0
# Meteorological Calculations
1

2
MetPy provides over 150 calculation functions covering all aspects of atmospheric science including thermodynamics, dynamic meteorology, and kinematics. All functions handle units properly through Pint integration and work seamlessly with numpy arrays, xarray DataArrays, and scalar values.
3

4
## Capabilities
5

6
### Thermodynamic Functions
7

8
Temperature, moisture, and energy calculations fundamental to atmospheric thermodynamics.
9

10
```python { .api }
11
def potential_temperature(pressure, temperature):
12
    """
13
    Calculate potential temperature.
14
    
15
    Parameters:
16
    - pressure: atmospheric pressure
17
    - temperature: air temperature
18
    
19
    Returns:
20
    Potential temperature
21
    """
22

23
def equivalent_potential_temperature(pressure, temperature, dewpoint):
24
    """
25
    Calculate equivalent potential temperature.
26
    
27
    Parameters:
28
    - pressure: atmospheric pressure  
29
    - temperature: air temperature
30
    - dewpoint: dewpoint temperature
31
    
32
    Returns:
33
    Equivalent potential temperature
34
    """
35

36
def virtual_temperature(temperature, mixing_ratio, molecular_weight_ratio=epsilon):
37
    """
38
    Calculate virtual temperature.
39
    
40
    Parameters:
41
    - temperature: air temperature
42
    - mixing_ratio: water vapor mixing ratio
43
    - molecular_weight_ratio: ratio of molecular weights (optional)
44
    
45
    Returns:
46
    Virtual temperature
47
    """
48

49
def wet_bulb_temperature(pressure, temperature, dewpoint):
50
    """
51
    Calculate wet bulb temperature.
52
    
53
    Parameters:
54
    - pressure: atmospheric pressure
55
    - temperature: air temperature  
56
    - dewpoint: dewpoint temperature
57
    
58
    Returns:
59
    Wet bulb temperature
60
    """
61

62
def heat_index(temperature, relative_humidity, mask_undefined=True):
63
    """
64
    Calculate heat index from temperature and relative humidity.
65
    
66
    Parameters:
67
    - temperature: air temperature
68
    - relative_humidity: relative humidity (0-100%)
69
    - mask_undefined: whether to mask undefined values
70
    
71
    Returns:
72
    Heat index
73
    """
74

75
def apparent_temperature(temperature, relative_humidity, wind_speed):
76
    """
77
    Calculate apparent temperature (Australian formula).
78
    
79
    Parameters:
80
    - temperature: air temperature
81
    - relative_humidity: relative humidity
82
    - wind_speed: wind speed
83
    
84
    Returns:
85
    Apparent temperature
86
    """
87
```
88

