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Atomic chlorine (Cl) is a strong atmospheric oxidant that shortens the lifetimes of pollutants and methane in the springtime Arctic, where the molecular halogens Cl 2 and BrCl are known Cl precursors. Here, we quantify the contributions of reactive chlorine trace gases and present the first observations, to our knowledge, of ClNO 2 (another Cl precursor), N 2 O 5 , and HO 2 NO 2 in the Arctic. During March - May 2016 near Utqiaġvik, Alaska, up to 21 ppt of ClNO 2 , 154 ppt of Cl 2 , 27 ppt of ClO, 71 ppt of N 2 O 5 , 21 ppt of BrCl, and 153 ppt of HO 2 NO 2 were measured using chemical ionization mass spectrometry. The main Cl precursor was calculated to be Cl 2 (up to 73%) in March, while BrCl was a greater contributor (63%) in May, when total Cl production was lower. Elevated levels of ClNO 2 , N 2 O 5 , Cl 2 , and HO 2 NO 2 coincided with pollution influence from the nearby town of Utqiaġvik and the North Slope of Alaska (Prudhoe Bay) Oilfields. We propose a coupled mechanism linking NO x with Arctic chlorine chemistry. Enhanced Cl 2 was likely the result of the multiphase reaction of Cl - (aq) with ClONO 2 , formed from the reaction of ClO and NO 2 . In addition to this NO x -enhanced chlorine chemistry, Cl 2 and BrCl were observed under clean Arctic conditions from snowpack photochemical production. These connections between NO x and chlorine chemistry, and the role of snowpack recycling, are important given increasing shipping and fossil fuel extraction predicted to accompany Arctic sea ice loss.