Final answer:
Daily insolation varies with latitude primarily due to the Earth's tilt, which causes different sun angles and lengths of day across the year, leading to varying seasonal temperatures. Weather and cloud cover also affect insolation by either allowing more or less sunlight to reach the surface.
Step-by-step explanation:
The amount of daily insolation, or incoming solar radiation, varies with latitude due to several key factors. First, the Earth's tilt on its axis causes sunlight to strike the Earth at different angles. At high latitudes, sun rays hit the Earth at a lower angle, spreading the light over a larger area and thus reducing the intensity of the sunlight that reaches the ground. This phenomenon, coupled with the length of the day, leads to a significant difference in solar heat received during different seasons.
Additionally, near the equator seasons are defined by precipitation rather than sunlight because of the consistent day length, whereas in other latitudes, climatic seasons are highly pronounced due to the variations in the angle of sunlight. Weather and cloud cover also influence the amount of insolation, with cloudier areas receiving less sunlight. Furthermore, the angle at which the sun's rays reach the Earth dictates the amount of energy absorbed or reflected, impacting the overall climate.
Average insolation at Earth's surface is about 200 W/m², but this can vary considerably from one location to another based on latitude and weather patterns. The seasonal effects such as longer days and a higher sun elevation lead to more direct sunlight and warmer temperatures in the summer months, while the opposite happens in winter, emphasizing the importance of both day length and sunlight angle in relation to seasonal temperatures.