Kinetic energy operator approach to the quantum three-body problem with Coulomb interactions

We present a non-variational, kinetic energy operator approach to the solution of quantum three-body problem with Coulomb interactions, based on the utilization of symmetries intrinsic to the kinetic energy operator, i.e., the three-body Laplacian operator with the respective masses. Through a four-step reduction process, the nine dimensional problem is reduced to a one dimensional coupled system of ordinary differential equations, amenable to accurate numerical solution as an infinite-dimensional algebraic eigenvalue problem. A key observation in this reduction process is that in the functional subspace of the kinetic energy operator where all the rotational degrees of freedom have been projected out, there is an intrinsic symmetry which can be made explicit through the introduction of Jacobi-spherical coordinates. A numerical scheme is presented whereby the Coulomb matrix elements are calculated to a high degree of accuracy with minimal effort, and the truncation of the linear equations is carried out through a systematic procedureComment: 56 pages, 11 figure

Semivolatile behaviour and filter sampling artifacts for dicarboxylic acids during summer campaigns at three forested sites in Europe

The sampling artifacts for C(2)-C(5) dicarboxylic acids (DCAs) were studied by collecting high-volume PM(2.5) samples using front and back quartz-fibre filters. The filters were analysed for carbonaceous components, and for inorganic cationic and anionic and organic anionic species. Back/front filter ratios were determined for the C(2)-C(5) DCAs, but also for methanesulphonate (MSA(-)), the various inorganic species, and the carbonaceous components. The sampling artifacts for the inorganic species were small (< 5%) with the exception of those for nitrate. The median back/front filter ratios for MSA(-) and the C(2)-C(5)DCAs increased in the following order: oxalate (1.5%)-succinate (3%)-MSA(-) (4%)-malonate (2%-9%)-glutarate (7%-26%). Most of these ratios are smaller than those that were obtained for organic carbon, total carbon, and especially water-soluble organic carbon. Our back/front ratios for the C(2)-C(5) DCAs are lower to much lower than those found in other studies

Chemical characterisation of atmospheric aerosols during a 2007 summer field campaign at Brasschaat, Belgium : sources and source processes of biogenic secondary organic aerosol

Measurements of organic marker compounds and inorganic species were performed on PM2.5 aerosols from a Belgian forest site that is severely impacted by urban pollution ("De Inslag", Brasschaat, Belgium) during a 2007 summer period within the framework of the "Formation mechanisms, marker compounds, and source apportionment for biogenic atmospheric aerosols (BIOSOL)" project. The measured organic species included (i) low-molecular weight (MW) dicarboxylic acids (LMW DCAs), (ii) methanesulfonate (MSA), (iii) terpenoic acids originating from the oxidation of alpha-pinene, beta-pinene, d-limonene and Delta(3)-carene, and (iv) organosulfates related to secondary organic aerosol from the oxidation of isoprene and alpha-pinene. The organic tracers explained, on average, 5.3% of the organic carbon (OC), of which 0.7% was due to MSA, 3.4% to LMW DCAs, 0.6% to organosulfates, and 0.6% to terpenoic acids. The highest atmospheric concentrations of most species were observed during the first five days of the campaign, which were characterised by maximum day-time temperatures >22 degrees C. Most of the terpenoic acids and the organosulfates peaked during day-time, consistent with their local photochemical origin. High concentrations of 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA) and low concentrations of cis-pinonic acid were noted during the first five days of the campaign, indicative of an aged biogenic aerosol. Several correlations between organic species were very high (r>0.85), high (0.70.7) and showed an Arrhenius-type relationship, consistent with their formation through OH radical chemistry

Chemical characterisation of humic-like substances from urban, rural and tropical biomass burning environments using liquid chromatography with UV/vis photodiode array detection and electrospray ionisation mass spectrometry

