Sea Level Rise and Atmospheric Circulation
Global sea level is on the rise, and researches have indicated that the rise is likely to accelerate this century owing to thermal expansion experienced in oceans and the melting of glacier. A rise in sea level results to a shift of the shoreline, leading to change of activities along the coastal region. A change in sea level interferes with the equilibrium of erosion and deposition in the coastal zone. Rise in global temperatures has resulted in melting of glaciers at the poles and, consequently, submerging the cities and islands throughout the world. Rise in sea level can also be influenced by ocean currents, as well as differences in atmospheric pressure.
To grasp the large-scale motions that occur in the atmosphere, studying about general circulation is obligatory. Atmospheric circulation involves a large-scale progression of air where heat spread over the Earth’s surface. The wind belts, as well as the jet steams strapping the planet are driven by three convection cells, namely Hadley, Ferrel, and Polar cell. The continuous effects created by the three circulation cells, together with the effect of the Coriolis, generates the global circulation. Discrepancies in temperature create a set of longitudinal circulation cell, leading to an overall atmospheric motion. The Earth’s rotation is one of the factors that make the atmospheric air remain in constant movement.
Does Sea Level Rise Effect Earth’s Rotation?
The Earth normally rotates around its axis, and to complete one rotation, it takes approximately 24 hours. The Earth’s rotation has critical environmental outcomes. One, the rotation generates a diurnal cycle, which controls light and darkness, temperatures, as well as humidity. Two, the Earth’s rotation follows standardized time zones. There are 24 such zones, as each zone takes one hour. Three, Earth’s rotation causes tides, as the sea level undergoes rise and fall. Four, rotation is accountable for the deflection of ocean, as well as air current. However, the melting of glaciers, which is witnessed at the poles, allows more liquid water to enter the global system and, at the same time, allowing tones of ice to exit the poles towards the equator.
According to Walter Munk, a renowned oceanographer, the glacial process is capable of slightly shifting the Earth’s axis, leading to a decline in the rate of Earth’s spin (Puiu n.p). The Earth’s axial spin is bound to change slightly when the distribution of Earth’s mass changes. Earth’s rotation is believed to be gradually slowing down by about two thousand times in a second every day, leading to prolonging of a day. Researchers from Canada have approved the glacier concept by asserting that the melting of ice at the poles lead to a mass movement of water towards the equator, and such movement is equated to a figure skater, who extends her arms out (Puiu n.p). Thus, the melting of glaciers happens to diminish the rate of Earth spin in a quantifiable way.
Sea level does not change often, but geophysical adjustments have shown a change from a previous position. According to Murray-Wallace and Woodroffe, redistribution of water masses that usually accompanies glacio-eustatic sea-level changes influences the Earth’s rotation, in addition to troubling near-Earth satellites in a time-constant gravity field (3). Earth rotational change is demonstrated through variations in angular velocity along its axis.
Does Sea Level Rise Affect Atmospheric Circulation?
The movement of large air masses over the Earth’s surface causes the balancing of temperature between the equator and the poles (Davis and Fitzgerald 77). Atmosphere and oceans act as carriers of surplus heat from the equator region to the poles. The temperature difference created by the sun’s radiation between the equatorial region and the polar region cause a strong temperature gradient, which exists between the high latitudes and low latitudes, as shown in Figure 1.
Figure 1: Temperature variation based on latitudes (Source: Davis and Fitzgerald 79).
The rise in sea level is bound to affect the atmospheric circulation since the temperature is liable to change during the circulation of the air. As the warm air proceeds towards the poles, it cools and descends back to the Earth. However, due to global warming, the poles are becoming hotter than before; hence, the atmospheric circulation is like to be slowed by higher temperatures. Changes in temperatures, which result in atmospheric circulation, cause sea water to expand while the density becomes low.
Arise in sea level would prolong the time that the water takes to heat. Since the land cools a bit faster than the ocean does, a decline in landmass is likely to affect the cooling process. Consequently, the circulation process is likely to be affected, as it would take time before the less dense water begins to rise. Sea level rise causes water to swallow part of the coastline, leading to reduction in land surface mass. Landmasses affect air movement and, subsequently, the progress of pressure systems. According to Buynevich, numerical values indicated in atmospheric circulation are usually connected to change in sea level, as well as atmospheric precipitation (61). This is because changes in sea level increase moisture in the air, leading to heavy downpour
Buynevich, Ilya V. Geology and Geoarchaeology of the Black Sea Region: Beyond the Flood Hypothesis. Boulder, Colo: Geological Society of America, 2011. Print.
Davis, Richard, and Duncan Fitzgerald. Beaches and Coasts. Chichester: John Wiley & Sons, 2009. Internet resource.
Puiu, Tibi. “Earth rotates slower from sea-level rise: ‘Munk’s Enigma’ now solved.” ZME Science. December 15, 2015. Web. 7 April 2016. http://www.zmescience.com/science/geology/earth-axis-rotation-sea-level-rise-053434/