Notes on Heat Budget

Some insolation is absorbed by the Earth, radiating heat back out to space through terrestrial or long-wave radiation. The Earth’s heat budget is how the Earth maintains a constant temperature through the input and export of energy. The most potent source of heat is the sun. And the sun’s warmth is distributed unevenly over the world, which is the root of all climatic characteristics.

As a result, understanding the patterns of temperature distribution in different seasons is critical for comprehending other climatic elements such as pressure systems, wind systems, precipitation, etc. This paper will cover the concept of the heat budget of the Earth and its distribution on temperature. 

What Is The Heat Budget?

The Earth is not heated uniformly by the sun. The sun heats equator regions more often than Polar Regions because Earth is spherical. During evaporation of seawater, convection, rain, winds, and ocean circulation, the environment and ocean work nonstop to balance solar heating imbalances.

The heat on Earth is maintained in the following ways by this coupled atmospheric and ocean circulation:

• The Earth’s climate heat engine must transport solar heat from across the equator to the poles and transfer heat from Earth’s surface or asthenosphere to space.
• When an equal heat transfer to space meets the stream of incident solar radiation, Earth is in thermodynamic equilibrium, and temperature rise is relatively stable.
• The equator and the latitudes of 40° N or S receive a lot of sunlight. Thus they have plenty of energy. Heat is lost quicker than it is received from the sun above 40° N or S latitudes, resulting in energy shortages.
• The Earth’s atmosphere carries excess heat from the equator to the poles, making up for energy loss at higher latitudes.
• The mid-latitudes (30° to 50°) are responsible for much of the torrential rain since they are where the majority of heat transfer happens.
• As a result, the movement of surplus power from latitudes to the deficit energy zone at higher latitudes keeps the Earth’s surface in overall equilibrium.

What Is The Current Heat Budget Of Earth?

The earth’s heat budget is the balance between incoming and exiting heat. The budget should be managed to maintain constant circumstances so that the entering heat equals the departing heat, just like any other budget.

About 30% of the solar energy that reaches the Earth is reflected into space by the Earth’s atmosphere, clouds, and surface. Water vapour, clouds, and dust absorb an additional 23% of the energy, transformed into heat. The land and ocean absorb about under half (47 %) of the incoming solar, which heats the Earth’s surface. The energy received by the Earth is returned to the atmosphere in three ways: radiation, conduction, and absorption.

Longwave infrared radiation is emitted by all bodies with a temperature greater than absolute zero (-273 degree celsius). The warming Earth is nothing like that, with the atmosphere receiving around 16 per cent of its total solar energy. While some radiated energy will be lost to space, the atmosphere will collect a substantial amount of heat. The greenhouse effect is founded on this.

The transport of heat by immediate communication between the surface and atmosphere is known as conduction. Because air is a poor thermal conductor, conduction accounts for just a small portion of the transfer of energy between the Earth’s atmospheres; around 7% of the coming from the solar energy is transferred by conduction.

The greenhouse effect is causing widespread concern worldwide, not because it exists in the first place, but because it is intensifying, affecting the climate or global warming. Because of industrialization, the combustion of fossil fuels, plus deforestation, atmospheric levels of the primary greenhouse gases, especially Co2 and methane, have risen considerably since the Industrial Revolution.

Latent heat exchanged through phase shifts is the largest conduit for heat exchange between the ground or oceans and the atmosphere; heat is released or collected when water travels between liquid, solid, and vapour forms.

Discuss the Heat Budget of the Earth and Distribution of Temperature

The sun is the most powerful source of heat. And the sun’s heat is distributed differently over the globe, which is the ultimate cause of all climatic traits. As a result, knowing the temperature distribution patterns in various seasons is crucial for understanding other climatic aspects such as wind systems, differential pressure, and precipitation, among others.

Such factors that are affecting the distribution of the temperatures are, 

• Atmosphere Transparency
• Differential Land-Sea
• Winds of Change
• Slope Altitude’s Different Facets
• The Earth’s distance from the sun

Conclusion

According to the heat budget, the temperature profile in January and July can be used to understand the worldwide temperature distribution. Isotherms are commonly used to depict the temperature distribution on a map. Isotherms are lines that connect sites with the same temperature. Because the isotherms are often parallel to the latitude, the effect of latitude on temperatures is well visible on the map. In January, particularly in the northern hemisphere, the departure from the overall tendency is more pronounced than in July.