The tables below compile the symbols which are used by TrenchR functions:
SymbolA |
Descriptionsurface or cross-sectional area (m2) |
================: | |
| a | altitude angle of the sun (degrees) (subscripts: s, for normal to a slope; c ,for the axis of a cylinder); solar absorptivity (proportion) (subscripts: l, lizard thermal absorptivity; s, lizard solar absorptivity) | | ||
| Acondfact | proportion of the animal surface area that is in contact with the ground | ||
| Agradfact | proportion of the animal projected area exposed to radiation from the ground | ||
| airpressure | air pressure (kPa) | ||
| aran | scale performance value for performance curve? if aran = 0, no scaling; if aran = 1, includes a thermodynamic effect on mean performance | ||
| breadth | breadth of the thermal performance curve | ||
| c | specific heat capacity (subscripts: a, air; p, air at constant pressure; so, soil) (Jkg−1K−1 or Jkg−1°C−1) | ||
| CT | critical thermal limit (°C) (subscripts: min, minima; max, maxima), the lower and upper temperature limit for performance | ||
| D | characteristic dimension (m); thoracic diameter (cm) | ||
| d | thickness of material (m); diameter of a cylinder (m) | ||
| day or doy | day of year | ||
| deg | angle (degrees) | ||
| depth | depth (cm) | ||
| e | water vapor pressure (Nm−2, mbar) (subscripts: a, of the air; s, at saturation) | ||
| ef | enhancement factor, used to adjust convective heat transfer coefficient to field conditions | ||
| elev | elevation above mean sea level (m). | ||
| F | view factor between the animal and radiation stream (dimensionless) (subscripts: a, atmospheric radiation; d, diffuse solar radiation; g, ground thermal radiation; r, reflected solar radiation) | ||
| ga | a shape factor for soil particles | | | ||
| HL or H | convective heat transfer coefficient (Wm−2°C−1 or Wm−2K−1) | | | ||
| h | height (m); length of a cylinder (m); relative humidity (decimal fraction); Planck’s constant (Js); hour angle (rad) | | | ||
| hp | mean month relative humidity (percentage) | | | ||
| hour | hour (0-24) | ||
| K | thermal conductance (Wm−2°C−1) (subscripts f, fur; g, substrate; s, skin; sf, skin and fur; o, overall heat conductance for an animal; c, surface boundary layer for convection; so, soil). | ||
| k | von Karman’s constant (dimensionless), k~0.41 | ||
| kso | soil thermal conductivity (Wm−1K−1 or Wm−1C−1) | | | ||
| Kt or kt | clearness index, the ratio of the global solar radiation measured at the surface to the total solar radiation at the top of the atmosphere (dimensionless) | ||
| L | Monin-Obukhov length (m), a measure of the instability of heat flow | ||
| l or L | length (m) | ||
| lon | longitude (degrees) | ||
| lat | latitude (degrees) | ||
| LDT | lower developmental threshold (°C) | ||
| lw | downward flux of near-infrared radiation (Wm−2) | ||
| m | mass (kg or g); air mass (dimensionless) | ||
| P | monthly precipitation (mm) | ||
| psa | proportion surface exposed (dimensionless) (subscripts: air, for exposure to air; ref, for exposure to ground; dir, for exposure to sky or enclosure; g, for exposure to substrate) | ||
| Qabs | solar and thermal radiation absorbed (W) | ||
| Qemit | thermal radiation emitted (W) | ||
| Qconv | energy exchange between an animal and the surrounding substance due to convection (W) | ||
| Qcond | energy exchange between an animal and the surface due to conduction (W) | ||
| Qmet | energy emitted due to metabolism (W) | ||
| Qevap | energy emitted due to evaporative water loss (W) | ||
