Analysis of Water Vapor Change and Precipitation Conversion Efficiency Based on HYSPLIT Backward Trajectory Model over the Three-River Headwaters Region

2020 ◽  
Vol 105 (sp1) ◽  
Author(s):  
Anfeng Qiang ◽  
Ni Wang ◽  
Jiancang Xie ◽  
Jiahua Wei
Keyword(s):  
Water Vapor ◽  
Conversion Efficiency ◽  
Backward Trajectory ◽  
Trajectory Model

THE CATALYTIC ACTION OF ALUMINUM SILICATES: III. THE CONVERSION OF 1,1-DIPHENYLETHANE TO STYRENE OVER MORDEN BENTONITE

1948 ◽  
Vol 26b (8) ◽  
pp. 581-591 ◽  
Author(s):  
R. V. V. Nicholls ◽  
Maurice Morton
Keyword(s):  
Water Vapor ◽  
Conversion Efficiency ◽  
Vapor Phase ◽  
Carbon Deposition ◽  
Hydrogenation Product ◽  
Reaction Products ◽  
Optimum Conditions ◽  
Phase Conversion ◽  
Vapor Velocity ◽  
Styrene Content

Optimum conditions for the vapor phase conversion of 1,1-diphenylethane to styrene and benzene over activated Morden bentonite have been found to be a temperature of 600 °C., rapid feed rates, and the use of water vapor as diluent. Ethylbenzene has been found in the reaction products as a hydrogenation product. Styrene content has been found to be dependent directly upon vapor velocity while the conversion efficiency was found to be related directly to the use of water vapor as an inhibitor of carbon deposition on the catalyst.

scholarly journals Impact of convectively lofted ice on the seasonal cycle of tropical lower stratospheric water vapor

2019 ◽  
Author(s):  
Xun Wang ◽  
Andrew E. Dessler ◽  
Mark R. Schoeberl ◽  
Wandi Yu ◽  
Tao Wang
Keyword(s):  
Water Vapor ◽  
Seasonal Cycle ◽  
Climate Model ◽  
Boreal Summer ◽  
Small Contribution ◽  
Asian Monsoon Region ◽  
Stratospheric Water Vapor ◽  
Trajectory Model ◽  
Tropical Tropopause ◽  
Important Region

Abstract. We use a forward Lagrangian trajectory model to diagnose mechanisms that produce the tropical lower stratospheric (LS) water vapor seasonal cycle observed by the Microwave Limb Sounder (MLS) and reproduced by the Goddard Earth Observing System Chemistry Climate Model (GEOSCCM) in the tropical tropopause layer (TTL). We confirm in both the MLS and GEOSCCM that the seasonal cycle of water vapor is primarily determined by the seasonal cycle of TTL temperatures. However, we find that the seasonal cycle of temperature predicts a smaller seasonal cycle of LS water vapor between 10° N–40° N than observed by MLS. We show that including evaporation of convectively lofted ice in the trajectory model increases the simulated maximum value in the 10° N–40° N water vapor seasonal cycle by 1.9 ppmv (47 %) and increases the seasonal amplitude by 1.26 ppmv (123 %), which improves the prediction of LS water vapor annual cycle. We conclude that the moistening effect from convective ice evaporation in the TTL plays a key role regulating and maintaining the tropical LS water vapor seasonal cycle. Most of the convective moistening in the 10° N–40° N range comes from convective ice evaporation occurring at the same latitudes. A small contribution to the moistening comes from convective ice evaporation occurring between 10° S–10° N. Within 10° N–40° N, the Asian monsoon region is the most important region for convective ice evaporation and convective moistening during boreal summer and autumn.

scholarly journals Impact of convectively lofted ice on the seasonal cycle of water vapor in the tropical tropopause layer

2019 ◽  
Vol 19 (23) ◽  
pp. 14621-14636 ◽  
Author(s):  
Xun Wang ◽  
Andrew E. Dessler ◽  
Mark R. Schoeberl ◽  
Wandi Yu ◽  
Tao Wang
Keyword(s):  
Water Vapor ◽  
Seasonal Cycle ◽  
Climate Model ◽  
Boreal Summer ◽  
Small Contribution ◽  
Asian Monsoon Region ◽  
Tropical Tropopause Layer ◽  
Trajectory Model ◽  
Tropical Tropopause ◽  
Important Region

