mc_calc_snow: Snow detection from temperature

In myClim: Microclimatic Data Processing

Snow detection from temperature

Description

This function creates a new virtual sensor on locality within the myClim data object. Virtual sensor hosts values of snow cover presence/absence detected from temperature time-series.

Usage

mc_calc_snow(
  data,
  sensor,
  output_sensor = "snow",
  localities = NULL,
  range = 1,
  tmax = 1.25,
  days = 3
)

Arguments

data	cleaned myClim object see myClim-package
sensor	name of temperature sensor used for snow estimation. (e.g. TMS_T2)
output_sensor	name of output snow sensor (default "snow")
localities	list of locality_ids where snow will be calculated; if NULL then all (default NULL)
range	maximum temperature range threshold for snow-covered sensor (default 1°C)
tmax	maximum temperature threshold for snow-covered sensor (default 1.25°C)
days	number of days to be used for moving-window for snow detection algorithm (default 3 days)

Details

Function detects snow cover from temperature time-series. Temperature sensor is considered as covered by snow when the maximal temperature in the preceding or subsequent time-window (specified by days param) does not exceed specific tmax threshold value (default 1.25°C) and the temperature range remain below specified range threshold (default 1°C). This function rely on insulating effect of a of snow layer, significantly reducing diurnal temperature variation and restricting the maximal temperature near the ground close to freezing point. Temperature sensor near the ground (TMS_T2) is default choice for snow-cover detection from Tomst TMS loggers. Snow detection with default values accurately detects snow of depth > 15cm (unpublished data). For detection of thin snow, range parameter should be set to 3-4 °C. The function returns vector of snow cover (TRUE/FLASE) with same time-step as input data. To get number of days with snow cover and more snow summary characteristics use mc_calc_snow_agg after snow detection.

Value

myClim object with added virtual sensor 'snow' (logical) indicating snow presence/absence (TRUE/FALSE).

Examples

data <- mc_calc_snow(mc_data_example_agg, "TMS_T2", output_sensor="TMS_T2_snow",
                     localities = c("A2E32", "A6W79"))

myClim documentation built on Oct. 21, 2024, 5:07 p.m.