Temporal Variation of Atmospheric Fossil and Modern CO2 Excess at a Central European Rural Tower Station between 2008 and 2014

Radiocarbon ◽  
2018 ◽  
Vol 60 (5) ◽  
pp. 1285-1299 ◽  
Author(s):  
István Major ◽  
László Haszpra ◽  
László Rinyu ◽  
István Futó ◽  
Árpád Bihari ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Mole Fraction ◽  
Fossil Fuel ◽  
Carbon Isotopic Composition ◽  
Central European ◽  
Boundary Layer Height ◽  
Carbon Isotopic ◽  
The Mean ◽  
Co2 Excess ◽  
Annual Decline

AbstractIn 2008, the atmospheric CO2 measurements at the Hegyhátsál rural tower station were extended further by 14CO2 air sampling from two elevations (115 and 10 m a.g.l.), in cooperation with HEKAL (ICER). Since then, a complete six-year-long (2008–2014) dataset of atmospheric CO2, Δ14C, fossil, and modern CO2 excess (relative to Jungfraujoch) has been assembled and evaluated. Based on our results, the annual mean CO2 mole fraction rose at both elevations in this period. The annual mean Δ14CO2 values decreased with a similar average annual decline. Based on our comparison, planetary boundary layer height obtained by modeling has a larger influence on the variation of mole fraction of CO2 (relative to Jungfraujoch), than on its carbon isotopic composition, i.e. the boundary layer rather represents a physical constraint. Fossil fuel CO2 excess at both elevations can rather be observed in wintertime and mainly due to the increased anthropogenic emission of nearby cities in the region. The mean modern CO2 excess at both elevations was even larger in winter, but it drastically decreased at 115 m by summer, while it remained at the winter level at 10 m.

scholarly journals Assessment of fossil fuel carbon dioxide and other anthropogenic trace gas emissions from airborne measurements over Sacramento, California in spring 2009

2011 ◽  
Vol 11 (2) ◽  
pp. 705-721 ◽  
Author(s):  
J. C. Turnbull ◽  
A. Karion ◽  
M. L. Fischer ◽  
I. Faloona ◽  
T. Guilderson ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Mole Fraction ◽  
Fossil Fuel ◽  
Trace Gases ◽  
Emission Inventories ◽  
Airborne Measurements ◽  
Boundary Layer Height ◽  
The Difference ◽  
Emission Ratios

Abstract. Direct quantification of fossil fuel CO2 (CO2ff) in atmospheric samples can be used to examine several carbon cycle and air quality questions. We collected in situ CO2, CO, and CH4 measurements and flask samples in the boundary layer and free troposphere over Sacramento, California, USA, during two aircraft flights over and downwind of this urban area during spring of 2009. The flask samples were analyzed for Δ14CO2 and CO2 to determine the recently added CO2ff mole fraction. A suite of greenhouse and other trace gases, including hydrocarbons and halocarbons, were measured in the same samples. Strong correlations were observed between CO2ff and numerous trace gases associated with urban emissions. From these correlations we estimate emission ratios between CO2ff and these species, and compare these with bottom-up inventory-derived estimates. Recent county level inventory estimates for carbon monoxide (CO) and benzene from the California Air Resources Board CEPAM database are in good agreement with our measured emission ratios, whereas older emissions inventories appear to overestimate emissions of these gases by a factor of two. For most other trace species, there are substantial differences (200–500%) between our measured emission ratios and those derived from available emission inventories. For the first flight, we combine in situ CO measurements with the measured CO:CO2ff emission ratio of 14 ± 2 ppbCO/ppmCO2 to derive an estimate of CO2ff mole fraction throughout this flight, and also estimate the biospheric CO2 mixing ratio (CO2bio) from the difference of total and fossil CO2. The resulting CO2bio varies dramatically from up to 8 ± 2 ppm in the urban plume to −6 ± 1 ppm in the surrounding boundary layer air. Finally, we use the in situ estimates of CO2ff mole fraction to infer total fossil fuel CO2 emissions from the Sacramento region, using a mass balance approach. The resulting emissions are uncertain to within a factor of two due to uncertainties in wind speed and boundary layer height. Nevertheless, this first attempt to estimate urban-scale CO2ff from atmospheric radiocarbon measurements shows that CO2ff can be used to verify and improve emission inventories for many poorly known anthropogenic species, separate biospheric CO2, and indicates the potential to constrain CO2ff emissions if transport uncertainties are reduced.

