Engee documentation

atmositu

The use of ITU reference atmospheres.

Library

EngeePhased

Syntax

Function call

  • T,P,wvden = atmositu(h) — calculates the standard atmospheric model of the International Telecommunication Union (ITU), known as the Mean Annual Global Reference Atmosphere (MAGRA), and returns the temperature of the atmosphere T, total atmospheric pressure P and absolute humidity wvden. MAGRA approximates the 1976 standard atmosphere of the United States with a slight relative error.

  • T,P,wvden = atmositu(h;Name=Value) — returns atmospheric temperature, total pressure, and absolute humidity with additional parameters specified by one or more arguments like «name-value».

  • atmositu(___;out=:plot) — builds the following graphs:

    • Dependence of atmospheric temperature T from height on a linear scale;

    • Atmospheric pressure dependence P from height on a logarithmic scale along the axis ;

    • Dependence of absolute humidity in the atmosphere wvden from height on a logarithmic scale along the axis .

Arguments

Input arguments

# h — geometric heights

+ vector

Details

Geometric heights corresponding to the height above mean sea level in meters, set as a vector string. Function atmositu returns NaN for any input value outside the interval [0, 100000].

Типы данных

Float64

Input arguments «name-value»

Specify optional argument pairs in the format Name = Value, where Name — the name of the argument, and Value — the appropriate value. Type arguments «name-value» they should be placed after the other arguments, but the order of the pairs does not matter.

Example: atmositu(h; LatitudeModel = "High", Season = "Winter") sets a reference model for latitudes over 45° in winter.

# WaterVaporDensity — standard absolute humidity at ground level

+ 7.5 (by default) | scalar

Details

The standard absolute humidity at ground level in g/m 3, given as a scalar.

To use this argument, set for the argument LatitudeModel meaning "Standard".

Типы данных

Float64

# ScaleHeight — height scale

+ 2.0e3 (by default) | scalar

Details

The height scale in meters, set as a scalar.

To use this argument, set for the argument LatitudeModel meaning "Standard". In a dry atmosphere, set this argument to 6.0e3 m.

Типы данных

Float64

# LatitudeModel — Latitude reference model

+ "Standard" (by default) | "Low" | "Mid" | "High"

Details

The reference model of latitude, set as one of the following values:

  • "Standard" — The model represents the Standard Global Atmosphere (MAGRA), characterized by annual averages of temperature and pressure around the globe.

  • "Low" — the model is designed for low latitudes less than 22 degrees, where seasonal fluctuations are insignificant.

  • "Mid" — the model is designed for mid-latitudes from 22 before 45 degrees with seasonal profiles for values "Summer" and "Winter", set using the argument Season.

  • "High" — the model is designed for higher latitudes than 45 degrees with seasonal profiles for values "Summer" and "Winter", set using the argument Season.

# Season — seasonal profile

+ "Summer" (by default) | "Winter"

Details

Seasonal profile for latitude models "Mid" and "High", set as "Summer" or "Winter". Other latitude models ignore this argument.

# out — type of output data

+ :data (by default) | :plot

Details

Type of output data:

  • :data — the function returns data;

  • :plot — the function returns a graph.

Output arguments

# T — temperature

+ vector

Details

The temperature of the atmosphere in kelvin, returned as a vector string of length .

Functions atmositu, gaspl and tropopl Different units of pressure and temperature are used.

Function Pressure measurement units Temperature measurement units

atmositu

Hectopascals (hPa)

Kelvins (K)

gaspl

Hectopascals (hPa)

Kelvins (K)

tropopl

Pascali (Pa)

Degrees Celsius (°C)

1 The gPa is equal to 100 Dad, eh . Care should be taken when using these three functions together.

# P — total atmospheric pressure

+ vector

Details

The total or barometric atmospheric pressure in gPa, returned as a vector string of length .

# wvden — absolute humidity

+ vector

Details

Absolute humidity in g/m3, returned as a vector string of length .

Examples

Determination of temperature, pressure and absolute humidity

Details

Calculate the temperature, pressure, and absolute humidity at altitude 5 km, using a model of high latitudes in summer.

import EngeePhased.Functions: atmositu

h = 5e3

T, P, wvden = atmositu(h, LatitudeModel = "High")

println("T = ", T, "\nP = ", P, "\nwvden = ", wvden)
T = 259.42990000000003
P = 540.3008
wvden = 1.0095102924625434

Calculation and visualization of atmospheric profiles

Details

Let’s calculate the temperature, pressure, and absolute humidity in the atmosphere at mid-latitudes in winter. Setting the height range from 2 before 88 km.

import EngeePhased.Functions: atmositu

h = (2:88) * 1e3

T, P, wvden = atmositu(h, LatitudeModel = "Mid", Season = "Winter")

Let’s output the first 6 values of temperature, pressure and absolute humidity.

[T[1:6] P[1:6] wvden[1:6]]
6×3 Matrix{Float64}:
 264.777  789.595  1.76014
 260.276  689.453  1.13204
 255.423  598.972  0.682941
 250.218  518.153  0.387506
 244.662  446.995  0.207357
 238.753  385.499  0.104924

Let’s plot the temperature, pressure, and absolute humidity profiles for this model.

atmositu(h, LatitudeModel = "Mid", Season = "Winter"; out = :plot)

atmositu

Literature

  1. International Telecommunication Union (ITU). «Reference Atmospheres». Recommendation ITU-R P.835-7, P Series, Radiowave Propagation (Aug. 2024).