The weather associated with a hurricane
Marjorie Henry, Contributor

In the last lesson, I started to discuss question four from the June 2007 examination paper. Part (a) of the question was done. I will continue discussing the question today. Section (b) is asking about a site over which the eye passes. Please note that it is not a general question on the weather associated with a hurricane, but that it is referring you to one aspect of the weather, namely WIND. Refer to the recommended text - The Caribbean Environment for CXC Geography by Mark Wilson for the information on this. Your response should include the following information:

• As the hurricane approaches, the wind becomes stronger.
• Near the centre of the storm, winds are strongest. To the west from the eye, the wind blows from the north.
• The eye is an area of very calm conditions. There are light winds blowing at perhaps 10-20 km/hr.
• When the eye passes, the wind drops suddenly.
• After the eye has passed, the wind suddenly starts again. To the east of the eye, it blows from the opposite direction - from the south.
• As the eye of the hurricane moves away, wind speeds gradually drop.

For sections (c) and (d), the focus is on the ecosystem. Section (c) is asking you to describe TWO of the components of an ecosystem. The text already mentioned has the information for your answer. This, I will share with you.

(I) Producers are the green plants. They grow through photosynthesis. They make direct use of rainwater, sunshine and minerals.

(ii)Primary consumers are animals which feed directly off the plants, such as parrots, tapirs, bees and monkeys. They are known as herbivores.

(iii) Secondary consumers feed off the primary consumers and off one another. They include lizards, jaguars, spiders and birds of prey.

How the vegetation adapted

The questions in section (d) are based on the tropical continental climate. In explaining how the vegetation of this area is adapted to the climate, you should state the type of vegetation associated with the climate, the feature of the vegetation and how it is adapted to the climate.

In the tropical continental climate, the vegetation consist of tall grass and short scattered trees. This is as a result of tropical wet-dry climate, transitional between that of the hot dessert and the tropical forest. Trees and plants have to adapt themselves to the savannah's climatic rhythm of long winter droughts and short summer rains.

Both trees and plants are deciduous in nature, shedding their leaves in the cool dry season to prevent excessive loss of water through transpiration and lying dormant during the long drought.

They have long roots (e.g. acacias) to search for groundwater.

Broad trunks (e.g baobab and bottle trees) to store excessive water. The baobab has small, thin leaves to reduce transpiration in dry season.

Many trees are umbrella-shaped to shield their roots from the scorching heat and to ensure they only expose a narrow edge to the strong trade winds that blow all year round.

The grass which grows in compact tufts has long roots, which reach deep down in search of water.

Sub-section (ii) of section (d) is asking for an explanation of how climate influences the development of the soil in the tropical continental areas. Here is a guideline for your answer:

• State an aspect of the climate, for example, rainfall.
• State the soil-forming processes evident in the soil, for example, leaching.
• Link these to the nature of the soil, colour and texture.

Your account should include the following -

Tropical continental areas experience alternating wet and dry seasons. During the rainy season, there is rapid leaching which removes silica from the upper horizon, leaving behind red coloured oxides of iron and aluminium. The soil is acidic since the bases are leached. During the dry season, the soil dries and capillary action brings bases to the upper layers of the soil. Calcification may leave mineral nodules in the B horizon.

This question ends section B of the question paper. Remember, you are required to do just ONE question from this section.

This student files a piece of metal during class at Denbigh High School. -Photo by Michael Lee

Marjorie Henry is an independent contributor.