The effect of atmospheric nitric acid vapor on cloud condensation nucleus activation

1993 ◽  
Vol 98 (D12) ◽  
pp. 22949 ◽  
Author(s):  
M. Kulmala ◽  
A. Laaksonen ◽  
P. Korhonen ◽  
T. Vesala ◽  
T. Ahonen ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Condensation Nucleus ◽  
Cloud Condensation Nucleus ◽  
Acid Vapor

scholarly journals Ammonium nitrate evaporation and nitric acid condensation in DMT CCN counters

2014 ◽  
Vol 7 (5) ◽  
pp. 1377-1384 ◽  
Author(s):  
S. Romakkaniemi ◽  
A. Jaatinen ◽  
A. Laaksonen ◽  
A. Nenes ◽  
T. Raatikainen
Keyword(s):  
Nitric Acid ◽  
Ammonium Nitrate ◽  
Gas Phase ◽  
Aerosol Particles ◽  
Condensation Nucleus ◽  
Cloud Condensation Nucleus ◽  
Ambient Conditions ◽  
Particle Activation ◽  
Maximum Water ◽  
Ccn Activity

Abstract. The effect of inorganic semivolatile aerosol compounds on the cloud condensation nucleus (CCN) activity of aerosol particles was studied by using a computational model for a DMT-CCN counter, a cloud parcel model for condensation kinetics and experiments to quantify the modelled results. Concentrations of water vapour and semivolatiles as well as aerosol trajectories in the CCN column were calculated by a computational fluid dynamics model. These trajectories and vapour concentrations were then used as an input for the cloud parcel model to simulate mass transfer kinetics of water and semivolatiles between aerosol particles and the gas phase. Two different questions were studied: (1) how big a fraction of semivolatiles is evaporated from particles after entering but before particle activation in the DMT-CCN counter? (2) How much can the CCN activity be increased due to condensation of semivolatiles prior to the maximum water supersaturation in the case of high semivolatile concentration in the gas phase? Both experimental and modelling results show that the evaporation of ammonia and nitric acid from ammonium nitrate particles causes a 10 to 15 nm decrease to the critical particle size in supersaturations between 0.1% and 0.7%. On the other hand, the modelling results also show that condensation of nitric acid or similar vapour can increase the CCN activity of nonvolatile aerosol particles, but a very high gas phase concentration (as compared to typical ambient conditions) would be needed. Overall, it is more likely that the CCN activity of semivolatile aerosol is underestimated than overestimated in the measurements conducted in ambient conditions.

Atmosphere × Canopy Interactions of Nitric Acid Vapor in Loblolly Pine Grown in Open‐Top Chambers

1993 ◽  
Vol 22 (1) ◽  
pp. 70-80 ◽  
Author(s):  
G. E. Taylor ◽  
J. G. Owens ◽  
T. Grizzard ◽  
W. J. Selvidge
Keyword(s):  
Nitric Acid ◽  
Loblolly Pine ◽  
Acid Vapor ◽  
Open Top Chambers

scholarly journals A global process-based study of marine CCN trends and variability

2014 ◽  
Vol 14 (11) ◽  
pp. 15771-15801
Author(s):  
E. M. Dunne ◽  
S. Mikkonen ◽  
H. Kokkola ◽  
H. Korhonen
Keyword(s):  
Wind Speed ◽  
Condensation Nucleus ◽  
Feedback Mechanism ◽  
Radiative Properties ◽  
Climate Feedback ◽  
Cloud Condensation Nucleus ◽  
Aerosol Model ◽  
The North ◽  
Nucleation Scavenging ◽  
Climate Cooling

Abstract. Low-level clouds have a strong climate-cooling effect in oceanic regions due to the much lower albedo of the underlying sea surface. Marine clouds typically have low droplet concentrations, making their radiative properties susceptible to changes in cloud condensation nucleus (CCN) concentrations. Here, we use the global aerosol model GLOMAP to investigate the processes that determine variations in marine CCN concentrations, and focus especially on the effects of previously identified wind speed trends in recent decades. Although earlier studies have found a link between linear wind speed trends and CCN concentration, we find that the effects of wind speed trends identified using a dynamic linear model in the Northern Equatorial Pacific (0.56 m s−1 per decade in the period 1990–2004) and the North Atlantic (−0.21 m s−1 per decade) are largely dampened by other processes controlling the CCN concentration, namely nucleation scavenging and transport of continental pollution. A CCN signal from wind speed change is seen only in the most pristine of the studied regions, i.e. over the Southern Ocean, where we simulate 3.4 cm−3 and 0.17 m s−1 increases over the fifteen-year period in the statistical mean levels of CCN and wind speed, respectively. Our results suggest that future changes in wind-speed-driven aerosol emissions from the oceans can probably have a climate feedback via clouds only in the most pristine regions. On the other hand, a feedback mechanism via changing precipitation patterns and intensities could take place over most oceanic regions, as we have shown that nucleation scavenging has by far the largest absolute effect on CCN concentrations.