89
### Moisture Calculations
90

91
Water vapor and humidity calculations for atmospheric moisture analysis.
92

93
```python { .api }
94
def mixing_ratio(partial_press, total_press, molecular_weight_ratio=epsilon):
95
    """
96
    Calculate water vapor mixing ratio.
97
    
98
    Parameters:
99
    - partial_press: water vapor partial pressure
100
    - total_press: total atmospheric pressure
101
    - molecular_weight_ratio: ratio of molecular weights
102
    
103
    Returns:
104
    Mixing ratio (dimensionless)
105
    """
106

107
def saturation_mixing_ratio(total_press, temperature):
108
    """
109
    Calculate saturation mixing ratio.
110
    
111
    Parameters:
112
    - total_press: total atmospheric pressure
113
    - temperature: air temperature
114
    
115
    Returns:
116
    Saturation mixing ratio
117
    """
118

119
def relative_humidity_from_mixing_ratio(mixing_ratio, temperature, pressure):
120
    """
121
    Calculate relative humidity from mixing ratio.
122
    
123
    Parameters:
124
    - mixing_ratio: water vapor mixing ratio
125
    - temperature: air temperature
126
    - pressure: atmospheric pressure
127
    
128
    Returns:
129
    Relative humidity (0-1)
130
    """
131

132
def relative_humidity_from_dewpoint(temperature, dewpoint, *, phase='liquid'):
133
    """
134
    Calculate relative humidity from dewpoint.
135
    
136
    Parameters:
137
    - temperature: air temperature
138
    - dewpoint: dewpoint temperature
139
    - phase: thermodynamic phase ('liquid' or 'ice')
140
    
141
    Returns:
142
    Relative humidity (0-1)
143
    """
144

145
def dewpoint_from_relative_humidity(temperature, relative_humidity):
146
    """
147
    Calculate dewpoint from relative humidity.
148
    
149
    Parameters:
150
    - temperature: air temperature
151
    - relative_humidity: relative humidity (0-1)
152
    
153
    Returns:
154
    Dewpoint temperature
155
    """
156

157
def vapor_pressure(pressure, mixing_ratio):
158
    """
159
    Calculate water vapor pressure from mixing ratio.
160
    
161
    Parameters:
162
    - pressure: total atmospheric pressure
163
    - mixing_ratio: water vapor mixing ratio
164
    
165
    Returns:
166
    Water vapor pressure
167
    """
168

169
def saturation_vapor_pressure(temperature):
170
    """
171
    Calculate saturation vapor pressure.
172
    
173
    Parameters:
174
    - temperature: air temperature
175
    
176
    Returns:
177
    Saturation vapor pressure
178
    """
179

180
def specific_humidity_from_mixing_ratio(mixing_ratio):
181
    """
182
    Calculate specific humidity from mixing ratio.
183
    
184
    Parameters:
185
    - mixing_ratio: water vapor mixing ratio
186
    
187
    Returns:
188
    Specific humidity (dimensionless)
189
    """
190

191
def mixing_ratio_from_specific_humidity(specific_humidity):
192
    """
193
    Calculate mixing ratio from specific humidity.
194
    
195
    Parameters:
196
    - specific_humidity: water vapor specific humidity
197
    
198
    Returns:
199
    Mixing ratio (dimensionless)
200
    """
201

202
def specific_humidity_from_dewpoint(pressure, dewpoint, phase='liquid'):
203
    """
204
    Calculate specific humidity from dewpoint and pressure.
205
    
206
    Parameters:
207
    - pressure: atmospheric pressure
208
    - dewpoint: dewpoint temperature
209
    - phase: thermodynamic phase ('liquid' or 'ice')
210
    
211
    Returns:
212
    Specific humidity
213
    """
214

215
def precipitable_water(pressure, dewpoint, bottom=None, top=None):
216
    """
217
    Calculate precipitable water through atmospheric column.
218
    
219
    Parameters:
220
    - pressure: pressure profile
221
    - dewpoint: dewpoint temperature profile
222
    - bottom: bottom pressure level (optional)
223
    - top: top pressure level (optional)
224
    
225
    Returns:
226
    Precipitable water amount
227
    """
228
```
229

230
### Pressure and Altitude
231

232
Atmospheric pressure and height relationship calculations.
233

234
```python { .api }
235
def height_to_pressure_std(height):
236
    """
237
    Convert height to pressure using standard atmosphere.
238
    
239
    Parameters:
240
    - height: height above sea level
241
    
242
    Returns:
243
    Atmospheric pressure
244
    """
245

246
def pressure_to_height_std(pressure):
247
    """
248
    Convert pressure to height using standard atmosphere.
249
    
250
    Parameters:
251
    - pressure: atmospheric pressure
252
    
253
    Returns:
254
    Height above sea level
255
    """
256

257
def altimeter_to_station_pressure(altimeter_value, height, temperature):
258
    """
259
    Convert altimeter setting to station pressure.
260
    
261
    Parameters:
262
    - altimeter_value: altimeter setting
263
    - height: station elevation
264
    - temperature: station temperature
265
    
266
    Returns:
267
    Station pressure
268
    """
269

270
def station_to_altimeter_pressure(station_pressure, height, temperature):
271
    """
272
    Convert station pressure to altimeter setting.
273
    
274
    Parameters:
275
    - station_pressure: station pressure  
276
    - height: station elevation
277
    - temperature: station temperature
278
    
279
    Returns:
280
    Altimeter setting
281
    """
282

283
def geopotential_to_height(geopotential):
284
    """
285
    Convert geopotential to geometric height.
286
    
287
    Parameters:
288
    - geopotential: geopotential
289
    
290
    Returns:
291
    Geometric height
292
    """
293
```
294

