Global Climate Models and the Southeast Pacific
Global Climate Models (GCMs) are run on fast supercomputers as a way to better understand Earth's climate. Scientists are always trying to make these models better so that the results are more accurate. We know that climate is not the same everywhere in the world. There are some places where it is relatively easy to model the climate. There are other places where it is tricky to get realistic results from climate models. The Southeast Pacific, near the west coast of South America, turns out to be one of those tricky places!
Why is it so difficult to model the climate of the Southeast Pacific? There are lots of reasons. There are a lot of connections between the land, ocean, and atmosphere in that area. Climate models have many different parts: the ocean, the clouds, chemicals in the atmosphere, and so on. In some places, these different systems influence each other a lot. That means the overall GCM only works well if the connections between parts of the model are good. It is challenging to get all of those relationships right in the Southeast Pacific.
There are other things happening in the Southeast Pacific that make it difficult to model. El Nino and La Nina are influenced by the climate of the Southeast Pacific. These events are also connected, however, to places in the Western Pacific thousands of kilometers away and even to phenomena that occur in the Atlantic Ocean! Climate model connections that have to cover that much area are especially difficult for scientists to accurately describe and predict.
VOCALS scientists intend to improve modeling of the Southeast Pacific region. They want to make better models of cloud formation. They want to better understand how upwelling of cold ocean waters in coastal regions influences climate. They hope to get a better picture of the roles of aerosols in cloud formation, and they want to understand the extent to which different aerosols and low-level cumulus clouds reflect away incoming sunlight.