A recent laboratory study suggests that water vapor displays structured absorption features over the 290–350 nm region, with maximum and minimum cross‐sections of 8.4 × 10⁻²⁵ and 1.4 × 10⁻²⁵ cm²/molecule at room temperature (Pei et al. 2019, https://doi.org/10.1029/2019jd030724; Du et al., 2013, https://doi.org/10.1002/grl.50935). To observe water vapor absorption features in the ultraviolet (UV) region in the atmosphere, a United States Department of Agriculture reference spectroradiometer was upgraded with a new fore‐optical module, enabling it to measure direct solar beam and sky radiance at given azimuth and elevation angles. This double Czerny‐Turner spectroradiometer enables wavelength scanning from 290 to 410 nm, with a nominal bandwidth of 0.1 nm. It can operate with a step‐size of 0.0005 nm and a full width at half maximum of 0.1 nm. It has an out‐of‐band rejection ratio of approximately 10⁻¹⁰. This high resolution spectroradiometer can be used as a reference instrument for UV radiation measurements and for monitoring atmospheric gases such as O₃, SO₂, and NO₂. A series of field observations were made using this spectroradiometer in the University at Albany campus. A residual analysis method is developed to analyze absorption by atmospheric components and to retrieve atmospheric optical depth. The residual optical depth was calculated by subtracting the optical depths of Rayleigh scattering, aerosol extinction, and absorption of typical atmospheric gases such as O₃, SO₂, and NO₂ from the retrieved total optical depth. Multiple case studies show that residual optical depth from the observed UV spectra is sensitive to the atmospheric water vapor amount. The greater the water vapor path, the larger the magnitude of residual optical depth. The ozone amount was inferred from the residual analysis; it is comparable to the satellite measurements. For example, in a case with water vapor path of 13 mm on October 24, 2019, the inferred ozone amount from residual analysis is 2.7% lower than retrievals from the Ozone Monitoring Instrument‐Total Ozone Mapping Spectrometer.

中文翻译：

---

高分辨率紫外光谱仪及其在太阳辐射测量中的应用

最近的一项实验室研究表明，水蒸气在290-350 nm范围内显示出结构化的吸收特征，最大和最小横截面分别为8.4×10 ^-25和1.4×10 ^-25  cm ²/分子在室温下（Pei等人2019，https://doi.org/10.1029/2019jd030724; Du等人，2013，https://doi.org/10.1002/grl.50935）。为了观察大气中紫外线（UV）区域的水蒸气吸收特征，美国农业部参考光谱辐射仪进行了升级，增加了新的前光学模块，使其能够在给定的方位角和仰角下测量直接的太阳光束和天空的辐射角度。这款双Czerny-Turner光谱辐射仪可进行290至410 nm的波长扫描，标称带宽为0.1 nm。它的步长为0.0005 nm，半峰全宽为0.1 nm。其带外抑制比约为10 ^-10。这种高分辨率的光谱辐射仪可用作紫外线辐射测量和监测O ₃，SO ₂和NO ₂等大气气体的参考仪器。使用该分光辐射计在奥尔巴尼大学的大学进行了一系列现场观察。开发了一种残差分析方法来分析大气成分的吸收并检索大气的光学深度。剩余光学深度是通过减去瑞利散射，气溶胶消光和典型大气气体（例如O ₃，SO ₂和NO _2）的吸收的光学深度来计算的从检索到的总光学深度开始。多个案例研究表明，从观察到的紫外线光谱中获得的剩余光学深度对大气中的水蒸气量敏感。水蒸气路径越大，剩余光学深度的大小越大。从残留分析中推断出臭氧量；它可与卫星测量结果相提并论。例如，在2019年10月24日的水蒸气路径为13毫米的情况下，从残留分析推断出的臭氧量比从臭氧监测仪器总臭氧测图仪获得的臭氧量低2.7％。