295
### Atmospheric Stability
296

297
Stability indices and parcel theory calculations.
298

299
```python { .api }
300
def lifted_index(pressure, temperature, parcel_profile):
301
    """
302
    Calculate lifted index.
303
    
304
    Parameters:
305
    - pressure: atmospheric pressure profile
306
    - temperature: environmental temperature profile
307
    - parcel_profile: parcel temperature profile
308
    
309
    Returns:
310
    Lifted index
311
    """
312

313
def cape_cin(pressure, temperature, dewpoint, parcel_profile, which_lfc='bottom', which_el='top'):
314
    """
315
    Calculate CAPE and CIN (Convective Available Potential Energy and Convective Inhibition).
316
    
317
    Parameters:
318
    - pressure: pressure profile
319
    - temperature: temperature profile  
320
    - dewpoint: dewpoint profile
321
    - parcel_profile: parcel temperature profile
322
    - which_lfc: which LFC to use when multiple exist
323
    - which_el: which EL to use when multiple exist
324
    
325
    Returns:
326
    Tuple of (CAPE, CIN) values
327
    """
328

329
def convective_inhibition(pressure, temperature, dewpoint, parcel_profile):
330
    """
331
    Calculate CIN (Convective Inhibition).
332
    
333
    Parameters:
334
    - pressure: pressure profile
335
    - temperature: temperature profile
336
    - dewpoint: dewpoint profile  
337
    - parcel_profile: parcel temperature profile
338
    
339
    Returns:
340
    CIN value
341
    """
342

343
def surface_based_cape_cin(pressure, temperature, dewpoint):
344
    """
345
    Calculate surface-based CAPE and CIN.
346
    
347
    Parameters:
348
    - pressure: atmospheric pressure profile (high to low pressure)
349
    - temperature: environmental temperature profile
350
    - dewpoint: dewpoint temperature profile
351
    
352
    Returns:
353
    Tuple of (CAPE, CIN) values for surface-based parcel
354
    """
355

356
def most_unstable_cape_cin(pressure, temperature, dewpoint, **kwargs):
357
    """
358
    Calculate most unstable CAPE and CIN.
359
    
360
    Parameters:
361
    - pressure: atmospheric pressure profile
362
    - temperature: environmental temperature profile
363
    - dewpoint: dewpoint temperature profile
364
    - **kwargs: keyword arguments for parcel selection
365
    
366
    Returns:
367
    Tuple of (CAPE, CIN) values for most unstable parcel
368
    """
369

370
def mixed_layer_cape_cin(pressure, temperature, dewpoint, **kwargs):
371
    """
372
    Calculate mixed-layer CAPE and CIN.
373
    
374
    Parameters:
375
    - pressure: atmospheric pressure profile
376
    - temperature: environmental temperature profile
377
    - dewpoint: dewpoint temperature profile
378
    - **kwargs: keyword arguments for mixed layer (e.g., depth)
379
    
380
    Returns:
381
    Tuple of (CAPE, CIN) values for mixed-layer parcel
382
    """
383

384
def downdraft_cape(pressure, temperature, dewpoint):
385
    """
386
    Calculate Downdraft CAPE (DCAPE).
387
    
388
    Parameters:
389
    - pressure: atmospheric pressure profile
390
    - temperature: environmental temperature profile
391
    - dewpoint: dewpoint temperature profile
392
    
393
    Returns:
394
    Downdraft CAPE value (negative buoyancy energy)
395
    """
396

397
def level_of_free_convection(pressure, temperature, dewpoint, parcel_temperature_profile=None):
398
    """
399
    Calculate Level of Free Convection (LFC).
400
    
401
    Parameters:
402
    - pressure: pressure profile
403
