# Title and the Authors:
Namelists and scripts from: Vertical Dependence of Horizontal Scaling Behavior 
of Orographic Wind and Moisture Fields in Atmospheric Models

Creators: Eghdami, Masih and Barros, Ana. P.
Contact: barros@duke.edu

Date: 2019

# Abstract:
Previous work showed that atmospheric model simulations exhibit different scaling behavior of vertically-averaged horizontal wind (u,v) and moisture (q) in the mesoscales for convective (spectral slopes β ~ -5/3) and nonconvective (β ~ -11/5) conditions. Here, the focus is on the transient behavior of horizontal scaling in the vertical during the evolution of extreme orographic precipitation storms in middle- (Appalachians, < 2,500 m) and high-mountains (Andes).  The results show that β exhibits a strong diurnal cycle switching between convective and nonconvective behavior following the space-time evolution of atmospheric stability in the lower troposphere (below 700 hPa) depending on latitude, topography, landform and the synoptic environment.  Anomalous flattening of the wind and moisture spectra (i.e. spectral saturation, |β| < 5/3) at high wavenumbers and up to 200 hPa is tied to convective activity, where and when strong vertical motions develop, corresponding to an abrupt directional switch from horizontal energy transfer to vertical energy transfer including latent heating release and parameterized microphysical processes. In the small mesoscales (< 50 km), β ~ -5/3 at all times up to 200 hPa with nighttime steepening (β ~ -11/5) below the orographic envelope where cold air pools form at low elevations and vertical motion weakens in the Appalachians. In the Andes, the scaling behavior exhibits a stronger diurnal cycle at low levels (below 700 hPa) with significant shoaling between tropical and high latitudes. Blocking and strong modification of regional circulations results in nighttime anisotropy at mid-levels on the altitudinal profile along the North-South topographic divide. 

# Description of the Files:
ANDES: This folder contains the namelists for running the ANDES simulation. The simulations are done using WRF-ARW and WPS version 3.8.1. First the boundary conditions are created using NCEP-FNL (ds083.2) forcing using namelist.wps.d0*. Note that D03 and D04 have created separately. The outer domains use standard smoothing pass but D03 uses 5 smoothing pass to avoid numerical instabilities due to high slope terrains (see GEOGRID.TBL). The rest of the simulation is carried out using the scripts named as step*.csh referring to namelist.input.*. The namelists ending with *.ndown are examples that can be used for obtaining the boundary conditions for the inner nests from the coarser resolution grids.  D03 and D04 are run independently after running D02 and do not affect each other.

APP: This folder contains the namelists for running APP simulation. The simulations are done using WRF-ARW and WPS version 3.8.1. First the boundary conditions are created using NCEP-FNL (ds083.2) forcing using namelist.wps.WV. The rest of the simulation is carried out using the namelist.input.WV following the standard procedure for running one way nested domains.

MATLAB_sample: This folder contains an example of MATLAB functions for calculating the spectra and linear fit. The scripts are run using MATLAB version R2016b.

# References:
National Centers for Environmental Prediction/National Weather Service/NOAA/U.S. Department of Commerce (2000), NCEP FNL Operational Model Global Tropospheric Analyses, continuing from July 1999, https://doi.org/10.5065/D6M043C6, Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory, Boulder, Colo. (Updated daily.) Accessed 05 May 2017.