scholarly journals Improving atmospheric CO2 retrievals using line mixing and speed-dependence when fitting high-resolution ground-based solar spectra

2016 ◽  
Vol 323 ◽  
pp. 15-27 ◽  
Author(s):  
J. Mendonca ◽  
K. Strong ◽  
G.C. Toon ◽  
D. Wunch ◽  
K. Sung ◽  
...  
Keyword(s):  
High Resolution ◽  
Atmospheric Co2 ◽  
Speed Dependence ◽  
Line Mixing

Dicke narrowing, speed dependence and line mixing of self-broadened CO2 absorption lines in the 30013 ← 00001 band. Measurements and line shape testing

2021 ◽  
Vol 34 (5) ◽  
pp. 334-342
Author(s):  
V.A. Kapitanov ◽  
K.Yu. Osipov ◽  
A.E. Protasevich ◽  
Yu.N. Ponomarev ◽  
Ya.Ya. Ponurovskii
Keyword(s):  
Line Shape ◽  
Absorption Lines ◽  
Speed Dependence ◽  
Line Mixing

scholarly journals Comparing high resolution WRF-VPRM simulations and two global CO<sub>2</sub> transport models with coastal tower measurements of CO<sub>2</sub>

2009 ◽  
Vol 6 (5) ◽  
pp. 807-817 ◽  
Author(s):  
R. Ahmadov ◽  
C. Gerbig ◽  
R. Kretschmer ◽  
S. Körner ◽  
C. Rödenbeck ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Fraction ◽  
Wrf Model ◽  
Co2 Concentration ◽  
Atmospheric Co2 ◽  
Concentration Data ◽  
Modeling Tools ◽  
Global Models ◽  
Diurnal Variability ◽  
Resolution Model

Abstract. In order to better understand the effects that mesoscale transport has on atmospheric CO2 distributions, we have used the atmospheric WRF model coupled to the diagnostic biospheric model VPRM, which provides high resolution biospheric CO2 fluxes based on MODIS satellite indices. We have run WRF-VPRM for the period from 16 May to 15 June in 2005 covering the intensive period of the CERES experiment, using the CO2 fields from the global model LMDZ for initialization and lateral boundary conditions. The comparison of modeled CO2 concentration time series against observations at the Biscarosse tower and against output from two global models – LMDZ and TM3 – clearly reveals that WRF-VPRM can capture the measured CO2 signal much better than the global models with lower resolution. Also the diurnal variability of the atmospheric CO2 field caused by recirculation of nighttime respired CO2 is simulated by WRF-VRPM reasonably well. Analysis of the nighttime data indicates that with high resolution modeling tools such as WRF-VPRM a large fraction of the time periods that are impossible to utilize in global models, can be used quantitatively and may help to constrain respiratory fluxes. The paper concludes that we need to utilize a high-resolution model such as WRF-VPRM to use continental observations of CO2 concentration data with more spatial and temporal coverage and to link them to the global inversion models.

scholarly journals Spatiotemporal patterns of the fossil-fuel CO<sub>2</sub> signal in central Europe: Results from a high-resolution atmospheric transport model

2017 ◽  
Author(s):  
Yu Liu ◽  
Nicolas Gruber ◽  
Dominik Brunner
Keyword(s):  
High Resolution ◽  
Central Europe ◽  
Western Europe ◽  
Fossil Fuel ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Temporal Variations ◽  
Atmospheric Co2 ◽  
Fuel Component ◽  
Atmospheric Transport Model

