Final answer:
The sun's atmosphere layer above the chromosphere where the temperature dramatically increases is the corona. This increase in temperature occurs within the transition region.
Step-by-step explanation:
The area in the sun's atmosphere located above the chromosphere (1500-10000 km) where the temperature rises dramatically is called the corona. The corona is the outermost part of the Sun's atmosphere which can reach temperatures of a million degrees or more. This dramatic increase in temperature from the chromosphere to the corona occurs in what is known as the transition region. It is important to note that the concept of distinct layers such as the photosphere, chromosphere, transition region, and corona, while helpful, does not fully capture the complexity of the solar atmosphere, which includes a mix of hotter and cooler regions.