Validation of trajectory statistical methods

Scheifinger, Helfried; Kaiser, August

doi:10.1016/j.atmosenv.2007.08.034

Cited by 40 publications

(28 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2, after first scaling both footprints by the respective number of data points. The relative footprint is directly proportional to the Potential Source Contribution Function (PSCF) proposed in other studies (Zeng and Hopke, 1989;Scheifinger and Kaiser, 2007) in which this concept was applied to trajectory rather than LPDM simulations. The only difference is the scaling by the number of footprints (or trajectories) which makes the relative footprint independent of the number of points selected in a given subset.…”

Section: Lagrangian Transport Simulations For Qualitative Allocation mentioning

confidence: 99%

European source and sink areas of CO2 retrieved from Lagrangian transport model interpretation of combined O2 and CO2 measurements at the high alpine research station Jungfraujoch

2011

View full text Add to dashboard Cite

Abstract. The University of Bern monitors carbon dioxide (CO 2 ) and oxygen (O 2 ) at the High Altitude Research Station Jungfraujoch since the year 2000 by means of flasks sampling and since 2005 using a continuous in situ measurement system. This study investigates the transport of CO 2 and O 2 towards Jungfraujoch using backward Lagrangian Particle Dispersion Model (LPDM) simulations and utilizes CO 2 and O 2 signatures to classify air masses. By investigating the simulated transport patterns associated with distinct CO 2 concentrations it is possible to decipher different source and sink areas over Europe. The highest CO 2 concentrations, for example, were observed in winter during pollution episodes when air was transported from Northeastern Europe towards the Alps, or during south Foehn events with rapid uplift of polluted air from Northern Italy, as demonstrated in two case studies.To study the importance of air-sea exchange for variations in O 2 concentrations at Jungfraujoch the correlation between CO 2 and APO (Atmospheric Potential Oxygen) deviations from a seasonally varying background was analyzed. Anomalously high APO concentrations were clearly associated with air masses originating from the Atlantic Ocean, whereas low APO concentrations were found in air masses advected either from the east from the Eurasian continent in summer, or from the Eastern Mediterranean in winter. Those air masses with low APO in summer were also strongly depleted in CO 2 suggesting a combination of CO 2 uptake by vegetation and O 2 uptake by dry summer soils. Other subsets of points in the APO-CO 2 scatter plot investigated with respect to air mass Correspondence to: M. Leuenberger (leuenberger@climate.unibe.ch) origin included CO 2 and APO background values and points with regular APO but anomalous CO 2 concentrations. Background values were associated with free tropospheric air masses with little contact with the boundary layer during the last few days, while high or low CO 2 concentrations reflect the various levels of influence of anthropogenic emissions and the biosphere. The pronounced cycles of CO 2 and O 2 exchanges with the biosphere and the ocean cause clusters of points and lead to a seasonal pattern.

show abstract

Section: Lagrangian Transport Simulations For Qualitative Allocation mentioning

confidence: 99%

European source and sink areas of CO2 retrieved from Lagrangian transport model interpretation of combined O2 and CO2 measurements at the high alpine research station Jungfraujoch

2011

View full text Add to dashboard Cite

show abstract

“…Statistical analysis of a large set of trajectories has been a popular tool for identifying the regions that serve as source areas of selected compounds and thus contribute to the concentrations measured at the receptor site (Stohl, 1996(Stohl, , 1998Scheifinger and Kaiser, 2007). Different methods have been developed for the purpose of tracing back registered concentrations.…”

Section: Introductionmentioning

confidence: 99%

Trajectory analysis of atmospheric transport of fine particles, SO2, NOx and O3 to the SMEAR II station in Finland in 1996–2008

et al. 2013

View full text Add to dashboard Cite

Abstract. Trajectory statistical methods that combine in situ measurements of trace gas or particle concentrations and back trajectories calculated for corresponding times have proven to be a valuable approach in atmospheric research; especially in investigating air pollution episodes, but also in e.g. tracing the air mass history related to high vs. low concentrations of aerosol particles of different sizes at the receptor site. A concentration field method was fine-tuned to take the presumable horizontal error in calculated trajectories into account, tested with SO2 and validated by comparison against EMEP (European Monitoring and Evaluation Programme) emission data. In this work we apply the improved method for characterizing the transport of atmospheric SO2, NOx, O3 and aerosol particles of different size modes to a Finnish measurement station located in Hyytiälä (61°51' N, 24°17' E). Our method did not reproduce the EMEP emission soures, but proved useful for qualitative analysis on where the measured compounds come from, from one measurement station point of view. We applied it to study trends and seasonal variation in atmospheric pollutant transport during 13 yr at the SMEAR II (Station for Measuring Ecosystem-Atmosphere Interactions) station.

