Toward accurate CO_2 and CH_4 observations from GOSAT

The column-average dry air mole fractions of atmospheric carbon dioxide and methane (X_(CO_2) and X_(CH_4)) are inferred from observations of backscattered sunlight conducted by the Greenhouse gases Observing SATellite (GOSAT). Comparing the first year of GOSAT retrievals over land with colocated ground-based observations of the Total Carbon Column Observing Network (TCCON), we find an average difference (bias) of −0.05% and −0.30% for X_(CO_2) and X_(CH_4) with a station-to-station variability (standard deviation of the bias) of 0.37% and 0.26% among the 6 considered TCCON sites. The root-mean square deviation of the bias-corrected satellite retrievals from colocated TCCON observations amounts to 2.8 ppm for X_(CO_2) and 0.015 ppm for X_(CH_4). Without any data averaging, the GOSAT records reproduce general source/sink patterns such as the seasonal cycle of X_(CO_2) suggesting the use of the satellite retrievals for constraining surface fluxes

Foundation of Academic Assessment

Student assessment is being impacted by the global economy concept. Students will be required to demonstrate inventive thinking and problem solving skills. This will require educators to rethink how to assess student\u27s performance. Traditional assessment that focus on subject content and consists of objectively scored criteria referenced tests will not meet future assessment requirements. Performance assessments will adequately measure many of these higher level thinking skills. The foundation of performance assessment is the performance objective that must possess validity. This validity is determined through a thorough needs assessment that results in educational goals that define the performance objectives. These objectives will then be the source for performance based assessment