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Chapter 1 Scientific Basis of Global Climate Change

Coriolis force, causing Northern Hemisphere westerlies to deflect southwestward and South-
ern Hemisphere westerlies to deflect northwestward. The climatic influence of the Westerlies
manifests primarily through their role in driving mid-latitude weather systems. Frontal zones
and cyclones frequently form within the Westerlies, generating the precipitation and temper-
ate storms common to these regions. For example, temperate cyclone activity in the North
Atlantic and North Pacific significantly impacts the climates of North America and Europe.
The Polar Easterlies Belt is the primary atmospheric circulation pattern in high-latitude
regions, mainly distributed in areas north of 60°N and south of 60°S. Characterized by pre-
vailing easterlies where air flows from east to west, this wind pattern is similarly influenced
by the Coriolis force. In the Northern Hemisphere, the easterlies shift northeastward, while
in the Southern Hemisphere, they shift southeastward. The climatic impact of the Polar East-
erlies Belt primarily manifests in its role of maintaining the frigid climate in polar regions.
Cold air within this belt continuously spreads toward lower latitudes, shaping the cold cli-
mate of polar and subpolar regions. For instance, the ice sheets and permafrost zones in the
Arctic and Antarctic are sustained under the influence of the Polar Easterlies Belt.
The Equatorial Convergence Zone is the primary atmospheric circulation pattern in the
equatorial region, located near the equator. The characteristic of the Equatorial Convergence
Zone is the convergence of air from both northern and southern sides toward the equator, cre-
ating intense upward motion. This upward motion leads to high precipitation rates in equato-
rial regions and the formation of tropical rainforests. The climatic influence of the Equatorial
Convergence Zone is primarily manifested in its role in shaping precipitation patterns in
tropical areas. For example, the year-round hot and rainy climates of the Amazon Rainforest
and the Congo Basin are formed under the influence of the Equatorial Convergence Zone.
Atmospheric circulation patterns not only directly influence the distribution of climate
but also indirectly affect climate change through complex physical processes. For example,
changes in atmospheric circulation patterns can alter the distribution of sea surface tempera-
tures, thereby further impacting the global climate system. In recent years, with global warm-
ing, significant changes have occurred in atmospheric circulation patterns. For instance, the
weakening of the polar easterlies belt in the Arctic has accelerated the melting of Arctic sea
ice, while the intensification of the westerlies belt in mid-latitude regions has led to frequent
extreme weather events. These changes demonstrate that atmospheric circulation patterns
play a crucial role in global climate change.

III. Role of Ocean Circulation
Ocean circulation plays a crucial role in global climate regulation, with its mechanisms
encompassing various aspects including heat transport, salinity variations, and biochemical
cycles. Through these processes, the ocean not only influences atmospheric temperatures
and precipitation patterns but also exerts profound impacts on Earth’s carbon cycle and other
biogeochemical cycles. This section will elaborate in detail on the specific roles of the ocean

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