scholarly journals Seasonal and latitudinal variations of column averaged volume-mixing ratios of atmospheric CO2

2005 ◽  
Vol 32 (3) ◽  
Author(s):  
T. Warneke
2011 ◽  
Vol 11 (3) ◽  
pp. 6875-6917
Author(s):  
D. Pillai ◽  
C. Gerbig ◽  
R. Ahmadov ◽  
C. Rödenbeck ◽  
R. Kretschmer ◽  
...  

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.


Land ◽  
2013 ◽  
Vol 2 (3) ◽  
pp. 304-327 ◽  
Author(s):  
Brittain Briber ◽  
Lucy Hutyra ◽  
Allison Dunn ◽  
Steve Raciti ◽  
J. Munger

2005 ◽  
Vol 5 (1) ◽  
pp. 847-862
Author(s):  
T. Warneke ◽  
R. de Beek ◽  
M. Buchwitz ◽  
J. Notholt ◽  
A. Schulz ◽  
...  

Abstract. CO, CH4, N2O and CO2 were retrieved from high resolution solar absorption spectra obtained during a ship cruise from Capetown to Bremerhaven in January/February 2003 by Fourier Transform Infrared (FTIR) spectroscopy. Precisions of better than 0.5% for the column averaged volume mixing ratios (VMR) of CH4 and CO2 are achieved using of O2 as a reference gas. Shipborne FTIR-measurements of CO and data from SCIAMACHY/ENVISAT retrieved by the Weighting Function Modified Differential Optical Absorption Spectroscopy (WFM-DOAS) retrieval algorithm show qualitatively the same latitudinal variations. WFM-DOAS data of CH4, N2O and CO2 measured over sea exhibit a great spread. The spread is significantly reduced for satellite measurements over land and a reasonable agreement can be obtained if the shipborne data is compared with the closest SCIAMACHY measurements over land. The number of comparisons is too small to draw conclusions. However, by including only WFM-DOAS data with small errors the shipborne and WFM-DOAS data compare within 5% for CH4 and CO2 and within 30% for N2O.


2016 ◽  
Author(s):  
Massimo Valeri ◽  
Massimo Carlotti ◽  
Jean-Marie Flaud ◽  
Piera Raspollini ◽  
Marco Ridolfi ◽  
...  

Abstract. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is a Fourier Transform Spectrometer that measured mid-infrared atmospheric limb emission spectra from July 2002 to April 2012 on board the polar-orbiting satellite ENVISAT. We have used MIPAS data to study the latitudinal variations of phosgene (COCl2 or carbonyl chloride) and, for the first time, its seasonal variation in the upper troposphere lower stratosphere region (UTLS). Retrievals of phosgene were made using the 830–860 cm−1 region, corresponding to the ν5 bands of COCl2. Unfortunately in that region the ν4 band of CFC-11, much stronger than COCl2 ν5, hides the phosgene emission. In order to evaluate seasonality and latitudinal distribution of phosgene we have analysed all the measurements made by MIPAS in the days 18 and 20 of each month of 2008 with the Optimized Retrieval Model (ORM) recently upgraded with the Multi-Target Retrieval technique and with the Optimal Estimation functionality to apply external constraints to the state vector. Average seasonal profiles of phosgene show an evident latitudinal variability with the largest values observed in the tropical regions (maximum ≈ 35 parts per trillion by volume (pptv) at about 300 hPa). In the mid-latitude and polar regions, the volume mixing ratios (VMR) values do not exceed 30 pptv and the vertical distributions are less peaked. Our analysis highlights that COCl2 seasonal variability is fairly low, apart from the polar regions.


2009 ◽  
Vol 6 (10) ◽  
pp. 2265-2280 ◽  
Author(s):  
L. F. Tolk ◽  
W. Peters ◽  
A. G. C. A. Meesters ◽  
M. Groenendijk ◽  
A. T. Vermeulen ◽  
...  

Abstract. We simulated meteorology and atmospheric CO2 transport over the Netherlands with the mesoscale model RAMS-Leaf3 coupled to the biospheric CO2 flux model 5PM. The results were compared with meteorological and CO2 observations, with emphasis on the tall tower of Cabauw. An analysis of the coupled exchange of energy, moisture and CO2 showed that the surface fluxes in the domain strongly influenced the atmospheric properties. The majority of the variability in the afternoon CO2 mixing ratio in the middle of the domain was determined by biospheric and fossil fuel CO2 fluxes in the limited area domain (640×640 km). Variation of the surface CO2 fluxes, reflecting the uncertainty of the parameters in the CO2 flux model 5PM, resulted in a range of simulated atmospheric CO2 mixing ratios of on average 11.7 ppm in the well-mixed boundary layer. Additionally, we found that observed surface energy fluxes and observed atmospheric temperature and moisture could not be reconciled with the simulations. Including this as an uncertainty in the simulation of surface energy fluxes changed simulated atmospheric vertical mixing and horizontal advection, leading to differences in simulated CO2 of on average 1.7 ppm. This is an important source of uncertainty and should be accounted for to avoid biased calculations of the CO2 mixing ratio, but it does not overwhelm the signal in the CO2 mixing ratio due to the uncertainty range of the surface CO2 fluxes.


