Hurricane and Severe Storm Sentinel (HS3) Global Hawk Cloud Physics Lidar (CPL)
Table of Contents
The Hurricane and Severe Storm Sentinel (HS3) Global Hawk Cloud Physics Lidar (CPL) dataset includes measurements gathered by the CPL instrument during the HS3 campaign which took place during the hurricane seasons of 2011 through 2014 in the Atlantic Ocean basin region. The CPL instrument returns information on the radiative and optical properties of cirrus clouds and aerosols at a high temporal and spatial resolution. CPL uses the 355, 532, and 1064 nm channels and has a small field of view, which eliminates multiple scattering; it offers 30 m vertical resolution and 200 m horizontal resolution. The CPL instrument measures the total (aerosol plus Rayleigh) attenuated backscatter as a function of altitude at each wavelength. Data is available in netCDF/CF and HDF5 formats, covering the Hurricane seasons of 2012 - 2014.Citation
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The Hurricane and Severe Storm Sentinel (HS3) was a five-year NASA mission specifically targeted to investigate the processes that underlie hurricane formation and intensity change in the Atlantic Ocean basin. Goals for HS3 included: assessing the relative roles of large-scale environment and storm-scale internal processes; and addressing the controversial role of the Saharan Air Layer (SAL) in tropical storm formation and intensification as well as the role of deep convection in the inner-core region of storms. To achieve these goals, sustained measurements over several years was needed to get a large enough sample of storms. Therefore, field measurements took place from 2012 through 2014 for one month during each hurricane season. The HS3 campaign utilized two Global Hawks, one with instruments geared toward measurement of the environment and the other with instruments suited to inner-core structure and processes. The environmental payload included the scanning High-resolution Interferometer Sounder (S-HIS) and the AVAPS dropsonde system; the over-storm payload included the HIWRAP conically scanning Doppler radar, the HIRAD multi-frequency interferometric radiometer, and the HAMSR microwave sounder. More information about the HS3 campaign can be found here http://hs3.nsstc.nasa.gov/.Instrument Description
The Cloud Physics Lidar (CPL) instrument is a multi-wavelength backscatter lidar which provides multi-wavelength measurements of cirrus and aerosols with high temporal and spatial resolution; it was originally designed to fly on the NASA ER-2 aircraft, and it was first deployed in 2000 for the Southern African Regional Science Initiative (SAFARI) campaign in southern Africa. A duplicate CPL was constructed for the NASA Global Hawk UAV; this CPL was used for the HS3 campaign. The CPL operates simultaneously at three wavelengths (355, 532, and 1064 nm) and has a small field of view, which eliminates multiple scattering; it offers 30 m vertical resolution and 200 m horizontal resolution. The CPL instrument measures the total (aerosol plus Rayleigh) attenuated backscatter as a function of altitude at each wavelength.
CPL utilizes a high repetition rate, low pulse energy transmitter and photon-counting detectors. It is designed specifically for three-wavelength operation and maximum receiver efficiency. An off-axis parabola is used for the telescope, allowing 100% of the laser energy to reach the atmosphere. CPL measures the total (aerosol plus Rayleigh) attenuated backscatter as a function of altitude at each wavelength. For transmissive cloud/aerosol layers, using optical depth measurements determined from attenuation of Rayleigh and aerosol scattering, and using the integrated backscatter, the extinction-to-backscatter parameter (S-ratio) can be directly derived. This permits unambiguous analysis of cloud optical depth since only the lidar data is required. Using the derived extinction-to-backscatter ratio, the internal cloud extinction profile can then be obtained. This approach to directly solving the lidar equation without assumption of aerosol climatology is a standard analysis approach for backscatter lidar (McGill et al 2003).Investigators
The Hurricane and Severe Storm Sentinel (HS3) Global Hawk Cloud Physics Lidar (CPL) data files are named with the following convention:
CPL browse images are named with the following convention:
CPL data files are available in both netCDF/CF and HDF5 formats. The CPL instrument measures the total (aerosol plus Rayleigh) attenuated backscatter as a function of altitude at each wavelength. More information about data format is available in the PI's documentation files . Read software is also available for the HDF CPL data files as IDL programs: read_atb_hdf5.pro and read_op_hdf5.pro. The netCDF files can be read using any programing language that supports the netCDF library.
McGill, M.J., D.L. Hlavka, W.D. Hart, E.J. Welton, and J.R. Campbell, "Airborne lidar measurements of aerosol optical properties during SAFARI-2000", J. Geophys. Res., 108, doi: 10.1029/2002JD002370, 2003.
Yorks, J. E., M. McGill, D. Hlavka and W. Hart (2011), Statistics of Cloud Optical Properties from Airborne Lidar Measurements, J. Atmos. Oceanic Technol., 28, 869-883, doi:10.1175/2011JTECHA1507.1.
Yorks, J. E., D. L. Hlavka, M. A. Vaughan, M. J. McGill, W. D. Hart, S. Rodier, and R. Kuehn (2011), Airborne validation of cirrus cloud properties derived from CALIPSO lidar measurements: Spatial properties, J. Geophys. Res., 116, D19207, doi:10.1029/2011JD015942.
Hlavka, D. L., J. E. Yorks, S. Young, M. A. Vaughan, R. Kuehn, M. J. McGill, and S. Rodier (2012), Airborne validation of cirrus cloud properties derived from CALIPSO lidar measurements: Optical properties, submitted to J. Geophys. Res.Contact Information
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