Top PDF A statistical analysis of North East Atlantic (submicron) aerosol size distributions

A statistical analysis of North East Atlantic (submicron) aerosol size distributions

A statistical analysis of North East Atlantic (submicron) aerosol size distributions

radiative effect). The shape of the aerosol size distribution is influenced by air mass origin which determines difference aerosol sources and evolution processes (Dall’Osto et al., 2010). Studies such as that of Dall’Osto et al. have focused on characterization via air mass origin over short periods of weeks to months rather than quantifying the frequency of oc- currence of each size distribution type over time scales of the order of a year (Charron et al., 2007; Costabile et al., 2009). Similarly, a number of studies have already focused on size distributions of particles detected at Mace Head, mainly focusing on marine aerosol constituents. Typical marine aerosol size distributions sampled at the coastal Mace Head research station showed low particle number concentrations with a sub-micron marine size distribution characterised by a bimodal shape, with an accumulation mode centred at 200 nm and an Aitken at 40 nm, indicative of a cloud-residual accumulation mode produced by the in-cloud growth of ac- tivated fine mode particles (Hoppel et al., 1994). A study on the seasonality of the clean marine particle size distributions was reported by Yoon et al. (2007), showing the aerosol size distribution modal diameters for different seasons: 31 nm in winter and 49 nm in summer for the Aitken mode and 103 nm in winter and 177 nm in summer for the accumulation mode, respectively. By contrast, air masses affected by anthro- pogenic pollution sampled at Mace Head during anticyclonic periods and conditions of continental outflow Aitken and ac- cumulation mode were enhanced by a factor of 5 compared to the marine sector (O’Dowd et al., 2001; Coe et al., 2006). As part of the EUCAARI (European Aerosol Cloud Cli- mate and Air Quality Interactions) Integrated Project, one of the major activities was to conduct and analyse size distribu- tion measurements at a range of European supersites (Kul- mala et al., 2009). The EUCAARI intensive measurement programme was throughout the full year of 2008. As one of the 12 atmospheric supersites EUCAARI supersites, Mace Head (Ireland) is uniquely located on the interface between the NE Atlantic and Europe, thus enabling sampling of both the cleanest air entering into Europe along with some of the most polluted air being exported out of Europe into the N. Atlantic (Jennings et al., 2003; O’Connor et al., 2008). Asmi et al. (2011) presented a combined statistical analysis of 22 stations (including all the 12 EUCAARI supersites) for the year 2008–2009 in terms of means and extremes of the num- ber concentration size distributions encountered.
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Coastal and open ocean aerosol characteristics: investigating the representativeness of coastal aerosol sampling over the North-East Atlantic Ocean

Coastal and open ocean aerosol characteristics: investigating the representativeness of coastal aerosol sampling over the North-East Atlantic Ocean

Ammonium (NH + 4 ) was detected in comparable concentration and mass size distribu- tion at MH and over the open ocean. Submicron NH + 4 concentration was always below the remote marine background concentrations reported by Jickells et al. (2003). Nitrate (NO − 3 ) was detected in all samples in the coarse mode, as a result of the reaction of gaseous nitric acid with NaCl. Indeed, both data sets show Cl/Na ratios lower than the

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An updated revision of shortfin mako size distributions in the Atlantic

An updated revision of shortfin mako size distributions in the Atlantic

Casey and Kohler (1992) suggested that the core distribution of shortfin makos in the northwest Atlantic is between 20-40°N bordered by the Gulf Stream in the west and the mid-Atlantic ridge in the east. In the northeast Atlantic it is presumed that the Strait of Gibraltar might be a nursery ground (Buencuerpo et al., 1998; Tudela et al., 2005). The area between 17° to 35°S off the coast of Brazil seems to be an area of birth, growth and mating in the southwest Atlantic (Amorim et al., 1998). Our study extends those previous observations from other authors, as the entire temperate area of the North and Central Atlantic seems to be a nursery for the species, especially the areas closer to continental and insular shelf waters. In the South Atlantic, both the southeast and southwest areas also seem to be nurseries for the species due to the large proportions of juveniles.
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Vertical distribution of sub-micron aerosol chemical composition from North-Western Europe and the North-East Atlantic

