Nitrogen, aerosol composition, and halogens on a Tall Tower (NACHTT): overview of a wintertime air chemistry field study in the front range urban corridor of Colorado
Yükleniyor...
Dosyalar
Tarih
2013
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Amer Geophysical Union
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
The Nitrogen, Aerosol Composition, and Halogens on a Tall Tower (NACHTT) field experiment took place during late winter, 2011, at a site 33km north of Denver, Colorado. The study included fixed-height measurements of aerosols, soluble trace gases, and volatile organic compounds near surface level, as well as vertically resolved measurements of nitrogen oxides, aerosol composition, soluble gas-phase acids, and halogen species from 3 to 270m above ground level. There were 1928 individual profiles during the three-week campaign to characterize trace gas and aerosol distributions in the lower levels of the boundary layer. Nitrate and ammonium dominated the ionic composition of aerosols and originated primarily from local or regional sources. Sulfate and organic matter were also significant and were associated primarily with longer-range transport to the region. Aerosol chloride was associated primarily with supermicron size fractions and was always present in excess of gas-phase chlorine compounds. The nighttime radical reservoirs, nitryl chloride, ClNO2, and nitrous acid, HONO, were both consistently present in nighttime urban air. Nitryl chloride was especially pronounced in plumes from large point sources sampled aloft at night. Nitrous acid was typically most concentrated near the ground surface and was the dominant contributor (80%) to diurnally averaged primary OH radical production in near-surface air. Large observed mixing ratios of light alkanes, both in near-surface air and aloft, were attributable to local emissions from oil and gas activities.
Açıklama
Anahtar Kelimeler
NACHTT, Winter Air Quality, Halogens, Aerosols, Nitrogen Oxides
Kaynak
Journal Of Geophysical Research-Atmospheres
WoS Q Değeri
N/A
Scopus Q Değeri
Q1
Cilt
118
Sayı
14
