Large conversion rates of NO2 to HNO2 observed in air masses from the South China Sea: Evidence of strong production at sea surface?

Qiaozhi Zha, Likun Xue, Tao Wang, Zheng Xu, Chungpong Yeung, Peter K.K. Louie, Connie W.Y. Luk

Research output: Journal article publicationJournal articleAcademic researchpeer-review


Nitrous acid (HONO) plays important roles in tropospheric chemistry, but its source(s) are not completely understood. Here we analyze measurements of HONO, nitrogen dioxide (NO2), and related parameters at a coastal site in Hong Kong during September-December 2012. The nocturnal NO2-to-HONO conversion rates were estimated in air masses passing over land and sea surfaces. The conversion rates in the "sea cases" (3.17-3.36 × 10-2 h-1) were significantly higher than those in the "land cases" in our study (1.20-1.30 × 10-2 h-1) and in previous studies by others. These results suggest that air-sea interactions may be a significant source of atmospheric HONO and need to be considered in chemical transport models. Key Points Strong HONO production in sea-coming air massesAir-sea interactions may significantly affect atmospheric chemistryChemical transport models may need to consider HONO production on the sea
Original languageEnglish
Pages (from-to)7710-7715
Number of pages6
JournalGeophysical Research Letters
Issue number21
Publication statusPublished - 16 Nov 2014


  • air-sea interactions
  • conversion rate
  • HONO
  • marine boundary layer
  • model parameterization
  • nitrous acid

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

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