.. _gcc-vgrids: ################################ GEOS-Chem Classic vertical grids ################################ On this page we provide information about the various vertical grids used in GEOS-Chem Classic. .. _gcc-grids-hybrid: ====================== Hybrid grid definition ====================== A hybrid sigma-pressure grid (aka :math:`\eta` grid) uses a terrain-following coordinate near the surface, which then transitions to a purely fixed-pressure coordinate. The pressure at the bottom edge of grid box :math:`(I,J,L)` of a hybrid grid may be defined as: .. math:: P_{edge}(I,J,L) = A_p(L) + B_p(L) \times P_{surface}(I,J) where - :math:`(I,J,L)` are the lon, lat, and level indices of the grid box; - :math:`P_{surface}(I,J)` is the "true" surface pressure at lon,lat location :math:`(I,J)`; - :math:`A_p(L)` are constants in surface pressure units (Pa or hPa), defined at level edges; - :math:`B_p(L)` are unitless constants, defined at level edges. The values of :math:`A_p(L)` and :math:`B_p(L)` specify the vertical properties of the grid. In GEOS-Chem, you may find these values in source code file :file:`GeosUtil/pressure_mod.F90`. The pressure at the vertical midpoint of grid box :math:`(I,J,L)` is computed as the average of the pressures at successive vertical edges: .. math:: P_{midpoint}(I,J,L) = \frac{P_{edge}(I,J,L) + P_{edge}(I,J,L+1)}{2} An :math:`\eta` coordinate can be constructed from :math:`P_{edge}(I,J,L)` and :math:`P_{midpoint}(I,J,L)` as follows: .. math:: \eta_{edge}(I,J,L) = \frac{P_{edge}(I,J,L) - P_{top}}{P_{surface}(I,J) - P_{top}} .. math:: \eta_{midpoint}(I,J,L) = \frac{P_{midpoint}(I,J,L) - P_{top}}{P_{surface}(I,J) - P_{top}} where :math:`P_{top}` is pressure at the top level of the vertical grid. Specifics for GMAO vertical grids --------------------------------- The the :math:`P_{edge}(I,J,L)` and :math:`P_{midpoint}(I,J,L)` values in GMAO meteorological products vary with the topography up to 170 hPa. Skyward of 170 hPa, :math:`P_{edge}(I,J,L)` and :math:`P_{midpoint}(I,J,L)` remain constant for all longitudes and latitudes :math:`(I,J)`. GMAO meteorological products use a model top of 0.01 hPa. .. _gcc-vgrids_gmao: =================================== Vertical grids for GMAO meteorology =================================== .. _gcc-vgrids-gmao-72: 72-level vertical grid ---------------------- This grid is used by the `GEOS-FP `_, `GEOS-IT `_, and `MERRA-2 `_ meteorological field products from NASA GMAO. It has 72 vertical levels and 73 edges. .. _gcc-vgrids-gmao-72-ind: Indexing ~~~~~~~~ .. list-table:: :header-rows: 1 * - Instance - Surface level - Top-of-atm level - Direction * - GEOS-Chem Classic using GMAO met - 1 - 72 - :literal:`positive:up` * - Emissions data for GEOS-Chem - 1 - 72 - :literal:`positive:up` * - Processed met fields for GEOS-Chem - 1 - 72 - :literal:`positive:up` * - Raw met fields for GEOS-Chem - 72 - 1 - :literal:`positive:down` .. _gcc-vgrids-gmao-72-ab: :math:`A_p` and :math:`B_p` ~~~~~~~~~~~~~~~~~~~~~~~~~~~ The table below lists the :math:`A_p` and :math:`B_p` parameters that define the 72-level vertical grid. The level edge indices run from 1 (surface) to 73 (top-of atmosphere). .. list-table:: :header-rows: 1 * - Level edge index - :math:`A_p` (hPa) - :math:`B_p` (unitless) * - 1 - 0.0 - 1.0 * - 2 - 0.04804826 - 0.984952 * - 3 - 6.593752 - 0.963406 * - 4 - 13.1348 - 0.941865 * - 5 - 19.61311 - 0.920387 * - 6 - 26.09201 - 0.898908 * - 7 - 32.57081 - 0.877429 * - 8 - 38.98201 - 0.856018 * - 9 - 45.33901 - 0.8346609 * - 10 - 51.69611 - 0.8133039 * - 11 - 58.05321 - 0.7919469 * - 12 - 64.36264 - 0.7706375 * - 13 - 70.62198 - 0.7493782 * - 14 - 78.83422 - 0.721166 * - 15 - 89.09992 - 0.6858999 * - 16 - 99.36521 - 0.6506349 * - 17 - 109.1817 - 0.6158184 * - 18 - 118.9586 - 0.5810415 * - 19 - 128.6959 - 0.5463042 * - 20 - 142.91 - 0.4945902 * - 21 - 156.26 - 0.4437402 * - 22 - 169.609 - 0.3928911 * - 23 - 181.619 - 0.3433811 * - 24 - 193.097 - 0.2944031 * - 25 - 203.259 - 0.2467411 * - 26 - 212.15 - 0.2003501 * - 27 - 218.776 - 0.1562241 * - 28 - 223.898 - 0.1136021 * - 29 - 224.363 - 0.06372006 * - 30 - 216.865 - 0.02801004 * - 31 - 201.192 - 0.006960025 * - 32 - 176.93 - 8.175413e-09 * - 33 - 150.393 - 0.0 * - 34 - 127.837 - 0.0 * - 35 - 108.663 - 0.0 * - 36 - 92.36572 - 0.0 * - 37 - 78.51231 - 0.0 * - 38 - 66.60341 - 0.0 * - 39 - 56.38791 - 0.0 * - 40 - 47.64391 - 0.0 * - 41 - 40.17541 - 0.0 * - 42 - 33.81001 - 0.0 * - 43 - 28.36781 - 0.0 * - 44 - 23.73041 - 0.0 * - 45 - 19.7916 - 0.0 * - 46 - 16.4571 - 0.0 * - 47 - 13.6434 - 0.0 * - 48 - 11.2769 - 0.0 * - 49 - 9.292942 - 0.0 * - 50 - 7.619842 - 0.0 * - 51 - 6.216801 - 0.0 * - 52 - 5.046801 - 0.0 * - 53 - 4.076571 - 0.0 * - 54 - 3.276431 - 0.0 * - 55 - 2.620211 - 0.0 * - 56 - 2.08497 - 0.0 * - 57 - 1.65079 - 0.0 * - 58 - 1.30051 - 0.0 * - 59 - 1.01944 - 0.0 * - 60 - 0.7951341 - 0.0 * - 61 - 0.6167791 - 0.0 * - 62 - 0.4758061 - 0.0 * - 63 - 0.3650411 - 0.0 * - 64 - 0.2785261 - 0.0 * - 65 - 0.211349 - 0.0 * - 66 - 0.159495 - 0.0 * - 67 - 0.119703 - 0.0 * - 68 - 0.08934502 - 0.0 * - 69 - 0.06600001 - 0.0 * - 70 - 0.04758501 - 0.0 * - 71 - 0.0327 - 0.0 * - 72 - 0.02 - 0.0 * - 73 - 0.01 - 0.0 .. _gcc-vgrids-gmao-72-prs-alt: Pressures and altitudes ~~~~~~~~~~~~~~~~~~~~~~~ The table below lists pressures and altitudes of the 72 layer grid for a column at atmospheric sea level. .. code-block:: text L Eta Edge Eta Mid Altitude Pressure (unitless) (unitless) (km) (hPa) ======================================================== 0.000000 80.581 0.010 72 0.000005 78.146 0.015 0.000010 76.357 0.020 71 0.000016 74.594 0.026 0.000022 73.180 0.033 70 0.000030 71.812 0.040 0.000037 70.657 0.048 69 0.000046 69.440 0.057 0.000055 68.392 0.066 68 0.000067 67.243 0.078 0.000078 66.245 0.089 67 0.000093 65.115 0.105 0.000108 64.130 0.120 66 0.000128 63.004 0.140 0.000148 62.021 0.159 65 0.000173 60.902 0.185 0.000199 59.924 0.211 64 0.000232 58.816 0.245 0.000265 57.846 0.279 63 0.000308 56.752 0.322 