Vertical Velocity From Accumulation Calculator
Apply explicit ideal steady column linear vertical-velocity profile, surface w=−ice-equivalent accumulation and bed w=0; local vertical positive up, no inferred horizontal divergence, emergence or basal melt.
Description
An ideal steady ice column can use a linear vertical-velocity profile.
An ideal steady ice column can use a linear vertical-velocity profile. The declared convention takes upward velocity as positive.1
Enter finite signed accumulation, positive densities/thickness and depths within 0–thickness. Return velocities from surface −accumulation to bed zero; an empty depth list is allowed.
When to use Vertical Velocity From Accumulation Calculator
Use Vertical Velocity From Accumulation Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. No horizontal divergence, emergence velocity, basal melt or observed steady state is inferred.
Prepare the observed ice, snow, water or geometry measurements and explicit calibration parameters requested. Keep coordinates, datum, density and time units consistent.
How to use Vertical Velocity From Accumulation Calculator and understand its results
- Prepare the observed ice, snow, water or geometry measurements and explicit calibration parameters requested. Keep coordinates, datum, density and time units consistent.
- Enter accumulationMweYear, waterDensityKgM3, iceDensityKgM3, modeledIceThicknessM, depthBelowSurfaceM using the field table and calculation rules, then run the tool.
- Read idealVerticalVelocitiesMYear. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| accumulationMweYear | Accumulation mwe year | number | Required |
| waterDensityKgM3 | Water density kg m3 | number | Required |
| iceDensityKgM3 | Ice density kg m3 | number | Required |
| modeledIceThicknessM | Modeled ice thickness m | number | Required |
| depthBelowSurfaceM | Depth below surface m | list of number | Required |
Enter finite signed accumulation, positive densities/thickness and depths within 0–thickness. Return velocities from surface −accumulation to bed zero; an empty depth list is allowed.
accumulationIce=accumulationWater×waterDensity/iceDensity; w=−accumulationIce(1−depth/thickness) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| idealVerticalVelocitiesMYear | Ideal vertical velocities m year | list of number |
{
"input": {
"accumulationMweYear": 1,
"waterDensityKgM3": 1000,
"iceDensityKgM3": 500,
"modeledIceThicknessM": 100,
"depthBelowSurfaceM": [
0,
50,
100
]
},
"output": {
"idealVerticalVelocitiesMYear": [
-2,
-1,
0
]
}
}Limitations and assumptions
No horizontal divergence, emergence velocity, basal melt or observed steady state is inferred.
Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 10,000 entries; string lists to 128 strings of at most 128 characters each. The rules above may impose smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Transverse Strain Rate Calculator: Transverse normal strain is the gradient of transverse velocity along a cross-flow transect. Its sign distinguishes extension and compression. For a complementary task, use Close Off Age Lock In Depth Calculator: Layer mass and steady accumulation can estimate ice residence age at supplied firn depths. Ice age differs from trapped-gas age.
References
Similar or alternative tools
- Transverse Strain Rate Calculator
Transverse normal strain is the gradient of transverse velocity along a cross-flow transect. Its sign distinguishes extension and compression.
- Close Off Age Lock In Depth Calculator
Layer mass and steady accumulation can estimate ice residence age at supplied firn depths. Ice age differs from trapped-gas age.