The flow of energy through the earth's climate system


  • The National Center for Atmospheric Research is sponsored by the National Science Foundation.


The primary driver of the climate system is the uneven distribution of incoming and outgoing radiation on earth. The incoming radiant energy is transformed into various forms (internal heat, potential energy, latent energy, and kinetic energy), moved around in various ways primarily by the atmosphere and oceans, stored and sequestered in the ocean, land, and ice components of the climate system, and ultimately radiated back to space as infrared radiation. The requirement for an equilibrium climate mandates a balance between the incoming and outgoing radiation, and further mandates that the flows of energy are systematic. These drive the weather systems in the atmosphere, currents in the ocean, and fundamentally determine the climate. Values are provided for the seasonal uptake and release of heat by the oceans that substantially moderate the climate in maritime regions. In the atmosphere, the poleward transports are brought about mainly by large-scale overturning, including the Hadley circulation in low latitudes, and baroclinic storms in the extratropics, but the seamless nature of the transports on about monthly time-scales indicates a fundamental link between the two rather different mechanisms. The flows of energy can be perturbed, causing climate change. This article provides an overview of the flows of energy, its transformations, transports, uptake, storage and release, and the processes involved. The focus is on the region 60°N to 60°S, and results are presented for the solstitial seasons and their differences to highlight the annual cycle. Challenges in better determining the surface heat balance and its changes with time are discussed. Copyright © 2004 Royal Meteorological Society