Vertical distribution of sub-micron aerosol chemical composition from North-Western Europe and the North-East Atlantic

compared with those below 4000 m. This suggests large variability coupled with po- tentially low statistical significance above this level. Above approximately 5000 m, the variability and lower number of data points results in the error about the mean being more than two times greater than values in the boundary layer. The variability in the values for nitrate and sulphate are much lower due to improved SNR for these species

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Dependence of solar radiative forcing of forest fire aerosol on ageing and state of mixture

Dependence of solar radiative forcing of forest fire aerosol on ageing and state of mixture

1995) and on the aerosol particles’ number size distribution (Chylek and Wong, 1995). Current global circulation mod- els often use fixed microphysical properties of the absorb- ing aerosol, varying only its mass loading (Penner et al., 1998; Myhre et al., 1998; Schult et al., 1997). It has been pointed out that even the sign of the radiative forcing of ab- sorbing aerosol particles can change with the state of mixture of the absorbing component (Myhre et al., 1998). The mix- ture can be external with the absorbing component present as particles distinct from non-absorbing particles, or inter- nal with the absorbing component contained within the non- absorbing material. If the absorbing material is internally mixed, its absorption efficiency is higher compared to the ex- ternally mixed case, resulting in a more positive solar radia- tive forcing (Wendisch et al., 2001). When emitted, absorb- ing particles are usually externally mixed with non-absorbing background particles. The state of mixture shifts when ab- sorbing aerosol particles coagulate with non-absorbing back- ground particles during ageing. It has been argued that for black carbon, the resulting radiative forcing is, on global av- erage, comparable in magnitude and sign with the radiative forcing of methane (Jacobson, 2001). However, the range of solar radiative forcings calculated for absorbing aerosol com- ponents assuming different particle size distributions, ageing processes and thus mixture states leaves even the sign uncer- tain (IPCC, 2001).
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Distribution and conservation of three important bird groups of the Atlantic Forest in north-east Brazil

Distribution and conservation of three important bird groups of the Atlantic Forest in north-east Brazil

This current alarming situation of the PEC has occurred due to the removal of the native vegetation (Olmos, 2005; Silveira et al., 2003a). Currently there are only 157 protected areas in the region (Paula, 2012 ), and probably many of these are not functional for conservation of endemic and/or threatened birds, as noted by Giorgi et al. (2014) in southeastern Atlantic Forest. There are also the Important Bird Areas (IBA henceforth) which are places of great importance due to the significant number of endemic and/or threatened bird species, and they ensure the long-term conservation of these birds and areas (Bencke et al., 2006 ). Throughout the region there are 42 IBAs, many of which overlap protected areas.
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Size-dependent wet removal of black carbon in Canadian biomass burning plumes

Size-dependent wet removal of black carbon in Canadian biomass burning plumes

a large region of forest fires in northwest Ontario, to the southwest of Hudson Bay and east of Lake Winnipeg. Plumes 2 and 3 were sampled approximately ∼ 1 day af- ter passing over the fires, while plume 1 was sampled after ∼ 2 days. The meteorology data used to calculate the HYSPLIT back trajectories does not take account of likely py- roconvection from the fires. Therefore the smoke plumes are expected to have formed

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The Tourism Development Strategy of the North-East Region of Romania. Myth or Reality?

The Tourism Development Strategy of the North-East Region of Romania. Myth or Reality?

The most relevant studies on the sustainable tourism development strategies provide a detailed quantitative and qualitative analysis of tourism components, these representing the foundation on which the measures for the development of this phenomenon are grafted. One relevant example is a study conducted by Fletcher and Cooper in 1996, in which the strategy was elaborated after the analysis of entire tourism potential, exogenous and endogenous conditionings, opportunities and threats. In 2002, Cho came up with a tourism redevelopment strategy, with the case of Kanhwon Land Resort Casino, where an in-depth analysis of the urban community, local economy, foreign exchange earnings, tax revenues, job creation was considered necessary. Taking into account the dimension of the study area , Cho’s area is diametrically opposed with the one analysed in our paper, but a detailed observation was considered compulsory (Cho, 2002). Another relevant example is the study conducted by Tony Binns and Etienne Nell (2002) on South Africa, where, for initiating such an action, they made an in-depth analysis on the economic, social, and environmental resources, but also on local government efforts.
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Analysis of alcohol dependence in indigenous peoples in Northern Siberia.

