Atmospheric Chemistry Measurements at Whiteface Mountain, NY: Ozone and Reactive Trace Gases

Abstract

Measurements of ozone and reactive trace gases spanning four decades at the Whiteface Mountain summit observatory are presented. Ozone (O 3 ) measurements began in the mid-1970's, and acid rain and O 3 precursor gas measurements became routine in the late 1980's and early 1990's. Measurements at the lower altitude lodge level have also been performed routinely since about 2000. The 40-year O 3 record shows up and down fluctuations through the 1980's, a relatively stable period into the early 2000's, and indications of a decreasing trend over the past ten years. Sulfur dioxide (SO 2 ) and carbon monoxide (CO) trends are clearly decreasing over the roughly 25-year period of measurements at the summit observatory. Oxides of nitrogen (NO y and NO 2 ) show rather more complicated trends, increasing to a maximum in the mid-2000's, and decreasing sharply until 2011 with slight increases in concentration since then. Wind rose analysis shows the greatest contribution to high concentrations of precursor gases are from the west, southwest, and southern sectors, with SO 2 and oxides of nitrogen having the most sharply defined high pollution sectors. Seasonal variations of trace gas concentrations at the summit and lodge levels are also examined. Ozone concentrations are highest in the spring months at both locations, and higher at the summit than the lodge. In contrast precursor gases (SO 2 and NO x ) show highest concentrations in winter months with the lodge consistently higher than the summit.

Atmospheric Science Research at Whiteface Mountain, NY: Site Description and History

“…The sampling and analytical measurement methodology has been diligently kept the same throughout to enable accurate determination of even small variations in SO 4 2-concentrations, and hence in SO 2 upwind emissions (Husain and Dutkiewicz, 1990;Dutkiewicz et al, 2000;Khan et al, 2010). SO 4 2-aerosol mass concentrations can be converted to effective mixing ratios, then combined with SO 2 measurements (see Brandt et al, 2016) to obtain total sulfur (TS).…”

Overview of the Special Issue “Selected Papers from the 2nd Atmospheric Chemistry and Physics at Mountain Sites Symposium”

“…Recent sulfur dioxide data indicates a strong source region west of Storm Peak Laboratory, and corresponding to the predominant wind direction observed during new particle formation events. Schwab et al (2016a, b) and Brandt et al (2016) are three companion papers describing measurements at Whiteface Mountain in the Andirondack Mountain region in northern New York. Schwab et al (2016a) presents a historical overview of the site and its measurements, making the case for the utility of long-term monitoring while the other two papers provide more detailed findings about the aerosol, cloud, and precipitation measurements (Schwab et al, 2016b) and ozone and trace gases (Brandt et al, 2016).…”

“…Schwab et al (2016a, b) and Brandt et al (2016) are three companion papers describing measurements at Whiteface Mountain in the Andirondack Mountain region in northern New York. Schwab et al (2016a) presents a historical overview of the site and its measurements, making the case for the utility of long-term monitoring while the other two papers provide more detailed findings about the aerosol, cloud, and precipitation measurements (Schwab et al, 2016b) and ozone and trace gases (Brandt et al, 2016). In particular, both the aerosol and gas phase measurements collected over a period of 40 years at Whiteface Mountain highlight the past success of air pollution regulation under the U.S. Clean Air Act and Amendments and pave the way for future progress in reducing air pollution.…”

Atmospheric Chemistry Measurements at Whiteface Mountain, NY: Cloud Water Chemistry, Precipitation Chemistry, and Particulate Matter

“…The sampling and analytical measurement methodology yields an uncertainty of 7% or better for SO 4 2-, and has been diligently kept the same throughout to enable accurate determination of even small variations in SO 4 2-concentrations, and hence in sulfur dioxide (SO 2 ) upwind emissions. SO 4 2-mixing ratios are combined with SO 2 measurements made, as described elsewhere in this paper and in Brandt et al (2016), to obtain total sulfur (TS). These data are collectively used to: (1) evaluate temporal and spatial trends of these species across the Northeast over the past 30 years; (2) study the impact of changes in regional emissions on the downwind (i.e., receptor) concentrations; (3) investigate the question of linearity/nonlinearity between regional SO 2 emissions and acid deposition; and (4) develop an empirical model for sulfur transport for the Northeast corridor.…”

“…Two companion papers in this issue Brandt et al, 2016) have focused on the history of research and monitoring efforts that have occurred at Whiteface Mountain, with an emphasis on gas-phase chemistry. In this paper, we focus on the long-term measurements of condensed-phase chemistrynamely clouds, precipitation, and particulate matter, and provide valuable long term measurement data of cloud water, precipitation and ambient air species from this region covering an approximate 15 or longer year period.…”