Abstract. We use a forward Lagrangian trajectory model to diagnose mechanisms that produce the water vapor seasonal cycle observed by the Microwave Limb Sounder (MLS) and reproduced by the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM) in the tropical tropopause layer (TTL). We confirm in both the MLS and GEOSCCM that the seasonal cycle of water vapor entering the stratosphere is primarily determined by the seasonal cycle of TTL temperatures. However, we find that the seasonal cycle of temperature predicts a smaller seasonal cycle of TTL water vapor between 10 and 40∘ N than observed by MLS or simulated by the GEOSCCM. Our analysis of the GEOSCCM shows that including evaporation of convective ice in the trajectory model increases both the simulated maximum value of the 100 hPa 10–40∘ N water vapor seasonal cycle and the seasonal-cycle amplitude. We conclude that the moistening effect from convective ice evaporation in the TTL plays a key role in regulating and maintaining the seasonal cycle of water vapor in the TTL. Most of the convective moistening in the 10–40∘ N range comes from convective ice evaporation occurring at the same latitudes. A small contribution to the moistening comes from convective ice evaporation occurring between 10∘ S and 10∘ N. Within the 10–40∘ N band, the Asian monsoon region is the most important region for convective moistening by ice evaporation during boreal summer and autumn.

Decomposition of Ethanethiol by a Corona Radical Injection System

2018 ◽  
Vol 921 ◽  
pp. 48-53 ◽  
Author(s):  
Zhan Guo Li ◽  
Hong Jie Zhao
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Conversion Efficiency ◽  
Gas Flow ◽  
Elemental Sulfur ◽  
Air Flow ◽  
Injection System ◽  
Decomposition Products ◽  
Vapor Injection ◽  
Decomposition Efficiency

The decomposition of ethanethiol by a corona radical injection system, using water vapor and O3as radical source, was investigated. It is found that only 83.6% of ethanethiol can be decomposed in dry air flow with relative humidity of 13.4%. A proper quantity of water vapor injection can improve the decomposition efficiency, but which is not always increased. The maximum decomposition efficiency of 99.1% can be obtained in wet air flow with relative humidity of 74.7%. 97.6% of ethanethiol can be decomposed when the relative humidity of gas flow is 51.6%, but it is found that only 76.3% of element sulfur is converted to SO2, based on sulfur balance. However, the conversion efficiency of sulfur to SO2increases obviously with the increasing of O3injection. The decomposition efficiency of ethanethiol and conversion efficiency of sulfur to SO2can reach 99.8% and 95.3% respectively, when O3is injected into the reactor by high voltage electrode tubes with concentration of 1 g/m3 and flow rate of 300 L/h. The decomposition products are SO2, CO2and H2O, while no organic product is found, based on which the decomposition mechanism is discussed. The weakest chemical bond C-S in ethanethiol molecule is firstly decomposed to ·SH and ·C2H5radicals. ·SH can be oxidized to elemental sulfur and SO2, and ·C2H5is oxidized to CO2and H2O.

scholarly journals Transport of mesospheric H<sub>2</sub>O during and after the stratospheric sudden warming of January 2010: observation and simulation

2011 ◽  
Vol 11 (12) ◽  
pp. 32811-32846
Author(s):  
C. Straub ◽  
B. Tschanz ◽  
K. Hocke ◽  
N. Kämpfer ◽  
A. K. Smith
Keyword(s):  
Water Vapor ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Microwave Radiometer ◽  
The Arctic ◽  
Strong Increase ◽  
Time Interval ◽  
Backward Trajectory ◽  
Stratospheric Sudden Warming ◽  
Vapor Distribution

Abstract. The transportable ground based microwave radiometer MIAWARA-C monitored the upper stratospheric and lower mesospheric (USLM) water vapor distribution over Sodankylä, Finland (67.4° N, 26.6° N) from January to June 2010. At the end of January, approximately 2 weeks after MIAWARA-C's start of operation in Finland, a stratospheric sudden warming (SSW) disturbed the circulation of the middle atmosphere. Shortly after the onset of the SSW water vapor in the USLM rapidly increased from approximately 5.5 to 7 ppmv in the end of January. Backward trajectory calculations show that this strong increase is due to the break down of the polar vortex and meridional advection of subtropical air to the arctic USLM region. In addition, mesospheric upwelling in the course of the SSW led to an increase in observed water vapor between 0.1 and 0.03 hPa. After the SSW MIAWARA-C observed a decrease in mesospheric water vapor volume mixing ratio (VMR) due to the subsidence of H2O poor air masses in the polar region. Backward trajectory analysis and the zonal mean water vapor distribution from the Microwave Limb Sounder on the Aura satellite (Aura/MLS) indicate the occurrence of two regimes of circulation from 50° N to the north pole: 1) regime of enhanced meridional mixing throughout February and 2) regime of an eastward circulation in the USLM region reestablished between early March and equinox. The polar descent rate determined from MIAWARA-C's 5.2 ppmv isopleth is 350 m d−1 in the pressure range 0.6 to 0.06 hPa between mid February and early March. For the same time interval the descent rate was determined using trajectories calculated from the Transformed Eulerian Mean (TEM) wind fields simulated by means of the Whole Atmosphere Community Climate Model (WACCM). The values found using these different methods are in good agreement.

