Search Results

You are looking at 51 - 60 of 3,974 items for :

  • Lidar observations x
  • All content x
Clear All
David M. Winker, Mark A. Vaughan, Ali Omar, Yongxiang Hu, Kathleen A. Powell, Zhaoyan Liu, William H. Hunt, and Stuart A. Young

our ability to predict future climate change are associated with uncertainties in the distribution and properties of aerosols and clouds and their interactions, as well as with limitations in how aerosols and clouds are represented in global climate models ( Solomon et al. 2007 ). The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission was developed as part of the National Aeronautics and Space Administration (NASA) Earth System Science Pathfinder (ESSP) program in

Full access
Maki Hirakata, Hajime Okamoto, Yuichiro Hagihara, Tadahiro Hayasaka, and Riko Oki

combination of microphysical and macrophysical characteristics determines the radiative characteristics of clouds. Light scattering models indicate that oriented ice crystals can increase cloud albedo by as much as 40% compared to randomly oriented crystals ( Takano and Liou 1989 ). In addition, the proper treatment of the oriented crystals is needed for accurate retrievals of ice microphysics when the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations ( CALIPSO ) and CloudSat are used

Full access
Yongxiang Hu, David Winker, Mark Vaughan, Bing Lin, Ali Omar, Charles Trepte, David Flittner, Ping Yang, Shaima L. Nasiri, Bryan Baum, Robert Holz, Wenbo Sun, Zhaoyan Liu, Zhien Wang, Stuart Young, Knut Stamnes, Jianping Huang, and Ralph Kuehn

there is a simple relationship between layer-integrated depolarization ratio and multiple scatter of layer-integrated backscatter. This relationship agrees reasonably well with ground-based measurements ( Hu et al. 2006 ) and CALIPSO observations ( Hu 2007 ; Hu et al. 2007 ): This relationship is shown as the curved blue line in Fig. 4 . The water cloud observations are clustered close to the theoretical curve in both the left (January 2007; lidar pointing at 0.3° off nadir) and right

Full access
Julien Delanoë, Alain Protat, Olivier Jourdan, Jacques Pelon, Mathieu Papazzoni, Régis Dupuy, Jean-Francois Gayet, and Caroline Jouan

1. Introduction Spaceborne radar and lidar on board CloudSat ( Stephens et al. 2002 ) and the Cloud Aerosol lidar and Infrared Pathfinder Satellite Observations ( CALIPSO ; Winker et al. 2003 ) satellite present us with an amazing opportunity to tackle questions about the influence of clouds in forecasts and climate predictions at global scale ( Waliser et al. 2009 ; Delanoë et al. 2011 ). The combination of spaceborne radar and lidar remains the most accurate technique for documenting

Full access
Richard M. Schotland, Kenneth Sassen, and Richard Stone

OCXO~ER1971 SCHOTLAND, SASSEN AND STONE 1011Observations by Lidar of Linear Depolarization Ratios for Hydrometeors~RICHARD M. SCHOTLAND, I~ENNETIt SASSEN AND RICHARD STONEDept. of Meteorology and Oceanography, New York University, University Heights (Manuscript received 30 March 1971, in revised form 27 May 1971) ABSTRACT Measurements by monostatic lidar have been performed in the

Full access
Maike Ahlgrimm and Martin Köhler

limitations either (as will be discussed in detail), the lidar’s small footprint of 100-m diameter is much more suitable for observing broken cloud cover, as is found in the trade cumulus (TCu) regions. Previous studies ( Chepfer et al. 2008 ; Wilkinson et al. 2008 ) have shown the value of these observations for model assessment but did not take full advantage of the high vertical resolution available from the lidar. Over 10 years ago, Jakob (1999) determined that the Integrated Forecasting System

Full access
Yansen Wang, Cheryl L. Klipp, Dennis M. Garvey, David A. Ligon, Chatt C. Williamson, Sam S. Chang, Rob K. Newsom, and Ronald Calhoun

( Taha 1999 ; Brown 2001 ; Martilli et al. 2002 ; Dupont et al. 2004 ). Observational data are a necessity for further improving urban parameterization schemes. Because of the difficulty of obtaining turbulence and wind observations at higher altitude over urban areas, there are, to our knowledge, no reported lidar observations on the LLJ interaction with the urban environment. The recent development of scanning Doppler lidar technologies enables us to observe this type of flow and its interaction

Full access
Kathleen A. Powell, Chris A. Hostetler, Mark A. Vaughan, Kam-Pui Lee, Charles R. Trepte, Raymond R. Rogers, David M. Winker, Zhaoyan Liu, Ralph E. Kuehn, William H. Hunt, and Stuart A. Young

-wavelength polarization-sensitive lidar [the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP)], a three-channel imaging infrared radiometer (IIR), and a single-channel high-resolution wide field-of-view camera (WFC). Although all three instruments provide high-quality observations of clouds and aerosols, CALIOP alone provides the height-resolved measurements that provide a long-term global mapping of the vertical structure of the earth’s atmosphere. CALIOP measures elastic backscatter at 532 and

Full access
Jothiram Vivekanandan, Virendra P. Ghate, Jorgen B. Jensen, Scott M. Ellis, and M. Christian Schwartz

spectra collected by in situ cloud and drizzle probes on the NSF–NCAR C-130 aircraft during VAMOS in the southeastern Pacific Ocean were used as input to the simulations of radar and lidar observations. The simulated radar and lidar observations were used for developing a retrieval method for estimating cloud microphysical products, namely, characteristic particle diameter and LWC. The practical applicability of the retrieval method was demonstrated using the radar and lidar measurements from CSET

Open access
Mark A. Vaughan, Kathleen A. Powell, David M. Winker, Chris A. Hostetler, Ralph E. Kuehn, William H. Hunt, Brian J. Getzewich, Stuart A. Young, Zhaoyan Liu, and Matthew J. McGill

1. Introduction On 28 April 2006, eight years of close collaboration between the National Aeronautics and Space Administration (NASA) and the Centre National d’Etudes Spatiales (CNES) came to fruition with the launch of the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission from Vandenberg Air Force Base in California ( Winker et al. 2007 ). Launched simultaneously with the Cloudsat satellite aboard a single Delta-II rocket, CALIPSO is now an integral part of

Full access