General Circulation Models – Historical and Future Perspective

The General Circulation Models (GCM) are weather forecast models that predict general weather patterns for many years out. Some of these models forecast out to 30 to 50 years. The main purpose is to run different variables to see what extent man impacts are on climate (Global Warming or Climate Change). One of the main variables is using different levels of CO2. However, the purpose of this article is not to discuss the heated topic (no pun intended) of global warming.

On the shorter time scale, we have numerical weather prediction (NWP) models that are used to predict the weather in the short (1-3 days) and medium (4-10 days) range future. On the other hand, General Circulation Models are run much longer, for years on end, long enough to learn about the climate. While a good NWP model accurately predicts the movement of frontal systems and tropical cyclones. The accuracy for these shorter term forecasts has greatly improved over the years.

How about General Circulation Models? In 1956 there was some early research done on these models but it was not until the late 1960’s that General Circulation Models forecast models were developed by NOAA. Then by the 1980’s National Center for Atmospheric Research (NCAR) developed some complex models. These complex models are called coupled models. Coupled meaning atmosphere-ocean models. They simulate surface and deep ocean circulations and the purpose of our article is not to get into the details of this. Click here for more information.

Accuracy? Well some of the early models many experts claim did not do well. However, the current models seems to be doing better. However, depending who you talk to one will get vastly different opinions on this accuracy. Frankly there needs to be more monitoring of the models as historical data needs compared to the model output. Time will tell us about the results.