Abstract. The emission of CO2 from the burning of fossil fuel is a prime determinant of variations in atmospheric CO2. Here, we simulate this fossil fuel signal together with the natural and background components with a regional high-resolution atmospheric transport model for central and southern Europe considering separately the emissions from different sectors and countries on the basis of emission inventories and hourly emission time functions. The simulated variations in atmospheric CO2 agree very well with observation-based estimates, although the observed variance is slightly underestimated, particularly for the fossil fuel component. Despite relatively rapid atmospheric mixing, the simulated fossil fuel signal reveals distinct annual mean structures deep into the troposphere reflecting the spatially dense aggregation of most emissions. The fossil fuel signal accounts for more than half of the total (fossil fuel + biospheric + background) temporal variations in atmospheric CO2 in most areas of northern and western central Europe, with the largest variations occurring on diurnal timescales owing to the combination of diurnal variations in emissions and atmospheric mixing/transport out of the surface layer. Their co-variance leads to a fossil-fuel diurnal rectifier effect with a magnitude as large as 9 ppm compared to a case with time-constant emissions. The spatial pattern of CO2 from the different sectors largely reflects the distribution and relative magnitude of the corresponding emissions, with power plant emissions leaving the most distinguished mark. An exception is southern and western Europe, where the emissions from the transportation sector dominate the fossil fuel signal. Most of the fossil fuel CO2 remains within the country responsible for the emission, although in smaller countries, up to 80 % of the fossil fuel signal can come from abroad. A fossil fuel emission reduction of 30 % is clearly detectable for a surface-based observing system for atmospheric CO2, while it is beyond the edge of detectability for the current generation of satellites with the exception of a few hotspot sites. Changes in variability in atmospheric CO2 might open an additional door for the monitoring and verification of changes in fossil fuel emissions, primarily for surface based systems.

Line mixing and speed dependence in CO2 at 6227.9cm−1: Constrained multispectrum analysis of intensities and line shapes in the 30013←00001 band

2007 ◽  
Vol 245 (1) ◽  
pp. 52-80 ◽  
Author(s):  
V. Malathy Devi ◽  
D. Chris Benner ◽  
L.R. Brown ◽  
C.E. Miller ◽  
R.A. Toth
Keyword(s):  
Line Shapes ◽  
Speed Dependence ◽  
Line Mixing

scholarly journals Los Angeles megacity: a high-resolution land–atmosphere modelling system for urban CO<sub>2</sub> emissions

2016 ◽  
Vol 16 (14) ◽  
pp. 9019-9045 ◽  
Author(s):  
Sha Feng ◽  
Thomas Lauvaux ◽  
Sally Newman ◽  
Preeti Rao ◽  
Ravan Ahmadov ◽  
...  
Keyword(s):  
High Resolution ◽  
Los Angeles ◽  
Co2 Emission ◽  
Fossil Fuel ◽  
Meteorological Data ◽  
Atmospheric Co2 ◽  
Co2 Concentrations ◽  
Emissions Modelling ◽  
Atmospheric Co2 Concentrations ◽  
Modelling System

Abstract. Megacities are major sources of anthropogenic fossil fuel CO2 (FFCO2) emissions. The spatial extents of these large urban systems cover areas of 10 000 km2 or more with complex topography and changing landscapes. We present a high-resolution land–atmosphere modelling system for urban CO2 emissions over the Los Angeles (LA) megacity area. The Weather Research and Forecasting (WRF)-Chem model was coupled to a very high-resolution FFCO2 emission product, Hestia-LA, to simulate atmospheric CO2 concentrations across the LA megacity at spatial resolutions as fine as  ∼  1 km. We evaluated multiple WRF configurations, selecting one that minimized errors in wind speed, wind direction, and boundary layer height as evaluated by its performance against meteorological data collected during the CalNex-LA campaign (May–June 2010). Our results show no significant difference between moderate-resolution (4 km) and high-resolution (1.3 km) simulations when evaluated against surface meteorological data, but the high-resolution configurations better resolved planetary boundary layer heights and vertical gradients in the horizontal mean winds. We coupled our WRF configuration with the Vulcan 2.2 (10 km resolution) and Hestia-LA (1.3 km resolution) fossil fuel CO2 emission products to evaluate the impact of the spatial resolution of the CO2 emission products and the meteorological transport model on the representation of spatiotemporal variability in simulated atmospheric CO2 concentrations. We find that high spatial resolution in the fossil fuel CO2 emissions is more important than in the atmospheric model to capture CO2 concentration variability across the LA megacity. Finally, we present a novel approach that employs simultaneous correlations of the simulated atmospheric CO2 fields to qualitatively evaluate the greenhouse gas measurement network over the LA megacity. Spatial correlations in the atmospheric CO2 fields reflect the coverage of individual measurement sites when a statistically significant number of sites observe emissions from a specific source or location. We conclude that elevated atmospheric CO2 concentrations over the LA megacity are composed of multiple fine-scale plumes rather than a single homogenous urban dome. Furthermore, we conclude that FFCO2 emissions monitoring in the LA megacity requires FFCO2 emissions modelling with  ∼  1 km resolution because coarser-resolution emissions modelling tends to overestimate the observational constraints on the emissions estimates.

