The complexity of the Earth system, in which spatial and temporal variability exists on a range of scales, requires that an organized scientific approach be developed for addressing the complex, interdisciplinary problems that exist, taking good care that in doing so there is a recognition of the objective to integrate science across the programmatic elements towards a comprehensive understanding of the Earth system. In the Earth system, these elements may be built around aspects of the Earth that emphasize the particular attributes that make it stand out among known planetary bodies. These include the presence of carbon-based life; water in multiple, interacting phases; a fluid atmosphere and ocean that redistribute heat over the planetary surface; an oxidizing and protective atmosphere, albeit one subject to a wide range of fluctuations in its physical properties (especially temperature, moisture, and winds); a solid but dynamically active surface that makes up a significant fraction of the planet’s surface; and an external environment driven by a large and varying star whose magnetic field also serves to shield the Earth from the broader astronomical environment.
These six focus areas include research that not only addresses challenging science questions, but drives the development of an Earth observing capability and associated Earth system models. In concert with the research community, NASA developed a hierarchy of science questions. The fundamental question: “How is the Earth changing and what are the consequences for life on Earth?” leads to five associated core questions, representing a paradigm of variability, forcing, response, consequences and prediction, leading in turn to the 24 detailed Earth science questions in Table 4.1. NASA strategy for linking the six interdisciplinary science focus areas is to solicit and fund research addressing combinations of these science questions.
The following sections describe each Science Focus Area. Each section describes the scientific field, NASA’s current contribution, and next major steps in the period 2007-2016.
The Atmospheric Composition focus area consists of research on the composition of Earth's atmosphere, particularly of the troposphere and stratosphere, in relation to climate forcing, atmospheric ozone and aerosols, solar effects, air quality, and surface emissions of radiatively and chemically active source gases and particulates.
Our weather system includes the dynamics of the atmosphere and its interaction with the oceans and land and involves phenomena ranging from local or microphysical processes lasting minutes to global-scale events predictable up to two weeks prior.
NASA's role in climate variability study is centered around providing the global scale observational data sets on oceans and ice, their forcings, and the interactions with the entire Earth system.
The Water & Energy Cycle focus area studies the distribution, transport and transformation of water and energy within the Earth System, with the long-term goal to improve hurricane prediction, quantify tropical rainfall and eventually begin to balance the water budget at global and regional scales.
This Focus Area deals with the cycling of carbon in reservoirs and ecosystems as it changes naturally, is changed by humans, and is affected by climate change.
NASA’s Earth Surface and Interior focus area supports research and analysis of solid-Earth processes and properties from crust to core. This includes providing the space geodetic observations and products foundational to many space missions.