Passive ground-based remote sensing of radiation fog
Passive ground-based remote sensing of radiation fog
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DOI：
10.5194/amt-15-5095-2022
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发表时间：
2022-09
影响因子：
3.8
通讯作者：
H. Guy;D. Turner;V. Walden;I. Brooks;Ryan Reynolds Neely
中科院分区：
文献类型：
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作者：
H. Guy;D. Turner;V. Walden;I. Brooks;Ryan Reynolds Neely
抽象的。准确的边界层温度和湿度廓线是成功预报雾的关键，而准确的液态水路径反演对于理解雾的气候学意义非常重要。无源地面遥感系统，如微波辐射计和红外光谱仪，如测量光谱分辨红外辐射（3.3至19.2微米）的大气发射辐射干涉仪，可以检索热力学廓线和液态水路径，这两种仪器都能够长期无人操作，并有可能支持业务预报。在这里，我们比较物理反演边界层热力学廓线和液态水路径在12例薄（LWP<40 g m−2）过冷辐射雾从MWR和AERI并置在格陵兰岛中部。我们比较这两套检索现场测量无线电探空仪和基于表面的温度和湿度传感器。基于AERI观测的反演准确地捕获了浅地表温度反演（0-10 m a.g.l.）的直减率高达-1.2 C m-1，而从MWR观测单独检索的地面温度逆温的强度与现场测量无关，突出了用准确的地面气象数据约束MWR热力学廓线检索的重要性。基于AERI观测的反演探测雾的发生我们认为，由于AERI仪器对近地表温度的高灵敏度和液态水路径的小变化，（或等效的红外光谱仪）可以是用于改进雾监测和临近预报的有用仪器，特别是对于在其他晴朗天空下的薄辐射雾的情况，这会对地表产生重要的辐射影响。
Abstract. Accurate boundary layer temperature and humidity profiles are crucial for successful forecasting of fog, and accurate retrievals of liquid water path are important for understanding the climatological significance of fog. Passive ground-based remote sensing systems such as microwave radiometers (MWRs) and infrared spectrometers like the Atmospheric Emitted Radiance Interferometer (AERI), which measures spectrally resolved infrared radiation (3.3 to 19.2 µm), can retrieve both thermodynamic profiles and liquid water path. Both instruments are capable of long-term unattended operation and have the potential to support operational forecasting. Here we compare physical retrievals of boundary layer thermodynamic profiles and liquid water path during 12 cases of thin (LWP<40 g m−2) supercooled radiation fog from an MWR and an AERI collocated in central Greenland. We compare both sets of retrievals to in-situ measurements from radiosondes and surface-based temperature and humidity sensors. The retrievals based on AERI observations accurately capture shallow surface-based temperature inversions (0–10 m a.g.l.) with lapse rates of up to −1.2 ∘C m−1, whereas the strength of the surface-based temperature inversions retrieved from MWR observations alone are uncorrelated with in-situ measurements, highlighting the importance of constraining MWR thermodynamic profile retrievals with accurate surface meteorological data. The retrievals based on AERI observations detect fog onset (defined by a threshold in liquid water path) earlier than those based on MWR observations by 25 to 185 min. We propose that, due to the high sensitivity of the AERI instrument to near-surface temperature and small changes in liquid water path, the AERI (or an equivalent infrared spectrometer) could be a useful instrument for improving fog monitoring and nowcasting, particularly for cases of thin radiation fog under otherwise clear skies, which can have important radiative impacts at the surface.