IAOOS MICROLIDAR DEVELOPMENT AND FIRST RESULTS OBTAINED DURING 2014 AND 2015 ARCTIC DRIFTS Vincent Mariage 1,3 , Jacques Pelon 1 , F. Blouzon 2 , Stéphane Victori 3 1 LATMOS, UPMC-CNRS, Paris, France 2 DT/INSU, Meudon, France 3 Cimel Electronique, Paris, France ABSTRACT The development of a first ever autonomous aerosol and cloud backscatter lidar system for on-buoy arctic observations has been achieved in 2014, within the French EQUIPEX IAOOS project developed in collaboration with LOCEAN at UPMC. This development is part of a larger set-up designed for integrated ocean-ice- atmosphere observations. First results have been obtained from spring to autumn 2014 after the system was installed at the North Pole at the Barneo Russian camp, and in winter-spring 2015 during the Norwegian campaign N-ICE 2015. The buoys were taking observations as drifting in the high arctic region where very few measurements have been made so far. This project required the design and the conception of an all-new lidar system to fit with the numerous constraints of such a deployment. We describe here the prototype and its performance. First analyzes are presented. 1. INTRODUCTION The arctic region is of main importance in the global climate changes, in particular because consequences of global warming are larger there. A better comprehension of this complex and fragile region goes through the analysis of the still poorly-known ocean-ice-atmosphere interactions. On the atmospheric field it means studies of vertical distribution of aerosols and clouds (type, height and optical/microphysical properties), to allow a better determination of the arctic cloud radiative forcing. To access these data vertically resolved measurements are needed, and more particularly LIDAR measurements in the high arctic region (above 75°N). Only a few campaigns have been previously performed to increase the knowledge of cloudiness arctic. Among them one can quote the SHEBA campaign (October 1997- October 1998) which provided lot of quantitative data and analysis between 75 and 78N [1]. Satellite observations provide the necessary regional and temporal coverage. CALIPSO is giving access to critical information on clouds. Still, the lower layers of the atmosphere may be occulted by upper layers, and the very high arctic regions above 82N are not sampled. The goal of the French EQUIPEX IAOOS project is to bridge this gap by deploying a network of autonomous LIDAR set on drifting buoys, as well as others oceanographic instruments in the high arctic region. LIDAR are planned to be working during at least two years with daily few periods of measurements (up to 4 averaged profiles over 10 minutes). The opto- mechanical design of the LIDAR has been led by performances objectives of daytime molecular range of 5km in clear sky. A first buoy loaded with a simple backscattering LIDAR (i.e. no polarization) has been deployed in mid-April 2014, close to the North Pole. During about 8 months the buoy has drifted toward the north of Svalbard, providing more than 750 profiles as a whole. More recently two systems have been deployed during the first two legs of the N- ICE2015 campaign (www.npolar.no), including polarized emission for one of them. The all-new design of the LIDAR developed within this project will be presented, in parallel with fallouts systems obtained during these drifts. Performances are also compared with simulations, and first results are given. 2. INSTRUMENT DESCRIPTION LIDAR systems are often expensive to develop or to buy and usually require regular maintenance. Consequently a specific attention must be paid to the design for an autonomous deployment. Besides this, autonomy also means that the whole system will have to work on DOI: 10.1051/ 02005 (2016) I 119 , 1190 LRC 27 EPJ Web of Conferences epjconf/2016 2005 © The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/).