scholarly journals Measurement of fossil fuel derived carbon dioxide and other anthropogenic trace gases above Sacramento, California in Spring 2009

2010 ◽  
Vol 10 (9) ◽  
pp. 21567-21613 ◽  
Author(s):  
J. C. Turnbull ◽  
A. Karion ◽  
M. L. Fischer ◽  
I. Faloona ◽  
T. Guilderson ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Mole Fraction ◽  
Fossil Fuel ◽  
Trace Gases ◽  
Emission Inventories ◽  
Boundary Layer Height ◽  
Trace Species ◽  
The Difference ◽  
Emission Ratios

Abstract. Direct quantification of fossil fuel CO2 (CO2ff) in atmospheric samples can be used to examine several carbon cycle and air quality questions. We collected in-situ CO2, CO, and CH4 measurements and flask samples in the boundary layer and free troposphere over Sacramento, California, USA, during two aircraft flights over and downwind of this urban area during spring of 2009. The flask samples were analyzed for Δ14CO2 and CO2 to determine the recently added CO2ff mole fraction. A suite of additional greenhouse gases including hydrocarbons and halocarbons were measured in the same samples. Strong correlations were observed between CO2ff and numerous trace gases associated with urban emissions. From these correlations we estimate emission ratios between CO2ff and these species, and compare these with bottom-up inventory-derived estimates. Recent county level inventory estimates for carbon monoxide (CO) and benzene from the California Air Resources Board CEPAM database are in good agreement with our measured emission ratios, whereas older emissions inventories appear to overestimate emissions of these gases. For most other trace species, there are substantial differences between our measured emission ratios and those derived from available emission inventories. For the first flight, we combine in situ CO measurements with the measured CO:CO2ff emission ratio of 14±2 ppbCO/ppmCO2 to derive an estimate of CO2ff mole fraction throughout this flight, and also estimate the biospheric CO2 mixing ratio (CO2bio) from the difference of total and fossil CO2. The resulting CO2bio varies substantially between air in the urban plume and the surrounding boundary layer air. Finally, we use the in situ estimates of CO2ff mole fraction to infer total fossil fuel CO2 emissions from the Sacramento region, using a mass balance approach. However the resulting emissions are uncertain to within a factor of two due to uncertainties in wind speed and boundary layer height. Nevertheless, this first attempt to estimate urban-scale CO2ff from atmospheric radiocarbon measurements shows that CO2ff can be used to verify and improve emission inventories for many poorly known anthropogenic species, separate biospheric CO2, and indicates the potential to constrain the CO2ff emissions if transport uncertainties are reduced.

scholarly journals Micro-Pulse Lidar Cruising Measurements in Northern South China Sea

2020 ◽  
Vol 12 (10) ◽  
pp. 1695
Author(s):  
Yuan Li ◽  
Baomin Wang ◽  
Shao-Yi Lee ◽  
Zhijie Zhang ◽  
Ye Wang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
South China Sea ◽  
South China ◽  
Vertical Profiles ◽  
Depolarization Ratio ◽  
Layer Height ◽  
Boundary Layer Height ◽  
The Mean ◽  
Micro Pulse Lidar ◽  
Atmospheric Boundary Layer Height