    - temperature: environmental temperature
404
    - dewpoint: dewpoint temperature
405
    - parcel_temperature_profile: parcel temperature profile
406
    
407
    Returns:
408
    LFC pressure and temperature
409
    """
410

411
def lcl(pressure, temperature, dewpoint, max_iters=50, eps=1e-5):
412
    """
413
    Calculate Lifting Condensation Level (LCL).
414
    
415
    Parameters:
416
    - pressure: starting pressure
417
    - temperature: starting temperature
418
    - dewpoint: starting dewpoint
419
    - max_iters: maximum iterations
420
    - eps: convergence criterion
421
    
422
    Returns:
423
    LCL pressure and temperature
424
    """
425

426
def parcel_profile(pressure, temperature, dewpoint):
427
    """
428
    Calculate parcel temperature profile.
429
    
430
    Parameters:
431
    - pressure: pressure levels
432
    - temperature: starting temperature
433
    - dewpoint: starting dewpoint
434
    
435
    Returns:
436
    Parcel temperature at each pressure level
437
    """
438

439
def mixed_parcel(pressure, temperature, dewpoint, parcel_start_pressure=None, height=None, bottom=None, depth=None):
440
    """
441
    Calculate mixed parcel properties.
442
    
443
    Parameters:
444
    - pressure: pressure profile
445
    - temperature: temperature profile
446
    - dewpoint: dewpoint profile
447
    - parcel_start_pressure: starting pressure for parcel
448
    - height: height profile
449
    - bottom: bottom of mixed layer
450
    - depth: depth of mixed layer
451
    
452
    Returns:
453
    Mixed parcel pressure, temperature, dewpoint
454
    """
455

456
def el(pressure, temperature, dewpoint, parcel_temperature_profile=None, which='top'):
457
    """
458
    Calculate the equilibrium level (EL).
459
    
460
    Parameters:
461
    - pressure: atmospheric pressure profile (high to low pressure)
462
    - temperature: environmental temperature at pressure levels
463
    - dewpoint: dewpoint temperature at pressure levels
464
    - parcel_temperature_profile: parcel temperature profile (optional)
465
    - which: which EL to return when multiple exist ('top', 'bottom')
466
    
467
    Returns:
468
    EL pressure and temperature
469
    """
470

471
def ccl(pressure, temperature, dewpoint, height=None, mixed_layer_depth=None, which='top'):
472
    """
473
    Calculate the Convective Condensation Level (CCL).
474
    
475
    Parameters:
476
    - pressure: atmospheric pressure profile (high to low pressure)
477
    - temperature: environmental temperature at pressure levels
478
    - dewpoint: dewpoint temperature at pressure levels
479
    - height: height profile (optional)
480
    - mixed_layer_depth: depth of mixed layer for averaging (optional)
481
    - which: which CCL to return when multiple exist ('top', 'bottom')
482
    
483
    Returns:
484
    CCL pressure and temperature
485
    """
486

487
def most_unstable_parcel(pressure, temperature, dewpoint, height=None, bottom=None, depth=None):
488
    """
489
    Calculate the most unstable parcel in a layer.
490
    
491
    Parameters:
492
    - pressure: atmospheric pressure profile
493
    - temperature: environmental temperature profile  
494
    - dewpoint: dewpoint temperature profile
495
    - height: height profile (optional)
496
    - bottom: bottom of layer to search (optional)
497
    - depth: depth of layer to search (optional)
498
    
499
    Returns:
500
    Most unstable parcel pressure, temperature, dewpoint
501
    """
502
```
503

