Hygroscopic and chemical characterisation of Po Valley aerosol

Białek, Jakub; Osto, M. Dall; Vaattovaara, P.; Decesari, Stefano; Ovadnevaitė, Jurgita; Laaksonen, A.; O’Dowd, Colin

doi:10.5194/acp-14-1557-2014

Cited by 14 publications

(11 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These figures are in keeping with the growth factors reported for the Po Valley by Svenningsson et al (1992) and by Bialek et al (2013), who measured HGfs of 1.44 ± 0.14 and 1.46, respectively.…”

Section: Drh Comparisonsupporting

confidence: 76%

Determination of aerosol deliquescence and crystallization relative humidity for energy saving in free-cooled data centers

Ferrero

D'Angelo

Rovelli

et al. 2014

Int. J. Environ. Sci. Technol.

View full text Add to dashboard Cite

This study examines an innovative application of the aerosol deliquescence and crystallization determination, for corrosion prevention and energy-saving strategies in free-cooled data centers. Aerosol deliquescence and crystallization were investigated by combining standardized aerosol sampling techniques (i.e. EN-14907) with the assessment of the electrical effects of aerosol, while varying relative humidity within a specially designed aerosol exposure chamber. Aerosol samples collected in the Po Valley (Northern Italy) were analysed; a clearly defined hysteresis cycle (deliquescence and crystallization at 60.5 ± 0.8 and 47.9 ± 0.7 % of RH, respectively) was found. Results were applied to a data center designed for the Italian National Oil and Gas Company, making it possible to identify a critical area for direct free cooling at this data center. As a result, aerosol hydration was avoided (thus preventing aerosol from damaging electrical components) and a large amount of energy saved (using free cooling instead of air-conditioning); the potential energy saving achieved in this way was 79 % (compared to the energy consumption of a traditional air-conditioning system): 215 GWh of energy was saved, and 78 fewer kt of equivalent CO 2 was emitted per year. Moreover, in order to evaluate whether a real-time estimation of the aerosol hydration state within a data center could be performed, measured deliquescence and crystallization were compared through simulations performed using three different models: two thermodynamic models for deliquescence and a parametric model for crystallization. The results obtained tend to converge in terms of deliquescence, whereas in the case of crystallization, they failed to effectively simulate experimental aerosol behaviour.

show abstract

Section: Drh Comparisonsupporting

confidence: 76%

Determination of aerosol deliquescence and crystallization relative humidity for energy saving in free-cooled data centers

Ferrero

D'Angelo

Rovelli

et al. 2014

Int. J. Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…S2, the average GF of 110 nm and 165 nm particles showed a clear diurnal pattern, which peaked at about 11:00 every day and reached a minimum at 20:00. This trend was similar to the GF observation in Po Valley (Bialek et al, 2014) or Oklahoma site (Mahish and Collins, 2017) and is often attributed to a shallower and more stagnant boundary layer during the night with temperature inversions arising from radiative cooling of the surface.…”

Section: Continental Air Massessupporting

confidence: 83%

Aerosol hygroscopicity and its link to chemical composition in coastal atmosphere of Mace Head: marine and continental air masses

Xu¹,

Ovadnevaitė²,

Fossum³

et al. 2019

Preprint

View full text Add to dashboard Cite

Abstract. Chemical composition and hygroscopicity closure of marine aerosol in high time resolution has not been yet achieved because of the difficulty in measuring refractory sea-salt concentration in near-real time. In this study, attempts were made to achieve a closure for marine aerosol based on a humidified tandem differential mobility analyser (HTDMA) and a high-resolution time-of-flight aerosol mass spectrometer (AMS) for wintertime aerosol at Mace Head, Ireland. The aerosol hygroscopicity was examined as a growth factor (GF) at 90&#8201;% relative humidity (RH). The corresponding GFs of 35, 50, 75, 110 and 165&#8201;nm particles were 1.54&#8201;&#177;&#8201;0.26, 1.60&#8201;&#177;&#8201;0.29, 1.66&#8201;&#177;&#8201;0.31, 1.72&#8201;&#177;&#8201;0.29 and 1.78&#8201;&#177;&#8201;0.30 (mean&#8201;&#177;&#8201;standard deviation), respectively. Two contrasting air masses (continental and marine) were selected to study the temporal variation in hygroscopicity and the results demonstrated a clear diurnal pattern in continental air masses, while no diurnal pattern was found in marine air masses. In addition, the winter time aerosol was observed to be largely externally mixed in both contrasting air masses. Concurrent high time resolution PM1 (particulate matter <&#8201;1&#8201;&#181;m) chemical composition by combined AMS and MAAP measurements comprising of organic matter, non-sea-salt sulphate, nitrate, ammonium, sea-salt and black carbon (BC) were used in predicting aerosol hygroscopicity using the Zdanovskii&#8211;Stokes&#8211;Robinson (ZSR) mixing rule. A generally good agreement (r2&#8201;=&#8201;0.824, slope&#8201;=&#8201;1.02) was found between HTDMA measured growth factor (GF_HDTMA) of 165&#8201;nm particles and AMS+MAAP bulk chemical composition derived growth factor (GF_AMS). Over 95&#8201;% of the estimated GF exhibited less than 10&#8201;% deviation for the whole dataset and the deviation was mostly attributed to the neglected mixing state as a result of bulk PM1 composition.

