The main cause of the land-sea temperature contrast, which drives phenomena like the sea breeze and the Indian summer monsoon, is the difference in the specific heat capacities between the land and the sea. The specific heat capacity of water is much higher than that of land. This means that water requires more heat to change its temperature compared to land. During the day, the land heats up faster than the sea, creating a temperature contrast. This contrast drives the movement of air, creating the sea breeze during the day and contributing to the development of the Indian summer monsoon.
- Difference in the cloud cover between the land and the sea (Option A) can affect local weather but is not the primary factor driving the temperature contrast.
- Difference in the albedo between the land and the sea (Option B) can affect radiation absorption but does not directly explain the temperature contrast as effectively as specific heat differences.
- Difference in the surface roughness between the land and the sea (Option D) can influence wind patterns but is secondary to the heat capacity contrast in driving temperature differences.
Thus, the correct answer is (C) Difference in the specific heat capacities between the land and the sea.