Analysis of alcohol dependence in indigenous peoples in Northern Siberia.

In most cases, alcohol psychoses worsen the prognosis and are accompanied by neurohu- moral, immunological and neurological disor- ders. In both groups patients most frequently dis- play delirium tremens (more than 60% of acute psychoses), and significantly less often – acute al- cohol hallucinosis. Low population density and isolation from major regional centres often result in late detection of alcoholism, which is also a risk factor for alcoholic psychosis in north Siberia. The basic structure of hallucinosis is related to archaic superstitions on the conditions of life in the north. The analysis of comorbid somatic pathology in in the two groups revealed that the most com- mon conditions were diseases of the gastrointes- tinal tract and the cardiovascular system. These are typical complications of alcoholism and are not specific to indigenous peoples of north Sibe- ria. However, indigenous patients often turned to traditional healers for help (shamans etc.), which makes it difficult to identify and account for these patients by psychiatric services at the initial stag- es of alcoholism, and delays medical treatment of alcohol psychoses and comorbid pathology. Su- perstitious beliefs among indigenous peoples re- flect an increased suggestibility, and propensity to form a psychological and physical addiction in general and alcoholism in particular. A great- er risk of suicide in indigenous peoples is also considered an ethno-cultural factor. On the other hand, people coming to the north are more like- ly to suffer various kinds of psychological break- downs and crises that may be associated with a change in their way of life and be an effect of chal-
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Long-term observations of aerosol size distributions in semi-clean and polluted savannah in South Africa

Long-term observations of aerosol size distributions in semi-clean and polluted savannah in South Africa

Laakso, L., Vakkari, V., Virkkula, A., Laakso, H., Backman, J., Kulmala, M., Beukes, J. P., van Zyl, P. G., Tiitta, P., Josipovic, M., Pienaar, J. J., Chiloane, K., Gilardoni, S., Vignati, E., Wiedensohler, A., Tuch, T., Birmili, W., Piketh, S., Collett, K., Fourie, G. D., Komppula, M., Lihavainen, H., de Leeuw, G., and Kerminen, V.-M.: South African EUCAARI measurements: seasonal variation of trace gases and aerosol optical properties, Atmos. Chem. Phys., 12,

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Regional impacts of ultrafine particle emissions from the surface of the Great Lakes

Regional impacts of ultrafine particle emissions from the surface of the Great Lakes

Abstract. Quantifying the impacts of aerosols on climate re- quires a detailed knowledge of both the anthropogenic and the natural contributions to the aerosol population. Recent work has suggested a previously unrecognized natural source of ultrafine particles resulting from breaking waves at the sur- face of large freshwater lakes. This work is the first model- ing study to investigate the potential for this newly discov- ered source to affect the aerosol number concentrations on regional scales. Using the WRF-Chem modeling framework, the impacts of wind-driven aerosol production from the sur- face of the Great Lakes were studied for a July 2004 test case. Simulations were performed for a base case with no lake surface emissions, a case with lake surface emissions included, and a default case wherein large freshwater lakes emit marine particles as if they were oceans. Results indi- cate that the lake surface emissions can enhance the surface- level aerosol number concentration by ∼20 % over the re- mote northern Great Lakes and by ∼5 % over other parts of the Great Lakes. These results were highly sensitive to the new particle formation (i.e., nucleation) parameterization within WRF-Chem; when the new particle formation process was deactivated, surface-layer enhancements from the lake emissions increased to as much as 200 %. The results re- ported here have significant uncertainties associated with the lake emission parameterization and the way ultrafine parti- cles are modeled within WRF-Chem. Nevertheless, the mag- nitudes of the impacts found in this study suggest that further study to quantify the emissions of ultrafine particles from the surface of the Great Lakes is merited.
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Physical and optical properties of aged biomass burning aerosol from wildfires in Siberia and the Western USA  at the Mt. Bachelor Observatory

Physical and optical properties of aged biomass burning aerosol from wildfires in Siberia and the Western USA at the Mt. Bachelor Observatory

