During predawn hours on 16 April 2018, surface ozone monitors in a band from roughly Richmond, Virginia, to Philadelphia, Pennsylvania, observed concentration increases of 30-50+ ppbv
in a matter of minutes.
The amount is still small compared to Earth, where it is about 1,800 ppbv
- meaning for every billion molecules, 1,800 are methane.
Planetary scientists have debated methane's presence on Mars for decades, and Curiosity's iffy detection in 2012--which placed an upper limit of 1.3 parts per billion by volume (ppbv
Using a specially crafted high-resolution time-of-flight (TOF) mass spectrometer including the Qi, in combination with proprietary PTR technology, the new analyzer achieves a mass resolution of more than 6,000 (up to 10,000 m/[DELTA]m FWHM), a limit of detection below 1 pptv (in 30 sec) and sensitivity of more than 1500 (up to 4500 cps/ ppbv
Chovelon, "Photocatalytic oxidation of toluene at indoor air levels (ppbv
): towards a better assessment of conversion, reaction intermediates and mineralization," Applied Catalysis B: Environmental, vol.
Canister blank concentrations were <0.2 ppbv
; the average relative standard deviation (RSD) of calibration relative response factors (RRFs) was 9.31%; average scan and selected ion monitoring (SIM) method detection limits were 0.06 ppbv
and 35.9 pptv, respectively; average replicate precision was 6.86 %RSD; and average analytical accuracy for all 65 targeted TO-15 VOCs was 103%.
The global average populationweighted 8-hr maximum ozone concentration was projected to increase by 9.4 parts per billion per volume (ppbv
) compared with a simulation of the concentration in 2000, with the largest increases over South Asia (nearly 15 ppbv
) and with large increases in the Middle East, Southeast Asia, Latin America, and East Asia.
The atmospheric concentration of [N.sub.2]O continues to rise at a rate of approximate 0.26% per year and has reached a concentration of 319 ppbv
([10.sup.-9] mol/mol) in 2005 (IPCC 2007).
Most concentrations of acetone found in air samples range from 50 to 200 parts per billion by volume (ppbv
) (0.05-0.2 ppm).