Passive ground-based remote sensing of radiation fog

Abstract. Accurate boundary layer temperature and humidity profiles are crucial for successful forecasting of fog, accurate retrievals liquid water path important understanding the climatological significance fog. Passive ground-based remote sensing systems such as microwave radiometers (MWRs) infrared spectrometers like Atmospheric Emitted Radiance Interferometer (AERI), which measures spectrally resolved radiation (3.3 to 19.2 µm), can retrieve both thermodynamic path. Both instruments capable long-term unattended operation have potential support operational forecasting. Here we compare physical during 12 cases thin (LWP<40 g m−2) supercooled fog from an MWR AERI collocated in central Greenland. We sets in-situ measurements radiosondes surface-based sensors. The based on observations accurately capture shallow inversions (0–10 m a.g.l.) with lapse rates up −1.2 ∘C m−1, whereas strength retrieved alone uncorrelated measurements, highlighting importance constraining profile surface meteorological data. detect onset (defined by a threshold path) earlier than those 25 185 min. propose that, due high sensitivity instrument near-surface small changes path, (or equivalent spectrometer) could be useful improving monitoring nowcasting, particularly under otherwise clear skies, radiative impacts at surface.