A shipborne micro-pulse lidar (Sigma Space Mini-MPL) was used to measure aerosol extinction coefficient over the northern region of the South China Sea from 9 August to 7 September 2016, the first time a mini-MPL was used for aerosol observation over the cruise region. The goal of the experiment was to investigate if the compact and affordable mini-MPL was usable for aerosol observation over this region. The measurements were used to calculate vertical profiles of volume extinction coefficient, depolarization ratio, and atmospheric boundary layer height. Aerosol optical depth (AOD) was lower over the southwest side of the cruise region, compared to the northeast side. Most attenuation occurred below 3.5 km, and maximum extinction values over coastal areas were generally about double of values offshore. The extinction coefficients at 532 nm (aerosol and molecular combined) over coastal and offshore areas were on average 0.04 km−1 and 0.02 km−1, respectively. Maximum values reached 0.2 km−1 and 0.14 km−1, respectively. Vertical profiles and back-trajectory calculations indicated vertical and horizontal layering of aerosols from different terrestrial sources. The mean volume depolarization ratio of the aerosols along the cruise was 0.04. The mean atmospheric boundary layer height along the cruise was 653 m, with a diurnal cycle reaching its mean maximum of 1041 m at 12:00 local time, and its mean minimum of 450 m at 20:00 local time. Unfortunately, only 11% of the measurements were usable. This was due to ship instability in rough cruise conditions, lack of stabilization rig, water condensation attached to the eye lens, and high humidity attenuating the echo signal. We recommend against the use of the mini-MPL in this cruise region unless substantial improvements are made to the default setup, e.g., instrument stabilization, instrument protection cover, and more theoretical work taking into account atmospheric gas scattering or absorption.

scholarly journals TransCom continuous experiment: comparison of <sup>222</sup>Rn transport at hourly time scales at three stations in Germany

2011 ◽  
Vol 11 (19) ◽  
pp. 10071-10084 ◽  
Author(s):  
S. Taguchi ◽  
R. M. Law ◽  
C. Rödenbeck ◽  
P. K. Patra ◽  
S. Maksyutov ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Transport ◽  
Inversion Layer ◽  
Temporal Variations ◽  
Transport Models ◽  
Layer Height ◽  
Boundary Layer Height ◽  
Diurnal Amplitude ◽  
Local Inversion ◽  
The Mean

Abstract. Fourteen global atmospheric transport models were evaluated by comparing the simulation of 222Rn against measurements at three continental stations in Germany: Heidelberg, Freiburg and Schauinsland. Hourly concentrations simulated by the models using a common 222Rn-flux without temporal variations were investigated for 2002 and 2003. We found that the mean simulated concentrations in Heidelberg are related to the diurnal amplitude of boundary layer height in each model. Summer mean concentrations simulated by individual models were negatively correlated with the seasonal mean of diurnal amplitude of boundary layer height, while in winter the correlation was positive. We also found that the correlations between simulated and measured concentrations at Schauinsland were higher when the simulated concentrations were interpolated to the station altitude in most models. Temporal variations of the mismatch between simulated and measured concentrations suggest that there are significant interannual variations in the 222Rn exhalation rate in this region. We found that the local inversion layer during daytime in summer in Freiburg has a significant effect on 222Rn concentrations. We recommend Freiburg concentrations for validation of models that resolve local stable layers and those at Heidelberg for models without this capability.

scholarly journals Edge Detection Method for Determining Boundary Layer Height Based on Doppler Lidar

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1103
Author(s):  
Ya’ni Pan ◽  
Zhili Jin ◽  
Pengfei Tong ◽  
Weiwei Xu ◽  
Wei Wang
Keyword(s):  
Boundary Layer ◽  
Edge Detection ◽  
Critical Role ◽  
Pollution Prevention ◽  
Doppler Lidar ◽  
Atmospheric Conditions ◽  
Layer Height ◽  
Variance Method ◽  
Boundary Layer Height ◽  
The Mean

