atmoshwm

Implement horizontal wind model

Description

example

wind = atmoshwm(latitude,longitude,altitude) implements the U.S. Naval Research Laboratory Horizontal Wind Model (HWM™) routine to calculate the meridional and zonal components of the wind for one or more sets of geographic coordinates: latitude, longitude, and altitude.

example

wind = atmoshwm(latitude,longitude,altitude,Name,Value) uses additional options specified by one or more Name,Value pair arguments.

Examples

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Calculate the total horizontal wind model for a latitude of 45 degrees south, longitude of 85 degrees west, and altitude of 25,000 m above mean sea level (msl). The date is the 150th day of the year, at 11 am UTC, using an Ap index of 80. The horizontal model version is 14.

w = atmoshwm(-45,-85,25000,'day',150,'seconds',39600,'apindex',80,'model','total', 'version', '14')
w =

3.2874   25.8735

Calculate the quiet horizontal wind model for a latitude of 50 degrees north, two altitudes of 100,000 m and 150,000 m above msl, and a longitude of 20 degrees west. The date is midnight UTC of January 30. The default horizontal model version is 14.

w = atmoshwm([50;50],[-20;-20],[100000;150000],'day',[30;30])
w =

-42.9350  -40.3693
29.1106    0.6253

Calculate the disturbed horizontal wind model for an altitude of 150,000 m above msl at latitude 70 degrees north, longitude 65 degrees west. The date is midnight UTC of June 15. The default horizontal model version is 14.

dw = atmoshwm(70,-65,150000,'day',166,'model','disturbance')
dw =
1.7954   -1.7130

Input Arguments

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Geodetic latitudes, in degrees, specified as a scalar or M-by-1 array.

Example: -45

Data Types: double

Geodetic longitudes, in degrees, specified as a scalar or M-by-1 array.

Example: -85

Data Types: double

Geopotential heights, in meters, within the range of 0 to 500 km, specified as a scalar or M-by-1 array. Values are held outside the range 0 to 500 km.

Example: 25000

Data Types: double

Name-Value Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Example: 'apindex',80,'model','total' specifies that the total horizontal wind model be calculated for an Ap index of 80.

Ap index for the Universal Coordinated Time (UTC) at which atmoshwm evaluates the model, specified as an M-by-1 array of zeroes, a scalar, or an M-by-1 array. M is the number of requested geographic coordinates. Select the index from the NOAA National Geophysical Data Center, which contains three-hour interval geomagnetic disturbance index values. If the Ap index value is greater than zero, the model evaluation accounts for magnetic effects.

Specify the Ap index as a value from 0 through 400. Specify an Ap index value for only the disturbance or total wind model type.

Data Types: double

Day of year in UTC. Specify the day as a value from 1 through 366 (for a leap year), specified as an M-by-1 array of zeroes, a scalar, or an M-by-1 array. Values are wrapped to within 1 to 366 days.

Data Types: double

Elapsed seconds since midnight for the selected day, in UTC, specified as specified as an M-by-1 array of zeroes, a scalar, or an M-by-1 array.

Specify the seconds as a value from 0 through 86,400. Values are wrapped to within 0 to 86400 seconds.

Data Types: double

Horizontal wind model type for which to calculate the wind components. This setting applies to all the sets of geophysical data in M.

• 'quiet'

Calculates the horizontal wind model without the magnetic disturbances. Quiet model types do not account for Ap index values. For this model type, do not specify an Ap index value when using this model type.

• 'disturbance'

Calculates the effect of only magnetic disturbances in the wind. For this model type, specify Ap index values greater than or equal to zero.

• 'total'

Calculates the combined effect of the quiet and magnetic disturbances. for this model type, specify Ap index values greater than or equal to zero.

Data Types: char | string

Function behavior when inputs are out of range, specified as one of these values. This type applies to all the sets of geophysical data in M.

ValueDescription
'None'No action.
'Warning'Warning in the MATLAB® Command Window, model simulation continues.
'Error'MATLAB returns an exception, model simulation stops.

Data Types: char | string

Implements specified horizontal wind model type.

• '14'

Horizontal Wind Model 14.

• '07'

Horizontal Wind Model 07.

Data Types: char | string

Output Arguments

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Meridional and zonal wind components of the horizontal wind model, returned as an M-by-2 array, in m/s.

Compatibility Considerations

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Behavior changed in R2021b

Introduced in R2016b

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