World Library  


Add to Book Shelf
Flag as Inappropriate
Email this Book

Homogeneous Nucleation of Nad and Nat in Liquid Stratospheric Aerosols: Insufficient to Explain Denitrification : Volume 2, Issue 3 (12/06/2002)

By Knopf, D. A.

Click here to view

Book Id: WPLBN0003997329
Format Type: PDF Article :
File Size: Pages 19
Reproduction Date: 2015

Title: Homogeneous Nucleation of Nad and Nat in Liquid Stratospheric Aerosols: Insufficient to Explain Denitrification : Volume 2, Issue 3 (12/06/2002)  
Author: Knopf, D. A.
Volume: Vol. 2, Issue 3
Language: English
Subject: Science, Atmospheric, Chemistry
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Historic
Publication Date:
2002
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

Citation

APA MLA Chicago

Luo, B. P., Weers, U. G., Koop, T., Knopf, D. A., & Peter, T. (2002). Homogeneous Nucleation of Nad and Nat in Liquid Stratospheric Aerosols: Insufficient to Explain Denitrification : Volume 2, Issue 3 (12/06/2002). Retrieved from http://ebooklibrary.org/


Description
Description: Institute for Atmospheric and Climate Science, Swiss Federal Institute of Technology, Zurich, Switzerland. The nucleation of NAD and NAT from HNO3/H2O and HNO3/H2O/H2SO4 solution droplets is investigated both theoretically and experimentally with respect to the formation of polar stratospheric clouds (PSCs). Our analysis shows that homogeneous NAD and NAT nucleation from liquid aerosols is insufficient to explain the number densities of large nitric acid containing particles recently observed in the Arctic stratosphere. This conclusion is based on new droplet freezing experiments employing optical microscopy combined with Raman spectroscopy. The homogeneous nucleation rate coefficients of NAD and NAT in liquid aerosols under polar stratospheric conditions derived from the experiments are < 2 x 10-5 cm-3 s-1 and < 8 x 10-2 cm-3 s-1 , respectively. These nucleation rate coefficients are smaller by orders of magnitude than the value of ~ 103 cm-3 s-1 used in a recent denitrification modelling study that is based on a linear extrapolation of laboratory nucleation data to stratospheric conditions (Tabazadeh et al., Science, 291, 2591--2594, 2001). We show that this linear extrapolation is in disagreement with thermodynamics and experimental data and, therefore, must not be used in microphysical models of PSCs. Our analysis of the experimental data yields maximum hourly production rates of nitric acid hydrate particles per cm3 of air of about 3 x 10-10 cm-3 h-1 under polar stratospheric conditions. Assuming PSC particle production to proceed at this rate for two months we arrive at particle number densities of < 5 x 10-7 cm-3, much smaller than the value of ~ 10-4 cm-3 reported in recent field observations. This clearly shows that homogeneous nucleation of NAD and NAT from liquid supercooled ternary solution aerosols cannot explain the observed polar denitrification.



Summary
Homogeneous nucleation of NAD and NAT in liquid stratospheric aerosols: insufficient to explain denitrification

 

Click To View

Additional Books


  • A New Parametrization for Ambient Partic... (by )
  • Ground Based Aerosol Characterization Du... (by )
  • Weather Response to Management of a Larg... (by )
  • Hygroscopic Properties of Different Aero... (by )
  • Hydration and Dehydration at the Tropica... (by )
  • Aerosol Hygroscopicity in the Marine Atm... (by )
  • Particle Size Distributions in the Easte... (by )
  • Hygroscopic Properties of the Paris Urba... (by )
  • All Weather Iasi Single Field-of-view Re... (by )
  • Towards Improving the Simulation of Mete... (by )
  • Aerosols' Influence on the Interplay Bet... (by )
  • Evaluation of in Situ Measurements of At... (by )
Scroll Left
Scroll Right

 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.