show abstract

“…Source area analysis based on combining in situ measurements of trace gas or particle concentrations and corresponding back trajectories has proven to be a valuable approach in atmospheric research: especially in investigating air pollution episodes, but also as a statistical method for tracing back the source areas of air masses related to high vs. low concentrations of trace gases or aerosol particles of different sizes measured at the receptor site (Stohl, 1998;Scheifinger and Kaiser, 2007;Engler, 2007). From Hyytiälä measurement site's perspective statistical trajectory methods have been used for particles of different size modes (Sogacheva et al, 2005) and trace gas concentrations Hulkkonen, 2010;Hulkkonen et al, 2010).…”

mentioning

confidence: 99%

Seasonal cycle, size dependencies, and source analyses of aerosol optical properties at the SMEAR II measurement station in Hyytiälä, Finland

et al. 2011

View full text Add to dashboard Cite

Abstract. Scattering and absorption were measured at the Station for Measuring Ecosystem-Atmosphere Relations (SMEAR II) station in Hyytiälä, Finland, from October 2006 to May 2009. The average scattering coefficient σ SP (λ = 550 nm) 18 Mm −1 was about twice as much as at the Pallas Global Atmosphere Watch (GAW) station in Finnish Lapland. The average absorption coefficient σ AP (λ = 550 nm) was 2.1 Mm −1 . The seasonal cycles were analyzed from hourly-averaged data classified according to the measurement month. The ratio of the highest to the lowest average σ SP and σ AP was ∼1.8 and ∼2.8, respectively. The average single-scattering albedo (ω 0 ) was 0.86 in winter and 0.91 in summer. σ SP was highly correlated with the volume concentrations calculated from number size distributions in the size range 0.003-10 µm. Assuming that the particle density was 1.5 g cm −3 , the PM 10 mass scattering efficiency was 3.1 ± 0.9 g m −2 at λ = 550 nm. Scattering coefficients were also calculated from the number size distributions by using a Mie code and the refractive index of ammonium sulfate. The linear regression yielded σ SP (modelled) = 1.046 × σ SP (measured) for the data with the low nephelometer sample volume relative humidity (RH NEPH = 30 ± 9 %) and σ SP (modelled) = 0.985 × σ SP (measured) when RH NEPH = 55 ± 4 %. The effective complex refractive index was obtained by an iterative approach, by matching the measured and the modelled σ SP and σ AP . The average effective complex refractive index was (1.517 ± 0.057) + (0.019 ± 0.015)i at λ = 550 nm. The iterated imaginary part had a strong seasonal cycle, with smallest values in summer and highest in winter. The contribution of submicron particles to scattering was ∼90 %. TheÅngström exponent of scattering, α SP , Correspondence to: A. Virkkula (aki.virkkula@helsinki.fi) was compared with the following weighted mean diameters: count mean diameter (CMD), surface mean diameter (SMD), scattering mean diameter (ScMD), condensation sink mean diameter (CsMD), and volume mean diameter (VMD). If α SP is to be used for estimating some measure of the size of particles, the best choice would be ScMD, then SMD, and then VMD. In all of these the qualitative relationship is similar: the larger theÅngström exponent, the smaller the weighted mean diameter. Contrary to these, CMD increased with increasing α SP and CsMD did not have any clear relationship with α SP . Source regions were estimated with backtrajectories and trajectory statistics. The geometric mean σ SP and σ AP associated with the grid cells in Eastern Europe were in the range 20-40 Mm −1 and 4-6 Mm −1 , respectively. The respective geometric means of σ SP and σ AP in the grid cells over Norwegian Sea were in the range 5-10 Mm −1 and <1 Mm −1 . The source areas associated with high α SP values were norther than those for σ SP and σ AP . The trajectory statistical approach and a simple wind sector classification agreed well.

show abstract

Validation of trajectory statistical methods

Cited by 40 publications

References 19 publications

European source and sink areas of CO<sub>2</sub> retrieved from Lagrangian transport model interpretation of combined O<sub>2</sub> and CO<sub>2</sub> measurements at the high alpine research station Jungfraujoch

European source and sink areas of CO<sub>2</sub> retrieved from Lagrangian transport model interpretation of combined O<sub>2</sub> and CO<sub>2</sub> measurements at the high alpine research station Jungfraujoch

Trajectory analysis of atmospheric transport of fine particles, SO<sub>2</sub>, NO<sub>x</sub> and O<sub>3</sub> to the SMEAR II station in Finland in 1996–2008

Seasonal cycle, size dependencies, and source analyses of aerosol optical properties at the SMEAR II measurement station in Hyytiälä, Finland

Contact Info

Product

Resources

About

Validation of trajectory statistical methods

Cited by 40 publications

References 19 publications

European source and sink areas of CO&lt;sub&gt;2&lt;/sub&gt; retrieved from Lagrangian transport model interpretation of combined O&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt; measurements at the high alpine research station Jungfraujoch

European source and sink areas of CO&lt;sub&gt;2&lt;/sub&gt; retrieved from Lagrangian transport model interpretation of combined O&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt; measurements at the high alpine research station Jungfraujoch

Trajectory analysis of atmospheric transport of fine particles, SO&lt;sub&gt;2&lt;/sub&gt;, NO&lt;sub&gt;x&lt;/sub&gt; and O&lt;sub&gt;3&lt;/sub&gt; to the SMEAR II station in Finland in 1996–2008

Seasonal cycle, size dependencies, and source analyses of aerosol optical properties at the SMEAR II measurement station in Hyytiälä, Finland

Contact Info

Product

Resources

About

European source and sink areas of CO<sub>2</sub> retrieved from Lagrangian transport model interpretation of combined O<sub>2</sub> and CO<sub>2</sub> measurements at the high alpine research station Jungfraujoch

European source and sink areas of CO<sub>2</sub> retrieved from Lagrangian transport model interpretation of combined O<sub>2</sub> and CO<sub>2</sub> measurements at the high alpine research station Jungfraujoch

Trajectory analysis of atmospheric transport of fine particles, SO<sub>2</sub>, NO<sub>x</sub> and O<sub>3</sub> to the SMEAR II station in Finland in 1996–2008