Humic-like substances (HULIS) are ubiquitously present in the troposphere and make up a major fraction of continental fine-sized water-soluble organic compounds. They are regarded as material with strong polar, acidic and chromophoric properties; however, structural information at the individual component level is rather limited. In the present study, we have characterised HULIS from different locations using liquid chromatography coupled to photodiode array detection and negative ion electrospray ionisation mass spectrometry. Aerosol samples with particles less than 2.5 mu mm in diameter (PM2.5) were collected in Budapest and K-puszta, Hungary, during 2007 and 2008 spring and summer periods, and in Rondonia, Brazil, during a 2002 biomass burning experiment. Major components of the Budapest 2007 and Brazil 2002 HULIS corresponded to chromophoric substances, of which 4-nitrocatechol (molecular weight (MW) 155) was identified as the most abundant organic species and less abundant ones were attributed to mono-and dimethyl nitrocatechols (MWs 169 and 183). The mass concentrations of 4-nitrocatechol in the water-soluble organic carbon (WSOC) of the Budapest 2007 and day-and night-time Brazil 2002 HULIS were 0.46, 0.50 and 1.80 %. Abundant components of K-puszta 2008 HULIS were assigned to alpha-pinene secondary organic aerosol (SOA) tracers, i.e. 3-methyl-1,2,3-butanetricarboxylic acid and terpenylic acid; their mass concentrations in the HULIS WSOC were 0.75 and 0.40 %. Tere- and ortho-phthalic acids (MW 166) were major components of the Budapest and K-puszta HULIS, but only minor ones of the Brazil 2002 biomass burning HULIS, consistent with a source that is different from biomass burning and likely related to open waste burning of phthalate ester-containing material such as plastic

Chemical composition and mass closure for fine and coarse aerosols at a kerbside in Budapest, Hungary, in spring

ABSTRACT A comprehensive chemical aerosol characterisation was carried out at a kerbside in downtown Budapest in spring 2002. Several filter samplers were deployed in parallel for day and night collections, and a total of 23 parallel collections were made. All samples were analysed for the particulate mass (PM) by weighing. Depending upon the sampler type and/or collection substrate, further analyses were done for up to 46 elements by a combination of PIXE and instrumental neutron activation analysis (INAA), for major anions and cations by ion chromatography, and for organic carbon and elemental carbon by a thermal-optical transmission technique. Aerosol chemical mass closure calculations were done for the separate fine (&lt;2 µm) and coarse (2-10 µm) size fractions. For reconstituting the gravimetric PM, eight aerosol types were considered, whereby three aerosol types were deduced from the PIXE/INAA elemental data set. Organic matter (OM) and elemental carbon were the dominant aerosol types in the fine fraction; they explained on average 43 and 21% of the fine PM. The coarse PM consisted mainly of crustal matter (49%) and of OM (30%). The large contribution from crustal matter (road dust) to the coarse fraction is consistent with other data from kerbside sites in Europe

Contribution from selected organic species to PM2.5 aerosol during a summer field campaign at K-Puszta, Hungary

A summer field campaign was conducted at the forested background site of K-puszta in Hungary. The main aim was to assess the contribution of terpene-derived particulate organic compounds to the PM2.5 organic carbon (OC) and of the secondary organic carbon (SOC) from -pinene to the OC. The study lasted from 24 May to 29 June 2006; the first half the weather was cold, while the second half was warm. Separate daytime and night-time PM2.5 samples were collected with a high-volume sampler and the samples were analysed by several analytical techniques, including ion chromatography (IC) and liquid chromatography-mass spectrometry (LC/MS). The latter technique was used for measuring the terpene-derived species. Ancillary high time resolution measurements of volatile organic compounds (VOCs) were made with proton-transfer reaction-mass spectrometry. The temporal and diurnal variability of the particulate compounds and VOCs and interrelationships were examined. It was found that the monoterpenes and a number of terpene-derived particulate compounds, such as cis-pinic and cis-caric acid, exhibited a strong day/night difference during the warm period, with about 10 times higher levels during the night-time. During the warm period, the IC compounds and LC/MS compounds accounted, on average, for 3.1% and 2.0%, respectively, of the OC, whereas the contribution of SOC from -pinene to the OC was estimated at a minimum of 7.1%

