scholarly journals Technical Note: Adapting a fixed-lag Kalman smoother to a geostatistical atmospheric inversion framework

2008 ◽  
Vol 8 (22) ◽  
pp. 6789-6799 ◽  
Author(s):  
A. M. Michalak
Keyword(s):  
Carbon Dioxide ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Temporal Correlation ◽  
Technical Note ◽  
Surface Fluxes ◽  
Computationally Efficient ◽  
Carbon Dioxide Fluxes ◽  
Kalman Smoother ◽  
Geostatistical Approach

Abstract. Inverse modeling methods are now commonly used for estimating surface fluxes of carbon dioxide, using atmospheric mass fraction measurements combined with a numerical atmospheric transport model. The geostatistical approach to flux estimation takes advantage of the spatial and/or temporal correlation in fluxes and does not require prior flux estimates. In this work, a previously-developed, computationally-efficient, fixed-lag Kalman smoother is adapted for application with a geostatistical approach to atmospheric inversions. This method makes it feasible to perform multi-year geostatistical inversions, at fine resolutions, and with large amounts of data. The new method is applied to the recovery of global gridscale carbon dioxide fluxes for 1997 to 2001 using pseudodata representative of a subset of the NOAA-ESRL Cooperative Air Sampling Network.

scholarly journals Technical note: A geostatistical fixed-lag Kalman smoother for atmospheric inversions

2008 ◽  
Vol 8 (2) ◽  
pp. 7755-7779
Author(s):  
A. M. Michalak
Keyword(s):  
Carbon Dioxide ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Temporal Correlation ◽  
Technical Note ◽  
Surface Fluxes ◽  
Carbon Dioxide Fluxes ◽  
Kalman Smoother ◽  
Geostatistical Approach ◽  
Flux Estimation

Abstract. Inverse modeling methods are now commonly used for estimating surface fluxes of carbon dioxide, using atmospheric mass fraction measurements combined with a numerical atmospheric transport model. The geostatistical approach to flux estimation takes advantage of the spatial and/or temporal correlation in fluxes and does not require prior flux estimates. In this work, a geostatistical implementation of a fixed-lag Kalman smoother is developed to improve the computational efficiency of the inverse problem. This method makes it feasible to perform multi-year inversions, at fine resolutions, and with large amounts of data. The new method is applied to the recovery of global gridscale carbon dioxide fluxes for 1997 to 2001 using pseudodata representative of a subset of the NOAA-ESRL Cooperative Air Sampling Network.

scholarly journals Technical Note: A new coupled system for global-to-regional downscaling of CO<sub>2</sub> concentration estimation

2009 ◽  
Vol 9 (6) ◽  
pp. 23187-23210 ◽  
Author(s):  
K. Trusilova ◽  
C. Rödenbeck ◽  
C. Gerbig ◽  
M. Heimann
Keyword(s):  
Transport Model ◽  
Atmospheric Transport ◽  
Near Field ◽  
Coupled System ◽  
Technical Note ◽  
Surface Fluxes ◽  
Global Model ◽  
Atmospheric Concentration ◽  
Mixing Ratios ◽  
Measured Time

Abstract. We introduce a global-to-regional nesting scheme for atmospheric transport models that are used for simulating concentrations of green house gases from globally distributed surface fluxes. The coupled system of the regional Stochastic Time-Inverted Lagrangian Transport (STILT) model and the global atmospheric transport model (TM3) is designed to resolve atmospheric trace gas concentrations at high temporal and spatial resolutions in a specified domain e.g. for regional inverse applications. The nesting technique used for the coupling is based on a decomposition of the atmospheric concentration signal into a far-field and a near-field contribution that allows global and regional models being of different type, i.e. Eulerian (grid) and Lagrangian (trajectory). For illustrating the performance of the coupled TM3-STILT system we compare simulated mixing ratios of carbon dioxide with available observations at 10 sites in Europe. For all chosen sites the TM3-STILT provided higher correlations between the modelled and the measured time series than the TM3 global model. The autocorrelation analysis showed that in contrast to the global model TM3-STILT model is capable to represent the variability of the measured tracer concentrations.

scholarly journals Technical Note: A novel approach to estimation of time-variable surface sources and sinks of carbon dioxide using empirical orthogonal functions and the Kalman filter

