scholarly journals Observations of methyl nitrate in the lower stratosphere during STRAT: Implications for its gas phase production mechanisms

1998 ◽  
Vol 25 (11) ◽  
pp. 1891-1894 ◽  
Author(s):  
F. Flocke ◽  
E. Atlas ◽  
S. Madronich ◽  
S. M. Schauffler ◽  
K. Aikin ◽  
...  
Keyword(s):  
Gas Phase ◽  
Lower Stratosphere ◽  
Methyl Nitrate ◽  
Production Mechanisms ◽  
Phase Production

ZIEGLER-NATTA PROPYLENE POLYMERIZATION IN GAS PHASE: PRODUCTION OF HIGHLY ISOTACTIC POLYMERS

1972 ◽  
Vol 1 (4) ◽  
pp. 327-329 ◽  
Author(s):  
Yoshiharu Doi ◽  
Ichiro Okura ◽  
Tominaga Keii
Keyword(s):  
Gas Phase ◽  
Propylene Polymerization ◽  
Phase Production

Effect of Reactor Shape and Gas Mixing on Gas Phase Production of Fine SiO2 Particles by Hydrolysis of Tetramethoxysilane

2008 ◽  
Vol 34 (2) ◽  
pp. 261-265 ◽  
Author(s):  
Toshinori Kojima ◽  
Kengo Tachi ◽  
Jun-ichi Sakai ◽  
Shigeru Kato ◽  
Shigeo Satokawa
Keyword(s):  
Gas Phase ◽  
Gas Mixing ◽  
Sio2 Particles ◽  
Hydrolysis Of ◽  
Phase Production

scholarly journals Ultrathin Tropical Tropopause Clouds (UTTCs): I. Cloud morphology and occurrence

2003 ◽  
Vol 3 (4) ◽  
pp. 1083-1091 ◽  
Author(s):  
Th. Peter ◽  
B. P. Luo ◽  
M. Wirth ◽  
C. Kiemle ◽  
H. Flentje ◽  
...  
Keyword(s):  
Gas Phase ◽  
Large Scale ◽  
Lower Stratosphere ◽  
Western Indian Ocean ◽  
Ice Crystals ◽  
Mixing Ratio ◽  
Efficient Point ◽  
Tropical Tropopause ◽  
Cold Point

Abstract. Subvisible cirrus clouds (SVCs) may contribute to dehydration close to the tropical tropopause. The higher and colder SVCs and the larger their ice crystals, the more likely they represent the last efficient point of contact of the gas phase with the ice phase and, hence, the last dehydrating step, before the air enters the stratosphere. The first simultaneous in situ and remote sensing measurements of SVCs were taken during the APE-THESEO campaign in the western Indian ocean in February/March 1999. The observed clouds, termed Ultrathin Tropical Tropopause Clouds (UTTCs), belong to the geometrically and optically thinnest large-scale clouds in the Earth's atmosphere. Individual UTTCs may exist for many hours as an only 200--300 m thick cloud layer just a few hundred meters below the tropical cold point tropopause, covering up to 105 km2. With temperatures as low as 181 K these clouds are prime representatives for defining the water mixing ratio of air entering the lower stratosphere.

Distinct particle modes in the lower stratosphere constrain secondary aerosol chemistry and gas-phase concentrations

2021 ◽  
Author(s):  
Daniel Murphy ◽  
Karl Froyd ◽  
Greg Schill ◽  
Charles Brock ◽  
Agnieszka Kupc ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Gas Phase ◽  
Lower Stratosphere ◽  
Aerosol Particles ◽  
Organic Content ◽  
Aerosol Chemistry ◽  
Volatile Organics ◽  
Organic Sulfate ◽  
Concentration Limits ◽  
Distinct Particle

<p>There are distinct types of aerosol particles in the lower stratosphere. Stratospheric sulfuric acid particles with and without meteoric metals coexist with mixed organic-sulfate particles that originated in the troposphere. That these particles remain distinct has important implications for aerosol chemistry and the concentrations of several gas-phase species. Neither semi-volatile organics nor ammonia can be in equilibrium with the gas phase. The gas-phase concentrations of semi-volatile organics and ammonia must be very low, or else the sulfuric acid particles would not stay so pure. The upper concentration limits are around a pptv. Yet the sulfuric acid particles in the Northern Hemisphere show a very small but measurable uptake of organics and ammonia, indicating non-zero gas-phase concentrations of those species. Finally, the organic-sulfate particles must be resistant to photochemical loss, or else they would no longer retain their organic content.</p>

Gas‐Phase Production of NHD2in L134N

2001 ◽  
Vol 553 (2) ◽  
pp. 613-617 ◽  
Author(s):  
S. D. Rodgers ◽  
S. B. Charnley
Keyword(s):  
Gas Phase ◽  
Phase Production

scholarly journals Measurement and interpretation of gas phase formaldehyde concentrations obtained during the CHABLIS campaign in coastal Antarctica

2008 ◽  
Vol 8 (14) ◽  
pp. 4085-4093 ◽  
Author(s):  
R. A. Salmon ◽  
S. J.-B. Bauguitte ◽  
W. Bloss ◽  
M. A. Hutterli ◽  
A. E. Jones ◽  
...  
Keyword(s):  
Gas Phase ◽  
Austral Summer ◽  
Research Station ◽  
Steady State Analysis ◽  
Sources And Sinks ◽  
Data Coverage ◽  
Absolute Concentrations ◽  
Instrumental Detection Limit ◽  
Phase Production

Abstract. Gas phase formaldehyde concentrations were measured during the 2004–2005 CHABLIS campaign at Halley research station, Antarctica. Data coverage span from May 2004 through to January 2005, thus capturing the majority of the year, with a wintertime minimum of near or below the instrumental detection limit rising to between 50 and 200 pptv during the austral summer. Factors controlling HCHO concentration include local chemical sources and sinks, and exchange with the snow surface. The measured seasonality is in line with previous observations from Neumayer station, with maximum in summer and minimum during the winter months, but with lower absolute concentrations throughout the year. The gas-phase production of HCHO was dominated by methane oxidation and a steady-state analysis showed that reactions of iodine and bromine species substantially reduced the predicted HCHO levels based upon in situ chemistry. This indicates a substantial additional HCHO source to be present that could be explained by a snowpack source.

scholarly journals Gas-Phase Production of Nanoparticles

2002 ◽  
Vol 20 (0) ◽  
pp. 24-37 ◽  
Author(s):  
Andreas Gutsch ◽  
Michael Krämer ◽  
Günther Michael ◽  
Heike Mühlenweg ◽  
Markus Pridöhl ◽  
...  
Keyword(s):  
Gas Phase ◽  
Phase Production

scholarly journals The atmospheric HCHO budget at Dumont d'Urville (East Antarctica): Contribution of photochemical gas-phase production versus snow emissions

2013 ◽  
Vol 118 (23) ◽  
pp. 13,319-13,337 ◽  
Author(s):  
Susanne Preunkert ◽  
Michel Legrand ◽  
Guillaume Pépy ◽  
Hubert Gallée ◽  
Anna Jones ◽  
...  
Keyword(s):  
Gas Phase ◽  
East Antarctica ◽  
Phase Production
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