<p>We describe the characteristics and performances of our newly built broadband cavity-enhanced absorption spectrometer for measurements of nitrate radical (NO<sub>3</sub>), nitrogen dioxide (NO<sub>2</sub>), and water vapor (H<sub>2</sub>O). A customized vibration-resistance cavity layout incorporated with N<sub>2</sub> purging on high-reflection mirror surfaces was implemented with a red light-emitting diode (LED) as a light source. In general, this system achieved over 40 km (up to 101.5 km) of effective light path length at 662 nm from a 0.52 m long cavity. For the accurate NO<sub>3</sub> measurement, the measured absorption spectrum of H<sub>2</sub>O was used for simultaneous concentration retrievals with the other species, instead of being treated as interferences to be removed or corrected prior to NO<sub>3</sub> detection. Synthesized N<sub>2</sub>O<sub>5</sub> crystals under atmospheric pressure were used for performance tests of linear response and transmission efficiency. From the standard injection experiments of NO<sub>3</sub>, NO<sub>2</sub>, and H<sub>2</sub>O, high linearities were observed (R<sup>2</sup> ≥0.9918). The total NO<sub>3</sub> transmission efficiency through the system was determined to be 81.2 % (±2.9, 1σ) within the residence time of 2.59 seconds. The precisions (1σ) of NO<sub>3</sub>, NO<sub>2</sub>, and H<sub>2</sub>O in 1 Hz measurement from a single pixel on the CCD were 1.41 pptv, 6.92 ppbv, and 35.0 ppmv with uncertainties of 10.8, 5.2, and ≥20.5 %, respectively, mainly from the errors in literature absorption cross-sections. The instrument was successfully deployed aboard the Korean icebreaker R/V <em>Araon</em> for an expedition conducted in remote marine boundary layer in the Arctic Ocean during the summer of 2021.</p>