1.) Introduction

Importance of shallow cumulus (grand challenges), advent of cloud-resolving global models  \cite{Heinze_2017}, summarize Katzwinkel and Jonker paper, what is possible with ground-based Doppler lidar? can we obtain any additional (=new) information?

2.) Data and Methodology

Dessribe ARM data streams, location and time spans of data analyisis - Doppler lidar (DL) level1 and level 2 products, ARSCL, LWP from microwave radiometer. Selection of days with shallow cumulus cases, cloud bases height analysis with DL, detection of cloud lateral boundaries, detection of cloud top. Sub-selection of single-layer clouds (minimum distance, maximum depth, maximum clouds base height,..), calculation of cloud length and distance to cloud rim by means of closest-to-cloud-base horizontal wind speed (nearest neighbor?) 
I suggest we add 4 plots, then we have a maximum of 4000 words for the text.