Multi-wavelength aerosol light absorption measurements in the Amazon rainforest

The most important light-absorbing aerosol is black carbon (BC), which is emitted by incomplete combustion of fossil fuels and biomass. BC is considered the second anthropogenic contributor to global warming. Beyond BC, other aerosols like some organics, dust, and primary biological aerosol particles are able to absorb radiation. In contrast to BC, the light absorption coefficient of these aerosols is wavelength dependent. Therefore, multi-wavelength measurements become important in environments where BC is not the predominant light-absorbing aerosol like in the Amazon. The Amazon Tall Tower Observatory (ATTO) site is located in the remote Amazon rainforest, one of the most pristine continental sites in the world during the wet season. In the dry season, winds coming from the southern hemisphere are loaded with biomass burning aerosol particles originated by farming-related deforestation. BC and aerosol number concentration data from the last two years indicate this is the most polluted period. Two different techniques have been implemented to measure the light absorption at different wavelengths; one of them is the 7-wavelengths Aethalometer, model AE30, an instrument that measures the light attenuation on a filter substrate and requires multiple scattering and filter-loading corrections to retrieve the light absorption coefficient. The other method is an offline technique, the Multi-Wavelength Absorbance Analysis (MWAA), which is able to measure reflectance and absorbance by aerosols collected on a filter and, by means of a radiative model, can retrieve the light absorption coefficient. Filters collected during May-September 2014, comprehending wet-to-dry transition and most of the dry season, were analyzed. The results indicate that the Absorption \uc5ngstr\uf6m Exponent (AAE), a parameter that is directly proportional to the wavelength dependence of the aerosol light absorption, is close to 1.0 during the transition period and slightly decreases in the beginning of the dry season. However, during strong biomass burning episodes in the dry season, the AAE increases significantly, and reaches values higher than 1.3, indicating the presence of wavelength dependent light-absorbing aerosols like organics (brown carbon). The present study is a contribution to the understanding of the optical properties of light-absorbing aerosol particles under pristine and biomass-burning conditions

On the mode-segregated aerosol particle number concentration load : contributions of primary and secondary particles in Hyytiälä and Nanjing

Aerosol particle concentrations in the atmosphere are governed by their sources and sinks. Sources include directly-emitted (primary) and secondary aerosol particles formed from gas-phase precursor compounds. The relative importance of primary and secondary aerosol particles varies regionally and with time. In this work, we investigated primary and secondary contributions to mode-segregated particle number concentrations by using black carbon as a tracer for the primary aerosol number concentration. We studied separately nucleation, Aitken and accumulation mode concentrations at a rural boreal forest site (Hyytiala, Finland) and in a rather polluted megacity environment (Nanjing, China) using observational data from 2011 to 2014. In both places and in all the modes, the majority of particles were estimated to be of secondary origin. Even in Nanjing, only about half of the accumulation mode particles were estimated to be of primary origin. Secondary particles dominated particularly in the nucleation and Aitken modes.Peer reviewe

Observations of aerosol optical properties at a coastal site in Hong Kong, South China

Temporal variations in aerosol optical properties were investigated at a coastal station in Hong Kong based on the field observation from February 2012 to February 2015. At 550 nm, the average light-scattering (151 +/- 100Mm(-1) / and absorption coefficients (8.3 +/- 6.1Mm(-1) / were lower than most of other rural sites in eastern China, while the single-scattering albedo (SSA = 0.93 +/- 0.05) was relatively higher compared with other rural sites in the Pearl River Delta (PRD) region. Correlation analysis confirmed that the darkest aerosols were smaller in particle size and showed strong scattering wavelength dependencies, indicating possible sources from fresh emissions close to the measurement site. Particles with D-p of 200-800 nm were less in number, yet contributed the most to the light-scattering coefficients among submicron particles. In summer, both Delta BC / Delta CO and SO2 / BC peaked, indicating the impact of nearby combustion sources on this site. Multi-year backward Lagrangian particle dispersion modeling (LPDM) and potential source contribution (PSC) analysis revealed that these particles were mainly from the air masses that moved southward over Shenzhen and urban Hong Kong and the polluted marine air containing ship exhausts. These fresh emission sources led to low SSA during summer months. For winter and autumn months, contrarily, Delta BC / Delta CO and SO2 / BC were relatively low, showing that the site was more under influence of well-mixed air masses from long-range transport including from South China, East China coastal regions, and aged aerosol transported over the Pacific Ocean and Taiwan, causing stronger abilities of light extinction and larger variability of aerosol optical properties. Our results showed that ship emissions in the vicinity of Hong Kong could have visible impact on the light-scattering and absorption abilities as well as SSA at Hok Tsui.Peer reviewe

