The research goal of this project is to advance the capabilities of the University of Wyoming (UW) King Air research aircraft for cloud, aerosol, and water vapor observations through the development of two new airborne lidar systems. The instrument development is coupled with development of some retrieval algorithms that combine multiple remote sensor measurements and others that combine remotely sensed and in situ measurements. Project objectives are to develop:
1) a compact airborne elastic lidar to be used onboard the UW King Air alongside the Wyoming cloud radar, a 183 GHz radiometer, and in situ cloud and precipitation probes for studying cloud processes and properties;
2) retrieval algorithms to provide cloud microphysical properties in ice-, mixed-phase, and warm clouds including: ice water content, ice particle effective radius, liquid water path, water droplet effective radius, and drizzle size;
3) a compact airborne Raman lidar system and associated data processing/analysis software to measure aerosol backscattering and extinction coefficients and to derive water vapor mixing ratio profiles in the boundary layer;
and to conduct
4) exploratory experiments to test and refine the two lidars plus the microwave radiometer, and to collect data for algorithm development and validation;
5) studies of the evolution of mid-level, mixed-phase clouds using these new observational capabilities.
The main intellectual merit of this project is development of an advanced airborne observation instrumentation suite and associated data processing algorithms that will be capable of providing better observations to study the aerosol direct and indirect effects, cloud microphysical processes, and land-atmosphere and air-sea interactions.
Broader impacts of this work include:
1) Enhancing the capabilities of the UW King Air research aircraft as a combined in situ/ remote sensing platform. Following the development and demonstration of these capabilities, they will become available to the atmospheric research community as part of the UW King Air national facility (A NSF-supported, lower-atmosphere observing facility). 2) Use of the new observational capabilities to help improve our of understanding of clouds, aerosols, and boundary layer processes, which are needed to confidently predict human impacts on climate. 3) Training the next generation of researchers to use observations to address current science questions. 4) Strengthening the atmospheric observation curricula and teaching at UW.
The research goal of this project was to advance the capabilities of UWKA for cloud, aerosol, and water vapor observations through combining multiple remote sensor measurements and in situ measurements. Under this support, we completed and tested three airborne lidar systems. The Wyoming Airborne Integrated Cloud Observation (WAICO) experiment and the Wyoming King Air PBL Exploratory Experiment (KAPEE) were conducted, under NSF Lower Atmospheric Observation Facility (LAOF) deployment funding, to test and demonstrate enhanced the UWKA’s cloud and boundary layer observation capabilities. Three lidar systems: The Wyoming Cloud Lidars (WCL-I and WCL-II) are compact polarization lidars for measurement of vertical profiles of aerosol and cloud backscatter and depolarization ratio. The WCLs are designed to complement the Wyoming Cloud Radar (WCR) to improve measurement of cloud macrophysical and microphysical properties from the UWKA and NSF/NCAR C130. With a 12-inch telescope and a YAG laser (50 mj at 355nm) from the PI’s University start-up funding, we developed a compact Raman lidar for boundary layer aerosol and short-range water vapor measurements. To provide the stability needed for airborne operation, the design integrated the laser, telescope, and receiving optics into one box. This system was successfully tested during KAPEE in June, 2010. An integrated cloud observation platform: The WAICO experiment, conducted during February-March 2008 and 2009 in SE Wyoming, was designed to develop and demonstrate new cloud observation capabilities by integrating remote sensors and in situ probes on the UWKA. We successfully integrated the newly developed WCLs and a G-band water vapor radiometer (GVR) alongside the WCR while maintaining a full complement of in situ probes. Combined use of these remote sensor measurements yields a more complete description of the vertical structure of cloud microphysical properties and cloud scale dynamics. Together with detailed in situ data on aerosols, hydrometeors, water vapor, thermodynamic and air motion parameters, an advanced observational capability was created to study cloud-scale processes from a single aircraft. Attached images show the arrangement of sensors and one observation example. We also collected data for the development and validation of combined WCR-WCL-GVR retrieval algorithms for liquid, ice, and mixed-phase clouds to support comprehensive data analyses. A platform for ABL Observations: The main goal in the development of the compact airborne Raman lidar was to provide an integrated airborne capability for Atmospheric Boundary Layer (ABL) aerosol and water vapor study by combining Raman lidar profiling with in situ sampling. KAPEE was conducted during June 2010 in order to explore these new capabilities. During KAPEE, in situ water vapor measurements were available from both a LI-COR CO2/H2O analyzer and a chilled mirror hygrometer. Comparisons of lidar near-range measurements to in situ sampling indicate reliable Raman lidar water vapor measurements and demonstrate the unique capability of Raman lidar to provide high spatially resolved water vapor structure. One such example, a dry-line case observed during KAPEE, is shown in the attached image. Science achievements: Combining WCR, WCL and in situ data provide better capabilities to study ice generation in mixed phase clouds. ICE-L data showed biological particles can enhance the impact of desert dust storms on the formation of cloud ice. Wave cloud cases during the WAICO showed a strong evidence of temporal dependent of heterogeneous ice generation in wave clouds. The enhanced boundary layer observation capabilities from UWKA open new opportunities to study boundary layer processes and phenomena. For example, we observed strong horizontal gradient of water vapor up to 10 g/kg/km and complex dynamics interaction across the dry line during the KAPEE. A mesoscale convective storm was initialized along the sampled dryline. So far, we have published 9 journal papers and 8 conference papers or presentation. Education and Outreach: Three graduate students and one graduate student participated the project. The WCL was also used as a teaching tool in the UW and the outside. At UW, students can gain first hand experience of lidar system and operation in our lidar lab and from UWKA. Additionally, UWKA with the integrated cloud observation comparability was a part of 2009 NCAR Advanced Study Program summer Colloquium, Exploring the Atmosphere: Observational Instruments and Techniques, to provide student updated knowledge on atmospheric observations. Contributions to resources for research: The successful installation and operation of WCL, GVR and WCR together with in situ probes on the UWKA and on the NSF/NCAR C-130 aircraft provide an important new cloud observation capability. Now this new capability is part of the NSF LAOF and is available to wide research community. The new compact Raman lidar could be an important tool for boundary layer aerosol and water vapor study from the UWKA and the NSF/NCAR C-130 although the water vapor measurement range is limited to ~500m below the aircraft during daytime.
