scholarly journals Concentrations of Atmospheric Sulfur Compounds in an Extremely Snowy Region, the Hokuriku District, Japan

2004 ◽  
Vol 4 ◽  
pp. 248-255
Author(s):  
Tomonori Kawakami ◽  
Jun Murayama
Keyword(s):  
Sulfur Dioxide ◽  
Aerosol Particles ◽  
Sulfur Compounds ◽  
Cloud Base ◽  
Spatial Spread ◽  
Seasonal Characteristics ◽  
Lower Cloud ◽  
Spread Pattern ◽  
Gaseous Sulfur ◽  
Local Emissions

The diurnal and seasonal characteristics in gaseous sulfur dioxide and sulfate in aerosol particles, as well as the concentrations of sulfate in rain and snow, were measured in the Hokuriku District, Japan in order to investigate the spatial spread pattern of sulfur compounds and identify the origin of sulfur. The concentration of sulfur dioxide showed a distinct diurnal pattern, while the concentrations of nss-SO42−in precipitation and aerosol particles did not. These results implied that the sulfur dioxide might originate in local emissions and did not affect the concentration of nss-SO42−in precipitation, while nss-SO42−in aerosol particles seemed to be widespread and might result from long-range transportation. The deposition of nss-SO42−in precipitation increased in winter, while the concentration of nss-SO42−in aerosol particles decreased. This could be attributed to the lower cloud base often observed in this district in winter associated with a higher washout ratio.

scholarly journals Differences between Nonprecipitating Tropical and Trade Wind Marine Shallow Cumuli

2016 ◽  
Vol 144 (2) ◽  
pp. 681-701 ◽  
Author(s):  
Virendra P. Ghate ◽  
Mark A. Miller ◽  
Ping Zhu
Keyword(s):  
Surface Fluxes ◽  
Cloud Base ◽  
Trade Wind ◽  
Cumulus Clouds ◽  
Wind Speeds ◽  
Lower Cloud ◽  
Observational Site ◽  
Velocity Scale ◽  
Atmospheric Radiation Measurement ◽  
The Mean

Abstract Marine nonprecipitating cumulus topped boundary layers (CTBLs) observed in a tropical and in a trade wind region are contrasted based on their cloud macrophysical, dynamical, and radiative structures. Data from the Atmospheric Radiation Measurement (ARM) observational site previously operating at Manus Island, Papua New Guinea, and data collected during the deployment of ARM Mobile Facility at the island of Graciosa, in the Azores, were used in this study. The tropical marine CTBLs were deeper, had higher surface fluxes and boundary layer radiative cooling, but lower wind speeds compared to their trade wind counterparts. The radiative velocity scale was 50%–70% of the surface convective velocity scale at both locations, highlighting the prominent role played by radiation in maintaining turbulence in marine CTBLs. Despite greater thicknesses, the chord lengths of tropical cumuli were on average lower than those of trade wind cumuli, and as a result of lower cloud cover, the hourly averaged (cloudy and clear) liquid water paths of tropical cumuli were lower than the trade wind cumuli. At both locations ~70% of the cloudy profiles were updrafts, while the average amount of updrafts near cloud base stronger than 1 m s−1 was ~22% in tropical cumuli and ~12% in the trade wind cumuli. The mean in-cloud radar reflectivity within updrafts and mean updraft velocity was higher in tropical cumuli than the trade wind cumuli. Despite stronger vertical velocities and a higher number of strong updrafts, due to lower cloud fraction, the updraft mass flux was lower in the tropical cumuli compared to the trade wind cumuli. The observations suggest that the tropical and trade wind marine cumulus clouds differ significantly in their macrophysical and dynamical structures.

scholarly journals Possible Aerosol Effects on Lightning Activity and Structure of Hurricanes

2008 ◽  
Vol 65 (12) ◽  
pp. 3652-3677 ◽  
Author(s):  
A. Khain ◽  
N. Cohen ◽  
B. Lynn ◽  
A. Pokrovsky
Keyword(s):  
Tropical Cyclone ◽  
Mesoscale Model ◽  
Cloud Model ◽  
Aerosol Particles ◽  
Supercooled Water ◽  
Lightning Activity ◽  
Ice Crystals ◽  
Cloud Base ◽  
Weekly Cycle ◽  
Aerosol Effects

Abstract According to observations of hurricanes located relatively close to the land, intense and persistent lightning takes place within a 250–300-km radius ring around the hurricane center, whereas the lightning activity in the eyewall takes place only during comparatively short periods usually attributed to eyewall replacement. The mechanism responsible for the formation of the maximum flash density at the tropical cyclone (TC) periphery is not well understood as yet. In this study it is hypothesized that lightning at the TC periphery arises under the influence of small continental aerosol particles (APs), which affect the microphysics and the dynamics of clouds at the TC periphery. To show that aerosols change the cloud microstructure and the dynamics to foster lightning formation, the authors use a 2D mixed-phase cloud model with spectral microphysics. It is shown that aerosols that penetrate the cloud base of maritime clouds dramatically increase the amount of supercooled water, as well as the ice contents and vertical velocities. As a result, in clouds developing in the air with high AP concentration, ice crystals, graupel, frozen drops and/or hail, and supercooled water can coexist within a single cloud zone, which allows collisions and charge separation. The simulation of possible aerosol effects on the landfalling tropical cyclone has been carried out using a 3-km-resolution Weather Research and Forecast (WRF) mesoscale model. It is shown that aerosols change the cloud microstructure in a way that permits the attribution of the observed lightning structure to the effects of continental aerosols. It is also shown that aerosols, which invigorate clouds at 250–300 km from the TC center, decrease the convection intensity in the TC center, leading to some TC weakening. The results suggest that aerosols change the intensity and the spatial distribution of precipitation in landfalling TCs and can possibly contribute to the weekly cycle of the intensity and precipitation of landfalling TCs. More detailed investigations of the TC–aerosol interaction are required.

