AMTD Atmospheric Measurement Techniques Discussions AMTD Atmos. Meas. Tech. Discuss. 1867-8610 Göttingen, Germany 10.5194/amt-2016-162 Identification of the cloud base height over the central Himalayan region: Intercomparison of Ceilometer and Doppler Lidar Shukla K. K. 1 2 Niranjan Kumar K. 3 Phanikumar D. V. 1 Newsom R. K. 4 Kotamarthi V. R. https://orcid.org/0000-0002-2612-7590 5 Ouarda T. B. M. J. 3 6 Ratnam M. V. 7 Aryabhatta Research Institute of observational sciences, Nainital, India Pt. Ravishankar Shukla University, Raipur, Chhattisgarh, India Institute Center for Water and Environment, Masdar Institute of Science and Technology, Abu Dhabi, United Arab Emirates Pacific Northwest National Laboratory, Richland, Washington, USA Argonne National Laboratory, Argonne, Illinois, USA INRS-ETE, Quebec City (Qc), Canada National Atmospheric Research Laboratory, Gadanki, Tirupati, India 13 07 2016 2016 1 26 Copyright: © 2016 K. K. Shukla et al. 2016 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://amt.copernicus.org/preprints/amt-2016-162/ The full text article is available as a PDF file from https://amt.copernicus.org/preprints/amt-2016-162/amt-2016-162.pdf

We present the measurement of cloud base height (CBH) derived from the Doppler Lidar (DL), Ceilometer (CM) and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite over a high altitude station in the central Himalayan region for the first time. We analyzed six cases of cloud overpass during the daytime convection period by using the cloud images captured by total sky imager. The occurrence of thick clouds (> 50 %) over the site is more frequent than thin clouds (< 40 %). In every case, the CBH indicates less than 1.2 km, above ground level (AGL) observed by both DL and CM instruments. The presence of low level clouds in the height-time variation of signal to noise ratio of DL and backscatter of CM shows a similar diurnal pattern on all days. Cloud fraction is found to be maximum during the convective period. The CBH estimated by the DL and CM showed reasonably good correlation (R<sup>2</sup> = 0.76). The DL observed updraft fraction and cloud base vertical velocity also shows good correlation (R<sup>2</sup> = 0.66). The inter-comparison between DL and CM will have implications in filling the gap of CBH measurements by the DL, in absence of CM. More deployments of such instruments will be invaluable for the validations of meteorological models over the observationally sparse Indian regions.