#NATURAL CONSTANTS -> SOURCE(NAT.CONST.R)


#EARTH BODY
    g <-	9.81		#gravitational acceleration
    Tearth <- 86164.1	        #rotation period of the Earth (one sidereal day) [s]
    Oearth <- 2 * pi / Tearth   #angular speed of earth [rad s-1]
    coriolis <- function(latitude) 2 * Oearth * sin(d2r * latitude)	#Coriolis parameter [rad s-1]

#GEOMETRY
    r2d <- 180/pi		#convert radians to degree
    d2r <- pi/180		#convert degree to radians


#THERMODYNAMICS
  #standard atmosphere
    p0 = 100000			#1000 hPa standard pressure
    T0 = 273.15			#conversion between K and B0C
	  R  = 8.31432        #NB7m/(molB7K)
    R_igl <- 8.314462175	#ideal gas constant [J mol-1 K-1 == kg m2 s-2 mol-1 K-1]
    kap <- 0.40				#von-Karman constant accordig to Foken (2008) [-]
    
  #molar masses
    Md <- 28.97			#dry air [kg kmol-1]
    Mv <- 18.02			#water vapor [kg kmol-1]
    Mc <- 44.01			#co2 [kg kmol-1]
    M_CH4 <- 16.04  	#CH4 [kg kmol-1]
	  Mch4 <- 16.04246    #CH4[g mole-1]
    mvmd <- Mv / Md		#molar mass ratio water vapour / dry air
    mdmv <- Md / Mv		#molar mass ratio dry air / water vapour

  #dry air (d)
    cpd <- 1004.64		#dry air specific heat at constant pressure 	[J kg-1 K-1]
    cvd <- 717.6		#dry air specific heat at constant volume	[J kg-1 K-1]
    Rd <- cpd - cvd		#specific gas constant for dry air		[J kg-1 K-1]
    gammad <- cpd / cvd	
    Kad <- Rd / cpd		#Kappa exponent for ideal gas law (Poisson)	[-]

  #water vapor (v)
    cpv <- 1846			#water vapor specific heat at constant pressure [m2 K s-2]
    cvv <- 1384.04		#water vapor specific heat at constant volume	[m2 K s-2]
    Rv <- cpv - cvv		#specific gas constant for water vapor		[m2 K s-2]
    gammav <- cpv / cvv
    Kav <- Rv / cpv		#Kappa exponent for ideal gas law (Poisson)	[-]