Enhanced Gaseous Absorption , Earth ’ s Energy

Project Summary This proposal outlines a program of scientific research and educational development focused on radiative forcing and climate. The scientific program consists of determining the role of three gaseous species in closing Earth's energy budget and in radiatively forcing present and future climate. The gases are water vapor, collision complexes of oxygen (O 2 ·X), and nitrogen dioxide. Absorption by these gases has heretofore been oversimplified or neglected in large scale atmospheric models, so their radiative forcing and climate impact remain uncertain. By representing these missing absorption processes, this project will directly improve predictions of atmospheric heating, estimates of Earth's energy budget, and, likely, the accuracy of climate predictions. Oversimplifications in current representations of H 2 O, O 2 ·X, and NO 2 in large scale models are known and will be reduced or eliminated. First, water vapor absorption of solar and terrestrial radiation in cloudy atmospheres is systematically underestimated and biased by neglecting the sub-gridscale partitioning of vapor between the saturated cloud and the sub-saturated clear sky. Second, collision complexes of oxygen absorb about 1 W m −2 globally annually averaged, but the climate response to this forcing is unknown. Third, neglected NO 2 absorption will be examined using a combination of satellite and model data to constrain its distribution. These mechanisms are, in sum, expected to reduce the current discrepancy in the global annual mean atmospheric energy budget by 2–8 W m −2 (10–30% of the total discrepancy). Moreover, H 2 O and NO 2 forcings are likely to change with climate. The educational component of the proposal is to found a project to coordinate the development , solicitation, standardization, and dissemination of Freely Available Community Texts (FACTs) suitable for education and teaching in the Earth system sciences. Each FACT will be a living monograph available via the World Wide Web to students and scientists anywhere to study, modify, and improve. The license ensures authors retain recognition, copyright, and review priveleges over modifications to their original material. The project will begin with two existing, pilot FACTs designed to educate students about radiative forcing and aerosols. We envision contributions of new material and FACTs from students and faculty within our department, but, more significantly, from the international geosciences community.