Line mixing and speed dependence in CO2 at 6348cm−1: Positions, intensities, and air- and self-broadening derived with constrained multispectrum analysis

2007 ◽  
Vol 242 (2) ◽  
pp. 90-117 ◽  
Author(s):  
V. Malathy Devi ◽  
D. Chris Benner ◽  
L.R. Brown ◽  
C.E. Miller ◽  
R.A. Toth
Keyword(s):  
Speed Dependence ◽  
Line Mixing

scholarly journals Can we use hourly CO<sub>2</sub> concentration data in inversions? Comparing high resolution WRF-VPRM simulations with coastal tower measurements of CO<sub>2</sub>

2008 ◽  
Vol 5 (6) ◽  
pp. 4745-4776 ◽  
Author(s):  
R. Ahmadov ◽  
C. Gerbig ◽  
R. Kretschmer ◽  
S. Körner ◽  
C. Rödenbeck ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Fraction ◽  
Wrf Model ◽  
Co2 Concentration ◽  
Atmospheric Co2 ◽  
Concentration Data ◽  
Modeling Tools ◽  
Global Models ◽  
Diurnal Variability ◽  
Resolution Model

Abstract. In order to better understand the effects that mesoscale transport has on atmospheric CO2 distributions, we have used the WRF model coupled to the diagnostic biospheric model VPRM, which provides high-resolution biospheric CO2 fluxes based on MODIS satellite indices. We have run WRF-VPRM for the period from 16 May to 15 June in 2005 covering the intensive period of the CERES experiment, using the CO2 fields from the global model LMDZ for initialization and lateral boundary conditions. The comparison of modeled CO2 concentration time series against observations at the Biscarosse tower and against output from two global models – LMDZ and TM3 – clearly reveals that WRF-VPRM can capture the measured CO2 signal much better than the global models with lower resolution. Also the diurnal variability of the atmospheric CO2 field caused by recirculation of nighttime respired CO2 is simulated by WRF-VRPM reasonably well. Analysis of the nighttime data indicates that with high resolution modeling tools such as WRF-VPRM a large fraction of the time periods that are impossible to utilize in global models, can be used quantitatively and help constraining respiratory fluxes. The paper concludes that we need to utilize a high-resolution model such as WRF-VPRM to use continental observations of CO2 concentration data with more spatial and temporal coverage and to link them to the global inversion models.

scholarly journals High-resolution simulations of atmospheric CO<sub>2</sub> over complex terrain – representing the Ochsenkopf mountain tall tower

2011 ◽  
Vol 11 (3) ◽  
pp. 6875-6917
Author(s):  
D. Pillai ◽  
C. Gerbig ◽  
R. Ahmadov ◽  
C. Rödenbeck ◽  
R. Kretschmer ◽  
...  
Keyword(s):  
High Resolution ◽  
Complex Terrain ◽  
Atmospheric Co2 ◽  
Spatial And Temporal Variability ◽  
Mountain Range ◽  
Tracer Transport ◽  
Modeling Tools ◽  
Mixing Ratios ◽  
High Resolution Models ◽  
Tall Tower