504
### Additional Stability Indices
505

506
Classical stability indices for severe weather forecasting and convective analysis.
507

508
```python { .api }
509
def k_index(pressure, temperature, dewpoint, vertical_dim=0):
510
    """
511
    Calculate K Index stability index.
512
    
513
    Parameters:
514
    - pressure: atmospheric pressure profile
515
    - temperature: environmental temperature profile
516
    - dewpoint: dewpoint temperature profile
517
    - vertical_dim: vertical dimension index
518
    
519
    Returns:
520
    K Index value
521
    """
522

523
def showalter_index(pressure, temperature, dewpoint):
524
    """
525
    Calculate Showalter Index.
526
    
527
    Parameters:
528
    - pressure: atmospheric pressure profile
529
    - temperature: environmental temperature profile
530
    - dewpoint: dewpoint temperature profile
531
    
532
    Returns:
533
    Showalter Index value
534
    """
535

536
def total_totals_index(pressure, temperature, dewpoint, vertical_dim=0):
537
    """
538
    Calculate Total Totals Index.
539
    
540
    Parameters:
541
    - pressure: atmospheric pressure profile
542
    - temperature: environmental temperature profile
543
    - dewpoint: dewpoint temperature profile
544
    - vertical_dim: vertical dimension index
545
    
546
    Returns:
547
    Total Totals Index value
548
    """
549

550
def vertical_totals(pressure, temperature, vertical_dim=0):
551
    """
552
    Calculate Vertical Totals Index.
553
    
554
    Parameters:
555
    - pressure: atmospheric pressure profile
556
    - temperature: environmental temperature profile
557
    - vertical_dim: vertical dimension index
558
    
559
    Returns:
560
    Vertical Totals value
561
    """
562

563
def cross_totals(pressure, temperature, dewpoint, vertical_dim=0):
564
    """
565
    Calculate Cross Totals Index.
566
    
567
    Parameters:
568
    - pressure: atmospheric pressure profile
569
    - temperature: environmental temperature profile
570
    - dewpoint: dewpoint temperature profile
571
    - vertical_dim: vertical dimension index
572
    
573
    Returns:
574
    Cross Totals value
575
    """
576

577
def sweat_index(pressure, temperature, dewpoint, speed, direction, vertical_dim=0):
578
    """
579
    Calculate SWEAT (Severe Weather Threat) Index.
580
    
581
    Parameters:
582
    - pressure: atmospheric pressure profile
583
    - temperature: environmental temperature profile
584
    - dewpoint: dewpoint temperature profile
585
    - speed: wind speed profile
586
    - direction: wind direction profile
587
    - vertical_dim: vertical dimension index
588
    
589
    Returns:
590
    SWEAT Index value
591
    """
592
```
593

