Monday, 23 January 2012
GHG Observations At Smaller Spatial and Temporal Scales
Hall E (New Orleans Convention Center )
Over the next five years, Earth Networks will deploy 100 cavity ring-down spectrometers (CRDS) continuously measuring CO2 and CH4. It is planned to place sensors at 50 tall towers in the United States, 25 in Europe and 25 around the world. Data from this network will be used for inverse modeling to estimate natural and anthropogenic sources and sinks of CO2 and CH4. Instruments are calibrated every few hours using a standard gas mixture from NOAA (National Oceanic and Atmospheric Administration). Sampling rate of the raw data from spectrometers and collocated weather stations is at the sub-minute range and higher than in flask networks previously used for regional inversions. We discuss features that appear in this high temporal resolution data stream, such as short duration spikes and wind direction changes, and whether these might potentially contain useful information about local GHG sources and sinks. We also discuss whether the variability in the high time resolution data can be used to estimate uncertainties due to representation error. Relevance of brief GHG spikes - both for CO2 and CH4 - to the direction of wind gusts, detected at the collocated weather station, conditions of nearby vegetation as seen from satellite data, and the boundary layer height as can be inferred from change in atmospheric stability, is analyzed.
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