Modularized Flux Testbed

Modularized Flux Testbed

The Modularized Flux Testbed (MFT) has been developed to allow users to combine a wide range of parameterizations related to air/sea interaction. The parameterizations can be selected to match those used in a publication, or to combine parameterizations for momentum roughness length, temperature and moisture roughness lengths, boundary-Layer stability, sea state dependency. The output includes fluxes of momentum (stress), sensible heat, and latent heat, as well as height adjustments for wind, temperature, and humidity, and in some cases wave-related variables. The solutions are consistent with each other, unless the code returns a warning that the solutions did not converge. There are some parameterizations that should not be combined because they are not physically consistent. Some options allow directional wave data and currents to be considered.

NEW: A stand alone Python version is now available.

Current Version: 2017.0a, Updated 11 August 2017: Update History

Review of Relevant Concepts

Winds and Stresses

Energy Fluxes

Atmospheric Stability

Sea State (out of date)

Routines in MFT Library (Short description and I/O)

Examples of calls to these routines are given for C, FORTRAN, and IDL in the links for these compilers in the section 'Required Files and Examples' Examples of variable declarations are also provided.

pmix: Main subroutine for determining fluxes and wave values. This subroutine can be run to determine fluxes based on input from any observation heights, but will not adjust these inputs to a uniform height. The next routine will adjust input values to a user specified height (fluxes do not require this adjustment).

ht_adj: Uses the boundary-layer model in routine pmix to adjust known values of wind speeds, potential temperatures, and humidities to values at a user specified height.

find_q: There are many methods of measuring the moisture content of air. When data sets are combined, it is likely that several methods have been used. In most boundary layer applications, these measurements must be converted to specific humidity. This routine converts all the common humidity measurements to specific humidity.

Test Routines for MFT Library

Routines have been developed to test the installation of pmix. Tests can be made on C, FORTRAN, and IDL versions of the code. Note that each of these versions calls the C routines: mixed language compilers are required. The code is designed for SGIs, for which the same source code can easily be used produce C and FORTRAN routines. The test programs are ctest_mft12.c, ctest_ht_adj12.c, ftest_mft12.f, ftest_ht_adj12.f,, and Input data and the expected output are given in testdata12.dat.

Required Files and Examples

The example Makefiles are for SGIs. An examples for FORTRAN compilation on other systems is given near the end of that linked page.

These files can be downloaded through this web site or taken from our public FTP site (anonymous FTP to, change directories to pub/bourassa/MFT) or . The linked pages (below) provided examples of variable declarations and calls to the routines.

Python users:,, testdata12.dat

C users: mft12.c, mft12.h, ctest_mft12.c, ctest_ht_adj12.c, testdata12.dat.

FORTRAN users: mft12.c, mft12.h, ftest_mft12.f, ftest_ht_adj12.f, testdata12.dat, Makefile (for SGIs), and call_mft12.c & call_ht_adj12 (for non-SGI users who want to call be address - the FORTRAN default). Warning: the FORTRAN version has not been updated for modern compilers or for FORTRAN90. Updates will be needed for it to work on a modern system.

IDL users: mft12.c, mft12.h, call_mft12.c,, call_ht_adj.c,, test_mft12.c, test_ht_adj12.c, testdata12.dat

Matlab users: mexmft12.c, mft12.c, mft12.h, testdata12.dat or tesdata12mex.xlsx or testdata12.csv. Warning: the z/L parameter is not successfully passed out of the mft.


Bourassa, M. A., D. G. Vincent, W. L. Wood, 1999: A flux parameterization including the effects of capillary waves and sea state. J. Atmos. Sci., 56, 1123-1139.

Bourassa, M. A. (2006). Satellite-based observations of surface turbulent stress during severe weather. W. Perrie (Ed.), Atmosphere - Ocean Interactions, Vol. 2 (pp. 35 - 52). Southampton, UK: Wessex Institute of Technology Press.