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Sybille Y. Schoger, Dmitri Moisseev, Annakaisa von Lerber, Susanne Crewell, and Kerstin Ebell

in section 4 . 2) Micro Rain Radar The MRR is a vertically pointing frequency modulated continuous wave (FM-CW) Doppler radar manufactured by METEK GmbH ( Klugmann et al. 1996 ). It operates at a frequency of f = 24 GHz (K band; wavelength λ = 12.38 mm). Relative to (pulsed) radars in the same frequency range, the MRR has a low power consumption of 25 W. If the installed dish heater is turned on, a consumption of 500 W is added. The heating system prevents snow accumulation on the parabolic

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Randy J. Chase, Stephen W. Nesbitt, and Greg M. McFarquhar

attenuation from snowfall at W band is nontrivial, up to 1 dB km −1 whereas at Ku and Ka band are estimated to be around 0.1 dB km −1 or less ( Kneifel et al. 2011 ), only the Ku- and Ka-band reflectivities are used. To ensure correct absolute calibration of the radars, the Ku-band radar is calibrated by considering surface echoes of a water body in nonprecipitating conditions (GCPEX: Lake Huron and Lake Ontario; OLYMPEX: Pacific Ocean; Tanelli et al. 2006 ). Then the Ka band is calibrated against the

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George Duffy, Greg Mcfarquhar, Stephen W. Nesbitt, and Ralf Bennartz

global oceans ( Liu 2009 ; Hiley et al. 2011 ; Behrangi et al. 2014 ; Kulie et al. 2016 ; Duffy and Bennartz 2018 ; Milani et al. 2018 ). The Global Precipitation Measurement (GPM; Hou et al. 2014 ) Dual-Frequency Precipitation Radar (DPR) is the third and most recent satellite precipitation radar. The DPR is a combination of two radars, one at Ku band (13.6 GHz) and one at Ka band (35.5 GHz), arranged to provide collocated measurements. These radar measurements can be combined to create a

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Xiang Ni, Chuntao Liu, and Edward Zipser

of MAXHT20 and MAXHT30 over tropical (20°S–20°N) (top) land and (bottom) ocean. With different wavelengths at Ku and Ka bands, the electromagnetic waves interact with particles differently. The combination of the two channels would help in the retrieval of microphysical parameters. Typically, based on the radar equation, there are three likely influences on DFR profiles: 1) the Mie scattering effect, 2) the path-integrated attenuation, and 3) multiple scattering. Based on the Mie scattering

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Toshio Iguchi, Nozomi Kawamoto, and Riko Oki

estimate the particle size more accurately than a single-frequency radar so that we can improve the estimates of rainfall rate and identify snow precipitation regions. In fact, by using the difference in the scattering and attenuation properties of liquid and solid water particles between Ku- and Ka-band electromagnetic (EM) waves, it is possible to estimate the mean diameter of precipitation particles once an appropriate particle size distribution (PSD) model is chosen. Since the mean particle size

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E. F. Stocker, F. Alquaied, S. Bilanow, Y. Ji, and L. Jones

improved precipitation detection and bias corrections (K. Kanemaru 2017, personal communication). The 17+-yr record of TRMM PR showed a time-dependent drift of approximately 0.2 dB in the surface cross section over ocean, which has also been mitigated in GPM V05 ( Takahashi and Iguchi 2004 ). Further details on the calibration changes for GPM V05 processing of PR are outside the scope of this work and will be detailed in another publication. This paper provides information about the work undertaken to

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Robert A. Houze Jr., Lynn A. McMurdie, Walter A. Petersen, Mathew R. Schwaller, William Baccus, Jessica D. Lundquist, Clifford F. Mass, Bart Nijssen, Steven A. Rutledge, David R. Hudak, Simone Tanelli, Gerald G. Mace, Michael R. Poellot, Dennis P. Lettenmaier, Joseph P. Zagrodnik, Angela K. Rowe, Jennifer C. DeHart, Luke E. Madaus, Hannah C. Barnes, and V. Chandrasekar

mountain range with permanent snow cover. Figure 1 shows the terrain of the Olympic Mountain range, which occupies the Olympic Peninsula of the state of Washington. The peninsula has a north–south coastline on the Pacific Ocean and is separated from Canada’s Vancouver Island on its north side by the narrow Strait of Juan de Fuca. Fig . 1. Map of the region where the OLYMPEX campaign occurred, including the mountainous terrain of the Olympic Peninsula. The motivation for OLYMPEX was not only to better

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W.-K. Tao, T. Iguchi, and S. Lang

–liquid phases). LH and its vertical distribution not only have a strong influence on a variety of tropical circulations, including tropical waves and tropical cyclone intensity, but also on midlatitude cyclones and weather systems. Moreover, the processes associated with LH result in significant nonlinear changes in atmospheric radiation through the creation, dissipation, and modulation of clouds and precipitation. Although more recent efforts have been made to estimate the LH associated with weakly

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Sara Q. Zhang, T. Matsui, S. Cheung, M. Zupanski, and C. Peters-Lidard

processes. For example, at synoptic time scales, variability of the rainfall is observed linking to tropical wave dynamics ( Mounier et al. 2007 ) and the extratropical intrusion of dry air ( Roca et al. 2005 ). The dominant mode of synoptic variability of precipitation is correlated with African easterly waves (AEWs) through the dynamic relationship to organized convection systems ( Kiladis et al. 2006 ; Skinner and Diffenbaugh 2013 ). Satellite observations and numerical model simulations are

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Jackson Tan, George J. Huffman, David T. Bolvin, Eric J. Nelkin, and Manikandan Rajagopal

Imager (prior to May 2014). These correlations are computed at 20° × 20° regions (ocean) or 10° latitude bands (land) every month over a 3-month period that is either centered on (Final) or trailing (Late and Early) that month. The spatial and temporal coarseness is needed to ensure sufficient sample sizes, with additional postprocessing to reduce fluctuations due to noise. Therefore, the Kalman correlations give us a quantitative measure at every location of the skill of, say, an estimate from

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