scholarly journals Transport of mesospheric H2O during and after the stratospheric sudden warming of January 2010: observation and simulation

2012 ◽  
Vol 12 (12) ◽  
pp. 5413-5427 ◽  
Author(s):  
C. Straub ◽  
B. Tschanz ◽  
K. Hocke ◽  
N. Kämpfer ◽  
A. K. Smith
Keyword(s):  
Water Vapor ◽  
Pressure Range ◽  
Climate Model ◽  
Middle Atmosphere ◽  
The Arctic ◽  
Strong Increase ◽  
Time Interval ◽  
Backward Trajectory ◽  
Stratospheric Sudden Warming ◽  
Vapor Distribution

Abstract. The transportable ground based microwave radiometer MIAWARA-C monitored the upper stratospheric and lower mesospheric (USLM) water vapor distribution over Sodankylä, Finland (67.4° N, 26.6° E) from January to June 2010. At the end of January, approximately 2 weeks after MIAWARA-C's start of operation in Finland, a stratospheric sudden warming (SSW) disturbed the circulation of the middle atmosphere. Shortly after the onset of the SSW water vapor rapidly increased at pressures between 1 and 0.01 hPa. Backward trajectory calculations show that this strong increase is due to the breakdown of the polar vortex and meridional advection of subtropical air to the Arctic USLM region. In addition, mesospheric upwelling in the course of the SSW led to an increase in observed water vapor between 0.1 and 0.03 hPa. After the SSW MIAWARA-C observed a decrease in mesospheric water vapor volume mixing ratio (VMR) due to the subsidence of H2O poor air masses in the polar region. Backward trajectory analysis and the zonal mean water vapor distribution from the Microwave Limb Sounder on the Aura satellite (Aura/MLS) indicate the occurrence of two regimes of circulation from 50° N to the North Pole: (1) regime of enhanced meridional mixing throughout February and (2) regime of an eastward circulation in the USLM region reestablished between early March and the equinox. The polar descent rate determined from MIAWARA-C's 5.2 parts per million volume (ppmv) isopleth is 350 &amp;pm; 40 m d−1 in the pressure range 0.6 to 0.06 hPa between early February and early March. For the same time interval the descent rate in the same pressure range was determined using Transformed Eulerian Mean (TEM) wind fields simulated by means of the Whole Atmosphere Community Climate Model with Specified Dynamics (SD-WACCM). The average value of the SD-WACCM TEM vertical wind is 325 m d−1 while the along trajectory vertical displacement is 335 m d−1. The similar descent rates found indicate good agreement between the model and MIAWARA-C's measurements.

scholarly journals Trajectory analysis on the origin of air mass and moisture associated with Atmospheric Rivers over the west coast of the United States

2011 ◽  
Vol 11 (4) ◽  
pp. 11109-11142 ◽  
Author(s):  
J.-M. Ryoo ◽  
D. E. Waliser ◽  
E. J. Fetzer
Keyword(s):  
United States ◽  
Water Vapor ◽  
West Coast ◽  
Moisture Transport ◽  
The United States ◽  
Transport Processes ◽  
The West ◽  
Atmospheric Rivers ◽  
Air Masses ◽  
Trajectory Model

Abstract. The origins and pathways of air masses leading to heavy rainfall over the west coast of the United States are examined by computing the back-trajectories in a Lagrangian quasi-isentropic trajectory model. Extreme precipitation over the west coast of the United States often coincides with transport in a deep and narrow corridor of concentrated water vapor band from the ocean, commonly referred to as Atmospheric Rivers (ARs). They also occur in conjunction with moisture plumes emanating from the tropics, or along the mid-latitude storm track. However, the actual moisture sources and the dynamic and thermodynamic processes of the moisture transport, are still unclear. Trajectories are found to be insensitive to the reanalysis data set used; we examined NCEP, GMAO MERRA, and ECMWF ERA-Interim. Reconstructed water vapor mixing ratios along trajectories are in generally good agreement among the reanalysis datasets in most of the subtropics and extratropics, indicating that the large-scale circulation is a primary control for moisture transport over those regions. Clustering and pdf (probability density function) analyses illustrate that trajectories over the west coast of United States have different origins. One group of trajectories (cluster 1) originates in the warm part of extratropical cyclones in the low level. The other group of trajectories (cluster 2) originates in the cold and dry regions in the mid-level (pressures less than 600 hPa) over northeastern Asia, then cross the Pacific Ocean. This study demonstrates that the quasi-isentropic Lagrangian trajectory model and clustering analysis (that have been typically used to analyze trajectories in the upper troposphere and higher altitudes) can be used to examine sources of air masses and moisture, and also associated transport processes in the lower troposphere.

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