2005 ◽  
Vol 5 (8) ◽  
pp. 2029-2034 ◽  
Author(s):  
T. Warneke ◽  
R. de Beek ◽  
M. Buchwitz ◽  
J. Notholt ◽  
A. Schulz ◽  
...  

Abstract. CO, CH4, N2O and CO2 were retrieved from high resolution solar absorption spectra obtained during a ship cruise from Capetown to Bremerhaven in January/February 2003 by Fourier Transform Infrared (FTIR) spectroscopy. Precisions of better than 0.5% for the column averaged volume mixing ratios (VMR) of CH4 and CO2 are achieved using of O2 as a reference gas. Shipborne FTIR-measurements of CO and data from SCIAMACHY/ENVISAT retrieved by the Weighting Function Modified Differential Optical Absorption Spectroscopy (WFM-DOAS) retrieval algorithm show qualitatively the same latitudinal variations. WFM-DOAS data of CH4, N2O and CO2 measured over sea exhibit a great spread. The spread is significantly reduced for satellite measurements over land and a reasonable agreement can be obtained if the shipborne data are compared with the closest SCIAMACHY measurements over land. The number of comparisons is too small to draw conclusions. However, by including only WFM-DOAS data with small errors the shipborne and WFM-DOAS data compare within 5% for CH4 and CO2 and within 30% for N2O.


2013 ◽  
Vol 6 (3) ◽  
pp. 5881-5922 ◽  
Author(s):  
L. Mandrake ◽  
C. Frankenberg ◽  
C. W. O'Dell ◽  
G. Osterman ◽  
P. Wennberg ◽  
...  

Abstract. Many modern instruments generate more data than may be fully processed in a timely manner. For some atmospheric sounders, much of the raw data cannot be processed into meaningful observations due to suboptimal viewing conditions, such as the presence of clouds. Conventional solutions are quick, empirical-threshold filters hand-created by domain experts to weed out unlikely or unreasonable observations, coupled with randomized down sampling when the data volume is still too high. In this paper, we describe a method for the construction of a sub-sampling and ordering solution that maximizes the likelihood that a requested data subset will be usefully processed. The method can be used for any metadata-rich source and implicitly discerns informative vs. non-informative data features while still permitting user feedback into the final features selected for filter implementation. We demonstrate the method by creating a selector for the spectra of the Japanese GOSAT satellite designed to measure column averaged mixing ratios of greenhouse gases including carbon dioxide (CO2). This is done within the Atmospheric CO2 Measurements from Space (ACOS) NASA project with the intention of eventual use during the early Orbiting Carbon Observatory-2 (OCO-2) mission. OCO-2 will have a 1.5 orders of magnitude larger data volume than ACOS, requiring intelligent pre-filtration.


2008 ◽  
Vol 5 (5) ◽  
pp. 3945-3964 ◽  
Author(s):  
I. García-Amorena ◽  
F. Wagner-Cremer ◽  
F. Gomez Manzaneque ◽  
T. B. van Hoof ◽  
S. García Álvarez ◽  
...  

Abstract. Here we analyse radiocarbon-dated Quercus leaf assemblages from northern Spain to obtain past atmospheric CO2 mixing ratios for the time period 9000–1100 cal BP by means of stomatal frequency analysis. Normalized, stomata based CO2 records show fluctuations of 20 ppmv during the Holocene that parallel Northern Hemisphere palaeotemperature reconstructions. The calculated radiative forcing of CO2 indicates a CO2 contribution of +0.1°C to the Holocene Thermal Maximum from 7 to 5 kyr BP, and −0.05°C to the Neoglacial cooling around 4 kyr BP. Derived northern hemispheric air-temperature anomalies forced by atmospheric CO2 variation suggest an active role of this trace gas as an amplifier of initial orbital forcing of Holocene climate.


2011 ◽  
Vol 11 (15) ◽  
pp. 7445-7464 ◽  
Author(s):  
D. Pillai ◽  
C. Gerbig ◽  
R. Ahmadov ◽  
C. Rödenbeck ◽  
R. Kretschmer ◽  
...  

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.


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