Search Results

You are looking at 1 - 10 of 1,040 items for :

  • Microwave observations x
  • Journal of the Atmospheric Sciences x
  • User-accessible content x
Clear All
Ingo Meirold-Mautner, Catherine Prigent, Eric Defer, Juan R. Pardo, Jean-Pierre Chaboureau, Jean-Pierre Pinty, Mario Mech, and Susanne Crewell

1. Introduction A strong need is emerging to have accurate radiative transfer simulations from realistic cloudy and rainy scenes at high microwave frequencies. First, efforts are made to assimilate satellite microwave radiation from cloudy and rainy atmospheres within numerical weather prediction (NWP) models. As a first step, precipitation affected satellite observations at microwave frequencies up to 22 GHz are assimilated in the European Centre for Medium-Range Weather Forecasts (ECMWF

Full access
Chinnawat Surussavadee and David H. Staelin

1. Introduction To assimilate passive microwave precipitation observations or retrievals into numerical weather prediction (NWP) models, the modeled radiances must be consistent with those observed. This paper tests the sensitivity of that consistency to assumptions in a particular radiative transfer model (RTM), and in a cloud-resolving NWP model that predicts hydrometeor habits and profiles. The precipitation and water path retrieval accuracies are shown to be less sensitive to the physical

Full access
Stephen R. Guimond, Gerald M. Heymsfield, and F. Joseph Turk

1. Introduction a. Instruments for tropical cyclone observation Advancements in the field of atmospheric science (and science in general) often arise because of new and innovative observations of the entity being studied. Such is the case with the problem of tropical cyclone (TC) intensification. In recent years, the plethora of instruments (e.g., dropsondes, aircraft Doppler radars, microwave satellite imagers and sounders) has led to an increase in the frequency and quality of TC inner core

Full access
Fuzhong Weng, Tong Zhu, and Banghua Yan

observations, many attempts were made to improve hurricane analyses for forecasts. Krishnamurti et al. (1991) developed a method to physically initialize the Florida State University global cumulus parameterization spectral model, which mainly depends upon the surface rain rates derived from the Special Sensor Microwave Imager (SSM/I). A comparison study was conducted by Tibbetts and Krishnamurti (2000) to evaluate the performance of four different rain-rate algorithms in hurricane track forecast using

Full access
F. J. Robinson, S. C. Sherwood, D. Gerstle, C. Liu, and D. J. Kirshbaum

convection between active and break-monsoon convection over northern Australia. Matsui et al. (1989) compared observed and modeled storm characteristics in the South China Sea Monsoon Experiment (SCSMEX) and the Kwajelein Experiment (KWAJEX), finding that peak SCSMEX storms reached higher in both observations and two CRMs tested. Unfortunately, differences in other indicators of storm intensity, such as radar retrievals at middle and lower levels or microwave brightness temperatures, were generally not

Full access
Christopher W. O’Dell, Peter Bauer, and Ralf Bennartz

several more computationally efficient approaches to serve as fast alternatives to the reference scheme. Section 5 characterizes the accuracy of the fast models as compared to the reference overlap model, whereas section 6 examines the full forward-model errors as compared with actual microwave observations. A brief discussion of the results is given in section 7 . 2. Base profiles and microphysics The profile datasets were drawn from the ECMWF efforts to assimilate cloud- and precipitation

Full access
Mark S. Kulie, Ralf Bennartz, Thomas J. Greenwald, Yong Chen, and Fuzhong Weng

1. Introduction Satellite-based passive microwave instruments have provided routine retrievals of important geophysical parameters over the past few decades, while recent spaceborne active microwave instruments have generated valuable datasets of cloud and precipitation profiles. Cloud and precipitation research has particularly benefited from sustained microwave observations that have enabled the development and continual improvement of global cloud and precipitation climatologies (e.g., Weng

Full access
Rei Ueyama and John M. Wallace

microwave measurements: Method and results 1979–84. J. Climate , 3 , 1111 – 1128 . Thompson , D. W. J. , and S. Solomon , 2005 : Recent stratospheric climate trends as evidenced in radiosonde data: Global structure and tropospheric linkages. J. Climate , 18 , 4785 – 4795 . Trenberth , K. E. , and Coauthors , 2007 : Observations: Surface and atmospheric climate change. Climate Change 2007: The Physical Science Basis. S. Solomon et al., Eds., Cambridge University Press . Uppala , S

Full access
Grant W. Petty and Wei Huang

retrieval scheme—that is, the higher dimensional the space in which observations are compared with model calculations, the greater the vulnerability of that scheme to errors in the computed radiative properties of atmospheric scatterers, including spectral dependence, polarization, and the relationship between microwave emission or attenuation and radar backscatter. With this in mind, and in view of the near-absence of corroborating in situ measurements of these properties for snow, a reevaluation of

Full access
Xiaofeng Zhao and Sixun Huang

observations were assumed to be the electric field u , which was a complex field. But in practical RFC estimations, the received clutter power P r is a real number field. Through the PE model, P r is determined by | u |—that is, the absolute value of u , but not u ( Barrios 1991 ; Gerstoft et al. 2003b ). How to establish the relationship between the complex equation and the real number cost function is an intractable problem. This paper is an extension of the work of Zhao and Huang (2011) in

Full access