Currently there are few field measurements of well-aged BB emissions. Our knowledge of BB aerosol primarily comes from laboratory experiments and near-field measure- ments taken within a few hours of a wildfire (May et al., 2015, 2014; Okoshi et al., 2014; Vakkari et al., 2014; Yokel- son et al., 2013b, 2009). Holder et al. (2016) showed that lab- oratory measurements of aerosol optical properties do not ac- curately reproduce field measurements. Freshly emitted BB particles are small in diameter (30–100 nm) (Hosseini et al., 2010; Levin et al., 2010). As the plume ages, the aerosol undergoes rapid chemical and physical changes on the time scale of minutes to hours (Reid et al., 2005a, b; Vakkari et al., 2014). The change in particle size is due to coagulation and the condensation of organic material onto the existing parti- cles (Reid et al., 2005b; Seinfeld and Pandis, 2006). The co- agulation rate can be very high in fresh BB plumes since this is equivalent to the square of particle number concentration. This process increases the size of the particles while decreas- ing the number concentration. Condensation of secondary organic aerosol (SOA) onto particles in BB plumes also in- creases particle size. The condensation of SOA is counter- balanced by the loss of primary organic aerosol, which can evaporate during plume dilution (May et al., 2015, 2013). The net condensation/evaporation effect is highly variable. Some studies have observed an increase in mass with plume age due to SOA production (Briggs et al., 2016; Hobbs, 2003; Vakkari et al., 2014; Yokelson et al., 2009), while others have observed limited SOA formation (Akagi et al., 2012; Jolleys et al., 2015). All of these uncertainties in the aging process of biomass burning underscores the importance of characteriz- ing the physical and optical properties of well-aged biomass burning aerosol.
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Distribution of intermediate water masses in the subtropical northeast Atlantic

Distribution of intermediate water masses in the subtropical northeast Atlantic

various modes of the North Atlantic Central Water are formed. The subduction is the most efficient in winter, when the internal water structure is not sheltered by the sea- sonal thermocline. The deep convection is a results of the gravitational instability and is mostly active in weakly stratified polar waters in winter due to intensive heat loss and salinification in the course of ice formation (van Aken, 2000a).

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Data of hydraulic properties of North East and North Central German soils

Data of hydraulic properties of North East and North Central German soils

Abstract. The paper presents a data base of soil physical and hydrological properties of North East and North Central German soils. Included are measured data of the soil water retention curve and the unsaturated hydraulic conductivity function. Information on geo-reference, soil type and horizon are given. Soil hydraulic functions were measured with the evaporation method. The applied measurement technique is described and information to actual innovations and advanced technology is given. Additional soil physical data like particle size distribution, dry bulk density, organic matter content and other variables are presented. The data base includes original measurement results of 278 organic and of 497 mineral soil samples from 103 sites. The mineral soils cover a wide range of texture classes and dry bulk densities. The organic soils and samples represent different states of decomposition and mineralization. Furthermore hydraulic functions are included of soils anthropogenically altered by deep plough sand covering measures.
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ANALYSIS OF THE STATISTICAL BEHAVIOUR OF DAILY MAXIMUM AND MONTHLY AVERAGE RAINFALL ALONG WITH RAINY DAYS VARIATION IN SYLHET, BANGLADESH

ANALYSIS OF THE STATISTICAL BEHAVIOUR OF DAILY MAXIMUM AND MONTHLY AVERAGE RAINFALL ALONG WITH RAINY DAYS VARIATION IN SYLHET, BANGLADESH

Sylhet, the north eastern administrative division of Bangladesh, located at 24˚53′ latitude and 91˚52′ longitude, has a number of topographical features like rivers, hills and hillocks (tilas), haors (wetland) and high flood plain; which made it quite different from the rest of the parts of Bangladesh. Sylhet is located close to Cherrapunji, Meghalaya India which receives the highest amount of rainfall in the world. Hilly Sylhet region not only plays an important role in the socio economic development of Bangladesh but also important for ecological balance of the country. The region is famous for its vast reserve of forest, intense tea gardens and growing rubber gardens in the hillocks, lakes and wetlands etc. Among the topographical features of the region, hills are the most dominating one, which is determining its climatic and morphological features. Heavy rainfall, tea garden, dense bamboo and cane bushes, high flood plain and the flashy rivers; all the features are very related and contributed by the hills of this region [25].
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The multi-scale aerosol-climate model PNNL-MMF: model description and evaluation

