Conference Agenda

A3-ID32296: LIDAR Studies and Validation
Wednesday, 28/Jun/2017:
2:00pm - 3:30pm

Location: Room 101

Oral presentation

Long-Range Dust Transport And Validation Using Ground-Based And Satellite Lidar Observations:Field Campaigns

Songhua Wu1, Dietrich Althausen2, Xiaoquan Song1, Guangyao Dai1,2, Xiaochun Zhai1

1Ocean University of China (OUC), Qingdao, China; 2Leibniz Institute for Tropospheric Research (TROPOS), Leipzig, Germany

The atmospheric particles have a remarkable impact on the global environment and climate change. The long-range transport of dust is an important part of the global biogeochemical cycles. It is significant and urgent to investigate dust on its optical properties, long-range transport, aging, and deposition. ESA decided to implement the Atmospheric Dynamics Mission ADM-Aeolus and the Earth Clouds, Aerosol and Radiation Explorer (EarthCARE) to provide global profiles of wind, clouds, aerosols, and properties together with derived radiative fluxes and heating rates. ADM-Aeolus will carry the first wind lidar in space and launch is currently scheduled for the end of 2017. EarthCARE will carry cloud profiling radar, HSRL (High Spectral Resolution Lidar) and multispectral imager and is scheduled for launch in 2018. The research goals of TROPOS are investigations to aerosol type characterizations and the impact of aerosols on clouds and their properties. For this purpose, TROPOS developed several multiwavelengths and polarization Raman lidar systems (about 10 PollyXTs, MARTHA and BERTHA) and is using these systems at different continents. The recent and ongoing campaigns are the Central Asian Dust Experiment (CADEX), the Widefield Sky Scatterer Tomography by Lidar Anchor together with Technion Haifa, the Atlantic atmospheric observation experiment (OCEANET), and the Cyprus Clouds and Aerosol and precipitation experiment (CyCARE). Ground-based WACAL (WAter vapor, Cloud and Aerosol Lidar) was developed by the lidar group at OUC (Ocean University of China) and deployed during several field campaigns, including the third Tibetan Plateau Experiment of Atmospheric Sciences (TIPEX III) in Naqu (31.5°N, 92.05°E) with a mean elevation of more than 4500 m above MSL in summer of 2014. HSRL and CDL (Coherent Doppler Wind Lidar) developed by OUC were also deployed in several field campaigns in the coastal zone and China Seas. Lanzhou University (LZU) established a Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL) and conducted lidar observations of dust aerosol physical optical characteristics near the resource area in the northwest of China. In order to investigate the characterization of atmospheric bioaerosols along transported pathways of dust aerosols, a multi-channel lidar spectrometer system was developed to observe Mie, Raman scattering and laser-induced fluorescence excitation at 355 nm from the atmosphere. Long-range transport of Asian dust from the Taklimakan and Gobi deserts was studied based on CALIPSO lidar measurements. German Aerospace Center's (Deutsches Zentrum für Luft- und Raumfahrt; DLR) Institute of Atmospheric Physicsa (IPA) is a member of ESA´s ADM-Aeolus Mission Advisory Group, Head of ESA funded pre-launch campaign study and contributor to algorithm and processor studies for Aeolus data products. DLR-IPA conducted several flights in the Mediterranean area which aimed at aerosol (incl. Saharan dust) detection using the ALADIN Airborne Demonstrator (A2D).

The first project objective is the comprehensive observations of vertical profiles of optical properties, flux and the deposition of dust during the long-range transport over continents of Europe and Asia. Based on the ground-based PollyXT, WACAL, CDL and HSRL, ADM-Aeolus and EarthCARE satellites, combining back trajectory model from NOAA, it is available to determine the dust source region, the main transport route and the main deposition areas. The second project objective is to validate the ADM-Aeolus and EarthCARE wind, cloud and aerosol data products. Ground-based co-located measurements with PollyXT, BERTHA, WACAL, CDL and HSRL lidars during overpasses of Aeolus and EarthCARE are foreseen in China (Costal cities, China Seas, inland cities, Tibetan Plateau, Taklimakan desert) and in Central Europe. An overview of the field campaigns will be presented in this report together with observation results from the ongoing data analysis.

