Search Results

You are looking at 1 - 10 of 8,348 items for :

  • Cloud retrieval x
  • Refine by Access: All Content x
Clear All
Min Deng, Gerald G. Mace, Zhien Wang, and R. Paul Lawson

these two active remote sensors, when combined with the passive remote sensors of the A-Train constellation ( Stephens et al. 2008 ), have provided an unprecedented global view of clouds ( Sassen et al. 2009 ; G. G. Mace et al. 2009 ) and precipitation ( Stephens et al. 2010 ) and also motivated development of a series of cloud property retrieval algorithms using various combinations of radar, lidar, and radiometer measurements ( Austin and Stephens 2001 ; Hogan et al. 2006 ; Young and Vaughan

Full access
Chenxi Wang, Ping Yang, Bryan A. Baum, Steven Platnick, Andrew K. Heidinger, Yongxiang Hu, and Robert E. Holz

Resolution Imaging Spectroradiometer (MODIS) operational cloud-property retrieval is a bispectral method employing solar-reflectance bands ( Platnick et al. 2003 ). The premise of this approach is that a weakly absorbing, visible or near-infrared window band (VIS/NIR) (e.g., 0.64 or 0.86 μ m) is sensitive mainly to τ , whereas an ice absorbing shortwave infrared (SWIR) band (e.g., 1.6 or 2.13 μ m) is sensitive to both D eff and τ . To be more specific, in a VIS band, scattering is dominant so that

Full access
Shaima L. Nasiri, H. Van T. Dang, Brian H. Kahn, Eric J. Fetzer, Evan M. Manning, Mathias M. Schreier, and Richard A. Frey

each instrument to sample the physical state within some types of cloud regimes is still poorly understood ( Fetzer et al. 2006 , 2008 ) and must be compared further before the derived geophysical variables reach a nominal level of maturity for application to climate monitoring and trends. Furthermore, before AIRS and MODIS can be combined together in joint retrievals of surface and/or atmospheric properties (e.g., L’Ecuyer et al. 2006 ; Li et al. 2005 ), a rigorous intercomparison of retrieval

Full access
Thomas Auligné

because they can significantly impact the quality of the analysis. There are many approaches to detect clouds, but not all meet the constraints of operational assimilation. The need for robustness and speed makes collocation between different instruments difficult in real time. An alternative method is proposed in this paper for efficient retrieval of information about the clouds and identification of clear channels. This paper is organized in the following manner. The description of the new method is

Full access
Kevin J. Garrett, Ping Yang, Shaima L. Nasiri, Christopher R. Yost, and Bryan A. Baum

from various general circulation models (GCMs) and in model comparisons with flux measurements ( Potter and Cess 2004 ; Webb et al. 2001 ). To increase confidence in climate prediction, global observations on fine spatial and temporal scales from satellite-based instruments are needed to retrieve ice cloud properties such as effective particle size and cloud optical thickness, which are essential to climate studies ( Wielicki et al. 1995 ). Methodologies have been developed for daytime retrievals

Full access
Gabriela Seiz, Stephen Tjemkes, and Philip Watts

resulting from the different scan period (i.e., 30 and 15 min, respectively). By contrast, the time difference between Meteosat-5 and Meteosat - 7 observations is small (on average less than ±10 s, except for regions toward the image borders). Hence, it is not obvious that by replacing Meteosat-7 with Meteosat-8 HRV observations, the CTH accuracy would increase as expected by Campbell and Holmlund (2004) . This paper extends the multiview cloud-top height and motion retrievals described in

Full access
Ming Fang, Bruce Albrecht, Eunsil Jung, Pavlos Kollias, Haflidi Jonsson, and Ivan PopStefanija

weather phenomena passing over the radar sites. Airborne Doppler radars enable the study of clouds and precipitation structure over remote locations and oceans ( Heymsfield et al. 1996 ; French et al. 1999 ; Guimond et al. 2010 ; Lorsolo et al. 2010 ; Rogers et al. 2013 ). Because of their compact design, millimeter wavelength Doppler (cloud) radars operating at 95 GHz are particularly well suited for use on aircraft (e.g., Li et al. 2004 ; Kollias et al. 2007 ). The retrieval of the vertical

Full access
George Tselioudis, William Rossow, Yuanchong Zhang, and Dimitra Konsta

of several years of cloud vertical structure (CVS) retrievals from CloudSat and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations ( CALIPSO ) now makes it possible to investigate the relationship of CVS and the WSs. The study of Zhang et al. (2007) derived tropical cloud clusters applying the same clustering technique to CloudSat histograms of CVSs and found good correspondence and clear physical connections between those clusters and the ones derived from ISCCP PC

Full access
Erwin L. A. Wolters, Robert A. Roebeling, and Arnout J. Feijt

only be applied during daytime. Because outgoing surface radiance significantly contributes to the radiance measured by a satellite instrument, thermally based cloud-phase retrievals are sensitive to errors when detecting optically thin and broken clouds. In addition, brightness temperature (BT) thresholding affects cloud phase by assuming a sudden transition from water to ice clouds below a certain temperature threshold, whereas in reality this transition depends on, for example, cloud dynamics

Full access
M. J. Bartholomew, R. M. Reynolds, A. M. Vogelmann, Q. Min, R. Edwards, and S. Smith

to determine all three critical properties for LWP < 100 g m −2 ( Turner et al. 2007b ). For example, micropulse lidars (MPLs) and microwave radiometers (MWRs) are instruments that have been commonly used for surface retrievals and satellite validation. MPL observations can provide COD for clouds up to about 3 (LWP < 25 g m −2 ), but the signal saturates beyond that point and does not offer information on Re or LWP. Dual-channel MWRs, operating at 23 and 31 GHz, are commonly used in the field

Full access