The top of the boundary layer, referred to as the planetary boundary layer height (BLH), is an important physical parameter in atmospheric numerical models, which has a critical role in atmospheric simulation, air pollution prevention, and climate prediction. The traditional methods for determining BLHs using Doppler lidar vertical velocity variance (σw2) can be classified into the variance and peak methods, which depend on atmospheric conditions due to their use of a single threshold, hence limiting their ability to estimate diurnal BLHs. Edge detection (ED) was later introduced in BLH estimation due to its ability to identify the 2D gradient of an image. A key step in ED is automatically identifying the edge of BLHs based on the peaks of the profile, hence avoiding the influence of extreme atmospheric conditions. Two cases in the diurnal cycle on 4 March 2019 and 8 July 2019 reveal that ED outperforms both the variance and peak methods in nighttime and extreme atmospheric conditions. The retrieved BLHs from 2018 to 2020 were compared with radiosonde (RS) measurements for the same time at the neutral, stable, and convective boundary layers. The correlation coefficient (R: 0.4 vs. 0.05, 0.14; 0.26 vs. −0.10, −0.16; 0.35 vs. 0.01, 0.16) and root mean square error (RMSE (km): 0.58 vs. 0.82, 0.90; 0.37 vs. 1.01, 0.50; 0.66 vs. 0.98, 0.82) obtained by the ED method were higher and lower than those obtained by the variance and peak methods, respectively. The mean absolute error (MAE) of the ED method under the NBL, SBL, and CBL conditions are lower than the variance and peak methods (MAE (km): 0.44, 0.14, 0.50 vs. 0.62, 0.34, 0.64; 0.59, 0.75, 0.74), respectively. The mean relative error (MRE) of the ED method is lower than the variance and peak methods under the NBL condition (MRE: −8.88% vs. −18.39%, 13.91%). Under the SBL, the MRE of the ED method is lower than the variance method and higher than the peak method (−38.64%, vs. −152.23%; 14.02%). Under the CBL, the MRE of the ED method is lower than the variance method and higher than the peak method (−15.07% vs. 2.24%; 5.64%). In addition, the comparison between ED and wavelet covariance transform (WCT) method and RS measurements showed that the ED method has a similar performance with the WCT method and is even better. In the long-term analysis, the hourly and monthly BLHs in the diurnal and annual cycles, respectively, as obtained by ED, were highly consistent with the RS measurements and obtained the lowest standard error. In the annual cycle, the retrieved BLHs in summer and autumn were higher than those retrieved in spring and winter.

scholarly journals Molecular distribution and compound-specific stable carbon isotopic composition of dicarboxylic acids, oxocarboxylic acids, and α-dicarbonyls in PM<sub>2.5</sub> from Beijing, China

2017 ◽  
Author(s):  
Wanyu Zhao ◽  
Kimitaka Kawamura ◽  
Siyao Yue ◽  
Lianfang Wei ◽  
Hong Ren ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Succinic Acid ◽  
Biomass Burning ◽  
Fossil Fuel ◽  
Carbon Isotopic Composition ◽  
Dicarboxylic Acids ◽  
Fossil Fuel Combustion ◽  
Stable Carbon ◽  
Carbon Isotopic ◽  
Oxocarboxylic Acids

Abstract. This study investigates the seasonal variation, molecular distribution and stable carbon isotopic composition of diacids, oxocarboxylic acids and α-dicarbonyls to better understand the sources and formation processes of fine aerosols (PM2.5) in Beijing. The concentrations of total dicarboxylic acids varied from 110 to 2580 ng m−3, whereas oxoacids (9.50–353 ng m−3) and dicarbonyls (1.50–85.9 ng m−3) were less abundant. Oxalic acid was found to be the most abundant individual species, followed by succinic acid or occasionally by terephthalic acid (tPh), a plastic burning tracer. Ambient concentrations of phthalic acid (37.9±27.3 ng m−3) and tPh (48.7±51.1 ng m−3) are larger in winter than in other seasons, illustrating that fossil fuel combustion and plastic waste incineration contribute more significantly to wintertime aerosols. The year-round mass concentration ratios of malonic acid to succinic acid (C3/C4) are relatively by comparison with those in other urban aerosols and remote marine aerosols, most of which are less than or equal to unity in Beijing; thus, the degree of photochemical formation of diacids in Beijing is insignificant. Moreover, positive correlations of some oxocarboxylic acids and α-dicarbonyls with nss-K+, a tracer for biomass burning, suggest biogenic combustion activities accounting for a large contribution of these organic acids and related precursors. The mean δ13C value of succinic acid is highest among all species with values of −17.1±3.9‰ (winter) and −17.1±2.0‰ (spring), while malonic acid is less enriched in 13C than others in autumn (−17.6±4.6‰) and summer (−18.7±4.0‰). The δ13C values of major species in the Beijing aerosols are generally lower with a wider range than those in downwind regions in the western North Pacific, which indicates that Beijing has diverse emission sources with weak photooxidation. Thus, our study demonstrates that in addition to photochemical oxidation, high abundances of diacids, oxocarboxylic acids and α-dicarbonyls in Beijing are largely associated with anthropogenic primary emissions, such as biomass burning, fossil fuel combustion, and plastic burning.

