Scientific Basis for NWP

Under construction (this web page, and most other web pages for this course).

Instructor:   Roland Stull

Learning Goals:   By the end of this module, you will be able to ...

• define numerical weather prediction (NWP)
• list the names of the equations of motion
• create a physical interpretation of each term in those equations
• convert terms in the eqs. of motion to and from vector notation
• convert between different forms of the continuity equation
• define flux and kinematic flux.
• compare and contrast flux-form with non-flux form of the eqs. of motion, and explain why the flux form is conservative.

Readings BEFORE class:

1. a thorough, but gentle, overview of NWP: Chapter 20 NWP from Stull, 2018: Practical Meteorology. 
2. brief history of NWP (from Stull, 2000: MSE3, p313-315) Brief history of NWP
3. Warner: Chapters1 & 2 . See our Textbooks webpage for a link to this book.  
   
4. skim the WRF home page (as of Jan 2023, the current version is 4.4.1): https://www.mmm.ucar.edu/models/wrf
5. skim the WRF v4.4 Users Guide (Apr 2022): https://www2.mmm.ucar.edu/wrf/users/docs/user_guide_v4/v4.4/contents.html
6. skim Chapter 1 of the WRF Tech Note, by Skamarock et al (2021).  See our Textbooks webpage for a link to this Tech Note.

Homework AFTER class:

1. Read WRF-v4 Tech Note, by Skamarock et al (2021).  Sections 2.1 and 2.2 in Chapter 2.
2. Read Cushman-Roisin & Beckers 2011: Intro to Geophys. Fluid Dyn. 2nd Ed., p 87-92 on the topics of Flux Formulation, Conservative Form, & Finite Volume Discretization.
3. Do written Homework (HW) 1 .   see HW on hybrid eta coordinates-v2.   Solve using any of  MatLab, R, Python, Excel, Fortran, etc..   Due in one week in class.  Submit a printed copy of your code, in addition to your answers.
   

Topics

A. Equations of Motion for a spherical earth.

1. Momentum (u, v, w)
2. Heat (T)
3. Moisture (r_T)
   
4. Mass (ρ)
5. State (P)

Physical Interpretation of some of the terms in the eqs.

B. Other forms of the Eqs. of Motion

1. Vector form
2. Continuity equation - many different versions
3. Eqs. used in the WRF model.

C. Brief history of NWP

1. L.F. Richardson
2. ENIAC
3. Moore's law
4. Lorenz strange attractor

D. Motivation for Coordinate Transformations