Open AccessA sensitivity study of photolysis rate coefficients during POLARIS
Author(s) -
Swartz William H.,
Lloyd Steven A.,
Kusterer Thomas L.,
Anderson Donald E.,
McElroy C. Thomas,
Midwinter Clive
Publication year - 1999
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999jd900364
Subject(s) - albedo (alchemy) , atmospheric sciences , zenith , ozone , solar zenith angle , altitude (triangle) , environmental science , flux (metallurgy) , spectroradiometer , irradiance , meteorology , physics , materials science , optics , reflectivity , art , geometry , mathematics , performance art , metallurgy , art history
Recent improvements in the agreement between observation‐derived and modeled photolysis rate coefficients ( j ‐values) have allowed for the close examination of the sensitivity of j ‐values to variations in physical parameters influencing their magnitude and temporal(spatial variability. Altitude and solar zenith angle profiles of j ‐values for two photolytic processes, NO 2 → NO + O( 3 P ) and O 3 → O 2 + O( 1 D ), are modeled, varying surface albedo, atmospheric baseheight, total column ozone, and ozone and temperature altitude profiles over the ranges observed during the NASA Photochemistry of Ozone Loss in the Arctic Region In Summer (POLARIS) high‐altitude ER‐2 aircraft campaign. The effect of atmospheric refraction at high solar zenith angles is also addressed. Modeled j ‐values using measured ozone/albedo input from the Composition and Photodissociative Flux Measurement (CPFM) spectroradiometer on board the ER‐2 exceed those derived from CPFM flux measurements by 6% for j NO 2 and 14% for j O 3 , within experimental uncertainties. The individual effects of albedo, baseheight, and ozone on j ‐values along specific ER‐2 flight tracks are modeled and related to the temporal and spatial variability observed. For j NO 2 , surface albedo has the greatest effect; for j O 3 , the ozone above the aircraft and surface albedo are the most important.