Qmelt
This module defined in Classqmelt to calculate the ground flux for hummuck-covered hillslopes in the Artic tundra.
Observations
- ta(°C) - average air temperature during time step. In original version was t but was changed to prevent conflict with CRHM.
- ts(°C) - average surface/skin temperature during time step.
Function Observations
- tmean (°C) - mean daily air temperature.
- tpos (°C) - sum of interval air temperatures above 0°C during a day.
- tsmean (°C) - mean daily surface/skin temperature.
- tspos (°C) - sum of interval surface/skin temperatures above 0°C during a day.
Variables
- Qm (MJ/m2 Dt) - snow melt during the time step, calculated using the mean daily air temperature.
- cum_Qm (MJ/m2 Dt) - cumulative snow melt (from daily mean air temperature) over time.
- Qg (MJ/m2) -ground heat flux during the time step, calculated using the mean daily surface/skin temperature.
- cum_Qg (MJ/m2) - cumulative ground heat flux (from daily mean surface/skin temperature) over time.
Parameters
- TIa0Mn (°C) - offset in temperature - index model in calculating QmD.
- TIa1Mn (MJ/day/°C) - coefficient for estimating QmD.
- TIs0Mn (°C) - offset in temperature - index model in calculating QgD.
- TIs1Mn (MJ/day/°C) - coefficient for estimating QgD.
Variable Inputs
- none
Notes
Snow melt from mean daily air temperature .
- if (tmean - TIa0Mn > 0.0) QmD = (tmean - TIa0Mn)*TIa1Mn,
- if time step t > 0.0 Qm = t*QmD/tpos else Qm = 0.0.
- cum_Qm = cum_Qm + Qm.
Ground heat flux from mean daily surface/skin temperature
- if (tsmean - TIs0Mn > 0.0) QgD = (tsmean - TIs0Mn)*TIs1Mn,
- if time step ts > 0.0 Qg = ts*QgD/tspos else Qg = 0.0.
- cum_Qg = cum_Qg + Qg.