In summer, what atmospheric feature causes warmer conditions on land as compared to over the oceans?

• A. High pressure systems
• B. Cold fronts
• C. Subtropical highs
• D. Polar vortex

Answer: (C)

The subtropical highs are persistent high-pressure systems found in the subtropical regions, primarily associated with descending warm air. During the summer months, these high-pressure systems can lead to prolonged periods of clear skies and increased solar heating over land areas. The land heats up much faster than the ocean due to its lower specific heat capacity, which means it absorbs and releases heat more quickly. Consequently, the areas under the influence of subtropical highs typically experience warmer temperatures compared to the ocean, which retains cooler temperatures due to its vastness and slower heat absorption and release.

In contrast, high pressure systems can also influence weather patterns, but it is specifically the subtropical highs that create the necessary conditions for significantly warmer land temperatures relative to the ocean during summer. Cold fronts are typically associated with drops in temperature and stormy weather rather than consistent warming. The polar vortex is related to cold air outbreaks in the winter, thus not applicable to summer comparisons.