scholarly journals Stability Functions in the Stable Surface Layer Derived from the Mellor–Yamada–Nakanishi–Niino (MYNN) Scheme

2022 ◽  
Author(s):  
Mikio NAKANISHI ◽  
Hiroshi NIINO ◽  
Taro ANZAI
Keyword(s):  
Surface Layer ◽  
Stability Functions ◽  
Stable Surface ◽  
Stable Surface Layer

Vertical dispersion in the nocturnal, stable surface layer above a forest canopy

2002 ◽  
Vol 36 (24) ◽  
pp. 3989-3997 ◽  
Author(s):  
Thomas E Stoughton ◽  
David R Miller
Keyword(s):  
Surface Layer ◽  
Forest Canopy ◽  
Stable Surface ◽  
Stable Surface Layer ◽  
Vertical Dispersion

Warm-Air Intrusions in Arizona’s Meteor Crater

2012 ◽  
Vol 51 (6) ◽  
pp. 1010-1025 ◽  
Author(s):  
Bianca Adler ◽  
C. David Whiteman ◽  
Sebastian W. Hoch ◽  
Manuela Lehner ◽  
Norbert Kalthoff
Keyword(s):  
Surface Layer ◽  
Atmospheric Stability ◽  
Crater Floor ◽  
Drainage Flow ◽  
Cold Air ◽  
Stable Surface ◽  
Isothermal Layer ◽  
Stable Surface Layer ◽  
Strong Winds ◽  
Spatial And Temporal Characteristics

AbstractEpisodic nighttime intrusions of warm air, accompanied by strong winds, enter the enclosed near-circular Meteor Crater basin on clear, synoptically undisturbed nights. Data analysis is used to document these events and to determine their spatial and temporal characteristics, their effects on the atmospheric structure inside the crater, and their relationship to larger-scale flows and atmospheric stability. A conceptual model that is based on hydraulic flow theory is offered to explain warm-air-intrusion events at the crater. The intermittent warm-air-intrusion events were closely related to a stable surface layer and a mesoscale (~50 km) drainage flow on the inclined plain outside the crater and to a continuous shallow cold-air inflow that came over the upstream crater rim. Depending on the upstream conditions, the cold-air inflow at the crater rim deepened temporarily and warmer air from above the stable surface layer on the surrounding plain descended into the crater, as part of the flowing layer. The flow descended up to 140 m into the 170-m-deep crater and did not penetrate the approximately 30-m-deep crater-floor inversion. The intruding air, which was up to 5 K warmer than the crater atmosphere, did not extend into the center of the crater, where the nighttime near-isothermal layer in the ambient crater atmosphere remained largely undisturbed. New investigations are suggested to test the hypothesis that the warm-air intrusions are associated with hydraulic jumps.

Wave-like wind fluctuations observed in the stable surface layer over a plant canopy

1984 ◽  
Vol 29 (3) ◽  
pp. 273-283 ◽  
Author(s):  
T. Maitani ◽  
Y. Hiramatsu ◽  
T. Seo
Keyword(s):  
Surface Layer ◽  
Plant Canopy ◽  
Stable Surface ◽  
Stable Surface Layer

The velocity spectra in the stable surface layer

1987 ◽  
Vol 40 (4) ◽  
pp. 407-414 ◽  
Author(s):  
Osvaldo L. L. Moraes ◽  
Mario Epstein
Keyword(s):  
Surface Layer ◽  
Stable Surface ◽  
Stable Surface Layer ◽  
Velocity Spectra

scholarly journals Improving the Stable Surface Layer in the NCEP Global Forecast System

2017 ◽  
Vol 145 (10) ◽  
pp. 3969-3987 ◽  
Author(s):  
Weizhong Zheng ◽  
Michael Ek ◽  
Kenneth Mitchell ◽  
Helin Wei ◽  
Jesse Meng
Keyword(s):  
Surface Layer ◽  
Air Temperature ◽  
Surface Air Temperature ◽  
Global Forecast System ◽  
Surface Cooling ◽  
Forecast System ◽  
Near Surface ◽  
Stable Surface ◽  
Stable Surface Layer ◽  
Ncep Global Forecast System

This study examines the performance of the NCEP Global Forecast System (GFS) surface layer parameterization scheme for strongly stable conditions over land in which turbulence is weak or even disappears because of high near-surface atmospheric stability. Cases of both deep snowpack and snow-free conditions are investigated. The results show that decoupling and excessive near-surface cooling may appear in the late afternoon and nighttime, manifesting as a severe cold bias of the 2-m surface air temperature that persists for several hours or more. Concurrently, because of negligible downward heat transport from the atmosphere to the land, a warm temperature bias develops at the first model level. The authors test changes to the stable surface layer scheme that include introduction of a stability parameter constraint that prevents the land–atmosphere system from fully decoupling and modification to the roughness-length formulation. GFS sensitivity runs with these two changes demonstrate the ability of the proposed surface layer changes to reduce the excessive near-surface cooling in forecasts of 2-m surface air temperature. The proposed changes prevent both the collapse of turbulence in the stable surface layer over land and the possibility of numerical instability resulting from thermal decoupling between the atmosphere and the surface. The authors also execute and evaluate daily GFS 7-day test forecasts with the proposed changes spanning a one-month period in winter. The assessment reveals that the systematic deficiencies and substantial errors in GFS near-surface 2-m air temperature forecasts are considerably reduced, along with a notable reduction of temperature errors throughout the lower atmosphere and improvement of forecast skill scores for light and medium precipitation amounts.

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