Exercises: Atmospheric and hydrospheric dynamics

The diagram shows what happens on a summer morning at the coast, with four numbered steps. Explain what happens in each of the steps labelled 1 to 4 and reason why warm air rises over the land and a sea breeze forms, blowing from the sea towards the coast.

Wind and ocean currents get their energy from the Sun. Using an everyday example (air moving when a radiator is turned on, or water in a heated pot), explain what happens to air or water when heated and how this movement gives rise to winds or currents.

Order the following steps in the formation of a sea breeze during the day: the cool air over the sea moves towards the coast, forming the breeze; the Sun heats the land faster than the sea; the air over the land warms up and rises; higher up, the air moves towards the sea and descends over it.

The simplified map shows two ocean currents bordering two coastlines located at the same latitude.

1. a) State where each current originates and where it is headed.
2. b) Reason which of the two locations, A or B, will have a milder and wetter climate and explain why.

The water cycle and winds are connected. Explain where the energy that evaporates seawater comes from, and what role winds play in transporting water vapour from the ocean to the interior of continents.

Two locations situated at the same latitude, one on the coast and another inland, have different climates: the coastal town has milder winters and cooler summers. Explain why, taking into account that seawater heats up and cools down more slowly than land.

London (United Kingdom) and Calgary (Canada) are located at virtually the same latitude (around 51° N). However, the average January temperature in London is 5.5 °C (with very rare snowfall), while in Calgary it is -7.5 °C (with continuous snow for months).

1. a) Justify this marked climatic difference by analysing how general atmospheric circulation and surface ocean currents interact in the North Atlantic.
2. b) A model predicts that global warming will trigger accelerated melting in Greenland, pouring huge volumes of freshwater into the ocean. Predict and justify what effect this input would have on ocean density, the North Atlantic thermohaline circulation (AMOC), and winter temperatures in north-western Europe.

Along a stretch of coast with limestone cliffs, a town council plans to build a large concrete sea wall at the base of the cliff to stop wave action, claiming that this single project will completely stop cliff retreat.

1. a) Critically evaluate this claim: justify why it is insufficient by analysing the weathering and erosion processes that the atmosphere (precipitation, wind, and thermal changes) and the continental hydrosphere (runoff and infiltration) will continue to exert on the upper and middle sections of the cliff.
2. b) Predict what medium-term consequences the installation of the sea wall will have on the adjacent beach, relating coastal transport and sedimentation dynamics.

Look at the temperature data for three locations situated at the same latitude (43° N) and at a similar altitude:

• Location 1: Average temp. in January: 9.2 °C; Average temp. in August: 21.1 °C.

• Location 2: Average temp. in January: 2.5 °C; Average temp. in August: 28.0 °C.

• Location 3: Average temp. in January: 12.0 °C; Average temp. in August: 17.5 °C.

1. a) Calculate the thermal amplitude (temperature range) of each one and deduce, with reasoned arguments, which corresponds to a small oceanic island, which to a continental coastal city, and which to the interior of a large continental landmass.
2. b) A classmate claims that seawater warms the coast in summer and cools it in winter. Refute their claim by explaining the thermal property of water (specific heat capacity) that turns the hydrosphere into a thermal regulator for the atmosphere.