Interactive comment on “ Ceilometer aerosol profiling vs . Raman lidar in the frame of INTERACT campaign of ACTRIS ” by F

Several types of ceilometers are widely distributed over the globe and have the potential to be used for quantitative studies of atmospheric aerosol properties. In this paper, the capabilities of three common ceilometer types are investigated by comparing their aerosol profiles to the ones of an advanced Raman lidar system during the inter-comparison campaign INTERACT conducted at CNR-IMAA Atmospheric Observatory in Potenza, Italy. This campaign lasted for about 6 month so that a sufficient number of observations appear to be available for this study.

Several types of ceilometers are widely distributed over the globe and have the potential to be used for quantitative studies of atmospheric aerosol properties.In this paper, the capabilities of three common ceilometer types are investigated by comparing their aerosol profiles to the ones of an advanced Raman lidar system during the inter-comparison campaign INTERACT conducted at CNR-IMAA Atmospheric Observatory in Potenza, Italy.This campaign lasted for about 6 month so that a sufficient number of observations appear to be available for this study.
The paper concludes, besides an overall agreement of each ceilometer and the lidar in aerosol properties, that there are discrepancies: 1) in the temperature stability of the ceilometers, 2) the water vapour interference for two of the instruments, 3) the stability of the overlap function in one case, and 4) they found that the difference in backscatter coefficient between the lidar and the ceilometers is proportional to the value of the retrieved backscatter coefficient.
However, these conclusions drawn are of more describing nature, than numbers and error bars.p.12415, l.17: normalisation constant -normalization factor may be more appropriate in this case.
► This is now fixed.p12416, l.21: How is the calibration factor automatically selected by the ceilometer?I guess you mean the amplification of the detectors sensitivity for adjustment of the signal to the atmospheric conditions.

To avoid any misinterpretation of the section, the authors have decided to limit the section to discuss two examples that show the differences between MUSA and the ceilometers as well as the instability in the region of incomplete overlap. To the authors opinion, these examples can still give a clear idea of the instability occurring in the region of incomplete overlap, though a statistical assessment of this instability is postponed to an expected follow-up paper also mentioned in the conclusions.
The authors think that in this way the section will be more in line with the reviewer's expectations opening the way to future and deeper studies on the topic.Finally the authors did their best to improve the quality of the axis labels on all the figure of the manuscript, in agreement also with the comments of the reviewer #1.

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Interactive comment on "Ceilometer aerosol profiling vs. Raman lidar in the frame of INTERACT campaign of ACTRIS" by F. Madonna et al.Anonymous Referee #2 Received and published: 30 January 2015 The authors of the manuscript "Ceilometer aerosol profiling vs. Raman lidar in the frame of INTERACT campaign of ACTRIS" by F. Madonna et al. would like to thank the anonymous reviewer #1 for his/herdetailed review and its effort to improve the quality of the text and of the content of the manuscript in general.In the following, the authors provide an answer to all the reviewer's comments.
, l.22: backscatter coefficients, see comment above.►Corrected.p. 12428-29: the advantage of the use of particle extinction at 355 nm instead of beta is not clear, see alsoFig 11.
MUSA and the attenuated backscatter ß' obtained at 1064 nm by MUSA and by the three ceilometers, respectively, have been compared (Figure 11) to further investigate the ceilometers' performance and their sensitivity to different aerosol types, i.e. different extinction coefficients." Actually, also the outcome of the comparison reveals how the performances of the ceilometer might be influenced by the observation of different aerosol optical depths typically of the South Italy in summer or by temperature interferences and/or the insufficient dynamic ranges of the systems.

Fig. 1
Fig. 1 is not used in the text.► Now, Fig.1 is mentioned in the manuscript.

Fig. 2 :
Fig. 2: The colours in the left panel seem to be mixed-up.► This is fixed in the new version of the manuscript.

Fig. 5 :
Fig. 5: The legend outside the figure (TITO) is not necessary, since its only one data series, IWP, shown here.► The legend outside the figure (TITO) has been removed.

Fig. 9 :
Fig. 9: Would an overlap correction really account for the discrepancies in the lower altitudes for the CHM15k?Backscatter coefficient ► See previous comments about the section of the manuscript dealing with the overlap.

► Vaisala, also following the comments of the reviewer #1. p
.12411, l.18:The "idiosyncrasies of cloud base detection" is not studied in this paper.