Recently published Atacama Large Millimeter Array (ALMA) observations suggest the presence of 20 ppb PH₃ in the upper clouds of Venus. This is an unexpected result, as PH₃ does not have a readily apparent source and should be rapidly photochemically destroyed according to our current understanding of Venus atmospheric chemistry. While the reported PH₃ spectral line at 266.94 GHz is nearly colocated with an SO₂ spectral line, the nondetection of stronger SO₂ lines in the wideband ALMA data is used to rule out SO₂ as the origin of the feature. We present a reassessment of wideband and narrowband data sets derived from these ALMA observations. The ALMA observations are re-reduced following both the initial and revised calibration procedures discussed by the authors of the original study. We also investigate the phenomenon of apparent spectral line dilution over varying spatial scales resulting from the ALMA antenna configuration. A 266.94 GHz spectral feature is apparent in the narrowband data using the initial calibration procedures, but this same feature cannot be identified following calibration revisions. The feature is also not reproduced in the wideband data. While the SO₂ spectral line is not observed at 257.54 GHz in the ALMA wideband data, our dilution simulations suggest that SO₂ abundances greater than the previously suggested 10 ppb limit would also not be detected by ALMA. Additional millimeter, submillimeter, and infrared observations of Venus should be undertaken to further investigate the possibility of PH₃ in the Venus atmosphere.

最近发表的阿塔卡马大毫米波阵列（ALMA）观测结果表明，金星上层云中存在20 ppb PH ₃。这是出乎意料的结果，因为根据我们目前对金星大气化学的理解，PH ₃没有明显的来源，应该迅速进行光化学破坏。虽然报告的266.94 GHz的PH ₃谱线几乎与SO ₂谱线并置，但未在宽带ALMA数据中检测到较强的SO ₂谱线以排除SO ₂作为要素的来源。我们提出了对来自这些ALMA观测值的宽带和窄带数据集的重新评估。原始研究作者讨论过的初始和修订校准程序都减少了ALMA观测值。我们还研究了由于ALMA天线配置而在不同空间尺度上出现的明显谱线稀释现象。使用初始校准程序，在窄带数据中可以看到266.94 GHz频谱特征，但是在校准修订后无法识别出相同的特征。该特征也不会在宽带数据中再现。虽然在ALMA宽带数据中未在257.54 GHz处观察到SO ₂谱线，但我们的稀释模拟表明SO ₂ALMA也不会检测到大于先前建议的10 ppb极限的丰度。应进一步进行金星的毫米，亚毫米和红外观测，以进一步调查金星大气中PH ₃的可能性。