| r | reflectance (decimal fraction) (subscripts: g, of ground; S, to direct sunlight; s, to skylight); diffusion resistance to water vapor (sm−1) (subscripts: b, boundary layer; i, internal or intercellular); resistance to heat flow (sm−1) (subscripts: h, ha, boundary layer; j, diffusion resistance to molecular species j; radius (m) (subscripts: b, of inside body wall of animal; r, of outer surface of animal) | ||
| rad | angle (radians) | ||
| raz | solar azimuth angle (degrees) | ||
| S | amount of sunlight incident upon the earth’s surface (Wm−2) (subscripts: dir, direct solar radiation; dif, diffuse solar radiation; h, on a horizontal surface; ref, reflected solar radiation) | ||
| shade | whether soil temperature is calculated in the shade or not | ||
| shift | mode of the thermal performance curve | ||
| skew | skewness of the thermal performance curve | ||
| sol.elev | solar elevation angles (degrees) | ||
| SSA | solar absorptivity of soil surface (proportion) | ||
| svl | lizard snout vent length (mm) | ||
| t | time (hr or s) (subscripts: as, after sunset; n, time of minimum temperature; r, sunrise; s, sunset; p, rise the following day; x, time of maximum temperature) | ||
| T | temperature (°C or K or °F) (subscripts: a, air; g, ground; s, surface; sh, shade; sky, effective radiant temperature of the sky) | ||
| Tdewpoint | dewpoint temperature (°C) | ||
| Te | Operative environmental temperature (°C) | ||
| Tmax | maximum temperature of the day (°C) | ||
| Tmin | minimum temperature of the day (°C) | ||
| Tgmax | maximum soil surface temperature of the day (°C) | ||
| Tgmin | minimum soil surface temperature of the day (°C) | ||
| Topt | thermal optima, the temperature at which peak performance occurs (°C) | ||
| Tsoil0 | initial soil temperature (°C) | ||
| tolerance | maximal breath (°C) of the thermal performance curve | ||
| u | wind speed (ms−1) (subscripts: r, reference height or heights) | ||
| UDT | upper developmental threshold (°C) | ||
| V | volume (m3) | | | ||
| watercontent | water content (percent) | ||
| x | vector of volume fractions of soil constituents (e.g., clay, quartz, minerals other than quartz, organic matter, water, air) | ||
| z | distance, or height above a surface (m) | | ||
| zr | reference height (m) | ||
| z0 | roughness height (m) | ||
| Symbol | Description | |
|---|---|---|
| α | angle (rad or degrees); azimuth angle of the sun (degrees); time difference between time of maximum temperature and noon (hr) | | | |
| β | slope angle, direction of normal from horizontal (degrees); time difference between time of maximum temperature and sunrise (hr) | |
| δ | thoracic fur thickness (mm) | |
| ϵ | emissivity (decimal fraction) (subscripts: a, of atmosphere; s, surface emissivity); angle (radian or degree); angle between axis of a cylinder and direction of the sun’s rays; equivalent temperature (°C); thermal absorptivity as a fraction (subscript: so, soil) | |
| γ | decay parameter for rate of time change from sunset to time of minimum temperature | |
| λ | vector of the thermal conductivities (Wm−1K−1) of the soil constituents | |
| μ | dynamic viscosity (mol s−1m−1) | |
| ν | kinematic viscosity coefficient (m2s−1) | |
| ψ | solar zenith angle (degrees) | |
| ρ | density (kgm−3) (subscripts: a, of dry air; j, of molecular species; o, of standard air; w, of water vapor; so, of soil); radius of a cylinder (m); reflectivity (decimal fraction) (subscript: S, surface albedo) | |
| τ | atmospheric transmissivity (proportion) (subscripts: d, to diffuse radiation; t, to total radiation); thermal time constant (s or hr) (superscript: a, apparent) | |
| θ | angle between the solar beam and the longitudinal axis (degrees) | |
| Symbol | Description | |
|---|---|---|
| Gr | Grashof number | |
| Nu | Nusselt number | |
| Re | Reynolds number |