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Fix ocean humidity calculation, adjust humidity based on altitude and calculate sea level temeprature based on ground level temperature and altitude.

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This commit is contained in:
Erik Hofman 2020-11-08 15:54:54 +01:00
parent 6e34ea5ab5
commit f21b9b651b
1 changed files with 25 additions and 24 deletions
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49
src/Environment/climate.cxx
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@ -123,9 +123,17 @@ void FGClimate::update(const SGGeod& position)
else if (_classicfication < 32) set_polar();
else set_ocean();
// Relative humidity decreases linearly with an increase in altitude at
// an average of 4% per kilometer
double alt_km = pos.getElevationM()/1000.0;
_relative_humidity -= 0.04*alt_km;
// Mark G. Lawrence:
_dew_point = _temperature_gl - ((100.0 - 100.0*_relative_humidity)/5.0);
// The temperature decreases by about 5.3°C per kilometer
_temperature_sl = _temperature_gl + 5.3*alt_km;
set_environment();
#if REPORT_TO_CONSOLE
@ -167,25 +175,23 @@ void FGClimate::set_ocean()
// temperature based on latitude, season and time of day
// the equator does not really have seasons, only day and night
double temp_equator_max = 31.0;
double temp_equator_min = 23.0;
double temp_equator = season_even(day, temp_equator_min, temp_equator_max);
double temp_equator_day = 31.0;
double temp_equator_night = 23.0;
double temp_equator = season_even(day, temp_equator_night, temp_equator_day);
// the poles do not really have day or night, only seasons
double temp_summer_pole = -8.0;
double temp_winter_pole = -48.0;
double temp_pole = season_even(summer, temp_winter_pole, temp_summer_pole);
double temp_pole = season_even(summer, -48.0, -8.0);
double fact_lat = pow(fabs(pos.getLatitudeDeg())/90.0, 2.5);
double ifact_lat = 1.0 - fact_lat;
_temperature_sl = season_even(ifact_lat, temp_pole, temp_equator);
_temperature_gl = season_even(ifact_lat, temp_pole, temp_equator);
double temp_mean_equator = 0.5*(temp_equator_max + temp_equator_min);
double temp_mean_equator = 0.5*(temp_equator_day + temp_equator_night);
_temperature_mean = season_even(ifact_lat, temp_pole, temp_mean_equator);
// relative humidity based on latitude
_relative_humidity = season_even(fact_lat, 0.1, 0.8);
_relative_humidity = triangular(fabs(fact_lat-0.5), 0.70, 0.87);
// steady winds
_wind = 3.0;
@ -218,8 +224,8 @@ void FGClimate::set_tropical()
double fact_lat = std::max(abs(latitude_deg), 15.0)/15.0;
double wind = 3.0*fact_lat*fact_lat;
double temp_night = _temperature_sl;
double temp_day = _temperature_sl;
double temp_night = _temperature_gl;
double temp_day = _temperature_gl;
double precipitation = _precipitation;
double relative_humidity = _relative_humidity;
switch(_classicfication)
@ -257,7 +263,6 @@ void FGClimate::set_tropical()
_temperature_gl = season_even(day, temp_night, temp_day);
_temperature_mean = 0.5*(temp_night + temp_day);
_temperature_sl = _temperature_gl;
_relative_humidity = relative_humidity;
_precipitation = precipitation;
@ -281,8 +286,8 @@ void FGClimate::set_dry()
_total_annual_precipitation *= 2.0;
}
double temp_night = _temperature_sl;
double temp_day = _temperature_sl;
double temp_night = _temperature_gl;
double temp_day = _temperature_gl;
double precipitation = _precipitation;
double relative_humidity = _relative_humidity;
switch(_classicfication)
@ -317,7 +322,6 @@ void FGClimate::set_dry()
_temperature_gl = season_even(day, temp_night, temp_day);
_temperature_mean = 0.5*(temp_night + temp_day);
_temperature_sl = _temperature_gl;
_relative_humidity = relative_humidity;
_precipitation = precipitation;
@ -335,8 +339,8 @@ void FGClimate::set_temperate()
double humidity_fact = season_even(winter, 0.5, 1.0-0.5*day);
double temp_night = _temperature_sl;
double temp_day = _temperature_sl;
double temp_night = _temperature_gl;
double temp_day = _temperature_gl;
double precipitation = _precipitation;
double relative_humidity = _relative_humidity;
switch(_classicfication)
@ -401,7 +405,6 @@ void FGClimate::set_temperate()
_temperature_gl = season_even(day, temp_night, temp_day);
_temperature_mean = 0.5*(temp_night + temp_day);
_temperature_sl = _temperature_gl;
_relative_humidity = relative_humidity;
_precipitation = precipitation;
@ -420,8 +423,8 @@ void FGClimate::set_continetal()
double humidity_fact = season_even(winter, 0.5, 1.0-0.5*day);
double temp_day = _temperature_sl;
double temp_night = _temperature_sl;
double temp_day = _temperature_gl;
double temp_night = _temperature_gl;
double precipitation = _precipitation;
double relative_humidity = _relative_humidity;
switch(_classicfication)
@ -504,7 +507,6 @@ void FGClimate::set_continetal()
_temperature_gl = season_even(day, temp_night, temp_day);
_temperature_mean = 0.5*(temp_night + temp_day);
_temperature_sl = _temperature_gl;
_relative_humidity = relative_humidity;
_precipitation = precipitation;
@ -525,8 +527,8 @@ void FGClimate::set_polar()
double humidity_fact = season_even(winter, 0.5, 1.0-0.5*day);
// polar climate also occurs high in the mountains
double temp_day = _temperature_sl;
double temp_night = _temperature_sl;
double temp_day = _temperature_gl;
double temp_night = _temperature_gl;
double precipitation = _precipitation;
double relative_humidity = _relative_humidity;
switch(_classicfication)
@ -549,7 +551,6 @@ void FGClimate::set_polar()
_temperature_gl = season_even(day, temp_night, temp_day);
_temperature_mean = 0.5*(temp_night + temp_day);
_temperature_sl = _temperature_gl;
_relative_humidity = relative_humidity;
_precipitation = precipitation;