0.000350 55.794 0.365 62 0.000405 54.717 0.420 0.000460 53.773 0.476 61 0.000529 52.716 0.546 0.000599 51.788 0.617 60 0.000687 50.754 0.706 0.000775 49.844 0.795 59 0.000886 48.835 0.907 0.000996 47.946 1.019 58 0.001135 46.962 1.160 0.001274 46.092 1.301 57 0.001446 45.134 1.476 0.001619 44.286 1.651 56 0.001834 43.355 1.868 0.002048 42.529 2.085 55 0.002312 41.627 2.353 0.002576 40.825 2.620 54 0.002900 39.951 2.948 0.003224 39.173 3.276 53 0.003619 38.328 3.677 0.004013 37.574 4.077 52 0.004492 36.759 4.562 0.004971 36.030 5.047 51 0.005548 35.244 5.632 0.006126 34.539 6.217 50 0.006818 33.782 6.918 0.007510 33.101 7.620 49 0.008336 32.372 8.456 0.009162 31.716 9.293 48 0.010141 31.015 10.285 0.011120 30.382 11.277 47 0.012287 29.701 12.460 0.013455 29.085 13.643 46 0.014844 28.423 15.050 0.016232 27.824 16.457 45 0.017878 27.180 18.124 0.019523 26.596 19.792 44 0.021467 25.971 21.761 0.023410 25.402 23.730 43 0.025699 24.794 26.049 0.027987 24.240 28.368 42 0.030673 23.648 31.089 0.033358 23.108 33.810 41 0.036499 22.531 36.993 0.039641 22.004 40.175 40 0.043326 21.438 43.910 0.047011 20.920 47.644 39 0.051326 20.364 52.016 0.055641 19.855 56.388 38 0.060682 19.309 61.496 0.065723 18.807 66.603 37 0.071600 18.269 72.558 0.077477 17.773 78.512 36 0.084313 17.243 85.439 0.091149 16.753 92.366 35 0.099191 16.222 100.514 0.107233 15.731 108.663 34 0.116695 15.198 118.250 0.126157 14.706 127.837 33 0.137287 14.170 139.115 0.148418 13.674 150.393 32 0.161513 13.134 163.661 0.174608 12.633 176.930 31 0.190061 12.086 192.587 0.205513 11.578 208.244 30 0.223772 11.021 226.745 0.242032 10.504 245.246 29 0.263587 9.936 267.087 0.285142 9.409 288.927 28 0.309854 8.846 313.966 0.334566 8.320 339.005 27 0.353349 7.943 358.038 0.372133 7.582 377.070 26 0.390927 7.237 396.112 0.409720 6.905 415.155 25 0.428528 6.585 434.212 0.447337 6.277 453.269 24 0.466153 5.980 472.335 0.484970 5.692 491.401 23 0.503795 5.413 510.475 0.522620 5.142 529.550 22 0.541449 4.879 548.628 0.560278 4.623 567.706 21 0.579115 4.375 586.793 0.597953 4.132 605.880 20 0.616790 3.896 624.967 0.635628 3.665 644.054 19 0.654471 3.439 663.146 0.673314 3.219 682.239 18 0.685878 3.074 694.969 0.698442 2.932 707.699 17 0.711006 2.792 720.429 0.723570 2.654 733.160 16 0.736134 2.517 745.890 0.748698 2.382 758.621 15 0.761265 2.249 771.354 0.773832 2.118 784.088 14 0.786400 1.988 796.822 0.798967 1.860 809.556 13 0.809021 1.759 819.743 0.819075 1.659 829.929 12 0.826616 1.584 837.570 0.834157 1.510 845.211 11 0.841698 1.436 852.852 0.849239 1.363 860.493 10 0.856781 1.290 868.135 0.864323 1.218 875.776 9 0.871864 1.146 883.418 0.879406 1.075 891.059 8 0.886948 1.004 898.701 0.894489 0.934 906.342 7 0.902031 0.864 913.984 0.909573 0.795 921.626 6 0.917116 0.726 929.268 0.924658 0.657 936.911 5 0.932200 0.589 944.553 0.939743 0.521 952.195 4 0.947285 0.454 959.837 0.954828 0.387 967.480 3 0.962370 0.320 975.122 0.969913 0.254 982.765 2 0.977456 0.189 990.408 0.984999 0.123 998.051 1 0.992500 0.058 