Which phenomenon would be considered a result of changes in solar irradiance?

Changes in solar irradiance refer to variations in the amount of solar energy that reaches the Earth. When solar irradiance increases or decreases, it directly impacts the Earth’s climate and weather systems. The changes in the amount of energy received can alter temperature patterns, air pressure systems, and consequently lead to shifts in weather patterns.

For instance, a decrease in solar irradiance could lead to cooler temperatures, affecting seasonal weather trends and potentially causing longer winters or altered rainfall patterns. Conversely, an increase in solar irradiance could result in warmer temperatures, influencing storm frequency and intensity.

Shifts in weather patterns encompass phenomena such as changes in precipitation, sustained temperature variations, and altered wind patterns—all of which are sensitive to the amount of solar energy the Earth receives.

The other phenomena listed, while they may be influenced by climate factors, are not direct results of changes in solar irradiance. Increased volcanic activity is primarily driven by geological processes, changes in ocean salinity are often a result of freshwater inputs or evaporation processes, and the expansion of polar ice caps can be influenced by temperature changes but are not a direct response to variations in solar energy. Thus, the direct consequence of changes in solar irradiance most clearly relates to shifts in weather patterns.