Air-sea Interaction

This relatively new subject deals with small and large scale interactions between the atmosphere (air) and oceans (sea) that govern our global climate.

The Hawaiian Islands are directly in the path of trade winds which are found in the tropics. These winds are powerful enough to cause dramatic changes in the temperature of the Pacific Ocean and enable sea-air interaction which confirms the influence of these islands.

Mutual tolerance

The oceans and atmosphere are mutually dependant upon each other and engage in a series of collaborations in which water, heat and energy are exchanged. These interactions help shape the climate on this planet and are currently the focus of a large body of research into the effects of these interactions.

Research studies

The aim is to discover more about how the air and seas co-exist with each as well as the extent of these exchanges. How precise are these interactions and what is their impact upon climate change?

The oceans are comprised of water, nutrients, heat and greenhouse gases and it is the effect of these on the atmosphere especially greenhouse gases which this study is most concerned with. 

Air-sea interaction is observed and analysed using a variety of methods which include numerical models and scientific data that are underpinned by a solid theoretical background.

Laws and mechanisms

These interactions are based upon a series of laws and systems which include thermodynamics and thermoclines.

Thermodynamics is discussed below.

A thermocline is a layer within the ocean which separates the upper and lower depths of water.  The temperature within this layer is subject to much more rapid changes than in the upper or lower depths. 

The thickness of this layer is dependant on several factors which include the weather, tides and currents.

Thermodynamics

This is the study of energy conversion via a series of processes involving heat and other variables such as temperature and pressure.

In regard to air-sea interaction: it looks at the various cycles associated with this exchange for example the transport of excess heat from tropical regions to the polar areas on the planet.

Another example is the movement of freshwater from areas which are subject to excessive rainfall to those regions which are vulnerable to droughts.

Heat and water vapour emitted from the oceans form part of a thermodynamic cycle which acts upon air circulation systems, for example the circulatory system which controls the easterly winds of the tropics.

These pass into the atmosphere and are helped on their way by winds which form part of the atmosphere circulatory systems. The energy of these winds acts as a form of control on the strength and intensity of this system.

Air-sea instability

This refers to a disturbance in the processes as part of air-sea interaction. Any instability will manifest itself as a storm, e.g. hurricane or a cyclone which occurs when air rises too quickly through the atmosphere.

Heat exchange

This means the process in which heat in the form of solar radiation from the sun heats up the ocean thereby increasing its temperature. Infrared radiation is released from the ocean which is in turn, reabsorbed into the atmosphere.

It is then re-emitted by the other substances in the atmosphere, for example, greenhouse gases, and transferred back into the ocean. This transmission actually cools down the ocean.

The warmer the temperature of the ocean the more moist and humid the atmosphere will be which has a direct impact on its greenhouse gases. These gases increase as the ocean heats up and prevent the ocean from emitting this heat as long wave radiation into the atmosphere.

Whenever the ocean emits heat the greenhouse gases bounce this back into the ocean which then lowers its temperature.