1005.650 1.000000 -0.006 1013.250 .. _gcc-vgrids-gmao-47: 47-layer reduced vertical grid ------------------------------ In order to save computational resources, GEOS-Chem Classic can collapse the :ref:`gcc-vgrids-gmao-72` down to a 47-level grid (with 48 edges) "on-the-fly". Groups of 2 and 4 levels are lumped together starting at ~70 hPa. See the table below for more information. .. _gcc-vgrids-gmao-47-ind: Indexing ~~~~~~~~ .. list-table:: :header-rows: 1 * - Instance - Surface level - Top-of-atm level - Direction * - GEOS-Chem Classic using GMAO met - 1 - 47 - :literal:`positive:up` .. _gcc-vgrids-gmao-47-lump: Lumping of vertical levels ~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text 47-level reduced vertical grid Bottom Bottom # levels edge of edge prs lumped level (hPa) together PTOP 0.010 47 0.066 4 46 0.211 4 45 0.617 4 44 1.651 4 43 4.077 4 42 9.293 4 41 19.792 4 40 28.368 2 39 40.175 2 38 56.388 2 37 78.512 2 %%%% START LUMPING LEVELS ABOVE HERE %%%%% 1-36 Levels are the same as in the 72-layer grid .. _gcc-vgrids-gmao-47-ab: :math:`A_p` and :math:`B_p` ~~~~~~~~~~~~~~~~~~~~~~~~~~~ The table below lists the :math:`A_p` and :math:`B_p` parameters that define the 47 level reduced vertical grid. The level edge indices run from 1 (surface) to 48 (top-of atmosphere). .. list-table:: :header-rows: 1 * - Level edge index - :math:`A_p` (hPa) - :math:`B_p` (unitless) * - 1 - 0.0 - 1.0 * - 2 - 0.04804826 - 0.984952 * - 3 - 6.593752 - 0.963406 * - 4 - 13.1348 - 0.941865 * - 5 - 19.61311 - 0.920387 * - 6 - 26.09201 - 0.898908 * - 7 - 32.57081 - 0.877429 * - 8 - 38.98201 - 0.856018 * - 9 - 45.33901 - 0.8346609 * - 10 - 51.69611 - 0.8133039 * - 11 - 58.05321 - 0.7919469 * - 12 - 64.36264 - 0.7706375 * - 13 - 70.62198 - 0.7493782 * - 14 - 78.83422 - 0.721166 * - 15 - 89.09992 - 0.6858999 * - 16 - 99.36521 - 0.6506349 * - 17 - 109.1817 - 0.6158184 * - 18 - 118.9586 - 0.5810415 * - 19 - 128.6959 - 0.5463042 * - 20 - 142.91 - 0.4945902 * - 21 - 156.26 - 0.4437402 * - 22 - 169.609 - 0.3928911 * - 23 - 181.619 - 0.3433811 * - 24 - 193.097 - 0.2944031 * - 25 - 203.259 - 0.2467411 * - 26 - 212.15 - 0.2003501 * - 27 - 218.776 - 0.1562241 * - 28 - 223.898 - 0.1136021 * - 29 - 224.363 - 0.06372006 * - 30 - 216.865 - 0.02801004 * - 31 - 201.192 - 0.006960025 * - 32 - 176.93 - 8.175413e-09 * - 33 - 150.393 - 0.0 * - 34 - 127.837 - 0.0 * - 35 - 108.663 - 0.0 * - 36 - 92.36572 - 0.0 * - 37 - 78.51231 - 0.0 * - 38 - 56.38791 - 0.0 * - 39 - 40.17541 - 0.0 * - 40 - 28.36781 - 0.0 * - 41 - 19.7916 - 0.0 * - 42 - 9.292942 - 0.0 * - 43 - 4.076571 - 0.0 * - 44 - 1.65079 - 0.0 * - 45 - 0.6167791 - 0.0 * - 46 - 0.211349 - 0.0 * - 47 - 0.06600001 - 0.0 * - 48 - 0.01 - 0.0 .. _gcc-vgrids-gmao-47-prs-alt: Pressures and altitudes ~~~~~~~~~~~~~~~~~~~~~~~ The table below lists pressures and altitudes of the 47 layer grid for a column at atmospheric sea level. .. code-block:: text L Eta Edge Eta Mid Altitude Pressure (unitless) (unitless) (km) (hPa) ======================================================== 