Bias Correction of Open Path CO2 Observations in a Complex Urban Environment for Carbon Cycle Model Inter-Comparison
Abstract
The GreenLITE™ trace gas measurement system, jointly developed by Atmospheric and Environmental Research, Inc. and Spectral Sensor Solutions LLC, provides high-precision, long-path measurements of atmospheric trace gases CO2 and CH4 over extended (0.04 km2 - 25 km2) areas of interest. In 2015, a prototype was deployed in Paris, France, to demonstrate its ability to provide continuous measurements of CO2 and two-dimensional maps of time-varying concentrations over a complex urban environment. Subsequently, these data have been bias corrected to create a physically consistent set of mean concentration values for inter-comparisons with: 1) Highly accurate collocated in situ point measurements obtained within the Greater Paris area, and 2) Results from high-spatial and temporal resolution regional carbon cycle model data. To achieve these ends, the GreenLITE™ data were corrected using existing point measurements to reconcile constant systematic as well as slowly varying temporal differences that exist between in situ and GreenLITE™ measurements. These efforts provide a method for comparisons and the potential for long-term co-assimilation of both measurements into urban-scale emission models. While both the constant systematic biases and the slowly varying differences may have different impacts on the measurement accuracy and/or precision, they are in part due to several potential common terms that include limitation in the instrument design, uncertainties in spectroscopy, and imprecise knowledge of the atmospheric state. This work provides a brief overview of the system design and the current gas concentration retrieval approach, a description of the bias correction approach, and the results as applied to data collected in Paris, France.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A51M2729Z
- Keywords:
-
- 0365 Troposphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0394 Instruments and techniques;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES;
- 3360 Remote sensing;
- ATMOSPHERIC PROCESSES