Isotopic composition of Antarctic Dry Valley nitrate: Implications for NOy sources and cycling in Antarctica
Nitrates minerals from the Dry Valleys of Antarctica have been analyzed for their oxygen and nitrogen isotopic compositions. The 15 N was depleted with δ 15 N values ranging from −9.5 to −26.2‰, whereas the 17 O and 18 O isotopes were highly enriched (with excess 17 O) with δ 18 O values spanning 62–76‰ and Δ 17 O values from 28.9 to 32.7‰. These are the largest 17 O enrichments observed in any known mineral. The oxygen isotopes indicate that nitrate is from a combination of tropospheric transport of photochemically produced HNO 3 and HNO 3 formed in the stratosphere.
Geophysical Research Letters↗