
%Units
KM = 1000;
PW = 1.e15;
DAY = 24*3600;
MONTH = 30*DAY; 
YEAR = 12*MONTH;
MB = 100; %millibar  (Pa)
SV = 1.e09; %Sverdrup (Sv), mass transport unit

%Planetary & Physical constants
RADIUS = 6371*KM;       %Earth Radius (m)
GRAVI = 9.81;           %Earth gravity (ms-2)
SIGMA = 5.67*1.e-08;    %Stefan Boltzmann (Wm-2K-4)
So = 1367;              %Solar constant (Wm-2) 
ALPHAp = .3;            %Planetary albedo (non dim.)
%Lv = 2.5 * 1.e06;       %Enthalpy of vaporization of water (J kg-1)
%Psurf = 1000*MB;        %Atm. surface pressure (Pa)

%Ocean
RHO = 1000;             %density of water (kg m-3)
CPO = 4000;             %specific heat capacity of water (J kg-1 K-1)
HO = 500;               %Thermocline thickness (m)
HCO = RHO*CPO*HO;       %heat capacity (J K-1 m-2)
DTO = 5;               %Vertical temperature gradient (K)

%Amosphere
CPA = 1000; %specific heat capacity of dry air (J kg-1 K-1)
PATM = 1000*MB; %surface atm. pressure (Pa)
HCA = CPA*PATM/GRAVI; %atmospheric heat capacity (J K-1 m-2)
RHA1 = .5; %relative humidity for Box 1 (adim)
RHA2 = .5; %relative humidity for Box 2 (adim)

%Convective & circulation parameterizations
DTcrit_conv = 40; %moist adiabatic lapse rate (K)
DTcrit_circ = 15; %equator-pole surf. temp. gradient threshold
CAheat = 2*CPA; %pseudo-heat capacity (to include moisture effects)
PSIfrac = 0.25; % ratio PSIo/PSIa of circulation intensity
BIGONE = 100;

%Radiation
TEMI = (So*(1-ALPHAp)/(4*SIGMA))^.25; %Global mean emission temp. (K)
TEMI1 = ((So*(1-ALPHAp)*(pi/3+sqrt(3)/2))/(2*pi*SIGMA))^.25; %Box1 Emission temp.(K)
TEMI2 = ((So*(1-ALPHAp)*(2*pi/3-sqrt(3)/2))/(2*pi*SIGMA))^.25; %Box2 Emission temp.(K)
GAMMA = 1.25; %non dim. factor for H2o emissivity calc. (See Emanuel, 2002)
ALPHA = .0015; %non dim. factor for CO2 emissivity calc. (see Emanuel, 2002)