Ground-based remote sensing of cloud particle sizes during the 26 November 1991 FIRE II cirrus case: comparisons with in situ data

The paper presents the results of retrieving characteristic particle sizes for the November 26 1991 FIRE II case using two methods that utilize ground-based remote sensors. The size information for the complete vertical depth of the cloud was obtained using combined Doppler radar and IR radiometer measurements and for two shorter periods using radar reflectivity and CO₂ lidar backscatter measurements. The results obtained with both remote sensing techniques are compared for these two periods. Possible retrieval uncertainties are discussed. Particle sizes retrieved by both methods were compared with 2D particle probe data sampled during 10 time intervals when a research aircraft was crossing the hub area.