Thin Layer Densitometric Determination of Rotenone and Deguelin

1969 ◽  
Vol 52 (1) ◽  
pp. 182-187
Author(s):  
Norman E Delfel ◽  
William H Tallent
Keyword(s):  
Acetic Acid ◽  
Standard Deviation ◽  
Nitric Acid ◽  
Thin Layer ◽  
Solvent System ◽  
Ammonia Vapor ◽  
Acid Vapor ◽  
Tephrosia Vogelii ◽  
Infrared Methods

Abstract Rutenone and deguelin are separated by chromatography on silver nitrate-impregnated silica gel G with chloroform acetone: acetic acid (196:3:1) solvent system. Glass plates, 20 × 20 cm, are coated with a special spreader producing a 0.25 mm layer and a 1.00 mm band at the upper end. Since additional solvent is required to saturate the thicker band, such plates give resolutions comparable to plates twice as long. Developed plates are treated with nitric acid vapor, then ammonia vapor, to produce dark spots for the rotenoids. Plates are scanned with a commercial densitometer, and the quantity of rotenoids is calculated from peak area in the resultant curve. Kecoveries of rotenone and deguelin added to extracts of Tephrosia vogelii, Lonchocarpus nicou, and Derris elliptica averaged 104.1 and 99.4%, respectively. The standard deviation of the method applied to plant extracts was 7.9% for rotenone and 8.3% for deguelin. The amounts of rotenone in the L. nicou samples were comparable to those determined by the AOAC crystallization and infrared methods.

scholarly journals A single parameter representation of hygroscopic growth and cloud condensation nucleus activity – Part 2: Including solubility

2008 ◽  
Vol 8 (20) ◽  
pp. 6273-6279 ◽  
Author(s):  
M. D. Petters ◽  
S. M. Kreidenweis
Keyword(s):  
Unit Volume ◽  
Condensation Nucleus ◽  
Single Parameter ◽  
Saturated Solution ◽  
Cloud Condensation Nucleus ◽  
Hygroscopic Growth ◽  
Solubility In Water ◽  
Parameter Representation ◽  
Model Complex ◽  
Ccn Activity

Abstract. The ability of a particle to serve as a cloud condensation nucleus in the atmosphere is determined by its size, hygroscopicity and its solubility in water. Usually size and hygroscopicity alone are sufficient to predict CCN activity. Single parameter representations for hygroscopicity have been shown to successfully model complex, multicomponent particles types. Under the assumption of either complete solubility, or complete insolubility of a component, it is not necessary to explicitly include that component's solubility into the single parameter framework. This is not the case if sparingly soluble materials are present. In this work we explicitly account for solubility by modifying the single parameter equations. We demonstrate that sensitivity to the actual value of solubility emerges only in the regime of 2×10−1–5×10−4, where the solubility values are expressed as volume of solute per unit volume of water present in a saturated solution. Compounds that do not fall inside this sparingly soluble envelope can be adequately modeled assuming they are either infinitely soluble in water or completely insoluble.

The Chemistry and Characteristics of Nitric Acid-Graphite Intercalation

1982 ◽  
Vol 20 ◽  
Author(s):  
Sophia R. Su ◽  
Daniel W. Oblas
Keyword(s):  
Mass Spectrometry ◽  
Nitric Acid ◽  
Gas Phase ◽  
Contributory Factor ◽  
Fourth Stage ◽  
Acid Vapor ◽  
Step Process ◽  
Second Stage ◽  
Graphite Intercalation ◽  
One Step

ABSTRACTGas-phase intercalation of graphite by nitric acid is a one-step process. The weight uptake of the sample is a function of nitric acid vapor pressure. A pure second stage compound was formed when the HNO3 reservoir was maintained at 17°C. Only a fourth stage compound was formed when the acid was kept at 0°C. The product gases due to intercalation and gas species evolved during deintercalation were analyzed by mass spectrometry. NO2 and H2O were the major components detected from the intercalation product gases. A small amount of oxygen was also present. The existence of O2 is probably due to the photo-chemical decomposition of nitric acid. As such, the photodecomposition of nitric acid is not a contributory factor in the intercalation chemistry.

scholarly journals A global process-based study of marine CCN trends and variability

2014 ◽  
Vol 14 (24) ◽  
pp. 13631-13642 ◽  
Author(s):  
E. M. Dunne ◽  
S. Mikkonen ◽  
H. Kokkola ◽  
H. Korhonen
Keyword(s):  
Wind Speed ◽  
Condensation Nucleus ◽  
Feedback Mechanism ◽  
Radiative Properties ◽  
Climate Feedback ◽  
Cloud Condensation Nucleus ◽  
Aerosol Model ◽  
The North ◽  
Nucleation Scavenging ◽  
Climate Cooling

Abstract. Low-level clouds have a strong climate-cooling effect in oceanic regions due to the much lower albedo of the underlying sea surface. Marine clouds typically have low droplet concentrations, making their radiative properties susceptible to changes in cloud condensation nucleus (CCN) concentrations. Here, we use the global aerosol model GLOMAP to investigate the processes that determine variations in marine CCN concentrations, and focus especially on the effects of previously identified wind speed trends in recent decades. Although earlier studies have found a link between linear wind speed trends and CCN concentration, we find that the effects of wind speed trends identified using a dynamic linear model in the Northern Equatorial Pacific (0.56 m s−1 per decade in the period 1990–2004) and the North Atlantic (−0.21 m s−1 per decade) are largely dampened by other processes controlling the CCN concentration, namely nucleation scavenging and transport of continental pollution. A CCN signal from wind speed change is seen only in the most pristine of the studied regions, i.e. over the Southern Ocean, where we simulate 3.4 cm−3 and 0.17 m s−1 increases over the 15-year period in the statistical mean levels of CCN and wind speed, respectively. Our results suggest that future changes in wind-speed-driven aerosol emissions from the oceans can probably have a climate feedback via clouds only in the most pristine regions. On the other hand, a feedback mechanism via changing precipitation patterns and intensities could take place over most oceanic regions, as we have shown that nucleation scavenging has by far the largest absolute effect on CCN concentrations.

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