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Sabine Göke, Harry T. Ochs III, and Robert M. Rauber

a characteristic time and total water content derived from the evolution of the X-band radar reflectivity field and sounding data. Since CCN and GN measurements were not available for the specific clouds used in this study, proxies were used to partition the clouds into four groups based on the cloud location and direction of movement. Specifically, we assumed that clouds forming over the ocean during onshore flow had maritime characteristics (group 1: low CCN, high GN), clouds forming over land

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Yizhak Feliks

oscillation of the height of the inversion due to the sea breeze is studied analytically by use of alinear model. The base of the inversion over the sea moved downward during daytime and upward duringnighttime. Over the land the diurnal movement of the inversion base is opposite to that over the sea. The changein the height of the inversion base reached about 250 m. An increase in the mean height of the inversion's baseand the stability of the inversion results in a smaller diurnal oscillation. The

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S. TWOMEY and T. A. WOJCIECHOWSKI

684JOURNAL OF THE ATMOSPHERIC SCIENCESVolume 26Observations of the Geographical Variation of Cloud NucleiS. TWOMEY1 AND T. A. WOJCIECHOWSKINaval Research Laboratory, Washington, D. C.(Manuscript received )ABSTRACTAirborne measurements at flight level of cloud nuclei have been carried out during approximately 100,000mi of flight over wide areas of the world. A thermal diffusion chamber was used to obtain cloud-nucleispectra which present the concentration of active nuclei as a function

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Peter R. Bannon

, the jet width,e-~ = 217 km, is too narrow, and the amplification ofthe cross-equatorial fl6w in the boundary current tothat far upstream, A = 85, is too large. Despitethese shortcomings, the solution (4) is used as astandard of comparison for the transient linearanalyses to be presented in the following subsections.a. Diurnal variation of friction coefficient over land During the day, increased insolation at the surface will result in increased convective activity and,hence, an increased

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Gerald F. Herman, Man-Li C. Wu, and Winthrop T. Johnson

, in final form 8 February 1980) ABSTRACTThe effect of global cloudiness on the solar and infrared components of the earth's radiation balance isstudied in general circulation model experiments. A wintertime simulation is conducted in which thecloud radiative transfer calculations use realistic cloud optical properties and are fully interactive withmodel-generated cloudiness. This simulation is compared to others in which the clouds are alternativelynon-interactive with

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Kenneth P. Bowman and Gordon D. Carrie

models are often compared to the observed circulation by using Eulerian statistics such as zonal means and eddy variances. Similarly, simulations of trace species distributions are often evaluated by computing such quantities as time-mean zonal-mean cross sections. It is now understood, however, that transport by the Eulerian-mean circulation is largely cancelled by eddy transport, so the mean transport circulation must, in general, be quite different from the Eulerian-mean circulation ( Boyd 1976

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Kerry Emanuel, Christopher DesAutels, Christopher Holloway, and Robert Korty

-induced SST anomalies occasionally affect the analyzed SSTs. Including these in the potential intensity used by the model would result in double counting of the SST feedback since the model produces its own storm-induced anomalies. The potential intensity is calculated from an algorithm described in Bister and Emanuel (2002) and is supplied daily by the Center for Land–Atmosphere Prediction (COLA; maps of potential intensity, generated by COLA, are available online at http

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Peter Bechtold, Noureddine Semane, Philippe Lopez, Jean-Pierre Chaboureau, Anton Beljaars, and Niels Bormann

the Maritime Continent). Experimentation shows that the improvements over coastal regions are primarily due to a better representation of the convection generated over land and advected over sea, along with the associated subsiding motions, but the modified adjustment over sea via τ BL also contributes. Fig . 2. As in Fig. 1 , but for the diurnal phase (LST) of the precipitation. Also TRMM radar data have been used instead of the radiometer data. White shading is applied for areas where the

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Mikhail D. Alexandrov, Andrew A. Lacis, Barbara E. Carlson, and Brian Cairns

spectroradiometer (MISR)], the increased emphasis on satellite aerosol retrievals has created the need for accurate ground-based, ground-truth aerosol measurements with which to validate satellite aerosol retrievals over land. In addition, measurements from ground-based sun photometer networks can also be also used to produce a land-based aerosol climatology that is complementary to the satellite retrievals. The multifilter rotating shadowband radiometer (MFRSR; Harrison et al. 1994 ) has become a popular

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Chih-Yue Jim Kao and Tetsuji Yamada

observations of both mean and turbulence fields of an anticyclonic, quasi-steady state, stratocumuluscapped boundary layer obtained with ground-based and balloonborne equipment during the night of 19/20November 1976 at Cardington, Bedford, UK, are simulated in relation to large-scale subsidence, longwaveradiative cooling, and large-scale moisture supply from sea to land, using a simplified second-order turbulenceclosure radiative model. Using a one-dimensional version of the model, most of the observed

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