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  • Author or Editor: Paul M. James x
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James E. Peak and Paul M. Tag

The U.S. Navy has plans to develop an automated system to analyze satellite imagery aboard its ships at sea. Lack of time for training, in combination with frequent personnel rotations, precludes the building of extensive imagery interpretation expertise by shipboard personnel. A preliminary design starts from pixel data from which clouds are classified. An image segmentation is performed to assemble and isolate cloud groups, which are then identified (e.g., as a cold front) using neural networks. A combination of neural networks and expert systems is subsequently used to transform key information about the identified cloud patterns as inputs to an expert system that provides sensible weather information, the ultimate objective of the imagery analysis.

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Robert W. Fett, Marie E. White, James E. Peak, Sam Brand, and Paul M. Tag

The Naval Research Laboratory Marine Meteorology Division, over a period of more than 15 years, has developed a series of satellite imagery training documents called the Navy Tactical Applications Guides (NTAGs). The NTAG materials are unique because of their innovative focus on operationally relevant meteorological and oceanographic phenomena of concern to naval forces throughout the world and the exceedingly high quality of printed images. Advances in hypermedia and CD-ROM technology are enabling the enhancement and continued distribution of the NTAGs through the development of an electronic application called LaserTAG. CD-ROM technology provides large reproduction and storage capacity at a relatively low cost ($25 for LaserTAG discs versus $1000 for the 11-volume NTAG set). Hypermedia and electronic conversion supply the ability to 1) rapidly locate material through keyword searches and navigate to those locations through hypermedia links, 2) read text and view graphics simultaneously using multiple windows, and 3) create electronic annotation and bookmark files. A second technology, expert systems, is further expanding potential uses of the information documented in the NTAG series. The Satellite Image Analysis Meteorological Expert System (SIAMES) encapsulates important conclusions and rules of analysis. The SIAMES prototype described here leads the user through a hierarchy of image interpretation expertise derived from the NTAG series by querying the user about details appearing in the satellite imagery. The ultimate goal, particularly important when resident expertise is minimal or nonexistent, is to develop an automated method to deduce sensible weather parameters that affect navy operations. Applications of these technologies to environmental satellite image analysis provide new opportunities for their use, not only in the operational community, but in training and research as well.

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Christopher S. Velden, Christopher M. Hayden, Steven J W. Nieman, W. Paul Menzel, Steven Wanzong, and James S. Goerss

The coverage and quality of remotely sensed upper-tropospheric moisture parameters have improved considerably with the deployment of a new generation of operational geostationary meteorological satellites: GOES-8/9 and GMS-5. The GOES-8/9 water vapor imaging capabilities have increased as a result of improved radiometric sensitivity and higher spatial resolution. The addition of a water vapor sensing channel on the latest GMS permits nearly global viewing of upper-tropospheric water vapor (when joined with GOES and Meteosat) and enhances the commonality of geostationary meteorological satellite observing capabilities. Upper-tropospheric motions derived from sequential water vapor imagery provided by these satellites can be objectively extracted by automated techniques. Wind fields can be deduced in both cloudy and cloud-free environments. In addition to the spatially coherent nature of these vector fields, the GOES-8/9 multispectral water vapor sensing capabilities allow for determination of wind fields over multiple tropospheric layers in cloud-free environments. This article provides an update on the latest efforts to extract water vapor motion displacements over meteorological scales ranging from subsynoptic to global. The potential applications of these data to impact operations, numerical assimilation and prediction, and research studies are discussed.