Oral presentation

Preparation of the Calibration – Validation phase with the Airborne Demonstrator for the ESA ADM – Aeolus Wind-Lidar Mission during the international campaign NAWDEX 2016

Christian Lemmerz, Oliver Lux, Uwe Marksteiner, Stephan Rahm, Oliver Reitebuch, Andreas Schaefler, Fabian Weiler, Benjamin Witschas

DLR, Germany

The spaceborne wind lidar ALADIN shall provide vertical wind profiles
within the ESA Earth Explorer Atmospheric Dynamics Mission (ADM) Aeolus. After
launch end of 2017 such profiles will be available on a global scale for the
first time to improve the quality of numerical weather prediction (NWP). The ALADIN
Airborne Demonstrator (A2D) was developed at DLR (German Aerospace Center)
focusing on a high degree of commonality in terms of laser source and Doppler
lidar receiver design. With these features operating at the same ultraviolet
wavelength of 355 nm as the satellite, it is the key instrument for the
planned calibration and validation activities. Since 2005, A2D has been
deployed in a series of ground and airborne campaigns to support the Aeolus
mission by validating retrieval algorithms, the instrument concept and
operation procedures. In September and October 2016, the international airborne
campaign NAWDEX (North Atlantic Waveguide and Downstream Impact Experiment)
based in Iceland was the framework to significantly extend the wind data-set
from A2D and the coherent 2-µm wind lidar, both on-board the DLR Falcon
research aircraft. While the Falcon mainly focused on jet-stream intersections
and calibration-validation procedures, other aircraft and ground stations
delivered a comprehensive suite of additional measurements to complement the
meteorological picture. For the first time flights with this payload of the
Falcon were performed in coordination with the German HALO deploying an aerosol
lidar, cloud radar and dropsondes as well as the French Falcon with on-board
cloud radar and UV aerosol Doppler lidar. Subsequent to the NAWDEX campaign additional
flights were conducted in the Mediterranean area which aimed at aerosol (incl. Saharan
dust) detection using the A2D. An overview of the field experiments will be
presented together with first results from the ongoing data analysis.

Oral presentation

Preparation of Cal/Val of Spaceborne Aerosol and Carbon dioxide Detection Lidar (ACDL) by Ground-based and Airborne sounding Instruments Observations

Jiqiao Liu1, Xiuhua Ma1, Shiguang Li1, Dong Liu2, Songhua Wu3, Xia Hou1, Weibiao Chen1

1Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences; 2Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences; 3Ocean University of China

The spaceborne Aerosol and Carbon dioxide Detection Lidar (ACDL) will measure the global column concentrations of carbon dioxide (CO2) and aerosols profiles. The column concentrations of carbon dioxide are measured by integrated path differential absorption (IPDA) lidar technique. The aerosols and clouds profiles are obtained by high resolution spectrum lidar (HRSL) technique. Both techniques are combined in the ACDL lidar payload. The dedicated atmosphere and environment monitoring satellite will carry the ACDL lidar and is scheduled to launch in about 2020. The spaceborne engineering prototype of the lidar with 1m SiC telescope was developed in 2016. And the single frequency and three wavelength laser with high pulse energy was developed and the environmental vibration testing was carried out. A ground-based double-pulse 1572 nm IPDA lidar is developed for carbon dioxide concentrations measurements. The lidar measured carbon dioxide concentrations continuously by receiving the scattered echo signals from a building about 1300 m away. On the same time the other two instruments of TDLAS (Tunable Diode Laser Absorption Spectroscopy) and in-situ carbon dioxide analyzer measured the carbon dioxide concentrations. The carbon dioxide concentrations bias between IPDA lidar and TDLAS measurement was validated to be less than 2 ppm. An airborne lidar prototype with high altitude platform is being developed to verify the retrieval algorithms of spaceborne ACDL lidar. The lidar will also be implemented to validate the Chinese passive CO2 measurement satellite TanSat in future.