Open AccessHNO 3 , N 2 O 5 , and ClONO 2 enhancements after the October–November 2003 solar proton events
Author(s) -
LópezPuertas M.,
Funke B.,
GilLópez S.,
von Clarmann T.,
Stiller G. P.,
Höpfner M.,
Kellmann S.,
Mengistu Tsidu G.,
Fischer H.,
Jackman C. H.
Publication year - 2005
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2005ja011051
Subject(s) - stratosphere , atmospheric sounding , atmosphere (unit) , atmospheric sciences , mesosphere , altitude (triangle) , atmosphere of earth , depth sounding , atmospheric chemistry , thermosphere , environmental science , polar , tropopause , ozone , meteorology , physics , geology , ionosphere , geophysics , astronomy , oceanography , geometry , mathematics
The large solar storm in October–November 2003 produced enormous amounts of high‐energy protons which reached the Earth and penetrated into the middle atmosphere in the polar regions. At this time, the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on board the Environmental Satellite (ENVISAT) was observing the atmosphere in the 6–68 km altitude range. MIPAS observed significant enhancements of the NO y components HNO 3 , N 2 O 5 , and ClONO 2 in the northern polar stratosphere after the intense solar proton events. Two distinct HNO 3 enhancements were observed. An instantaneous increase of 1–2 ppbv was observed immediately after the SPEs and is attributed to gas‐phase chemistry: NO 2 + OH + M → HNO 3 + M, accelerated by SPE‐produced excess OH. A very large second increase of 1–5 ppbv started around 10 November and lasted until the end of December. It is attributed to NO x (NO + NO 2 ) produced in the mesosphere during the major SPEs in late October/early November and then transported downward during November and December, partially converted to N 2 O 5 in the upper stratosphere, which finally formed HNO 3 via ion cluster reactions. N 2 O 5 was observed to increase by 0.1–0.4 ppbv 1–3 days after the major SPEs and reached down to 30 km altitude. A second, more pronounced N 2 O 5 enhancement of up to 1.2 ppbv at 40 km appeared about 12–13 days after the major SPEs. With a delay of 1–2 days after the major SPEs ClONO 2 increased by up to 0.4 ppbv (40%) at 32 km altitude. NO y enhancements in the Southern Hemisphere were generally less pronounced.