2011 ◽  
Vol 11 (1) ◽  
pp. 1367-1384
Author(s):  
R. Zhuravlev ◽  
B. Khattatov ◽  
B. Kiryushov ◽  
S. Maksyutov
Keyword(s):  
Carbon Dioxide ◽  
Kalman Filter ◽  
Carbon Dioxide Emissions ◽  
Transport Model ◽  
Technical Note ◽  
Empirical Orthogonal Functions ◽  
Computationally Efficient ◽  
Orthogonal Functions ◽  
Novel Approach ◽  
Variable Surface

Abstract. In this work we propose an approach to solving a source estimation problem based on representation of carbon dioxide surface emissions as a linear combination of a finite number of pre-computed empirical orthogonal functions (EOFs). We used NIES transport model for computing response functions and Kalman filter for estimating carbon dioxide emissions. Our approach produces results similar to these of other models participating in the TransCom3 experiment, while being more advantageous in that it is more computationally efficient, produces smooth emission fields, and yields smaller errors than the traditional region-based approach. Additionally, the proposed approach does not require additional effort of defining independent self-contained emission regions.

scholarly journals Investigating Alaskan methane and carbon dioxide fluxes using measurements from the CARVE tower

2015 ◽  
Vol 15 (23) ◽  
pp. 34871-34911 ◽  
Author(s):  
A. Karion ◽  
C. Sweeney ◽  
J. B. Miller ◽  
A. E. Andrews ◽  
R. Commane ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Transport Model ◽  
Carbon Sources ◽  
Wrf Model ◽  
Surface Fluxes ◽  
Carbon Dioxide Fluxes ◽  
Near Surface ◽  
Annual Carbon ◽  
Northern High Latitude ◽  
Carbon Dioxide Co2

Abstract. Northern high-latitude carbon sources and sinks, including those resulting from degrading permafrost, are thought to be sensitive to the rapidly warming climate. Because the near-surface atmosphere integrates surface fluxes over large (~ 500–1000 km) scales, atmospheric monitoring of carbon dioxide (CO2) and methane (CH4) mole fractions in the daytime mixed layer is a promising method for detecting change in the carbon cycle throughout boreal Alaska. Here we use CO2 and CH4 measurements from a NOAA tower 17 km north of Fairbanks AK, established as part of NASA's Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE), to investigate regional fluxes of CO2 and CH4 for 2012–2014. CARVE was designed to use aircraft and surface observations to better understand and quantify the sensitivity of Alaskan carbon fluxes to climate variability. We use high-resolution meteorological fields from the Polar Weather Research and Forecasting (WRF) model coupled with the Stochastic Time-Inverted Lagrangian Transport model (hereafter, WRF-STILT), along with the Polar Vegetation Photosynthesis and Respiration Model (PolarVPRM), to investigate fluxes of CO2 in boreal Alaska using the tower observations, which are sensitive to large areas of central Alaska. We show that simulated PolarVPRM/WRF-STILT CO2 mole fractions show remarkably good agreement with tower observations, suggesting that the WRF-STILT model represents the meteorology of the region quite well, and that the PolarVPRM flux magnitudes and spatial distribution are consistent with CO2 mole fractions observed at the CARVE tower. CO2 signals at the tower are larger than predicted, with significant respiration occurring in the fall that is not captured by PolarVPRM. Using the WRF-STILT model, we find that average CH4 fluxes in boreal Alaska are somewhat lower than flux estimates by Chang et al. (2014) over all of Alaska for May–September 2012; we also find emissions persist during some wintertime periods, augmenting those observed during the summer and fall. The presence of significant fall and winter CO2 and CH4 fluxes underscores the need for year-round in-situ observations to quantify changes in boreal Alaskan annual carbon balance.

scholarly journals Technical Note: A novel approach to estimation of time-variable surface sources and sinks of carbon dioxide using empirical orthogonal functions and the Kalman filter

2011 ◽  
Vol 11 (20) ◽  
pp. 10305-10315 ◽  
Author(s):  
R. Zhuravlev ◽  
B. Khattatov ◽  
B. Kiryushov ◽  
S. Maksyutov
Keyword(s):  
Carbon Dioxide ◽  
Kalman Filter ◽  
Carbon Dioxide Emissions ◽  
Transport Model ◽  
Technical Note ◽  
Empirical Orthogonal Functions ◽  
Surface Fluxes ◽  
Orthogonal Functions ◽  
Novel Approach ◽  
Variable Surface

