Bromine chemistry plays an important role in tropospheric ozone depletion events in polar regions. Autocatalytic reactions lead to bromine explosion events, causing ozone depletion to near-zero levels in the polar troposphere. Bromine chemistry over Antarctica is not fully understood, and ground-based observations are scarce. This work presents year-long observations of bromine oxide (BrO) over the Bharati station (69.41°S, 76.19°E) using Multi-axis Differential Optical Absorption Spectroscopy (MAX-DOAS) from December 2018 to February 2020. The results show that elevated BrO mixing ratios were found during spring (September), with a maximum value of 10.21 ± 4.38 pptv for clear sky conditions and 33.15 ± 2.23 pptv for cloudy conditions. BrO was not observed above the detection limit (∼3 × 10¹³ molecule cm⁻²) outside spring on clear days. In general, lower mixing ratios were observed on clear days over Bharati compared to stations in West Antarctica. This indicates a different source strength over East Antarctica compared to West Antarctica. BrO vertical column densities were high during spring, with a maximum value of 1.34 ± 0.35 × 10¹⁴ molecule cm⁻². The vertical profiles of the BrO mixing ratios show a peak at the surface during spring (average of 6.5 ± 1.91 pptv), decreasing sharply with altitude. Back trajectories show that air masses passing over the first year ice showed higher BrO, although factors such as meteorology play an important role in determining the absolute levels. Using a box model, we show that bromine chemistry can deplete as much as 2.15 ppb of ozone in a day at the Bharati Station on clear days, which shows that it does not lead to complete ozone depletion events over Bharati.

溴化学在极地地区对流层臭氧消耗事件中发挥着重要作用。自催化反应导致溴爆炸事件，导致极地对流层中的臭氧消耗接近于零水平。南极洲上空的溴化学尚未完全了解，地面观测也很少。这项工作展示了 2018 年 12 月至 2020 年 2 月期间使用多轴差分光学吸收光谱 (MAX-DOAS) 对巴拉蒂站（69.41°S，76.19°E）上空的氧化溴（BrO）进行的长达一年的观测。结果表明春季（9 月）发现 BrO 混合比升高，晴空条件下的最大值为 10.21 ± 4.38 pptv，多云条件下的最大值为 33.15 ± 2.23 pptv。在春季以外晴朗的日子里，未观察到 BrO 高于检测限（∼3 × 10¹³分子 cm^-2一般来说，与南极洲西部的观测站相比，在晴朗的日子里，巴拉蒂上空观测到的混合比较低。这表明与西南极洲相比，东南极洲的源强度不同。春季BrO垂直柱密度较高，最大值为1.34±0.35×10¹⁴分子cm^-2。BrO 混合比的垂直剖面显示春季期间地表出现峰值（平均值为 6.5 ± 1.91 pptv），随着海拔的升高而急剧下降。回溯轨迹显示，经过第一年冰层的气团显示出较高的 BrO，尽管气象等因素在确定绝对水平方面发挥着重要作用。使用盒模型，我们表明在晴朗的日子里，溴化学物质在巴拉蒂站一天内可以消耗多达 2.15 ppb 的臭氧，这表明它不会导致巴拉蒂上空的臭氧完全消耗事件。