Network of atmospheric GHG stations to estimate methane emissions at local scales in mid-Atlantic region
Abstract
Methane is one of the major greenhouse gases and in recent years, more efforts have been undertaken to estimate its emissions at local and regional scales utilizing new observing systems. During 2012, Earth Networks Inc. deployed a dense GHG observing network in mid-Atlantic region installing cavity ring-down spectrometers (CRDS) continuously measuring CO2, CH4 and H2O at tall towers. Atmospheric observations, provided by the network, and prior emission estimates, based on bottom-up inventories, are used in inverse models. The priors sometimes suffer from uncertainties and lack of timeliness, especially around the areas with potential fugitive emissions and dynamically changing anthropogenic sources. In this study we examined capabilities provided by Earth Networks' dense observing network to detect spatial and temporal patterns of emissions from localized sources in mid-Atlantic area, and carried out the inversions utilizing recent observations and a coupled WRF-STILT system. Through a series of forward runs, tracer dispersion from a group of separated sources is analyzed to estimate resolution of the system and sampling intervals that can be used for footprint analysis and can adequately resolve different sources. For inverse problem, observation sampling frequency, spatial resolution of priors, their error covariance matrices and temporal aggregation scales are examined to select a division of the region into blocks where emissions can be resolved for given inversion system setup. Both for forward and inverse simulations, transport model fields, including boundary layer heights, are validated on Earth Networks' weather observations as well as on radiometers and profilers data.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.A23B0207N
- Keywords:
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- 0345 ATMOSPHERIC COMPOSITION AND STRUCTURE / Pollution: urban and regional;
- 0365 ATMOSPHERIC COMPOSITION AND STRUCTURE / Troposphere: composition and chemistry;
- 0368 ATMOSPHERIC COMPOSITION AND STRUCTURE / Troposphere: constituent transport and chemistry