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. Following the release of the version 4 Cloud-Aerosol Lidar with OrthogonalPolarization (CALIOP) data products from Cloud-Aerosol Lidar and InfraredPathfinder Satellite Observations (CALIPSO) mission, a new version 4 (V4) ofthe CALIPSO Imaging Infrared Radiometer (IIR) Level 2 data products has beendeveloped. The IIR Level 2 data products include cloud effectiveemissivities and cloud microphysical properties such as effective diameter( De ) and water path estimates for ice and liquid clouds. This paper(Part II) shows retrievals over ocean and describes the improvements madewith respect to version 3 (V3) as a result of the significant changesimplemented in the V4 algorithms, which are presented in a companion paper(Part I). The analysis of the three-channel IIR observations (08.65,10.6, and 12.05  µ m) is informed by the scene classificationprovided in the V4 CALIOP 5 km cloud layer and aerosol layer products.Thanks to the reduction of inter-channel effective emissivity biases insemi-transparent (ST) clouds when the oceanic background radiance is derivedfrom model computations, the number of unbiased emissivity retrievals isincreased by a factor of 3 in V4. In V3, these biases caused inconsistenciesbetween the effective diameters retrieved from the 12 / 10 ( β eff 12 / 10 = τ a , 12 / τ a , 10 )and 12 / 08 ( β eff 12 / 08 = τ a , 12 / τ a , 08 )pairs ofchannels at emissivities smaller than 0.5. In V4, microphysical retrievalsin ST ice clouds are possible in more than 80 % of the pixels down toeffective emissivities of 0.05 (or visible optical depth ∼0.1 ). For the month of January 2008, which was chosen to illustrate the results, medianice De and ice water path (IWP) are, respectively, 38  µ mand 3 g m −2 in ST clouds, with random uncertainty estimates of 50 %.The relationship between the V4 IIR 12 / 10 and 12 / 08 microphysicalindices is in better agreement with the “severely roughened single column”ice habit model than with the “severely roughened eight-element aggregate”model for 80 % of the pixels in the coldest clouds (  K) and60 % in the warmest clouds ( >230  K). Retrievals in opaque iceclouds are improved in V4, especially at night and for 12 / 10 pair ofchannels, due to corrections of the V3 radiative temperature estimatesderived from CALIOP geometric altitudes. Median ice De and IWP are58  µ m and 97 g m −2 at night in opaque clouds, with againrandom uncertainty estimates of 50 %. Comparisons of ice retrievals withModerate Resolution Imaging Spectroradiometer (MODIS)/Aqua in the tropicsshow a better agreement of IIR De with MODIS visible–3.7  µ m thanwith MODIS visible–2.1  µ m in the coldest ST clouds and the oppositefor opaque clouds. In prevailingly supercooled liquid water clouds withcentroid altitudes above 4 km, retrieved median De and liquid waterpath are 13  µ m and 3.4 g m −2 in ST clouds, with estimated randomuncertainties of 45 % and 35 %, respectively. In opaque liquid clouds,these values are 18  µ m and 31 g m −2 at night, with estimateduncertainties of 50 %. IIR De in opaque liquid clouds is smallerthan MODIS visible–2.1  µ m and visible–3.7  µ m by 8 and 3  µ m,respectively.

Version 4 CALIPSO Imaging Infrared Radiometer ice and liquid water cloud microphysical properties – Part II: Results over oceans