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Florent Gasparin, Dean Roemmich, John Gilson, and Bruce Cornuelle

pairs of steric height (SH) anomalies from the climatological monthly fields, separated in time by less than 1 day and in latitude/longitude by increments of 0.5° in both the zonal and meridional directions ( Fig. 3 ). Both temperature at different levels (not shown) and 0–2000-dbar SH sample covariances ( Fig. 3 ) are similar and show a pronounced zonal elongation at the equator mainly due to the impacts of planetary waves and interannual variability. The sum of a small-scale Gaussian and a large

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Wei Li, Yuanfu Xie, Zhongjie He, Guijun Han, Kexiu Liu, Jirui Ma, and Dong Li

proposed in this paper. The multigrid technique is often used to solve numerical differential equation by allowing long waves to converge faster than short ones ( Briggs et al. 2000 ). In the variational data assimilation, the multigrid technique also allows longwave errors to be corrected faster than short ones. This could prevent the longwave errors from being incorporated into shortwave analyses. For example, at observation stations in one area, observation errors contain a 1000-km wavelength error

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Christoph Senff, Jens Bösenberg, and Gerhard Peters

data can be retrieved only above 400 m.The maximum height extends well beyond the planetary boundary layer unless low optically thick cloudsobstruct the laser beam. The range of the radar-RASSsystem is limited to about 700 m mostly due to anunavoidable drift of the sound waves caused by horizontal wind. This means that under favorable conditions-that is, no low clouds and sufficiently strongreturn signals--the usable range of the combinedDIAL-radar system extends from about 400 to 700 mabove the

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Daniel C. Bowman, Paul E. Norman, Michael T. Pauken, Sarah A. Albert, Darielle Dexheimer, Xiao Yang, Siddharth Krishnamoorthy, Attila Komjathy, and James A. Cutts

be the dark-colored tape used to attach the payload to the balloon envelope. The design flaw was rectified and two more flights were conducted in 2016, both of which remained aloft until sunset. A microbarometer on the second flight captured low-frequency sound waves, or “infrasound,” from a ground explosion 330 km away ( Young et al. 2018 ). We used solar hot-air balloons to deploy multiple infrasound microbarometers in the lower stratosphere as part of the Heliotrope experiment in 2017 ( Bowman

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Jeffry Rothermel, Cathy Kessinger, and Darien L. Davis

138 JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY VOLUM-2Dual-Doppler Lidar Measurement of Winds in the JAWS Experiment JEFFRY ROTHERMEL*Atmospheric Sciences Division. NASA/Marshall Space Flight Center, Huntsville, AL 35812 CATHY KESSINGER National Center for Atmospheric Research.** Boulder, CO 80307 DARIEN L. DAVISt NO/Ld/ERL, Wave

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S. J. Thomas, M. Desgagné, and R. Benoit

was coupled with version 3.5 of the RPN physical processes parameterization package [detailed documentation for this package is available in Mailhot (1994) ]. This package includes a planetary boundary layer scheme based on turbulent kinetic energy, a surface-layer scheme based on similarity theory, solar and infrared radiation, large-scale condensation, convective precipitation, and gravity wave drag schemes. The physics interface was modified also to support input–output to a fast file system

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Carol Anne Clayson and Lakshmi Kantha

1. Introduction Enormous effort has been expended over the past few decades to understand and model mixing within the active geophysical boundary layers, the atmospheric boundary layer (ABL) over both land and sea, and the oceanic mixed layer (OML). Mixing in these planetary boundary layers (PBLs) is invariably turbulent, and large eddy simulation (LES; e.g., Moeng and Sullivan 1994 ) and second-moment turbulence closure models (e.g., Mellor and Yamada 1982 ; Kantha 2003 ; Kantha and

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Robert A. Weller, Frank Bradley, and Roger Lukas

1. Introduction In this article we describe the interface or air–sea flux component of the Coupled Ocean–Atmosphere Response Experiment (COARE) of the Tropical Ocean Global Atmosphere (TOGA) research program. The background for and overall objectives of COARE are reviewed by Webster and Lukas (1992 , hereafter WL92). COARE was organized around six components: the interface or air–sea flux component, large-scale atmospheric circulation and waves, atmospheric convection, large-scale ocean

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John R. Banghoff, David J. Stensrud, and Matthew R. Kumjian

1. Introduction The depth of the planetary boundary layer (PBL) varies from a few tens of meters at night to several kilometers during the day. This single measurement and its evolution provide useful information on PBL structure. Not surprisingly, PBL depth influences air quality, turbulence, and cloud development. Both wildfire behavior ( Clements et al. 2007 ) and propagation of hazardous materials ( Dabberdt et al. 2004 ) exhibit a strong dependence on PBL depth. Yet, observations of PBL

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Dimitris Menemenlis and Carl Wunsch

persistence, and are easier to implement numerically. Because most of the energy of long planetary waves is in potential form, the initial geostrophic adjustment transients can be neglected. By contrast, the adjustment process cannot be neglected when the perturbations are initialized from vortices. This adjustment adds to the computational burden of the model Green’s functions as it may take up to a full month for the geostrophic adjustment transients to die down. Most of the useful information about the

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