Changeset 1685 in lmdz_wrf for trunk/tools/diag_tools.py

Timestamp:

Dec 4, 2017, 7:30:21 PM (7 years ago)

Author:

lfita

Message:

Adding:

• `var_td': Function to compute dew-point air temperature from temperature and pressure values

File:

• trunk/tools/diag_tools.py (modified) (2 diffs)

trunk/tools/diag_tools.py

@@ -30 +30 @@
 # var_clt: Function to compute the total cloud fraction following 'newmicro.F90' from LMDZ using 1D vertical column values
 # var_mslp: Fcuntion to compute mean sea-level pressure
+# var_td: Function to compute dew-point air temperature from temperature and pressure values
 # var_virtualTemp: This function returns virtual temperature in K, 
 # var_WRFtime: Function to copmute CFtimes from WRFtime variable
@@ -1070 +1071 @@
 
     return td, dnamesvar, dvnamesvar
+
+def var_td(t, p, qv):
+    """ Function to compute dew-point air temperature from temperature and pressure values
+      t= temperature [K]
+      p= pressure (Pa)
+      formula:
+          temp = theta*(p/p0)**(R/Cp)
+
+    """
+    fname = 'compute_td'
+
+    tk = (t)*(p/fdef.module_definitions.p0ref)**(fdef.module_definitions.rcp)
+    data1 = 10.*0.6112*np.exp(17.67*(tk-273.16)/(tk-29.65))
+    data2 = 0.622*data1/(0.01*p-(1.-0.622)*data1)
+
+    rh = qv/data2
+                
+    pa = rh * data1
+    td = 257.44*np.log(pa/6.1121)/(18.678-np.log(pa/6.1121))
+
+    return td