The variation of nitric acid vapor and nitrate aerosol concentrations near the island of Hawaii

Miscellaneous · Wed Jan 01 00:00:00 EST 1992

OSTI ID:5608477

Lee, G

Anthropogenic emissions of nitrogen oxides (NO + NO[sub 2]) are estimated to be half of the global emissions to the atmosphere. To understand the effect of increasing anthropogenic reactive nitrogen inputs to the global atmosphere, one needs to monitor their long-term variations. This dissertation examines the variations of total nitrate (nitric acid vapor and nitrate aerosol) at the Mauna Loa Observatory (MLO), Hawaii. During the Mauna Loa Observatory Photochemistry Experiment (MLOPEX) in May, 1988, six different air types were identified at MLO with statistical analysis. They were: (1) volcano influenced air, (2) stratosphere-like air, (3) boundary-layer air with recent anthropogenic influence, (4) photochemical haze, (5) marine boundary-layer air, (6) well-aged and modified marine air. Samples that might be influenced by marine air or human activity from local islands were eliminated with three meterological criteria (wind direction, condensation nuclei, and dew point). To examine the negative sampling artifacts of nitric acid vapor due to ground loss, mixing ratio gradients with height were measured during August of 1991. The observed gradients of nitric acid vapor indicated that the long-term samplers at 8 m at MLO may underestimate the free tropospheric nitric acid vapor mixing ratio by about 20%. The three year mean and median of free tropospheric total nitrate during long-term measurements were 113 pptv and 93 pptv, respectively. Each year, the total nitrate mixing ratios at MLO during the spring and summer were increased by more than a factor of two higher than fall and winter. NO[sub y] from remote continents (Asia and North America) are likely sources of these increased total nitrate at MLO during these seasons. However, other processes govern the total nitrate mixing ratios, e.g., degree of mixing between free tropospheric air and boundary air at source regions, stratospheric injection, and wet removal of total nitrate.

• Research Organization: Rhode Island Univ., Kingston, RI (United States)
• OSTI ID: 5608477
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
HAWAII
AIR POLLUTION MONITORING
NITRATES
ECOLOGICAL CONCENTRATION
AEROSOLS
NITROGEN OXIDES
CHALCOGENIDES
COLLOIDS
DEVELOPED COUNTRIES
DISPERSIONS
MONITORING
NITROGEN COMPOUNDS
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
SOLS
USA
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)