General comments:

This paper introduces the interesting method to transfer the observed cloud and aerosol parameters at the collocated observation of lidar and imager to the imager-only observation pixels developed by using the model simulation results for the EarthCARE satellite mission. I recommend the publication of this manuscript after the revision of the following two points.

1. The transfer method of cloud top height difference uses five criteria, but the influences of the five criteria on the results are not clear. The quality status in Figure 5 is not enough clear to understand it. Please show the figures of cloud type, cloud phase, surface type, brightness temperature, and reflectance.
2. The transfer method of aerosol parameters is only demonstrated in the marine aerosol case. This is an ideal situation. Please show the result when several types of aerosols exist or discuss about the scope of application of this method.

Specific comments:

Figure 2: It is not clear to me to understand which product is input to the processing of “scene classification” and “check for multi-layer cloud”. The solid arrows in figure are overlapped.

Line 196: Does “same value” mean same cloud phase and surface type?

Line 244: Is ice included in the aerosol classification? However, ice means cirrus in the sentence. Please add an appropriate explanation.  

Lines 304-310: It is difficult to understand the aerosol and cloud distributions. Please add the figures of simulation true results of Halifax scenes or refer to the figure number in Donovan et al. 2023a.

Line 317: Does this sentence only focus on the cloud at 2-3 km altitude at 55^oN? Half of CTH differences are lower than 1 km, while the other half are about 2 km between 55^oN and 60^oN. A more detailed discussion is needed.

Figure 5: This quality status means the summarized information of five criteria. The influence of the five criteria is not clear. In addition, the differences of results between day and night are not discussed. See also general comment 1.

Line 387: Is the cloud class in Figure 9 determined by using an extinction threshold of 20Mm^-1, pressure, and temperature?

Figure 11: Is the true AOT shown regardless of clouds? How about true AOT at 670 and 875 nm? Is the wavelength dependency of marine AOT small?

Line 422: The overestimation of AOT is about 0.05. It is possible to detect thin cirrus. Please show the figure of attenuated backscatter and discuss this issue.

Figure 12: Why are the patterns of AOT and quality status different? Is AOT at 355 nm estimated in the region which the values of quality status are -1 and 4?

Line 449: Do you plan to examine the other cases. See general comment 2.

Line 450: Which AOT product is validated?

Minor comments:

Line 38: clouds and aerosol layers --> cloud and aerosol layers

Line 158: after the complete ATLID L2a … --> after the ATLID L2a …

Line 193-194: The phrases of criteria 4 and 5 are different from those of criteria 1, 2, and 3. Please rephrase them. For example, the phrase of criterion 4 is written as “Satisfaction of the criterion of the brightness temperature (10.8 mm) difference threshold (Equation 1).”

Line 435: Ångström exponent usually has positive value. Does Ångström exponent in the sentence include minus sign of a negative power?