Write in your own words a short answer that describes the differences between weather and climate. Weather and Climate both take the same measuring elements of the environment and atmosphere (Temperature, humidity, pressure, wind speeds, precipitation, etc.). According to Sturman & Tapper (2006), weather is “the state of the atmosphere at a particular point in time within a defined areas.” This in turn is opposed to Sturman & Tapper’s (2006) take on climate which is “the synthesis of weather observed over a period of many years.” As a result, Sturman & Tapper have shown one clear difference between the weather and climate. The difference between the two is that weather is the measurements of a particular time and place while climate is observed over a number of years and can be in a defined place or across a much broader area.
Module 2 – Tutorial Exercise 2.1
Describe in form of a short answer the four main greenhouse gases in the atmosphere which are responsible for earth being much warmer than it would otherwise be. The four main greenhouse gases which contribute to significant global warming are as followed: •Water Vapour
These four greenhouse gases all contribute to global warming in different ways. Water Vapour is the most substantial quantity of greenhouse gas found in the atmosphere, however its increased existence if dictated by the other three greenhouse gases. It is seen that Carbon Dioxide, Methane, and Nitrosis Oxide have all increased by 39.5%, 150% and 52% respectively since the 1750’s (CSIRO, 2012). As a result of these increases the earth’s surface has warmed creating an increase in precipitation and condensation. This allows for further warming by the Water Vapour known in climatological terms as a “positive feedback”.
Module 3 – Tutorial Exercise 3.1
Explain in form of a brief essay (300 words) how greenhouse gases in the atmosphere interact with the short and long wave radiation, budget in the earth’s atmosphere. The earth’s radiation budget calculates the energy levels entering, reflecting, absorbing and re-emitting through-out the atmosphere. The incoming radiation, which predominantly consists of short-wave radiation comes from the sun, and is either reflected by the clouds and surface of the earth, absorbed by the surface or interacts with large aerosol particles creating heat. This is compared to long-wave radiation which is either emitted by the earth or is generated as a result of short-wave radiation and large aerosols interacting with one another.
Taking these two radiations into account, the earth’s radiation budget needs to balance to create a sustainable climate. Responsible for the main heating method of the lower atmosphere, long-wave radiation is emitted from the earth. Once emitted, some of this radiation will pass through the atmospheric window and will no longer be in the atmosphere. Opposed to this, greenhouse gases will prevent most of the surface radiation from escaping the atmosphere which in turns heats the lower atmosphere. When greenhouse gases become more prevalent in the atmosphere, they will restrict the amount of emitted radiation from escaping the earth’s atmosphere. This will cause the earths radiation budget to be unbalanced which can have dramatic effects on the lower atmospheric temperature. In return of higher greenhouse gas levels, the lower level of the atmosphere will increase in temperature. With an increase in temperature of the atmosphere, the surface will become warmer along with increased levels of Water Vapour in the atmosphere. This will then cause a ‘positive’ effect to creating a warmer earth.
Module 4 – Tutorial Exercise 4.1
Present a brief description of figure 4.2. Copy the graphic and show the generalized airflow directions using arrows and indicate the location of the semi-permanent high and low pressure surface regions.
Figure 4.2 represents the annual mean of horizontal wind velocities at around 300 HPA between 1968 and 1996. It is shown that the pressures within the easterly moving winds are always low compared to the westerly wind that run with the high pressure movements. Represented by circles the highs (purple) and lows (grey) are semi-permanent meaning that most of the time throughout the year the lows and highs are established. The pressure systems running along the belts known as the polar highs situated at both 90°, the sub polar lows, positioned at both 60°, along with the subtropical highs that run along earth’s 30° latitude co-ordinates and finally the equatorial low (0°).
Module 5 – Tutorial Exercise 5.1
Provide a 300-400 word brief essay that outlines the key climatological building blocks of the wind-driven oceanic surface layer circulation. Throughout the world there are many building blocks to the wind-driven oceanic surface layer circulation. The five main building blocks are: •Western boundary current regimes,
•Eastern boundary current regimes,
•Equatorial Current Systems,
•Subtropical and Sub polar gyres and
•Antarctic circumpolar current.
The western boundary current regimes are found all through-out the world and are typically narrow, fast moving (40-120Km) and deep (down to 1000m) streams. The western boundary currents typically weaker in the southern hemisphere transport water from the tropics to the polar waters. Opposed to this the eastern boundary current regimes are wider and slower moving. These currents transport the cool waters of the poles back to the tropics. With trade winds running from either hemisphere the two westward flowing equatorial currents are divided by an easterly flowing current. Both westward flowing currents coming from either hemisphere are influenced heavily by the winds. These currents move from the equator either north to blend with the countercurrents or south along the East Australian current (western boundary current). Throughout the world they are a number of gyres circulating water around the world.
These are divided into two groups, the subtropical gyres and sub polar gyres. The sub-tropical gyres centered on high pressure belts (30°) travel counterclockwise in the southern hemisphere. The waters center to the middle of the gyre amongst sub-tropical gyres creating equator ward flows. Different to this, the sub polar gyres are found along the belts of low pressure (60°). These gyres circulates outwards from the middle which in turn creates an up-welling in the center that have nutrient rich water from lower depths resulting in an abundance of life found in these areas. Another current heavily impacted by the westerly winds and in which also has an abundance of life throughout is the Antarctic circumpolar current. Travelling west to east around the Antarctica this current keeps warm waters away from Antarctica resulting in the conserving of its ice sheets. Within the oceanic circulation all currents are seemingly interrelated and create the warming and cooling process of the oceans waters which then in turn heats the atmosphere creating a stable living environment for both aquatic and terrestrial organisms.