warm-ocean mechanism AND vulnerability), a named example, accurate terms, and a clear judgement.