show abstract

“…This is different from those found in other studies in urban air. Lance et al (2013) and Bialek et al (2014) observed larger mean  value than in the present work, and its diurnal variability was different.…”

Section: Diurnal Variabilitycontrasting

confidence: 53%

Winter time hygroscopicity and volatility of ambient urban aerosol particles

Enroth¹,

Mikkilä²,

Németh³

et al. 2017

Preprint

View full text Add to dashboard Cite

Abstract. Hygroscopic and volatile properties of atmospheric aerosol particles with dry diameters of (20), 50, 75, 110 and 145 nm were determined in situ by using a VH-TDMA system with a relative humidity of 90% and denuding temperature of 270 C in central Budapest during two months in winter 2014-2015. The probability density function of the hygroscopic growth factor (GF) showed a distinct bimodal distribution. One of the modes was characterised by an overall mean GF of 10 approximately 1.07 (the corresponding hygroscopicity parameter  of 0.033) independently of the particle size, and was assigned to nearly hydrophobic (NH) particles. Its mean particle number fraction was large, and it was decreasing monotonically from 71% to 41% with particle diameter. The other mode showed a mean GF increasing slightly from 1.31 to 1.38 ( values from 0.186 to 0.196) with particle diameter, and it was attributed to less hygroscopic (LH) particles. These hygroscopicity values are low in general. The mode with more hygroscopic particles was not identified. The probability density 15 function of the volatility GF also exhibited a distinct bimodal distribution with an overall mean volatility GF of approximately 0.96 independently of the particle size, and with another mean GF increasing from 0.49 to 0.55 with particle diameter. The two modes were associated with less volatile (LV) and volatile (V) particles. The mean particle number fraction for the LV mode was decreasing from 34% to 21% with particle diameter. The bimodal distributions in the GF spectrum indicated that the urban atmospheric aerosol contained an external mixture of particles with a diverse chemical composition. The mean 20 diurnal variability of the particle number fractions for the NH and LV modes, and of the volatility GF for the LV mode followed the diurnal pattern of the vehicular road traffic, while the mean diurnal variability of the hygroscopicity parameter for the NH, and of the particle number fractions for the V mode on workdays were inversely linked to the road traffic. The particles corresponding to the NH and LV modes were assigned mainly to freshly emitted combustion particles, more specifically to vehicle emissions consisting of large mass fractions of soot likely coated with or containing some water-insoluble organic 25 compounds such as non-hygroscopic hydrocarbon-like organics. The particles related to the LH and V modes could be composed of moderately transformed aged combustion particles consisting of partly oxygenated organics, inorganic salts and soot. Both regional background sources and urban (local) emissions contribute to these particles. Dependency of the volatility GF and the volume fraction remaining after the thermal treatment on the mean hygroscopic GF suggested that the hygroscopic compounds were ordinarily volatile, and that the larger particles contained internally mixed non-volatile chemical species as 30 refractory residuals in 20-25% of the aerosol material (by volume), which could be core-like soot or organic polymers.

show abstract

Hygroscopic and chemical characterisation of Po Valley aerosol

Abstract: www.atmos-chem-phys.net/14/1557/2014/ doi:10.5194/acp-14-1557-201

Cited by 14 publications

References 52 publications

Determination of aerosol deliquescence and crystallization relative humidity for energy saving in free-cooled data centers

Determination of aerosol deliquescence and crystallization relative humidity for energy saving in free-cooled data centers

Aerosol hygroscopicity and its link to chemical composition in coastal atmosphere of Mace Head: marine and continental air masses

Winter time hygroscopicity and volatility of ambient urban aerosol particles

Contact Info

Product

Resources

About