594
### Dynamic Meteorology
595

596
Wind analysis, vorticity, and atmospheric dynamics calculations.
597

598
```python { .api }
599
def wind_direction(u, v, convention='from'):
600
    """
601
    Calculate wind direction from u and v components.
602
    
603
    Parameters:
604
    - u: u-component of wind
605
    - v: v-component of wind
606
    - convention: 'from' or 'to' direction convention
607
    
608
    Returns:
609
    Wind direction in degrees
610
    """
611

612
def wind_speed(u, v):
613
    """
614
    Calculate wind speed from u and v components.
615
    
616
    Parameters:
617
    - u: u-component of wind
618
    - v: v-component of wind
619
    
620
    Returns:
621
    Wind speed
622
    """
623

624
def wind_components(speed, direction):
625
    """
626
    Calculate u and v wind components from speed and direction.
627
    
628
    Parameters:
629
    - speed: wind speed
630
    - direction: wind direction
631
    
632
    Returns:
633
    u and v components
634
    """
635

636
def geostrophic_wind(geopotential, f=None, dx=None, dy=None):
637
    """
638
    Calculate geostrophic wind from geopotential field.
639
    
640
    Parameters:
641
    - geopotential: geopotential field
642
    - f: coriolis parameter
643
    - dx: grid spacing in x direction
644
    - dy: grid spacing in y direction
645
    
646
    Returns:
647
    u and v components of geostrophic wind
648
    """
649

650
def ageostrophic_wind(geopotential, u, v, dx=None, dy=None, f=None):
651
    """
652
    Calculate ageostrophic wind.
653
    
654
    Parameters:
655
    - geopotential: geopotential field
656
    - u: u-component of observed wind
657
    - v: v-component of observed wind
658
    - dx: grid spacing in x direction
659
    - dy: grid spacing in y direction
660
    - f: coriolis parameter
661
    
662
    Returns:
663
    u and v components of ageostrophic wind
664
    """
665

666
def vorticity(u, v, dx=None, dy=None, dim_order='yx'):
667
    """
668
    Calculate relative vorticity.
669
    
670
    Parameters:
671
    - u: u-component of wind
672
    - v: v-component of wind  
673
    - dx: grid spacing in x direction
674
    - dy: grid spacing in y direction
675
    - dim_order: dimension order
676
    
677
    Returns:
678
    Relative vorticity
679
    """
680

681
def absolute_vorticity(u, v, dx=None, dy=None, y_dim=-2, latitude=None, dim_order='yx'):
682
    """
683
    Calculate absolute vorticity.
684
    
685
    Parameters:
686
    - u: u-component of wind
687
    - v: v-component of wind
688
    - dx: grid spacing in x direction
689
    - dy: grid spacing in y direction
690
    - y_dim: y dimension index
691
    - latitude: latitude values
692
    - dim_order: dimension order
693
    
694
    Returns:
695
    Absolute vorticity
696
    """
697

698
def advection(scalar, u, v, dx=None, dy=None, dim_order='yx'):
699
    """
700
    Calculate advection of a scalar field.
701
    
702
    Parameters:
703
    - scalar: scalar field to advect
704
    - u: u-component of wind
705
    - v: v-component of wind
706
    - dx: grid spacing in x direction
707
    - dy: grid spacing in y direction
708
    - dim_order: dimension order
709
    
710
    Returns:
711
    Advection of scalar field
712
    """
713

714
def q_vector(geopotential, temperature, pressure, u, v):
715
    """
716
    Calculate Q-vectors.
717
    
718
    Parameters:
719
    - geopotential: geopotential field
720
    - temperature: temperature field
721
    - pressure: pressure level
722
    - u: u-component of wind
723
    - v: v-component of wind
724
    
725
    Returns:
726
    Q-vector components
727
    """
728

729
def frontogenesis(potential_temperature, u, v, dx=None, dy=None, dim_order='yx'):
730
    """
731
    Calculate frontogenesis.
732
    
733
    Parameters:
734
    - potential_temperature: potential temperature field
735
    - u: u-component of wind
736
    - v: v-component of wind
737
    - dx: grid spacing in x direction
738
    - dy: grid spacing in y direction
739
    - dim_order: dimension order
740
    
741
    Returns:
742
    Frontogenesis
743
    """
744

745
def divergence(u, v, dx=None, dy=None, x_dim=-1, y_dim=-2, parallel_scale=None, meridional_scale=None):
746
    """
747
    Calculate horizontal divergence of wind field.
748
    
749
    Parameters:
750
    - u: u-component of wind
751
    - v: v-component of wind
752
    - dx: grid spacing in x direction
753
    - dy: grid spacing in y direction
754
    - x_dim: x dimension index
755
    - y_dim: y dimension index
756
    - parallel_scale: parallel scale factor
757
    - meridional_scale: meridional scale factor
758
    
759
    Returns:
760
    Horizontal divergence
761
    """
762

763
def shearing_deformation(u, v, dx=None, dy=None, x_dim=-1, y_dim=-2, parallel_scale=None, meridional_scale=None):
764
    """
765
    Calculate shearing deformation of wind field.
766
    
767
    Parameters:
768
    - u: u-component of wind
769
    - v: v-component of wind
770
    - dx: grid spacing in x direction
771
    - dy: grid spacing in y direction
772
    - x_dim: x dimension index
773
    - y_dim: y dimension index
774
    - parallel_scale: parallel scale factor
775
    - meridional_scale: meridional scale factor
776
    
777
    Returns:
778
    Shearing deformation
779
    """
780

781
def stretching_deformation(u, v, dx=None, dy=None, x_dim=-1, y_dim=-2, parallel_scale=None, meridional_scale=None):
782
    """
783
    Calculate stretching deformation of wind field.
784
    
785
    Parameters:
786
    - u: u-component of wind
787
    - v: v-component of wind
788
    - dx: grid spacing in x direction
789
    - dy: grid spacing in y direction
790
    - x_dim: x dimension index
791
    - y_dim: y dimension index
792
    - parallel_scale: parallel scale factor
793
    - meridional_scale: meridional scale factor
794
    
795
    Returns:
796
    Stretching deformation
797
    """
798

799
def total_deformation(u, v, dx=None, dy=None, x_dim=-1, y_dim=-2, parallel_scale=None, meridional_scale=None):
800
    """
801
    Calculate total deformation of wind field.
802
    
803
    Parameters:
804
    - u: u-component of wind
805
    - v: v-component of wind
806
    - dx: grid spacing in x direction
807
    - dy: grid spacing in y direction
808
    - x_dim: x dimension index
809
    - y_dim: y dimension index
810
    - parallel_scale: parallel scale factor
811
    - meridional_scale: meridional scale factor
812
    
813
    Returns:
814
    Total deformation magnitude
815
    """
816
```
817