0.000000 80.581 0.010 47 0.000028 72.180 0.038 0.000055 68.392 0.066 46 0.000127 63.053 0.139 0.000199 59.924 0.211 45 0.000399 54.834 0.414 0.000599 51.788 0.617 44 0.001109 47.135 1.134 0.001619 44.286 1.651 43 0.002816 40.166 2.864 0.004013 37.574 4.077 42 0.006588 34.024 6.685 0.009162 31.716 9.293 41 0.014342 28.654 14.542 0.019523 26.596 19.792 40 0.023755 25.307 24.080 0.027987 24.240 28.368 39 0.033814 23.020 34.272 0.039641 22.004 40.175 38 0.047641 20.836 48.282 0.055641 19.855 56.388 37 0.066559 18.727 67.450 0.077477 17.773 78.512 36 0.084313 17.243 85.439 0.091149 16.753 92.366 35 0.099191 16.222 100.514 0.107233 15.731 108.663 34 0.116695 15.198 118.250 0.126157 14.706 127.837 33 0.137287 14.170 139.115 0.148418 13.674 150.393 32 0.161513 13.134 163.661 0.174608 12.633 176.930 31 0.190061 12.086 192.587 0.205513 11.578 208.244 30 0.223772 11.021 226.745 0.242032 10.504 245.246 29 0.263587 9.936 267.087 0.285142 9.409 288.927 28 0.309854 8.846 313.966 0.334566 8.320 339.005 27 0.353349 7.943 358.038 0.372133 7.582 377.070 26 0.390927 7.237 396.112 0.409720 6.905 415.155 25 0.428528 6.585 434.212 0.447337 6.277 453.269 24 0.466153 5.980 472.335 0.484970 5.692 491.401 23 0.503795 5.413 510.475 0.522620 5.142 529.550 22 0.541449 4.879 548.628 0.560278 4.623 567.706 21 0.579115 4.375 586.793 0.597953 4.132 605.880 20 0.616790 3.896 624.967 0.635628 3.665 644.054 19 0.654471 3.439 663.146 0.673314 3.219 682.239 18 0.685878 3.074 694.969 0.698442 2.932 707.699 17 0.711006 2.792 720.429 0.723570 2.654 733.160 16 0.736134 2.517 745.890 0.748698 2.382 758.621 15 0.761265 2.249 771.354 0.773832 2.118 784.088 14 0.786400 1.988 796.822 0.798967 1.860 809.556 13 0.809021 1.759 819.743 0.819075 1.659 829.929 12 0.826616 1.584 837.570 0.834157 1.510 845.211 11 0.841698 1.436 852.852 0.849239 1.363 860.493 10 0.856781 1.290 868.135 0.864323 1.218 875.776 9 0.871864 1.146 883.418 0.879406 1.075 891.059 8 0.886948 1.004 898.701 0.894489 0.934 906.342 7 0.902031 0.864 913.984 0.909573 0.795 921.626 6 0.917116 0.726 929.268 0.924658 0.657 936.911 5 0.932200 0.589 944.553 0.939743 0.521 952.195 4 0.947285 0.454 959.837 0.954828 0.387 967.480 3 0.962370 0.320 975.122 0.969913 0.254 982.765 2 0.977456 0.189 990.408 0.984999 0.123 998.051 1 0.992500 0.058 1005.650 1.000000 -0.006 1013.250 ========================================= Vertical grids for GCAP2/GISS meteorology ========================================= .. _gcc-vgrids-gcap-102: 102-level vertical grid ----------------------- GCAP2/GISS meteorology is produced on a grid with 102 vertical levels. To reduce the amount of computational overhead, GEOS-Chem Classic can regrid this "on-the-fly" to ether a :ref:`gcc-vgrids-gcap-74` or a :ref:`gcc-vgrids-gcap-40`. .. _gcc-vgrids-gcap-102-ind: Indexing ~~~~~~~~ .. list-table:: :header-rows: 1 * - Instance - Surface level - Top-of-atm level - Direction * - GEOS-Chem Classic using GCAP2 met - 1 - 102 - :literal:`positive:up` .. _gcc-vgrids-gcap-102-ab: :math:`A_p` and :math:`B_p` ~~~~~~~~~~~~~~~~~~~~~~~~~~~ The table below lists the :math:`A_p` and :math:`B_p` parameters that define the 102 level vertical grid. The level edge indices run from 1 (surface) to 103 (top-of atmosphere). .. list-table:: :header-rows: 1 * - Level edge index - :math:`A_p` (hPa) - :math:`B_p` (unitless) * - 1 - 0.0 - 1.0 * - 2 - 2.7871507 - 0.98192363 * - 3 - 5.5743014 - 0.96384725 * - 4 - 8.3614521 - 0.94577088 * - 5 - 11.1486028 - 0.92769451 * - 6 - 13.9357536 - 0.90961814 * - 7 - 16.7229043 - 0.89154176 * - 8 - 19.510055 - 0.87346539 * - 9 - 22.2972057 - 0.85538902 * - 10 - 25.0843564 - 0.83731265 * - 11 - 27.8715071 - 0.81923627 * - 12 - 30.6586578 - 0.8011599 * - 13 - 33.4458085 - 0.78308353 * - 14 - 36.2329593 - 0.76500716 * - 15 - 39.02011 - 0.74693078 * - 16 - 41.8087123 - 0.728845 * - 17 - 44.6089278 - 0.71068389 * - 18 - 47.4534183 - 0.69223563 * - 19 - 50.4082336 - 0.67307185 * - 20 - 53.5662786 - 0.65259001 * - 21 - 57.009571 - 0.63025815 * - 22 - 60.7533531 - 0.60597744 * - 23 - 64.7323011 - 0.58017154 * - 24 - 68.8549615 - 0.55343357 * - 25 - 73.0567364 - 0.5261825 * - 26 - 77.2969797 - 0.49868193 * - 27 - 81.5364973 - 0.47118607 * - 28 - 85.734643 - 0.44395854 * - 29 - 89.8565776 - 0.41722528 * - 30 - 93.8754457 - 0.39116047 * - 31 - 97.7709243 - 0.36589591 * - 32 - 101.5277712 - 0.34153047 * - 33 - 105.1350991 - 0.31813474 * - 34 - 108.5878272 - 0.2957417 * - 35 - 111.8859556 - 0.27435132 * - 36 - 115.03021 - 0.25395891 * - 37 - 118.0249453 - 0.23453623 * - 38 - 120.8854039 - 0.21598441 * - 39 - 123.6326345 - 0.19816694 * - 40 - 126.2811535 - 0.18098968 * - 41 - 128.8360417 - 0.16441967 * - 42 - 131.2987506 - 0.1484475 * - 43 - 133.6736353 - 0.13304493 * - 44 - 135.9708571 - 0.11814604 * - 45 - 138.2013035 - 0.10368024 * - 46 - 140.3700552 - 0.08961456 * - 47 - 142.481467 - 0.07592077 * - 48 - 144.5457005 - 0.06253295 * - 49 - 146.5692881 - 0.04940875 * - 50 - 148.5464231 - 0.03658583 * - 51 - 150.4712991 - 0.02410183 * - 52 - 152.3497225 - 0.01191911 * - 53 - 154.1875 - 0.0 * - 54 - 144.546875 - 0.0 * - 55 - 135.1875 - 0.0 * - 56 - 126.078125 - 0.0 * - 57 - 117.1914062 - 0.0 * - 58 - 108.5859375 - 0.0 * - 59 - 100.3671875 - 0.0 * - 60 - 92.5898438 - 0.0 * - 61 - 85.2265625 - 0.0 * - 62 - 78.2226562 - 0.0 * - 63 - 71.5546875 - 0.0 * - 64 - 65.2226562 - 0.0 * - 65 - 59.2226562 - 0.0 * - 66 - 53.5546875 - 0.0 * - 67 - 48.2226562 - 0.0 * - 68 - 43.2226562 - 0.0 * - 69 - 38.5546875 - 0.0 * - 70 - 34.2226562 - 0.0 * - 71 - 30.2226562 - 0.0 * - 72 - 26.5507812 - 0.0 * - 73 - 23.1875 - 0.0 * - 74 - 20.078125 - 0.0 * - 75 - 17.1896562 - 0.0 * - 76 - 14.5684375 - 0.0 * - 77 - 12.2865742 - 0.0 * - 78 - 10.3573086 - 0.0 * - 79 - 8.735375 - 0.0 * - 80 - 7.3664922 - 0.0 * - 81 - 6.2100156 - 0.0 * - 82 - 5.2343633 - 0.0 * - 83 - 4.4119297 - 0.0 * - 84 - 3.7186797 - 0.0 * - 85 - 3.1341479 - 0.0 * - 86 - 2.6404328 - 0.0 * - 87 - 2.2207877 - 0.0 * - 88 - 1.8587369 - 0.0 * - 89 - 