The multi-scale aerosol-climate model PNNL-MMF: model description and evaluation

A new type of global climate model called the multi-scale modeling framework (MMF) model, first introduced a decade ago (Grabowski, 2001; Khairoutdinov and Randall, 2001), uses a cloud resolving model (CRM) at each grid column of a host GCM to replace conventional parameterizations for moist convection and large scale conden- sation. This approach permits explicit simulations of deep convective clouds for the

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Statistical Assessment of the Effect of Chemical Composition on Mechanical Properties of Hypereutectic AlSi17CuNiMg Silumin

Statistical Assessment of the Effect of Chemical Composition on Mechanical Properties of Hypereutectic AlSi17CuNiMg Silumin

The paper presents a statistical assessment of the effect of chemical composition on mechanical properties of hypereutectic AlSi17 silumin, which is expected to act as a counterpart of alloys used by automotive industry and aviation for casting of high-duty engine parts in West European countries and USA. The studies on the choice of chemical composition of silumins were preceded by analysis of the reference literature to state what effect some selected alloying elements and manufacturing technology may have on the mechanical properties (HB, R m and A 5 ) of these alloys. As alloying additives, Cu, Ni and Mg in proper combinations were used. The alloy after
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Stability analysis of a biological network

Stability analysis of a biological network

In case of systems biology it is very crucial impression of modeling the qualitative behavior of biological and biochemical networks where molecules are represented as nodes and the molecular interactions are so called edges. Due to scope and complicated behavior of these networks it is very important to discuss and study their dynamical behavior. An interaction dynamics can be used instead of an explicit mathematical description of these biological networks and computer simulations can be used to study the dynamical behavior of these complex biological networks. It is well known fact that dynamics is related to the study of changes with respect to time. For example in case of classical mechanics an apple falling to the ground, or the growth of the human population. Particularly, in case of systems biology dynamics is related to the changes in concentrations of molecules (or numbers) within a cell. Differential equations and difference equations are main tools for modeling these biological networks.
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Statistical Distributions of Discrete Walsh Hadamard Transform Coefficients of Natural Images

Statistical Distributions of Discrete Walsh Hadamard Transform Coefficients of Natural Images

For low bit rate applications, the discrete Walsh Hadamard transform (WHT) shows almost comparable results when compared to the popular discrete Cosine transform (DCT) in terms of compression efficiency, peak signal to noise ratio (PSNR) and visual results. The discrete WHT is a best choice which compromises between the computational complexity and compression efficiency. The great advantage of the discrete WHT is its relatively very low computational complexity when compared to DCT. However there is no definitive study reported in literature regarding the statistical distributions of discrete WHT coefficients of natural images. This study performs a χ goodness of fit test to determine the distribution that best fits the 2 discrete WHT coefficients. The simulation results show that the distribution of a majority of the significant AC coefficients can be modelled by the Generalized Gaussian distribution. The knowledge of the appropriate distribution helps in design of optimal quantizers that may lead to minimum distortion and hence achieve optimal coding efficiency.
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A Strategic Analysis of Search Engine Advertising in Web  based-commerce

A Strategic Analysis of Search Engine Advertising in Web based-commerce

With the popularity of use of Search Engine Indian Online Market has seen the emergence of many local tailor made Search Engines. It has been analyzed that 90% of Internet search queries are local in nature e.g. When a user in India searches for “newspaper” Search Engine should display the top Indian newspaper websites rather then providing globalize results. To answer these queries there has been emergence of local search engines. Guruji.com backed by Sequoia Capital India is focused on providing better search results to Indian consumers, by leveraging proprietary algorithms and data in the Indian context. Khojguru, launched on 26 Sep 2006, is a local search engine which provides info about all the shops, vendors and service providers in Gurgaon. JustDial.com is a portal based Just dial service. It provides efficient search mechanism supporting synonyms and phonetics. Major Search Engines has come up with local versions to support different customers in India. Google came up with versions in Hindi, Oriya, Tamil, Telugu and more to help local people.
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