Typical Mistakes and Examiners Comments for Weather and Climate

Typical Mistakes and Examiners Comments for Weather and Climate

Typical Mistakes

• Remember that heat is simply a form of radiation. When solar radiation (short-wave) is absorbed by a surface it is converted to long-wave radiation, which is emitted as heat.
• Air masses cool as they are uplifted over hills and mountains because they expand as pressure falls with height (they are also warmed by compression on decent). This temperature  lapse is not due to any exchange of heat with the surrounding atmosphere.
• It is often overlooked that the characteristics weather brought by depression is fundamentally due to air rising throughout the troposphere.
• It is mistake to think that anticyclones and high pressure are synonymous with fine weather (i.e. clear skies and sunshine). Although anticyclones usually bring dry weather, conditions are often cloudy and overcast.
• Seasons can be determined by rainfall patterns as well as temperature. In the tropical savanna there are two seasons; wet and dry.
• Remember that urban heat islands are not permanent features. They are most apparent at night and readily dissipate in windy conditions.

Examiners Comments

• Think of the atmospheric circulation of planetary winds as a part of a system for evening-out imbalances in the heat budget between low latitudes (surplus) and high latitudes (deficit).
• Although latitudinal variation in solar radiation intensity is the main driver of climate, regional climates are controlled by a combination of other factors such as prevailing winds, ocean currents and altitude.
• Explanations of the geographical distribution of precipitation can be enhanced by the use of diagrams to show, for example, the effect of relief on precipitation.
• To predict the type of weather associated with an air mass you need to infer from its source region and track whether it will (a) be heated from below (making it unstable), (b) be cooled from below (making it stable), or (c) increase or decrease in humidity.
• The weather changes associated with the passage of a front refer to temperature, wind speed, wind direction, precipitation, cloud and pressure.
• The vulnerability of countries to tropical cyclone hazards is closely related to differences in poverty and levels of development. This point should be emphasised in discussion on the variable impact of tropical cyclones and other natural hazards.
• Your revsion of urban climates must not only cover their causes and characteristics, but also their impact on human health.
• any balanced discussion of the causes of global warming must make some reference to possible natural as well as human influences.
• Remember that the likely impact of global warming will be highly variable geographically. Economic status and physical conditions (altitude, climate, vegetation, fragility) will make some societies more vulnerable than others.
• Global warming is a transnational problem which can only be solved by agreement among major countries. Vested national interests have so far make this difficult to achieve.