Final answer:
When two substances or objects at different temperatures come into contact, heat will flow from the warmer object to the cooler object. This occurs spontaneously and can be observed in various natural systems, such as the transfer of heat between the atmosphere and the ocean, which affects weather patterns and ocean currents.
Step-by-step explanation:
When two substances or objects at different temperatures come into contact, heat will flow from the warmer object to the cooler object. This is observed to occur spontaneously, and it corresponds to a loss of thermal energy by the warmer object and a gain of thermal energy by the cooler object.
One place where this occurs in the Earth system is the transfer of heat between the atmosphere and the ocean. When warm air meets a cooler body of water, heat is transferred from the warmer air to the cooler water, resulting in changes in weather patterns and contributing to the formation of ocean currents.
Evidence of this heat transfer can be seen in the mixing of warm and cold ocean currents and the influence they have on climate and ocean ecosystems. For example, the Gulf Stream is a warm ocean current that originates in the Gulf of Mexico and flows along the eastern coast of North America. As it moves northward, it transfers heat to the surrounding colder waters, affecting the climate of regions it passes through and providing a habitat for various marine species.