Occurrence, latitudinal gradient and potential sources of perchlorate in the atmosphere across the hemispheres (31°N to 80°S)

Stratospheric Gas‐Phase Production Alone Cannot Explain Observations of Atmospheric Perchlorate on Earth

“…Modeled values are generally lower and have a narrower range (10 −3 -10 −1 ng m −3 ) compared to observations (10 −3 -10 2 ng m −3 ). Our modeled average [ClO 4 − (p)] (0.002 pmol mol −1) is an order of magnitude lower than observations reported byJiang et al (2021) at more remote locations (median: 0.023 pmol mol −1 ). We conducted Mann-Whitney U tests (details in Text S5 in the Supporting Information S1) and found that the observations from all published studies are statistically distinct from model predictions at the 95% significance level, except for the rural sites in Yuzhong County in China(Shi et al, 2011) and Lake Toya in Japan(Shirahata, 2012).…”

“…The blue‐shaded region and the orange bar in the right panel of (c) indicate observations by Jiang et al. (2021) and Murphy and Thomson (2000) (⨉ marker: median, range: maximum and minimum), respectively. Standard Temperature and Pressure (STP) condition is defined as T = 273 K and P = 1,013 hPa.…”

“…The Jiang et al. (2021) cruise observations that are ≥200 km away from the coast are classified as “open‐ocean.” For ice‐core/snow‐pit sites, we show the estimated post‐1980 deposition flux summarized by Jiang et al. (2020).…”

“…(2010) (Okinawa, Japan) and Jiang et al. (2021) (from a cruise between Shanghai, China and Antarctica). Measurements of perchlorate in deposition samples are available in North America (Andraski et al., 2014; Munster et al., 2009; Rajagopalan et al., 2009; Van Stempvoort et al., 2020) and East Asia (Lin et al., 2019; Yamada et al., 2009, 2012).…”

Widespread detection of chlorine oxyacids in the Arctic atmosphere

“…− in ice cores 21,22 , snow 51 , and aerosols 52 , where atmospheric sources are strongly implicated.…”