Abstract. In this work we propose an approach to solving a source estimation problem based on representation of carbon dioxide surface emissions as a linear combination of a finite number of pre-computed empirical orthogonal functions (EOFs). We used National Institute for Environmental Studies (NIES) transport model for computing response functions and Kalman filter for estimating carbon dioxide emissions. Our approach produces results similar to these of other models participating in the TransCom3 experiment. Using the EOFs we can estimate surface fluxes at higher spatial resolution, while keeping the dimensionality of the problem comparable with that in the regions approach. This also allows us to avoid potentially artificial sharp gradients in the fluxes in between pre-defined regions. EOF results generally match observations more closely given the same error structure as the traditional method. Additionally, the proposed approach does not require additional effort of defining independent self-contained emission regions.

scholarly journals Technical Note: A new coupled system for global-to-regional downscaling of CO<sub>2</sub> concentration estimation

2010 ◽  
Vol 10 (7) ◽  
pp. 3205-3213 ◽  
Author(s):  
K. Trusilova ◽  
C. Rödenbeck ◽  
C. Gerbig ◽  
M. Heimann
Keyword(s):  
Transport Model ◽  
Atmospheric Transport ◽  
Near Field ◽  
Coupled System ◽  
Technical Note ◽  
Surface Fluxes ◽  
Atmospheric Concentration ◽  
Mixing Ratios ◽  
Concentration Estimation ◽  
Measured Time

Abstract. We introduce a global-to-regional nesting scheme for atmospheric transport models used in simulating concentrations of green house gases from globally distributed surface fluxes. The coupled system of the regional Stochastic Time-Inverted Lagrangian Transport (STILT) model and the global atmospheric transport model (TM3) is designed to resolve atmospheric trace gas concentrations at high temporal and spatial resolutions in a specified domain e.g. for regional inverse applications. The nesting technique used for the coupling is based on a decomposition of the atmospheric concentration signal into a far-field and a near-field contribution enabling the usage of different model types for global (Eulerian) and regional (Lagrangian) scales. For illustrating the performance of the coupled TM3-STILT system we compare simulated mixing ratios of carbon dioxide with available observations at 10 sites in Europe. For all chosen sites the TM3-STILT provided higher correlations between the modelled and the measured time series than the TM3 global model. Autocorrelation analysis demonstrated that the TM3-STILT model captured temporal variability of measured tracer concentrations better than TM3 at most sites.

scholarly journals Investigating Alaskan methane and carbon dioxide fluxes using measurements from the CARVE tower

2016 ◽  
Vol 16 (8) ◽  
pp. 5383-5398 ◽  
Author(s):  
Anna Karion ◽  
Colm Sweeney ◽  
John B. Miller ◽  
Arlyn E. Andrews ◽  
Roisin Commane ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Transport Model ◽  
Carbon Sources ◽  
Wrf Model ◽  
Surface Fluxes ◽  
Carbon Dioxide Fluxes ◽  
Near Surface ◽  
Northern High Latitude ◽  
Carbon Dioxide Co2 ◽  
Good Agreement

Abstract. Northern high-latitude carbon sources and sinks, including those resulting from degrading permafrost, are thought to be sensitive to the rapidly warming climate. Because the near-surface atmosphere integrates surface fluxes over large ( ∼  500–1000 km) scales, atmospheric monitoring of carbon dioxide (CO2) and methane (CH4) mole fractions in the daytime mixed layer is a promising method for detecting change in the carbon cycle throughout boreal Alaska. Here we use CO2 and CH4 measurements from a NOAA tower 17 km north of Fairbanks, AK, established as part of NASA's Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE), to investigate regional fluxes of CO2 and CH4 for 2012–2014. CARVE was designed to use aircraft and surface observations to better understand and quantify the sensitivity of Alaskan carbon fluxes to climate variability. We use high-resolution meteorological fields from the Polar Weather Research and Forecasting (WRF) model coupled with the Stochastic Time-Inverted Lagrangian Transport model (hereafter, WRF-STILT), along with the Polar Vegetation Photosynthesis and Respiration Model (PolarVPRM), to investigate fluxes of CO2 in boreal Alaska using the tower observations, which are sensitive to large areas of central Alaska. We show that simulated PolarVPRM–WRF-STILT CO2 mole fractions show remarkably good agreement with tower observations, suggesting that the WRF-STILT model represents the meteorology of the region quite well, and that the PolarVPRM flux magnitudes and spatial distribution are generally consistent with CO2 mole fractions observed at the CARVE tower. One exception to this good agreement is that during the fall of all 3 years, PolarVPRM cannot reproduce the observed CO2 respiration. Using the WRF-STILT model, we find that average CH4 fluxes in boreal Alaska are somewhat lower than flux estimates by Chang et al. (2014) over all of Alaska for May–September 2012; we also find that enhancements appear to persist during some wintertime periods, augmenting those observed during the summer and fall. The possibility of significant fall and winter CO2 and CH4 fluxes underscores the need for year-round in situ observations to quantify changes in boreal Alaskan annual carbon balance.

scholarly journals Technical note: How are NH<sub>3</sub> dry deposition estimates affected by combining the LOTOS-EUROS model with IASI-NH<sub>3</sub> satellite observations?

