Numerical investigation of the coagulation mixing between dust and hygroscopic aerosol particles and its impacts

Tsai, I‐Chun; Chen, Jen‐Ping; Lin, Yung-Hsiang; Chou, Charles C.‐K.; Chen, Wei-Nai

doi:10.1002/2014jd022899

Cited by 12 publications

(10 citation statements)

References 78 publications

(96 reference statements)

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“…The physical processes included in SNAP are emission, nucleation, coagulation, condensation, mixing, and dry and wet deposition. SNAP has been applied to the US EPA Models-3/Community Multi-scale Air Quality (CMAQ; Byun and Schere, 2006) modeling system and been verified by observations (Chen et al, 2013;Tsai et al, 2015) with the Weather Research and Forecasting Model (WRF; Skamarock et al, 2005).…”

Section: Aerosolmentioning

confidence: 99%

See 1 more Smart Citation

Taiwan Earth System Model Version 1: description and evaluation of mean state

Lee¹,

Wang²,

Shiu³

et al. 2020

Geosci. Model Dev.

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Abstract. The Taiwan Earth System Model (TaiESM) version 1 is developed based on Community Earth System Model version 1.2.2 of National Center for Atmospheric Research. Several innovative physical and chemical parameterizations, including trigger functions for deep convection, cloud macrophysics, aerosol, and three-dimensional radiation–topography interaction, as well as a one-dimensional mixed-layer model optional for the atmosphere component, are incorporated. The precipitation variability, such as diurnal cycle and propagation of convection systems, is improved in TaiESM. TaiESM demonstrates good model stability in the 500-year preindustrial simulation in terms of the net flux at the top of the model, surface temperatures, and sea ice concentration. In the historical simulation, although the warming before 1935 is weak, TaiESM captures the increasing trend of temperature after 1950 well. The current climatology of TaiESM during 1979–2005 is evaluated by observational and reanalysis datasets. Cloud amounts are too large in TaiESM, but their cloud forcing is only slightly weaker than observational data. The mean bias of the sea surface temperature is almost 0, whereas the surface air temperatures over land and sea ice regions exhibit cold biases. The overall performance of TaiESM is above average among models in Coupled Model Intercomparison Project phase 5, particularly in that the bias of precipitation is smallest. However, several common discrepancies shared by most models still exist, such as the double Intertropical Convergence Zone bias in precipitation and warm bias over the Southern Ocean.

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Section: Aerosolmentioning

confidence: 99%

“…A novel parameterization for the impact of three-dimensional (3D) radiation-topography interactions (Lee et al, 2013) is added to CLM4. In addition, a one-dimensional (1D) mixed-layer ocean model with a high vertical resolution (Tsuang et al, 2009) is used for CAM5 with slab ocean simulation in TaiESM.…”

Section: Introductionmentioning

confidence: 99%

Taiwan Earth System Model Version 1: description and evaluation of mean state

Lee¹,

Wang²,

Shiu³

et al. 2020

Geosci. Model Dev.

Self Cite

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“…D p,aq << D p,CN . A substantial number of liquid−solid collisions can also occur between a large solid particle and ultrafine aqueous particles (18,19). Contact efflorescence could potentially occur in this scenario, as well.…”

Section: −3mentioning

confidence: 99%

“…greatly different compositions can coexist simultaneously in the same air parcel (3,7,11,18,19). Although immersion efflorescence requires the heterogeneous nuclei to be insoluble or sparingly soluble, there is no such inherent limitation for contact efflorescence.…”

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confidence: 99%

Contact efflorescence as a pathway for crystallization of atmospherically relevant particles

