Premium
Nighttime observation of the HO 2 radical by an LIF instrument at Oki Island, Japan, and its possible origins
Author(s) -
Kanaya Y.,
Sadanaga Y.,
Matsumoto J.,
Sharma U. K.,
Hirokawa J.,
Kajii Y.,
Akimoto H.
Publication year - 1999
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl900475
Subject(s) - radical , atmosphere (unit) , ozone , photochemistry , atmospheric chemistry , ozone depletion , environmental science , atmospheric sciences , analytical chemistry (journal) , chemistry , meteorology , environmental chemistry , geology , physics , organic chemistry
HO 2 (hydroperoxy) radical of unexpectedly high concentration around 3 ppt was measured by an instrument based on laser‐induced fluorescence with NO addition at Oki Island, Japan, on the night of August 9/10, 1998. We confirmed that the interference by atmospheric organic peroxy (RO 2 ) radicals was insignificant and concluded that the measured signal originated from nighttime HO 2 . Model calculations constrained to ancillary measurements indicated that HO 2 and RO 2 were produced primarily via the reactions of ozone with olefins, especially those with internal olefins, and that NO 3 chemistry was relatively unimportant. HO 2 concentration was kept high by nighttime NO (∼10 ppt) via RO 2 + NO reactions. Low NO 2 (∼150 ppt) slowed NO 3 production rate. Thus, the high observed HO 2 suggests that the reactions of O 3 with olefins are important HOx primary production mechanisms in the relatively clean atmosphere.