818
### Severe Weather Indices
819

820
Specialized calculations for severe weather forecasting.
821

822
```python { .api }
823
def bulk_shear(pressure, u, v, height=None, bottom=None, depth=None):
824
    """
825
    Calculate bulk wind shear.
826
    
827
    Parameters:
828
    - pressure: pressure profile
829
    - u: u-component of wind profile
830
    - v: v-component of wind profile
831
    - height: height profile
832
    - bottom: bottom of layer
833
    - depth: depth of layer
834
    
835
    Returns:
836
    Bulk shear magnitude and components
837
    """
838

839
def storm_relative_helicity(u, v, height, depth, bottom=None, storm_u=None, storm_v=None):
840
    """
841
    Calculate storm-relative helicity.
842
    
843
    Parameters:
844
    - u: u-component of wind
845
    - v: v-component of wind
846
    - height: height levels
847
    - depth: integration depth
848
    - bottom: bottom of integration layer
849
    - storm_u: storm motion u-component
850
    - storm_v: storm motion v-component
851
    
852
    Returns:
853
    Storm-relative helicity
854
    """
855

856
def supercell_composite_parameter(mucape, effective_shear, effective_srh):
857
    """
858
    Calculate Supercell Composite Parameter.
859
    
860
    Parameters:
861
    - mucape: most unstable CAPE
862
    - effective_shear: effective bulk shear
863
    - effective_srh: effective storm-relative helicity
864
    
865
    Returns:
866
    Supercell composite parameter
867
    """
868

869
def significant_tornado_parameter(sbcape, surface_based_lcl_height, bulk_shear_0to6, surface_based_srh_0to1km):
870
    """
871
    Calculate Significant Tornado Parameter.
872
    
873
    Parameters:
874
    - sbcape: surface-based CAPE
875
    - surface_based_lcl_height: surface-based LCL height
876
    - bulk_shear_0to6: 0-6 km bulk shear
877
    - surface_based_srh_0to1km: 0-1 km storm-relative helicity
878
    
879
    Returns:
880
    Significant tornado parameter
881
    """
882
```
883

884
## Exception Classes
885

886
```python { .api }
887
class InvalidSoundingError(ValueError):
888
    """Raised when sounding data is invalid or insufficient."""
889

890
class DataDimensionalityError(ValueError):
891
    """Raised when data has incorrect dimensionality for calculation."""
892
```