Search Results
1. Introduction In the absence of strong synoptic-scale forcing, when there is a weak horizontal pressure gradient, the structure and evolution of the nocturnal boundary layer (NBL) are dominated by mesoscale or even microscale conditions. Both regional and local circulations are driven mainly by surface heterogeneities, with the different scales of topographical features as the main forcing factor ( Cuxart et al. 2007 ; Martínez et al. 2010 ). Drainage flows, also known as katabatic winds and
1. Introduction In the absence of strong synoptic-scale forcing, when there is a weak horizontal pressure gradient, the structure and evolution of the nocturnal boundary layer (NBL) are dominated by mesoscale or even microscale conditions. Both regional and local circulations are driven mainly by surface heterogeneities, with the different scales of topographical features as the main forcing factor ( Cuxart et al. 2007 ; Martínez et al. 2010 ). Drainage flows, also known as katabatic winds and
Crater during undisturbed nights. They represent a regional-scale cold-air drainage flow that arrives down a mean 2° slope from higher terrain about 30 km to the southwest of the crater. A modeling study by Savage et al. (2008) showed that the regional-scale drainage flow produces peak winds of 3–5 m s −1 at heights of 30–50 m AGL above the sloping Colorado Plateau in the vicinity of Meteor Crater. Temperatures at the south and west rim ( Fig. 6a ) are several degrees colder than at the north and
Crater during undisturbed nights. They represent a regional-scale cold-air drainage flow that arrives down a mean 2° slope from higher terrain about 30 km to the southwest of the crater. A modeling study by Savage et al. (2008) showed that the regional-scale drainage flow produces peak winds of 3–5 m s −1 at heights of 30–50 m AGL above the sloping Colorado Plateau in the vicinity of Meteor Crater. Temperatures at the south and west rim ( Fig. 6a ) are several degrees colder than at the north and
1158 MONTHLY WEATHER REVIEW VOLUME122Regional Drainage Flows in the Pacific Northwest J. C. DOgAN AN~ S. ZHONOPacific Northwest Laboratory, Richlana~ Washington(Manuscript received 19 luly 1993, in final form 1 November 1993)ABSTRACT An analysis of regional drainage flows in the Pacific Northwest is presented using results from a network ofsurface observations and a series of simulations carried out with a nested
1158 MONTHLY WEATHER REVIEW VOLUME122Regional Drainage Flows in the Pacific Northwest J. C. DOgAN AN~ S. ZHONOPacific Northwest Laboratory, Richlana~ Washington(Manuscript received 19 luly 1993, in final form 1 November 1993)ABSTRACT An analysis of regional drainage flows in the Pacific Northwest is presented using results from a network ofsurface observations and a series of simulations carried out with a nested
FEBRUARY 1991 COULTER, MARTIN AND PORCH 157 A Comparison of Nocturnal Drainage Flow in Three Tributaries* RICHARD L. COULTER AND TIMOTHY J. MARTIN Environmental Research Division, Argonne National Laboratory, Argonne, Illinois WILLIAM m. PORCH Los Alamos National Laboratory, Los Alamos, New Mexico (Manuscript received 18 January 1990, in final form 18 June
FEBRUARY 1991 COULTER, MARTIN AND PORCH 157 A Comparison of Nocturnal Drainage Flow in Three Tributaries* RICHARD L. COULTER AND TIMOTHY J. MARTIN Environmental Research Division, Argonne National Laboratory, Argonne, Illinois WILLIAM m. PORCH Los Alamos National Laboratory, Los Alamos, New Mexico (Manuscript received 18 January 1990, in final form 18 June
1. Introduction With the onset of radiational cooling at the surface, the coldest air may form initially at the bottom of the slope in the basin or valley ( Bodine et al. 2009 ) or the flow may initially descend to the basin or valley floor ( Sheridan et al. 2014 ). Such drainage flow on the sideslope may descend the slope as a microfront ( Papadopoulos and Helmis 1999 ; Mahrt et al. 2010 ; Fernando et al. 2013 ) or may form simultaneously along the entire slope. Cuxart et al. (2007) found
1. Introduction With the onset of radiational cooling at the surface, the coldest air may form initially at the bottom of the slope in the basin or valley ( Bodine et al. 2009 ) or the flow may initially descend to the basin or valley floor ( Sheridan et al. 2014 ). Such drainage flow on the sideslope may descend the slope as a microfront ( Papadopoulos and Helmis 1999 ; Mahrt et al. 2010 ; Fernando et al. 2013 ) or may form simultaneously along the entire slope. Cuxart et al. (2007) found
