Imaging gravity waves in lower stratospheric AMSU-A radiances, Part 2: Validation case study

摘要: Abstract. Two-dimensional radiance maps from Channel 9 (~60–90 hPa) of the Advanced Microwave Sounding Unit (AMSU-A), acquired over southern Scandinavia on 14 January 2003, show plane-wave-like oscillations with a wavelength λh ~400–500 km and peak brightness temperature amplitudes up to 0.9 K. The wave-like pattern is observed in AMSU-A radiances 8 overpasses this region by 4 different satellites, revealing growth disturbance amplitude 00:00 UTC 12:00 change its horizontal structure between 20:00 UTC. Forecast hindcast runs for 2003 using high-resolution global regional numerical weather prediction (NWP) models generate lower stratospheric mountain wave 90 hPa ~5–7 K at similar wavelength, packet width, phase time evolution radiances. wave's vertical ~12 km. These NWP fields are validated against radiosonde wind profiles airborne lidar aerosol backscatter ratios NASA DC-8 during second SAGE III Ozone Loss Validation Experiment (SOLVE II). Both various agree well localized perturbation features these suborbital measurements. In particular, we that formed type II polar clouds measured lidar. To compare directly data, convert into swath-scanned temperatures three-dimensional weighting functions actual scan patterns each region. NWP-based contain two-dimensional due resolved have an amplitude, closely match those data. comparisons not only verify gravity detection imaging capabilities 9, but provide absolute validation anticipated signals given wave, based modeling Eckermann Wu (2006).