Abstract. Accurate simulation of the spatial and temporal variability of tracer mixing ratios over complex terrain is challenging, but essential in order to utilize measurements made in complex orography (e.g. mountain and coastal sites) in an atmospheric inverse framework to better estimate regional fluxes of these trace gases. This study investigates the ability of high-resolution modeling tools to simulate meteorological and CO2 fields around Ochsenkopf tall tower, situated in Fichtelgebirge mountain range – Germany (1022 m a.s.l.; 50°1'48'' N, 11°48'30'' E). We used tower measurements made at different heights for different seasons together with the measurements from an aircraft campaign. Two tracer transport models – WRF (Eulerian based) and STILT (Lagrangian based), both with a 2 km horizontal resolution – are used together with the satellite-based biospheric model VPRM to simulate the distribution of atmospheric CO2 concentration over Ochsenkopf. The results suggest that the high-resolution models can capture diurnal, seasonal and synoptic variability of observed mixing ratios much better than coarse global models. The effects of mesoscale transports such as mountain-valley circulations and mountain-wave activities on atmospheric CO2 distributions are reproduced remarkably well in the high-resolution models. With this study, we emphasize the potential of using high-resolution models in the context of inverse modeling frameworks to utilize measurements provided from mountain or complex terrain sites.

scholarly journals A global coupled Eulerian-Lagrangian model and 1 × 1 km CO<sub>2</sub> surface flux dataset for high-resolution atmospheric CO<sub>2</sub> transport simulations

2011 ◽  
Vol 4 (3) ◽  
pp. 2047-2080 ◽  
Author(s):  
A. Ganshin ◽  
T. Oda ◽  
M. Saito ◽  
S. Maksyutov ◽  
V. Valsala ◽  
...  
Keyword(s):  
High Resolution ◽  
High Frequency ◽  
Transport Model ◽  
Dispersion Model ◽  
Particle Dispersion ◽  
Surface Fluxes ◽  
Atmospheric Co2 ◽  
Lagrangian Model ◽  
Co2 Concentrations ◽  
Atmospheric Co2 Concentrations

Abstract. We designed a method to simulate atmospheric CO2 concentrations at several continuous observation sites around the globe using surface fluxes at a very high spatial resolution. The simulations presented in this study were performed using a Lagrangian particle dispersion model coupled to a global atmospheric tracer transport model with prescribed global surface CO2 flux maps at a 1 × 1 km resolution. The surface fluxes used in the simulations were prepared by assembling the individual components of terrestrial, oceanic and fossil fuel CO2 fluxes. This experimental setup (i.e., a transport model running at a medium resolution, coupled to a high-resolution Lagrangian particle dispersion model together with global surface fluxes at a very high resolution), which was designed to represent high-frequency variations in atmospheric CO2 concentration, has not been reported at a global scale previously. Two sensitivity experiments were performed: (a) using the global transport model without coupling to the Lagrangian dispersion model, and (b) using the coupled model with a reduced resolution of surface fluxes, in order to evaluate the performance of Eulerian-Lagrangian coupling and the role of high-resolution fluxes in simulating high-frequency variations in atmospheric CO2 concentrations. A correlation analysis between observed and simulated atmospheric CO2 concentrations at selected locations revealed that the inclusion of both Eulerian-Lagrangian coupling and high-resolution fluxes improves the high-frequency simulations of the model. The results highlight the potential of a coupled Eulerian-Lagrangian model in simulating high-frequency atmospheric CO2 concentrations at many locations worldwide. The model performs well in representing observations of atmospheric CO2 concentrations at high spatial and temporal resolutions, especially for coastal sites and sites located close to sources of large anthropogenic emissions. While this study focused on simulations of CO2 concentrations, the model could be used for other atmospheric compounds with known estimated emissions.

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