Photocatalytic degradation of gaseous sulfur compounds by silver-deposited titanium dioxide

2005 ◽  
Vol 57 (2) ◽  
pp. 109-115 ◽  
Author(s):  
Shinji Kato ◽  
Yuji Hirano ◽  
Misao Iwata ◽  
Taizo Sano ◽  
Koji Takeuchi ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Sulfur Compounds ◽  
Gaseous Sulfur

Flow injection determination of gaseous sulfur dioxide with gas permeation denuder-based online sampling and preconcentration

2002 ◽  
Vol 374 (6) ◽  
pp. 1141-1146 ◽  
Author(s):  
Zhong-Xian Guo ◽  
Yuan-Zong Li ◽  
Xin-Xiang Zhang ◽  
Wen-Bao Chang ◽  
Yun-Xiang Ci
Keyword(s):  
Sulfur Dioxide ◽  
Flow Injection ◽  
Gas Permeation ◽  
Gaseous Sulfur ◽  
Online Sampling

scholarly journals Fast oxidation of sulfur dioxide by hydrogen peroxide in deliquesced aerosol particles

2020 ◽  
Vol 117 (3) ◽  
pp. 1354-1359 ◽  
Author(s):  
Tengyu Liu ◽  
Simon L. Clegg ◽  
Jonathan P. D. Abbatt
Keyword(s):  
Hydrogen Peroxide ◽  
Air Quality ◽  
Sulfur Dioxide ◽  
Atmospheric Aerosol ◽  
Flow Reactor ◽  
Aerosol Particles ◽  
Quality Models ◽  
Atmospheric Aerosol Particles ◽  
Haze Pollution ◽  
Sulfate Formation

Atmospheric sulfate aerosols have important impacts on air quality, climate, and human and ecosystem health. However, current air-quality models generally underestimate the rate of conversion of sulfur dioxide (SO2) to sulfate during severe haze pollution events, indicating that our understanding of sulfate formation chemistry is incomplete. This may arise because the air-quality models rely upon kinetics studies of SO2 oxidation conducted in dilute aqueous solutions, and not at the high solute strengths of atmospheric aerosol particles. Here, we utilize an aerosol flow reactor to perform direct investigation on the kinetics of aqueous oxidation of dissolved SO2 by hydrogen peroxide (H2O2) using pH-buffered, submicrometer, deliquesced aerosol particles at relative humidity of 73 to 90%. We find that the high solute strength of the aerosol particles significantly enhances the sulfate formation rate for the H2O2 oxidation pathway compared to the dilute solution. By taking these effects into account, our results indicate that the oxidation of SO2 by H2O2 in the liquid water present in atmospheric aerosol particles can contribute to the missing sulfate source during severe haze episodes.

Sulfuric acid vapor and sulfur dioxide in the atmosphere of Venus as observed by VeRa

2020 ◽  
Author(s):  
Janusz Oschlisniok ◽  
Bernd Häusler ◽  
Martin Pätzold ◽  
Silvia Tellmann ◽  
Michael Bird
Keyword(s):  
Sulfuric Acid ◽  
Sulfur Dioxide ◽  
Local Times ◽  
Cloud Base ◽  
Acid Vapor ◽  
X Band ◽  
Upper Limits ◽  
Wide Range ◽  
Venus Express ◽  
Atmosphere Of Venus

<p>The main Venus clouds, covering the entire planet between approx. 50 and 70 km altitude, are believed to consist mostly of liquid sulfuric acid. Below the clouds, the temperature is high enough to evaporate those droplets into gaseous sulfuric acid forming a haze layer which extends to altitudes as deep as 35 km. H<sub>2</sub>SO<sub>4</sub>(g) is the main absorber of radio waves as was observed in Mariner, Pioneer Venus, Magellan and Venera radio occultation measurements. Radio wave absorption measurements can be used to derive the amount of H<sub>2</sub>SO<sub>4</sub> as well as to estimate upper limits of SO<sub>2</sub> in Venus’ atmosphere. The radio science experiment VeRa onboard Venus Express probed the atmosphere of Venus between 2006 and 2014 with radio signals at 13 cm (S-band) and 3.6 cm (X-band) wavelengths. Thanks to the orbit of VEX, a wide range of latitudes and local times was covered so that a global picture of the H<sub>2</sub>SO<sub>4</sub>(g) ditribution was obtained. We present H<sub>2</sub>SO<sub>4</sub>(g) profiles as well as upper limits of sulfur dioxide near the cloud base derived from the X-band radio signal from the entire Venus Express mission. More than 600 H<sub>2</sub>SO<sub>4</sub>(g) profiles show the global sulfuric acid vapor distribution covering the northern and southern hemisphere on the day- and night side of the planet. A distinct latitudinal H<sub>2</sub>SO<sub>4</sub>(g) and SO<sub>2</sub> variation and a southern northern symmetry are clearly visible. Observations over 8 years allow to study also long-term variations. Indications for temporal H<sub>2</sub>SO<sub>4</sub>(g) and SO<sub>2</sub> variations are found, at least at northern polar latitudes. The results shall be compared with observations retrieved by other experiments onboard Venus Express. Additionally, the observed H<sub>2</sub>SO<sub>4</sub>(g) distribution will be compared with results obtained from a mass transport model.</p>

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