2018 ◽  
Vol 18 (17) ◽  
pp. 13173-13196 ◽  
Author(s):  
Shelley C. van der Graaf ◽  
Enrico Dammers ◽  
Martijn Schaap ◽  
Jan Willem Erisman
Keyword(s):  
Dry Deposition ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Deposition Velocity ◽  
Monitoring And Evaluation ◽  
Technical Note ◽  
Deposition Flux ◽  
Deposition Fluxes ◽  
Po Valley ◽  
Spatial Coverage

Abstract. Atmospheric levels of reactive nitrogen have increased substantially during the last century resulting in increased nitrogen deposition to ecosystems, causing harmful effects such as soil acidification, reduction in plant biodiversity and eutrophication in lakes and the ocean. Recent developments in the use of atmospheric remote sensing enabled us to resolve concentration fields of NH3 with larger spatial coverage. These observations may be used to improve the quantification of NH3 deposition. In this paper, we use a relatively simple, data-driven method to derive dry deposition fluxes and surface concentrations of NH3 for Europe and for the Netherlands. The aim of this paper is to determine the applicability and the limitations of this method for NH3. Space-born observations of the Infrared Atmospheric Sounding Interferometer (IASI) and the LOTOS-EUROS atmospheric transport model are used. The original modelled dry NH3 deposition flux from LOTOS-EUROS and the flux inferred from IASI are compared to indicate areas with large discrepancies between the two. In these areas, potential model or emission improvements are needed. The largest differences in derived dry deposition fluxes occur in large parts of central Europe, where the satellite-observed NH3 concentrations are higher than the modelled ones, and in Switzerland, northern Italy (Po Valley) and southern Turkey, where the modelled NH3 concentrations are higher than the satellite-observed ones. A sensitivity analysis of eight model input parameters important for NH3 dry deposition modelling showed that the IASI-derived dry NH3 deposition fluxes may vary from ∼ 20 % up to ∼50 % throughout Europe. Variations in the NH3 dry deposition velocity led to the largest deviations in the IASI-derived dry NH3 deposition flux and should be focused on in the future. A comparison of NH3 surface concentrations with in situ measurements of several established networks – the European Monitoring and Evaluation Programme (EMEP), Meetnet Ammoniak in Natuurgebieden (MAN) and Landelijk Meetnet Luchtkwaliteit (LML) – showed no significant or consistent improvement in the IASI-derived NH3 surface concentrations compared to the originally modelled NH3 surface concentrations from LOTOS-EUROS. It is concluded that the IASI-derived NH3 deposition fluxes do not show strong improvements compared to modelled NH3 deposition fluxes and there is a future need for better, more robust, methods to derive NH3 dry deposition fluxes.

scholarly journals Impact of Ragweed Pollen Daily Release Intensity on Long-Range Transport in Western Europe

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 693
Author(s):  
Laurent Menut ◽  
Dmitry Khvorostyanov ◽  
Florian Couvidat ◽  
Frédérik Meleux
Keyword(s):  
Western Europe ◽  
Transport Model ◽  
Temporal Correlation ◽  
Surface Fluxes ◽  
Ragweed Pollen ◽  
Specific Humidity ◽  
Limiting Factors ◽  
Shortwave Radiation ◽  
Release Formulation ◽  
Regional Modelling

This study is dedicated to improving the daily release of ragweed pollen emission in the context of deterministic regional modelling for analysis and forecast. First, correlations are calculated between daily modelled meteorological variables (wind speed, temperature, humidity, precipitation, surface fluxes) and daily pollen counts at nine stations in Hungary, Croatia and France between 2005 and 2011. The 2 m temperature is the most correlated parameter, followed by convective velocity and incoming shortwave radiation, while precipitation rate and 2 m specific humidity act as limiting factors. Using these results, a ragweed pollen daily release formulation is proposed. This formulation is implemented in the CHIMERE chemistry-transport model and tested during the whole year of 2010. Results are compared to observations, and it is shown that the new formulation provides a more realistic day-to-day variability: the spatio-temporal correlation between surface measurements and modelled concentrations is 0.77, greater than two other known emission schemes.

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