Definition of vertical levels of the model used in JRA-25 and JCDAS

May, 2007 updated



Vertical levels are defined using parametesr A and B in a hybrid sigma-pressure vertical coordinate. Pressure of each full level is vertically interpolated from adjacent half levels. A number of vertical layers of a model is usually a number of full levels.

Reference:
Simmons, A. J. and D. M. Burridge, 1981: An energy and angular-momentum conserving vertical finite-difference scheme and hybrid vertical coordinates. Mon. Wea. Rev., 109, 758-766.


Level No. from lower
A
B
A+1000*B
  
     
half level
full level
     
representative pressure when surface pressure is equal to 1000hPa
  
1 0.000000 1.000000 1000.00 995.00
2 0.000000 0.990000 990.00 982.49
3 0.000000 0.975000 975.00 964.98
4 0.000000 0.955000 955.00 942.47
5 1.105610 0.928894 930.00 914.96
6 4.611954 0.895388 900.00 882.44
7 9.064261 0.855936 865.00 845.42
8 14.485500 0.811514 826.00 804.91
9 20.862747 0.763137 784.00 761.89
10 28.130577 0.711869 740.00 717.38
11 36.158020 0.658842 695.00 672.37
12 44.741348 0.605259 650.00 627.37
13 53.811684 0.551188 605.00 582.86
14 63.056015 0.497944 561.00 539.36
15 72.323532 0.445676 518.00 496.85
16 81.437820 0.394562 476.00 455.35
17 90.192863 0.344807 435.00 415.35
18 98.151306 0.297849 396.00 377.35
19 105.094887 0.253905 359.00 340.84
20 110.961449 0.212039 323.00 305.33
21 115.438545 0.172561 288.00 271.33
22 118.113609 0.136886 255.00 239.33
23 118.777374 0.105223 224.00 209.33
24 117.259979 0.077740 195.00 181.33
25 113.447090 0.054553 168.00 155.33
26 107.299492 0.035701 143.00 131.33
27 98.876595 0.021123 120.00 109.33
28 88.363998 0.010636 99.00 89.33
29 76.105057 0.003895 80.00 71.33
30 62.634430 0.000366 63.00 55.38
31 48.099998 0.000000 48.10 41.54
32 35.299999 0.000000 35.30 30.00
33 25.000000 0.000000 25.00 20.87
34 17.000000 0.000000 17.00 14.00
35 11.200000 0.000000 11.20 9.07
36 7.100000 0.000000 7.10 5.66
37 4.330000 0.000000 4.33 3.41
38 2.560000 0.000000 2.56 1.98
39 1.460000 0.000000 1.46 1.11
40 0.800000 0.000000 0.80 0.40
41 0.000000 0.000000 0.00  


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