602 JOURNAL OF APPLIED METEOROLOGY VOLUMe-28The Dispersion of Atmospheric Tracers in Nocturnal Drainage Flows PAUL H. GUDIKSENLawrence Livermore National Laboratory, Livermore, California DONALD L. SHEARER.4rmy .4trnospheric Sciences laboratory. White Sands Missile Range. Arew Mexico (Manuscript received 22 February 1988, in final form 24 June 1988) This paper summarizes the results of a
602 JOURNAL OF APPLIED METEOROLOGY VOLUMe-28The Dispersion of Atmospheric Tracers in Nocturnal Drainage Flows PAUL H. GUDIKSENLawrence Livermore National Laboratory, Livermore, California DONALD L. SHEARER.4rmy .4trnospheric Sciences laboratory. White Sands Missile Range. Arew Mexico (Manuscript received 22 February 1988, in final form 24 June 1988) This paper summarizes the results of a
936 JOURNAL OF APPLIED METEOROLOGY VoLO~m2$Modeling Bulk Atmospheric Drainage Flow in a Valley** RONALD J. DOBOSY*Atmospheric Turbulence and D~fusion Division. NOAA /ARL. Oak Ridge, Tennessee(Manuscript received 23 November 1988, in final form 30 March 1989) ABSTRACT Most simulations of bulk valley-drainage flows depend heavily on parameterizations- The 1984
936 JOURNAL OF APPLIED METEOROLOGY VoLO~m2$Modeling Bulk Atmospheric Drainage Flow in a Valley** RONALD J. DOBOSY*Atmospheric Turbulence and D~fusion Division. NOAA /ARL. Oak Ridge, Tennessee(Manuscript received 23 November 1988, in final form 30 March 1989) ABSTRACT Most simulations of bulk valley-drainage flows depend heavily on parameterizations- The 1984
), and a terrain gap ( Vassallo et al. 2021 ). Other campaigns, such as SABLES-98 ( Cuxart et al. 2000 ) and CASES-99 ( Poulos et al. 2002 ) were intended to focus more specifically on the stable boundary layer without terrain effects, and are generally considered homogeneous, although a single gully at the CASES-99 site did provide insight into drainage flows ( Soler et al. 2002 ) and showed up-gully flows can produce gravity waves ( Balsley et al. 2002 ). Still other campaigns such as LAFE
), and a terrain gap ( Vassallo et al. 2021 ). Other campaigns, such as SABLES-98 ( Cuxart et al. 2000 ) and CASES-99 ( Poulos et al. 2002 ) were intended to focus more specifically on the stable boundary layer without terrain effects, and are generally considered homogeneous, although a single gully at the CASES-99 site did provide insight into drainage flows ( Soler et al. 2002 ) and showed up-gully flows can produce gravity waves ( Balsley et al. 2002 ). Still other campaigns such as LAFE
stakeholders will require a more highly resolved depiction of submesoscale flows (e.g., drainage winds and lake-land breeze circulations) and turbulence structures ( Glasheen et al. 2020 ; Steiner 2019 ; Garrett-Glaser 2020 ). To meet these weather guidance needs, the accuracy of mesoscale predictions needs to be improved so that they can be downscaled to provide higher resolution guidance. As such, the distribution of observations of atmospheric state must more closely match the grid spacing of today
stakeholders will require a more highly resolved depiction of submesoscale flows (e.g., drainage winds and lake-land breeze circulations) and turbulence structures ( Glasheen et al. 2020 ; Steiner 2019 ; Garrett-Glaser 2020 ). To meet these weather guidance needs, the accuracy of mesoscale predictions needs to be improved so that they can be downscaled to provide higher resolution guidance. As such, the distribution of observations of atmospheric state must more closely match the grid spacing of today
the crater a 30–50-m-deep stable surface layer forms with a near-isothermal layer above, hereinafter called the residual layer . A mesoscale southwesterly drainage flow with a flow depth between 100 and 250 m typically forms on the plain ( Savage et al. 2008 ). Observations with a sonic detection and ranging (sodar) device positioned 1.5 km southwest of Meteor Crater from mid-September through mid-October of 2009 showed drainage flows with peak wind speeds of 6–8 m s −1 and jet heights of 20
the crater a 30–50-m-deep stable surface layer forms with a near-isothermal layer above, hereinafter called the residual layer . A mesoscale southwesterly drainage flow with a flow depth between 100 and 250 m typically forms on the plain ( Savage et al. 2008 ). Observations with a sonic detection and ranging (sodar) device positioned 1.5 km southwest of Meteor Crater from mid-September through mid-October of 2009 showed drainage flows with peak wind speeds of 6–8 m s −1 and jet heights of 20