scholarly journals Planetary boundary layer height variability over athens, greece, based on the synergy of raman lidar and radiosonde data: Application of the kalman filter and other techniques (2011-2016)

2018 ◽  
Vol 176 ◽  
pp. 06007 ◽  
Author(s):  
Dimitrios Alexiou ◽  
Panagiotis Kokkalis ◽  
Alexandros Papayannis ◽  
Francesc Rocadenbosch ◽  
Athina Argyrouli ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Radiosonde Data ◽  
Lidar Data ◽  
Planetary Boundary Layer Height ◽  
Raman Lidar ◽  
Extended Kalman Filtering ◽  
Layer Height ◽  
Boundary Layer Height ◽  
The Mean

In this paper we studied the temporal evolution of the Planetary Boundary Layer height (PBLH) over the basin of Athens, Greece during a 5-year period (2011-2016) using data from the EOLE Raman lidar system. The lidar data (range-corrected lidar signals-RCS) were selected around 12:00 UTC and 00:00 UTC for a total of 332 cases: 165 days and 167 nights. Extended Kalman filtering techniques were used for the determination of the PBLH. Moreover, several well established techniques for the PBLH estimation based on lidar data were also tested for a total of 35 cases. Comparisons with the PBLH values derived from radiosonde data were also performed. The mean PBLH over Athens was found to be of the order of 1617±324 m at 12:00 UTC and of 892±130 m at 00:00 UTC, for the period examined. The mean PBLH growth rate was found to be about 170±64 m h-1 and 90±17 m h-1, during daytime and nighttime, respectively.

scholarly journals Impact of the Planetary Boundary Layer Height on the Surface Aerosol Optical and Microphysical Properties

2020 ◽  
Vol 237 ◽  
pp. 02015
Author(s):  
Salvatore Romano ◽  
Maria Rita Perrone
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Particle Dispersion ◽  
Vertical Profiles ◽  
Particle Properties ◽  
Boundary Layer Height ◽  
Microphysical Properties ◽  
Surface Particle ◽  
The Mean ◽  
The Impact

Lidar, nephelometer, and aethalometer measurements at the surface, co-located in time and space with Particulate Matter (PM) measurements, have been performed to investigate the impact of the daily evolution of the Planetary Boundary Layer (PBL) height on the aerosol optical and microphysical properties. Measurements were performed at a coastal site of southeastern Italy characterized by a shallow (<1000 m) PBL height. The Standard Deviation technique applied to the vertical profiles of both the lidar range corrected signal (RCS) and the linear volume depolarization ratio (δr) has been used to determine the daily evolution of the PBL height and highlight benefits and limits of using RCS and δr vertical profiles. It is shown that the PBL height, which drives the particle dispersion at the surface, significantly affects the optical and microphysical properties of the surface particles since the particle dispersion varies with their size and, consequently, the mean optical and microphysical properties of the surface particles are affected. The impact of meteorological conditions on the daily trend of the PBL height and the surface particle properties has also been highlighted.

scholarly journals Three years of routine Raman lidar measurements of tropospheric aerosols: Planetary boundary layer heights, extinction and backscatter coefficients

2002 ◽  
Vol 2 (1) ◽  
pp. 75-107
Author(s):  
J. Schneider ◽  
R. Eixmann
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Raman Lidar ◽  
Data Set ◽  
Air Mass ◽  
Mean Values ◽  
Boundary Layer Height ◽  
Lidar Measurements ◽  
The Mean ◽  
Air Mass Origin

