Return the two-dimensional MCAPE, MCIN, LCL, and LFC. This function calculates the maximum convective available potential energy (MCAPE), maximum convective inhibition (MCIN), lifted condensation level (LCL), and level of free convection (LFC). This function uses the RIP [Read/Inter
(pres_hpa, tkel, qv, height, terrain, psfc_hpa, ter_follow,
missing=default_fill(np.float64), meta=True)
| 734 | |
| 735 | @set_cape_alg_metadata(is2d=True, copyarg="pres_hpa") |
| 736 | def cape_2d(pres_hpa, tkel, qv, height, terrain, psfc_hpa, ter_follow, |
| 737 | missing=default_fill(np.float64), meta=True): |
| 738 | """Return the two-dimensional MCAPE, MCIN, LCL, and LFC. |
| 739 | |
| 740 | This function calculates the maximum convective available potential |
| 741 | energy (MCAPE), maximum convective inhibition (MCIN), |
| 742 | lifted condensation level (LCL), and level of free convection (LFC). This |
| 743 | function uses the RIP [Read/Interpolate/plot] code to calculate |
| 744 | potential energy (CAPE) and convective inhibition |
| 745 | (CIN) [J kg-1] only for the parcel with max theta-e |
| 746 | in the column (i.e. something akin to Colman's MCAPE). CAPE is defined as |
| 747 | the accumulated buoyant energy from the level of free convection (LFC) to |
| 748 | the equilibrium level (EL). CIN is defined as the accumulated negative |
| 749 | buoyant energy from the parcel starting point to the LFC. |
| 750 | |
| 751 | The cape_2d algorithm works by first finding the maximum theta-e height |
| 752 | level in the lowest 3000 m. A parcel with a depth of 500 m is then |
| 753 | calculated and centered over this maximum theta-e height level. The |
| 754 | parcel's moisture and temperature characteristics are calculated by |
| 755 | averaging over the depth of this 500 m parcel. This 'maximum' parcel |
| 756 | is then used to compute MCAPE, MCIN, LCL and LFC. |
| 757 | |
| 758 | The leftmost dimension of the returned array represents four different |
| 759 | quantities: |
| 760 | |
| 761 | - return_val[0,...] will contain MCAPE [J kg-1] |
| 762 | - return_val[1,...] will contain MCIN [J kg-1] |
| 763 | - return_val[2,...] will contain LCL [m] |
| 764 | - return_val[3,...] will contain LFC [m] |
| 765 | |
| 766 | This function also supports computing MCAPE along a single vertical |
| 767 | column. In this mode, the *pres_hpa*, *tkel*, *qv* and *height* arguments |
| 768 | must be one-dimensional vertical columns, and the *terrain* and |
| 769 | *psfc_hpa* arguments must be scalar values |
| 770 | (:obj:`float`, :class:`numpy.float32` or :class:`numpy.float64`). |
| 771 | |
| 772 | This is the raw computational algorithm and does not extract any variables |
| 773 | from WRF output files. Use :meth:`wrf.getvar` to both extract and compute |
| 774 | diagnostic variables. |
| 775 | |
| 776 | Args: |
| 777 | |
| 778 | pres_hpa (:class:`xarray.DataArray` or :class:`numpy.ndarray`): Full |
| 779 | pressure (perturbation + base state pressure) in [hPa] with at |
| 780 | least three dimensions. The rightmost dimensions can be |
| 781 | top_bottom x south_north x west_east or bottom_top x south_north x |
| 782 | west_east. |
| 783 | When operating on only a single column of values, the vertical |
| 784 | column can be bottom_top or top_bottom. In this case, *terrain* |
| 785 | and *psfc_hpa* must be scalars. |
| 786 | |
| 787 | Note: |
| 788 | |
| 789 | The units for *pres_hpa* are [hPa]. |
| 790 | |
| 791 | Note: |
| 792 | |
| 793 | This variable must be |