Overview

Vortex Models

ADCIRC changelogs:

v56.0.4

Uses similar HollandGet subroutine from previous versions to implement symmetric vortex model (NWS=8 in fort.15).

v56.1.0

Uses new nws08get subroutine in new mod_nws08 module in src/nws08.F90 to implement symmetric vortex model.

from previous versions to implement symmetric vortex model (NWS=8 in fort.15).

Version differences between v56.0.4 and v56.1.0 (addition of CLE15

CLE15

From the ADCIRC Code: The CLE15GET subroutine calculates wind velocity at nodes based on the wind model described in Chavas et. al., 2015. This model consists of an inner vortex model described by:

$$ (M_i/M_m)^{\left(2-(C_k/C_d)\right)} = (2(r/r_m)^2)/(2-(C_k/C_d)+(C_k/C_d)(r/r_m)^2 $$ $$ M_m = r_mV_m + (1/2)fr_m^2 $$

where $M_i$ is the angular momentum at radius $r$, $M_m$ is the angular momentum at the radius of maximum winds, $C_k/C_d$ is the ratio of exchange coefficients of enthalpy and momentum, $r$ is the radius, $r_m$ is the radius of max winds, and $V_m$ is the maximum wind speed.

As well as an outer vortex model described by:

$$ dM_o/dr = \gamma[{rV}^2(r_0^2-r^2) $$

$$ \gamma = 2C_d/w_{cool} $$

where $M_o$ is the angular momentum at radius $r$, $C_d$ is the surface drag coefficient $w_{cool}$ is the free-tropospheric air subsidence rate, and $r_0$ is the radius of diminishing winds (i.e., at $r=r_0$, $V=0$). Angular momentum is calculated as $M = rV+(1/2)fr^2$

To find the complete wind profile, a radius $r_a$ is found where the angular momentum of the inner model and outer model as well as their derivatives match. Rather than solve for the angular momentum, this subroutine instead solves for V iteratively in both the inner and outer models with given $(r_m, V_m)$ and estimates of $r_0$ until $M_o(r_m,V_m,r_0,r_a) = M_i(r_m,V_m,r_0,r_a) = M_a$

Chavas et. al., 2015: https://doi.org/10.1175/JAS-D-15-0014.1

DesignSafe

Source code for New wind forcing option (CLE15 wind model) for hurricane surge simulation with ADCIRC in PRJ-3467 on DesignSafe. https://doi.org/10.17603/ds2-xd0r-bk81

Description: The complete hurricane surface wind profile model, CLE15, is added into the ADCIRC model as a new wind forcing option. To use the new wind forcing model in ADCIRC, the user should replace the file /ADCIRC_PATH/src/wind.F with wind_princeton.F and rename it as wind.F. The NWS option in file fort.22 should be set as 8. The dynamic Holland model for NWS=8 is replaced by the CLE15 wind model in file wind_princeton.F. For all the changes related to the CLE15 model, please search the wind_princeton.F file with "BY SHUAI START" and "BY SHUAI END".

Reference: Wang. S., Lin. N., and Gori. A. (2022): "Investigation of tropical cyclone wind models with application to storm tide simulations". Journal of Geophysical Research: Atmospheres.

Holland

LC12

Code

Examples

From the ADCIRC Test Suite:

CLE15 Vortex Model

CLE Vortex Model with LC12 Background Wind

Holland Vortex Model with LC12 Background Wind

Original ADCIRC Holland Vortex Mode

New ADCIRC Holland Vortex Model

Data Sources

• HURDAT2 main page
• HURDAT2 format documentation (PDF)

Andrew 1992 First Landfall:

19920823, 2100, L, HU, 25.4N,  76.6W, 140,  923, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999, -999

Parameter Definitions

From the new fort.15 namelist nws08Control :

• vortexModel = "Holland" ! Holland or CLE15
• backgroundWindModel = "radialVelocityWeighted" ! radialVelocityWeighted or LC12
• BCalc = "limited" ! limited or exact
• thetaLatDep = .false. ! theta used in calculation of radius dependent upon latitude
• useInflow = .false. ! whether to use inflow angle in translation speed calc
• windspeed_averaging_minute = 1 ! 1 or 10
• w_cool = 2.0 ! magnitude of the radiative-subsidence rate in the free troposphere (Chavas and Lin, 2016)
• CkCd_calc = .false. ! use constant (false) or best fit (true) for CkCd
• CkCd = 1.0 ! ratio of exchange coefficients of enthalpy (Ck) and momentum
• WindMultiplier = 1.0 ! wind multiplier applied to wind speed (default = 1.0, Holland model only)

Resources

Existing documentation on adcirc.org, the ADCIRC Wiki, and the ADCIRC ReadTheDocs site do not contain any documentation of the new symmetric vortex model implementation.

CLE Vortex Model

Chavas, et al (2015) A Model for the Complete Radial Structure of the Tropical Cyclone Wind Field. Part I: Comparison with Observed Structure DOI PDF

LC12 Background Wind Model

Lin and Chavas (2012) On hurricane parametric wind and applications in storm surge modeling PDF