Abstract. We have performed a three-year series of routine lidar measurements on a climatological base. To obtain an unbiased data set, the measurements were taken at preselected times. The measurements were performed between 1 December 1997, and 30 November 2000, at Kühlungsborn, Germany (54°07' N, 11°46' E). Using a Rayleigh/Mie/Raman lidar system, we measured the aerosol backscatter coefficients at three wavelengths in and above the planetary boundary layer. The aerosol extinction coefficient has been determined at 532 nm, but here the majority of the measurements has been restricted to heights above the boundary layer. Only after-sunset measurements are included in this data set since the Raman measurements were restricted to darkness. For the climatological analysis, we selected the cloud-free days out of a fixed measurement schedule. The annual cycle of the boundary layer height has been found to have a phase shift of about 25 days with respect to the summer/winter solstices. The mean values of the extinction and backscatter coefficients do not show significant annual differences. The backscatter coefficients in the planetary boundary layer were found to be about 10 times higher than above. The mean aerosol optical depth above the boundary layer and below 5 km is 0.26 (±1.0)  x 10-2 in summer, and 1.5 (±0.95)  x 10-2 in winter, which almost negligible compared to values measured in the boundary layer. A cluster analysis of the backward trajectories yielded two major directions of air mass origin above the planetary boundary layer and 4 major directions inside. A marked difference between the total aerosol load dependent on the air mass origin could be found for air masses originating from the west and travelling at high wind speeds. Comparing the measured spectral dependence of the backscatter coefficients with data from the Global Aerosol Data Set, we found a general agreement, but only a few conclusions with respect to the aerosol type could be draws due to the high variability of the measured backscatter coefficients.

scholarly journals Molecular distribution and compound-specific stable carbon isotopic composition of dicarboxylic acids, oxocarboxylic acids and <i>α</i>-dicarbonyls in PM<sub>2.5</sub> from Beijing, China

2018 ◽  
Vol 18 (4) ◽  
pp. 2749-2767 ◽  
Author(s):  
Wanyu Zhao ◽  
Kimitaka Kawamura ◽  
Siyao Yue ◽  
Lianfang Wei ◽  
Hong Ren ◽  
...  
Keyword(s):  
Succinic Acid ◽  
Fossil Fuel ◽  
Carbon Isotopic Composition ◽  
Dicarboxylic Acids ◽  
Plastic Waste ◽  
Fossil Fuel Combustion ◽  
Stable Carbon ◽  
Carbon Isotopic ◽  
Waste Burning ◽  
Oxocarboxylic Acids

Abstract. This study investigates the seasonal variation, molecular distribution and stable carbon isotopic composition of diacids, oxocarboxylic acids and α-dicarbonyls to better understand the sources and formation processes of fine aerosols (PM2.5) in Beijing. The concentrations of total dicarboxylic acids varied from 110 to 2580 ng m−3, whereas oxoacids (9.50–353 ng m−3) and dicarbonyls (1.50–85.9 ng m−3) were less abundant. Oxalic acid was found to be the most abundant individual species, followed by succinic acid or occasionally by terephthalic acid (tPh), a plastic waste burning tracer. Ambient concentrations of phthalic acid (37.9 ± 27.3 ng m−3) and tPh (48.7 ± 51.1 ng m−3) were larger in winter than in other seasons, illustrating that fossil fuel combustion and plastic waste incineration contribute more to wintertime aerosols. The year-round mass concentration ratios of malonic acid to succinic acid (C3 ∕ C4) were relatively low by comparison with those in other urban aerosols and remote marine aerosols. The values were less than or equal to unity in Beijing, implying that the degree of photochemical formation of diacids in Beijing is insignificant. Moreover, strong correlation coefficients of major oxocarboxylic acids and α-dicarbonyls with nss-K+ suggest that biomass burning contributes significantly to these organic acids and related precursors. The mean δ13C value of succinic acid is the highest among all species, with values of −17.1 ± 3.9 ‰ (winter) and −17.1 ± 2.0 ‰ (spring), while malonic acid is more enriched in 13C than others in autumn (−17.6 ± 4.6 ‰) and summer (−18.7 ± 4.0 ‰). The δ13C values of major species in Beijing aerosols are generally lower than those in the western North Pacific atmosphere, the downwind region, which indicates that stable carbon isotopic compositions of diacids depend on their precursor sources in Beijing. Therefore, our study demonstrates that in addition to photochemical oxidation, high abundances of diacids, oxocarboxylic acids and α-dicarbonyls in Beijing are largely associated with anthropogenic primary emissions, such as biomass burning, fossil fuel combustion and plastic waste burning.

Sign in / Sign up

Export Citation Format

Share Document