Laboratory studies of chemical and photochemical processes relevant to stratospheric ozone. Annual report No. 2, May 1993-April 1994

Technical Report · Fri Apr 01 00:00:00 EST 1994

OSTI ID:7106258

Zahniser, M S; Nelson, D D; Worsnop, D R; Kolb, C E

The purpose of this project is to reduce the uncertainty in several key gas-phase kinetic processes which impact present understanding of stratospheric ozone. The main emphasis of this work is on measuring rate coefficients and product channels for reactions of HO[sub x] and NO[sub x] species in the temperature range 200 K to 240 K relevant to the lower stratosphere. Other areas of study have included infrared spectroscopic studies of the HO2 radical, measurements of OH radical reactions with alternative fluorocarbons, and determination of the vapor pressures of nitric acid hydrates under stratospheric conditions. The results of these studies will improve models of stratospheric ozone chemistry and predictions of perturbations due to human influences. In this annual report, the authors focus on recent accomplishments in the quantitative spectroscopy of the HO2 radical. This report details the measurements of the broadening coefficients for the v[sub 2] vibrational band. Further measurements of the vapor pressures of nitric acid hydrates relevant to the polar stratospheric cloud formation indicate the importance of metastable crystalline phases of H2SO4, HNO3, and H2O. Large particles produced from these metastable phases may provide a removal mechanism for HNO3 in the polar stratosphere.

• Research Organization: Aerodyne Research, Inc., Billerica, MA (United States)
• OSTI ID: 7106258
• Report Number(s): N-94-29549; NASA-CR-195779; NAS-1.26:195779; ARI-RR-1072; CNN: NAS5-31847
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
HYDROXYL RADICALS
ATMOSPHERIC CHEMISTRY
REACTION KINETICS
NITROGEN OXIDES
PEROXIDES
HYDROGEN COMPOUNDS
NITRIC ACID
PROGRESS REPORT
STRATOSPHERE
SULFURIC ACID
CHALCOGENIDES
CHEMISTRY
DOCUMENT TYPES
EARTH ATMOSPHERE
INORGANIC ACIDS
KINETICS
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
RADICALS
540110*