The MATERHORN: Unraveling the Intricacies of Mountain Weather

Abstract

Emerging application areas such as air pollution in megacities, wind energy, urban security, and operation of unmanned aerial vehicles have intensified scientific and societal interest in mountain meteorology. To address scientific needs and help improve the prediction of mountain weather, the U.S. Department of Defense has funded a research effort—the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) Program—that draws the expertise of a multidisciplinary, multi-institutional, and multinational group of researchers. The program has four principal thrusts, encompassing modeling, experimental, technology, and parameterization components, directed at diagnosing model deficiencies and critical knowledge gaps, conducting experimental studies, and developing tools for model improvements. The access to the Granite Mountain Atmospheric Sciences Testbed of the U.S. Army Dugway Proving Ground, as well as to a suite of conventional and novel high-end airborne and surface measurement platforms, has provided an unprecedented opportunity to investigate phenomena of time scales from a few seconds to a few days, covering spatial extents of tens of kilometers down to millimeters. This article provides an overview of the MATERHORN and a glimpse at its initial findings. Orographic forcing creates a multitude of time-dependent submesoscale phenomena that contribute to the variability of mountain weather at mesoscale. The nexus of predictions by mesoscale model ensembles and observations are described, identifying opportunities for further improvements in mountain weather forecasting.

Introduction Ice Fog, Ice Clouds, and Remote Sensing

“…Turbulent heat and moisture fluxes over wet surfaces play an important role in fog formation Gultepe 2015;Vihma et al 2014). In particular, in marine environments and mountainous regions, atmosphere-surface interactions need to be properly understood (Fernando et al 2015). Although these issues are resolved in three-dimensional ice fog or cloud models, they are not currently applicable to large-scale NWP predictions, and these are computationally expensive.…”

“…Results discussed in this special issue are generated by research efforts among multinational team efforts, conducted globally. Results from the following international projects are included in this special issue: The MATERHORN (Mountain Terrain Atmospheric Modeling and Observations; Fernando et al 2015) Project and SAAWSO (Satellite Applications for Arctic Weather for SAR (Search and Rescue) Operations; ) Project. These projects have demonstrated state of the art research that was planned with various new instrumental platforms measuring highimpact weather conditions.…”

Evaluation of single and multiple Doppler lidar techniques to measure complex flow during the XPIA field campaign

“…In order to derive the twodimensional (2-D) or three-dimensional (3-D) wind velocity the use of suitable measurement strategies and/or velocity retrieval algorithms is required. The 2-D and 3-D wind measurements from Doppler lidars are useful in various fields of study such as boundary layer meteorology (Fernando et al, 2015;Vanderwende et al, 2015), air quality (Barlow et al, 2011;Collier et al, 2005), wind energy research (Banta et al, 2015;Käsler et al, 2010;Mikkelsen, 2014;Newsom et al, 2015) and others. The simplest techniques to derive a profile of wind speed and direction using a single-Doppler lidar are the velocity azimuth display (VAD) technique (Browning and Wexler, 1968) and the Doppler beam swinging (DBS) technique (Strauch et al, 1984).…”

Turbulent Mechanical Energy Budget in Stably Stratified Baroclinic Flows over Sloping Terrain

“…Recent experiments, such as the MATERHORN-X (Fernando et al 2015) and SELF-2010 (Nadeau et al 2013) field campaigns provided new information that encouraged many subsequent studies (e.g., Oldroyd et al 2014Oldroyd et al , 2016aGrachev et al 2016). One of the important aspects of this research is the turbulent exchange and turbulence structure close to the surface.…”