Land-Atmosphere Interactions Model (LAIM)

Land-Atmosphere Interactions Model (LAIM) by John Chun-Han Lin (John.Lin@utah.edu)

Simple 1-D model of the land and the atmosphere in order to study the coupling and interactions.

The LAIM model adopts numerous simplifications/assumptions as part of its “spherical cow” approach:

• No horizontal fluxes and horizontal advection
• Variations within mixed-layer is minimal
• Variations within thin surface layer neglected
• Inversion layer in the entrainment zone represented by a “jump”

Here are some specific steps to run LAIM in the R programming language:

1. Download the LAIM model from Github: https://github.com/John-C-Lin/LAIM.git
   
2. Run the coupled land-atmosphere surface model, coded up in LAIM.r. This can be done using the source command in R (see Chapt. 4 of "Intro to Land-Atmosphere Interactions"): source(“PATH/LAIM.r”)
   
3. Make sure that the R working directory is set to the directory where both LAIM.r and Ball_Berry_Farquhar.r are found. You can use the 'getwd' command in R to get the current working directory, and the 'setwd' command to set the working directory.
   Why? This is because LAIM.r also reads in the Ball_Berry_Farquhar.r script, which is the model of vegetation resistance, or stomatal opening. Ball_Berry_Farquhar.r creates a function named BBF, which is the Ball-Berry-Farquhar stomatal model that is called within LAIM.