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Timothy J. Schmit, Mathew M. Gunshor, W. Paul Menzel, James J. Gurka, Jun Li, and A. Scott Bachmeier

The Advanced Baseline Imager (ABI), designated to be one of the instruments on a future Geostationary Operational Environmental Satellite (GOES) series, will introduce a new era for U.S. geostationary environmental remote sensing. ABI is slated to be launched on GOES-R in 2012 and will be used for a wide range of weather, oceanographic, climate, and environmental applications. ABI will have more spectral bands (16), faster imaging (enabling more geographical areas to be scanned), and higher spatial resolution (2 km in the infrared and 1–0.5 km in the visible) than the current GOES Imager. The purposes of the selected spectral bands are summarized in this paper. There will also be improved performance with regard to radiometrics and image navigation/registration. ABI will improve all current GOES Imager products and introduce a host of new products. New capabilities will include detecting upper-level SO2 plumes, monitoring plant health on a diurnal time scale, inferring cloud-top phase and particle size and other microphysical properties, and quantifying air quality with improved aerosol and smoke detection. ABI will be operating in concert with the GOES-R high spectral resolution sounder, part of the Hyperspectral Environmental Suite (HES); several products will be improved through the combination of high spatial resolution imager data with collocated high spectral resolution measurements. This paper introduces the proposed ABI spectral bands, discusses the rationale for their selection, and presents simulated ABI examples gleaned from current airborne and satellite instrument data.

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Juanzhen Sun, Ming Xue, James W. Wilson, Isztar Zawadzki, Sue P. Ballard, Jeanette Onvlee-Hooimeyer, Paul Joe, Dale M. Barker, Ping-Wah Li, Brian Golding, Mei Xu, and James Pinto

Traditionally, the nowcasting of precipitation was conducted to a large extent by means of extrapolation of observations, especially of radar ref lectivity. In recent years, the blending of traditional extrapolation-based techniques with high-resolution numerical weather prediction (NWP) is gaining popularity in the nowcasting community. The increased need of NWP products in nowcasting applications poses great challenges to the NWP community because the nowcasting application of high-resolution NWP has higher requirements on the quality and content of the initial conditions compared to longer-range NWP. Considerable progress has been made in the use of NWP for nowcasting thanks to the increase in computational resources, advancement of high-resolution data assimilation techniques, and improvement of convective-permitting numerical modeling. This paper summarizes the recent progress and discusses some of the challenges for future advancement.

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Bart Geerts, David J. Raymond, Vanda Grubišić, Christopher A. Davis, Mary C. Barth, Andrew Detwiler, Petra M. Klein, Wen-Chau Lee, Paul M. Markowski, Gretchen L. Mullendore, and James A. Moore

Abstract

Recommendations are presented for in situ and remote sensing instruments and capabilities needed to advance the study of convection and turbulence in the atmosphere. These recommendations emerged from a community workshop held on 22–24 May 2017 at the National Center for Atmospheric Research and sponsored by the National Science Foundation. Four areas of research were distinguished at this workshop: i) boundary layer flows, including convective and stable boundary layers over heterogeneous land use and terrain conditions; ii) dynamics and thermodynamics of convection, including deep and shallow convection and continental and maritime convection; iii) turbulence above the boundary layer in clouds and in clear air, terrain driven and elsewhere; and iv) cloud microphysical and chemical processes in convection, including cloud electricity and lightning.

The recommendations presented herein address a series of facilities and capabilities, ranging from existing ones that continue to fulfill science needs and thus should be retained and/or incrementally improved, to urgently needed new facilities, to desired capabilities for which no adequate solutions are as yet on the horizon. A common thread among all recommendations is the need for more highly resolved sampling, both in space and in time. Significant progress is anticipated, especially through the improved availability of airborne and ground-based remote sensors to the National Science Foundation (NSF)-supported community.

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Thomas Spengler, Ian A. Renfrew, Annick Terpstra, Michael Tjernström, James Screen, Ian M. Brooks, Andrew Carleton, Dmitry Chechin, Linling Chen, James Doyle, Igor Esau, Paul J. Hezel, Thomas Jung, Tsubasa Kohyama, Christof Lüpkes, Kelly E. McCusker, Tiina Nygård, Denis Sergeev, Matthew D. Shupe, Harald Sodemann, and Timo Vihma
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Nicholas A. Bond, Clifford F. Mass, Bradley F. Smull, Robert A. Houze, Ming-Jen Yang, Brian A. Colle, Scott A. Braun, M. A. Shapiro, Bradley R. Colman, Paul J. Neiman, James E. Overland, William D. Neff, and James D. Doyle