1.5477125 - 0.0 * - 90 - 1.2782115 - 0.0 * - 91 - 1.0427319 - 0.0 * - 92 - 0.8367716 - 0.0 * - 93 - 0.6514691 - 0.0 * - 94 - 0.4772511 - 0.0 * - 95 - 0.3168814 - 0.0 * - 96 - 0.1785988 - 0.0 * - 97 - 0.1 - 0.0 * - 98 - 0.056 - 0.0 * - 99 - 0.032 - 0.0 * - 100 - 0.018 - 0.0 * - 101 - 0.01 - 0.0 * - 102 - 0.005 - 0.0 * - 103 - 0.002 - 0.0 .. _gcc-vgrids-gcap-74: 74-level reduced vertical grid ------------------------------ In order to save computational resources, GEOS-Chem Classic can collapse the :ref:`gcc-vgrids-gcap-102` down to a 74-level grid (with 75 edges) "on-the-fly". Groups of 2 and 4 levels are lumped together starting at ~85 hPa. See the table below for more information. .. _gcc-vgrids-gcap-74-ind: Indexing ~~~~~~~~ .. list-table:: :header-rows: 1 * - Instance - Surface level - Top-of-atm level - Direction * - GEOS-Chem Classic using GCAP2 met - 1 - 74 - :literal:`positive:up` .. _gcc-vgrids-gcap-74-lump: Lumping of vertical levels ~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text 74-level GISS grid (condensed from 102-layer grid) Bottom Bottom # levels edge of edge prs lumped level (hPa) together PTOP 0.0020000 74 0.0320000 4 73 0.3168814 4 72 1.0427319 4 71 2.2207877 4 70 4.4119297 4 69 8.7353750 4 68 17.1896562 4 67 23.1875000 2 66 30.2226562 2 65 38.5546875 2 64 48.2226562 2 63 59.2226562 2 62 71.5546875 2 61 85.2265625 2 %%%% START LUMPING LEVELS ABOVE HERE %%%%% 1-60 Levels are the same as for the 102 level vertical grid .. _gcc-vgrids-gcap-74-ab: :math:`A_p` and :math:`B_p` ~~~~~~~~~~~~~~~~~~~~~~~~~~~ The table below lists the :math:`A_p` and :math:`B_p` parameters that define the 74-level vertical grid. The level edge indices run from 1 (surface) to 75 (top-of atmosphere). .. list-table:: :header-rows: 1 * - Level edge index - :math:`A_p` (hPa) - :math:`B_p` (unitless) * - 1 - 0.0 - 1.0 * - 2 - 2.7871507 - 0.98192363 * - 3 - 5.5743014 - 0.96384725 * - 4 - 8.3614521 - 0.94577088 * - 5 - 11.1486028 - 0.92769451 * - 6 - 13.9357536 - 0.90961814 * - 7 - 16.7229043 - 0.89154176 * - 8 - 19.510055 - 0.87346539 * - 9 - 22.2972057 - 0.85538902 * - 10 - 25.0843564 - 0.83731265 * - 11 - 27.8715071 - 0.81923627 * - 12 - 30.6586578 - 0.8011599 * - 13 - 33.4458085 - 0.78308353 * - 14 - 36.2329593 - 0.76500716 * - 15 - 39.02011 - 0.74693078 * - 16 - 41.8087123 - 0.728845 * - 17 - 44.6089278 - 0.71068389 * - 18 - 47.4534183 - 0.69223563 * - 19 - 50.4082336 - 0.67307185 * - 20 - 53.5662786 - 0.65259001 * - 21 - 57.009571 - 0.63025815 * - 22 - 60.7533531 - 0.60597744 * - 23 - 64.7323011 - 0.58017154 * - 24 - 68.8549615 - 0.55343357 * - 25 - 73.0567364 - 0.5261825 * - 26 - 77.2969797 - 0.49868193 * - 27 - 81.5364973 - 0.47118607 * - 28 - 85.734643 - 0.44395854 * - 29 - 89.8565776 - 0.41722528 * - 30 - 93.8754457 - 0.39116047 * - 31 - 97.7709243 - 0.36589591 * - 32 - 101.5277712 - 0.34153047 * - 33 - 105.1350991 - 0.31813474 * - 34 - 108.5878272 - 0.2957417 * - 35 - 111.8859556 - 0.27435132 * - 36 - 115.03021 - 0.25395891 * - 37 - 118.0249453 - 0.23453623 * - 38 - 120.8854039 - 0.21598441 * - 39 - 123.6326345 - 0.19816694 * - 40 - 126.2811535 - 0.18098968 * - 41 - 128.8360417 - 0.16441967 * - 42 - 131.2987506 - 0.1484475 * - 43 - 133.6736353 - 0.13304493 * - 44 - 135.9708571 - 0.11814604 * - 45 - 138.2013035 - 0.10368024 * - 46 - 140.3700552 - 0.08961456 * - 47 - 142.481467 - 0.07592077 * - 48 - 144.5457005 - 0.06253295 * - 49 - 146.5692881 - 0.04940875 * - 50 - 148.5464231 - 0.03658583 * - 51 - 150.4712991 - 0.02410183 * - 52 - 152.3497225 - 0.01191911 * - 53 - 154.1875 - 0.0 * - 54 - 144.546875 - 0.0 * - 55 - 135.1875 - 0.0 * - 56 - 126.078125 - 0.0 * - 57 - 117.1914062 - 0.0 * - 58 - 108.5859375 - 0.0 * - 59 - 100.3671875 - 0.0 * - 60 - 92.5898438 - 0.0 * - 61 - 85.2265625 - 0.0 * - 62 - 71.5546875 - 0.0 * - 63 - 59.2226562 - 0.0 * - 64 - 48.2226562 - 0.0 * - 65 - 38.5546875 - 0.0 * - 66 - 30.2226562 - 0.0 * - 67 - 23.1875 - 0.0 * - 68 - 17.1896562 - 0.0 * - 69 - 8.735375 - 0.0 * - 70 - 4.4119297 - 0.0 * - 71 - 2.2207877 - 0.0 * - 72 - 1.0427319 - 0.0 * - 73 - 0.3168814 - 0.0 * - 74 - 0.032 - 0.0 * - 75 - 0.002 - 0.0 .. _gcc-vgrids-gcap-40: 40-level reduced vertical grid ------------------------------- In order to save computational resources, GEOS-Chem Classic can collapse the :ref:`gcc-vgrids-gcap-102` down to a 40-level grid (with 41 edges) "on-the-fly". .. _gcc-vgrids-gcap-40-ind: Indexing ~~~~~~~~ .. list-table:: :header-rows: 1 * - Instance - Surface level - Top-of-atm level - Direction * - GEOS-Chem Classic using GCAP2 met - 1 - 40 - :literal:`positive:up` .. _gcc-vgrids-gcap-40-ab: :math:`A_p` and :math:`B_p` ~~~~~~~~~~~~~~~~~~~~~~~~~~~ The table below lists the :math:`A_p` and :math:`B_p` parameters that define the 40-level vertical grid. The level edge indices run from 1 (surface) to 41 (top-of atmosphere). .. list-table:: :header-rows: 1 * - Level edge index - :math:`A_p` (hPa) - :math:`B_p` (unitless) * - 1 - 0.0 - 1.0 * - 2 - 3.597122 - 0.97601918 * - 3 - 7.553957 - 0.94964029 * - 4 - 12.05036 - 0.91966427 * - 5 - 16.906475 - 0.88729017 * - 6 - 22.302158 - 0.85131894 * - 7 - 28.597122 - 0.80935252 * - 8 - 35.791367 - 0.76139089 * - 9 - 43.884892 - 0.70743405 * - 10 - 52.517986 - 0.6498801 * - 11 - 61.510791 - 0.58992806 * - 12 - 70.683453 - 0.52877698 * - 13 - 80.035971 - 0.46642686 * - 14 - 89.028777 - 0.40647482 * - 15 - 97.661871 - 0.34892086 * - 16 - 105.755396 - 0.29496403 * - 17 - 113.309353 - 0.24460432 * - 18 - 120.143885 - 0.19904077 * - 19 - 126.258993 - 0.15827338 * - 20 - 131.834532 - 0.12110312 * - 21 - 136.870504 - 0.08752998 * - 22 - 141.546763 - 0.05635492 * - 23 - 145.863309 - 0.02757794 * - 24 - 150.0 - 0.0 * - 25 - 128.0 - 0.0 * - 26 - 108.0 - 0.0 * - 27 - 90.0 - 0.0 * - 28 - 73.0 - 0.0 * - 29 - 57.0 - 0.0 * - 30 - 43.0 - 0.0 * - 31 - 31.0 - 0.0 * - 32 - 20.0 - 0.0 * - 33 - 10.0 - 0.0 * - 34 - 5.62 - 0.0 * - 35 - 3.16 - 0.0 * - 36 - 1.78 - 0.0 * - 37 - 1.0 - 0.0 * - 38 - 0.562 - 0.0 * - 39 - 0.316 - 0.0 * - 40 - 0.178 - 0.0 * - 41 - 0.1 - 0.0