Davis

Lance

Gordon

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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Inadequate knowledge of the phase state of atmospheric particles represents a source of uncertainty in global climate and air quality models. Hygroscopic aqueous inorganic particles are often assumed to remain liquid throughout their atmospheric lifetime or only (re)crystallize at low relative humidity (RH) due to the kinetic limitations of efflorescence (salt crystal nucleation and growth from an aqueous solution). Here we present experimental observations of a previously unexplored heterogeneous nucleation pathway that we have termed "contact efflorescence," which describes efflorescence initiated by an externally located solid particle coming into contact with the surface of a metastable aqueous microdroplet. This study demonstrates that upon a single collision, contact efflorescence is a pathway for crystallization of atmospherically relevant aqueous particles at high ambient RH (≤80%). Soluble inorganic crystalline particles were used as contact nuclei to induce efflorescence of aqueous ammonium sulfate [(NH 4 ) 2 SO 4 ], sodium chloride (NaCl), and ammonium nitrate (NH 4 NO 3 ), with efflorescence being observed in several cases close to their deliquescence RH values (80%, 75%, and 62%, respectively). To our knowledge, these observations represent the highest reported efflorescence RH values for microdroplets of these salts. These results are particularly important for considering the phase state of NH 4 NO 3 , where the contact efflorescence RH (∼20-60%) is in stark contrast to the observation that NH 4 NO 3 microdroplets do not homogeneously effloresce, even when exposed to extremely arid conditions (<1% RH). Considering the occurrence of particle collisions in the atmosphere (i.e., coagulation), these observations of contact efflorescence challenge many assumptions made about the phase state of inorganic aerosol.efflorescence | coagulation | aerosol | climate | air quality N ucleation of the solid phase from a liquid solution (crystallization) is an important process in pharmaceuticals, manufacturing, and atmospheric science (1). In the atmosphere, the phase state and water content of particulate matter influences both heterogeneous chemistry and the aerosol direct and indirect effect on climate (2-6). Despite its importance, there is no comprehensive understanding of the phase state of atmospheric particulate, and the aerosol radiative forcing remains one of the largest uncertainties in climate predictions (6).A significant fraction of aqueous atmospheric aerosol contains soluble inorganics such as chlorides, sulfates, and nitrates that can undergo efflorescence, i.e., the process of salt crystallization and water evaporation. Efflorescence often occurs at a significantly lower relative humidity (RH) than the reverse process of deliquescence (2, 7-12). A potent example of this hydration hysteresis is demonstrated with ammonium nitrate (NH 4 NO 3 ), a hygroscopic component of atmospheric aerosol (9-11). NH 4 NO 3(s) crystals will deliquesce to form an aqueous droplet at ∼62% RH (T = 295 K) (13). However...

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“…Moreover, Taiwan is located on the lee side of the East Asian winter monsoon region and thus receives air pollutants and dust particles transported with Asian outflows. A number of intensive short‐term investigations on concentration and physicochemical properties of aerosol particles have been conducted in specific areas and cities in Taiwan [e.g., Tsai et al ., ; Hung et al ., ]. While these snapshots provide insight into the physicochemical features of aerosols, a clear understanding of seasonal patterns is not yet available.…”

Section: Introductionmentioning

confidence: 99%

Seasonality of the mass concentration and chemical composition of aerosols around an urbanized basin in East Asia

Chou

Hsu²,

Chang

et al. 2017

JGR Atmospheres

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This study investigated seasonal variations in the mass concentration and chemical composition of ambient aerosols observed at three stations (coastal, mountainous, and downtown sites) in northern Taiwan from March 2009 to February 2012. The results show that the major aerosol components include ammonium, sulfate, nitrate, sea salt, dust, organic carbon, and elemental carbon, whereas the mass fraction of each species depends on the sampling location and season. A significant correlation (r = 0.7–0.8) was observed in aerosol concentrations measured at the respective stations, indicating that aerosol concentrations were dominated by regional‐scale factors. Ammonium, sulfate, and nitrate consistently reached respective peak values in the spring in conjunction with dust particle levels. This shows that the transport of dust and particulate air pollutants from the Asian continent has affected the atmospheric environment in this area. Distinct seasonality was observed for sea salt and secondary organic carbon (SOC): sea salt levels peaked in the autumn, whereas SOC levels peaked in the summer, implying that their sources were regulated by independent seasonal factors. Correlation between sea salt concentration and surface wind speed was derived from coastal measurements and showed a high value for the wind speed sensitivity parameter of around 0.37 for our location. In addition, it was revealed that the SOC concentration in aerosols was positively correlated with oxidant photolysis index (Ox × UVB), suggesting that the SOC seasonality was dominated by hydroxyl radical production.

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Numerical investigation of the coagulation mixing between dust and hygroscopic aerosol particles and its impacts

Cited by 12 publications

References 78 publications

Taiwan Earth System Model Version 1: description and evaluation of mean state

Taiwan Earth System Model Version 1: description and evaluation of mean state

Contact efflorescence as a pathway for crystallization of atmospherically relevant particles

Seasonality of the mass concentration and chemical composition of aerosols around an urbanized basin in East Asia

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