Estimating cloud condensation nuclei number concentrations using aerosol optical properties : role of particle number size distribution and parameterization

The concentration of cloud condensation nuclei (CCN) is an essential parameter affecting aerosol–cloud interactions within warm clouds. Long-term CCN number concentration (NCCN) data are scarce; there are a lot more data on aerosol optical properties (AOPs). It is therefore valuable to derive parameterizations for estimating NCCN from AOP measurements. Such parameterizations have already been made, and in the present work a new parameterization is presented. The relationships between NCCN, AOPs, and size distributions were investigated based on in situ measurement data from six stations in very different environments around the world. The relationships were used for deriving a parameterization that depends on the scattering Ångström exponent (SAE), backscatter fraction (BSF), and total scattering coefficient (σsp) of PM10 particles. The analysis first showed that the dependence of NCCN on supersaturation (SS) can be described by a logarithmic fit in the range SS 4. At SS >0.4 % the average bias ranged from ∼0.7 to ∼1.3 at most sites. For the marine-aerosol-dominated site Ascension Island the bias was higher, ∼1.4–1.9. In other words, at SS >0.4 % NCCN was estimated with an average uncertainty of approximately 30 % by using nephelometer data. The biases were mainly due to the biases in the parameterization related to the scattering Ångström exponent (SAE). The squared correlation coefficients between the AOP-derived and measured NCCN varied from ∼0.5 to ∼0.8. To study the physical explanation of the relationships between NCCN and AOPs, lognormal unimodal particle size distributions were generated and NCCN and AOPs were calculated. The simulation showed that the relationships of NCCN and AOPs are affected by the geometric mean diameter and width of the size distribution and the activation diameter. The relationships of NCCN and AOPs were similar to those of the observed ones.The concentration of cloud condensation nuclei (CCN) is an essential parameter affecting aerosol-cloud interactions within warm clouds. Long-term CCN number concentration (N-CCN) data are scarce; there are a lot more data on aerosol optical properties (AOPs). It is therefore valuable to derive parameterizations for estimating N-CCN from AOP measurements. Such parameterizations have already been made, and in the present work a new parameterization is presented. The relationships between N-CCN, AOPs, and size distributions were investigated based on in situ measurement data from six stations in very different environments around the world. The relationships were used for deriving a parameterization that depends on the scattering Angstrom exponent (SAE), backscatter fraction (BSF), and total scattering coefficient (sigma(sp)) of PM10 particles. The analysis first showed that the dependence of N-CCN on supersaturation (SS) can be described by a logarithmic fit in the range SS 4. At SS > 0 :4% the average bias ranged from similar to 0.7 to similar to 1.3 at most sites. For the marine-aerosol-dominated site Ascension Island the bias was higher, similar to 1.4-1.9. In other words, at SS > 0:4% N-CCN was estimated with an average uncertainty of approximately 30% by using nephelometer data. The biases were mainly due to the biases in the parameterization related to the scattering Angstrom exponent (SAE). The squared correlation coefficients between the AOP-derived and measured N-CCN varied from similar to 0.5 to similar to 0.8. To study the physical explanation of the relationships between N-CCN and AOPs, lognormal unimodal particle size distributions were generated and N-CCN and AOPs were calculated. The simulation showed that the relationships of N-CCN and AOPs are affected by the geometric mean diameter and width of the size distribution and the activation diameter. The relationships of N-CCN and AOPs were similar to those of the observed ones.Peer reviewe