The Coastal Observation and Simulation with Topography (COAST) program has examined the interaction of both steady-state and transient cool-season synoptic features, such as fronts and cyclones, with the coastal terrain of western North America. Its objectives include better understanding and forecasting of landfalling weather systems and, in particular, the modification and creation of mesoscale structures by coastal orography. In addition, COAST has placed considerable emphasis on the evaluation of mesoscale models in coastal terrain. These goals have been addressed through case studies of storm and frontal landfall along the Pacific Northwest coast using special field observations from a National Oceanic and Atmospheric Administration WP-3D research aircraft and simulations from high-resolution numerical models. The field work was conducted during December 1993 and December 1995. Active weather conditions encompassing a variety of synoptic situations were sampled. This article presents an overview of the program as well as highlights from a sample of completed and ongoing case studies.

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Paul W. Staten, Kevin M. Grise, Sean M. Davis, Kristopher B. Karnauskas, Darryn W. Waugh, Amanda C. Maycock, Qiang Fu, Kerry Cook, Ori Adam, Isla R. Simpson, Robert J Allen, Karen Rosenlof, Gang Chen, Caroline C. Ummenhofer, Xiao-Wei Quan, James P. Kossin, Nicholas A. Davis, and Seok-Woo Son

Abstract

Over the past 15 years, numerous studies have suggested that the sinking branches of Earth’s Hadley circulation and the associated subtropical dry zones have shifted poleward over the late twentieth century and early twenty-first century. Early estimates of this tropical widening from satellite observations and reanalyses varied from 0.25° to 3° latitude per decade, while estimates from global climate models show widening at the lower end of the observed range. In 2016, two working groups, the U.S. Climate Variability and Predictability (CLIVAR) working group on the Changing Width of the Tropical Belt and the International Space Science Institute (ISSI) Tropical Width Diagnostics Intercomparison Project, were formed to synthesize current understanding of the magnitude, causes, and impacts of the recent tropical widening evident in observations. These working groups concluded that the large rates of observed tropical widening noted by earlier studies resulted from their use of metrics that poorly capture changes in the Hadley circulation, or from the use of reanalyses that contained spurious trends. Accounting for these issues reduces the range of observed expansion rates to 0.25°–0.5° latitude decade‒1—within the range from model simulations. Models indicate that most of the recent Northern Hemisphere tropical widening is consistent with natural variability, whereas increasing greenhouse gases and decreasing stratospheric ozone likely played an important role in Southern Hemisphere widening. Whatever the cause or rate of expansion, understanding the regional impacts of tropical widening requires additional work, as different forcings can produce different regional patterns of widening.

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Jerome M. Schmidt, Piotr J. Flatau, Paul R. Harasti, Robert. D. Yates, David J. Delene, Nicholas J. Gapp, William J. Kohri, Jerome R. Vetter, Jason E. Nachamkin, Mark G. Parent, Joshua D. Hoover, Mark J. Anderson, Seth Green, and James E. Bennett

Abstract

Descriptions of the experimental design and research highlights obtained from a series of four multiagency field projects held near Cape Canaveral, Florida, are presented. The experiments featured a 3 MW, dual-polarization, C-band Doppler radar that serves in a dual capacity as both a precipitation and cloud radar. This duality stems from a combination of the radar’s high sensitivity and extremely small-resolution volumes produced by the narrow 0.22° beamwidth and the 0.543 m along-range resolution. Experimental highlights focus on the radar’s real-time aircraft tracking capability as well as the finescale reflectivity and eddy structure of a thin nonprecipitating stratus layer. Examples of precipitating storm systems focus on the analysis of the distinctive and nearly linear radar reflectivity signatures (referred to as “streaks”) that are caused as individual hydrometeors traverse the narrow radar beam. Each streak leaves a unique radar reflectivity signature that is analyzed with regard to estimating the underlying particle properties such as size, fall speed, and oscillation characteristics. The observed along-streak reflectivity oscillations are complex and discussed in terms of diameter-dependent drop dynamics (oscillation frequency and viscous damping time scales) as well as radar-dependent factors governing the near-field Fresnel radiation pattern and inferred drop–drop interference.

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