The function estimates body temperatures (C, operative environmental temperatures) of a grasshopper based on Lactin and Johnson (1998) . Part of the model is based on Swinbank (1963) , following Gates (1962) in Kingsolver (1983) .

Tb_grasshopper(
  T_a,
  T_g,
  u,
  H,
  K_t,
  psi,
  l,
  Acondfact = 0.25,
  z = 0.001,
  abs = 0.7,
  r_g = 0.3
)

Arguments

T_a

numeric air temperature (C).

T_g

numeric surface temperature (C). Kingsolver (1983) assumes T_g - T_a = 8.4.

u

numeric wind speed (m s-1).

H

numeric total (direct + diffuse) solar radiation flux (W m-2).

K_t

numeric clearness index (dimensionless), which is the ratio of the global solar radiation measured at the surface to the total solar radiation at the top of the atmosphere.

psi

numeric solar zenith angle (degrees).

l

numeric grasshopper length (m).

Acondfact

numeric the proportion of the grasshopper surface area that is in contact with the ground.

z

numeric distance from the ground to the grasshopper (m).

abs

numeric absorptivity of the grasshopper to solar radiation (proportion). See Anderson et al. (1979) .

r_g

numeric substrate solar reflectivity (proportion). See Kingsolver (1983) .

Value

numeric predicted body (operative environmental) temperature (C).

Details

Total radiative flux is calculated as thermal radiative heat flux plus convective heat flux, following Kingsolver (1983) , with the Erbs et al. (1982) model from Wong and Chow (2001) .

Energy balance is based on Kingsolver (1983) .

Radiation is calculated without area dependence (Anderson et al. 1979) .

The body of a grasshopper female is approximated by a rotational ellipsoid with half the body length as the semi-major axis (Samietz et al. 2005) .

The diffuse fraction is corrected following Olyphant (1984) .

References

Anderson RV, Tracy CR, Abramsky Z (1979). “Habitat Selection in Two Species of Short-Horned Grasshoppers. The Role of Thermal and Hydric Stresses.” Oecologia, 38(3), 359--374. doi:10.1007/BF00345194 .

Erbs D, Klein S, Duffie J (1982). “Estimation of the diffuse radiation fraction for hourly, daily and monthly-average global radiation.” Solar Energy, 28, 293-302.

Gates DM (1962). “Leaf temperature and energy exchange.” Archiv fur Meteorologie, Geophysik und Bioklimatologie, Serie B volume, 12, 321-336.

Kingsolver JG (1983). “Thermoregulation and Flight in Colias Butterflies: Elevational Patterns and Mechanistic Limitations.” Ecology, 64(3), 534-545. doi:10.2307/1939973 .

Lactin DJ, Johnson DL (1998). “Convective heat loss and change in body temperature of grasshopper and locust nymphs: Relative importance of wind speed, insect size and insect orientation.” Journal of Thermal Biology, 23(1), 5-13. ISSN 0306-4565, doi:10.1016/S0306-4565(97)00037-5 , https://www.sciencedirect.com/science/article/pii/S0306456597000375.

Olyphant G (1984). “Insolation Topoclimates and Potential Ablation in Alpine Snow Accumulation Basins: Front Range, Colorado.” Water Resources Research, 20(4), 491-498.

Samietz J, Salser MA, Dingle H (2005). “Altitudinal variation in behavioural thermoregulation: local adaptation vs. plasticity in California grasshoppers.” Journal of Evolutionary Biology, 18(4), 1087-1096. doi:10.1111/j.1420-9101.2005.00893.x .

Swinbank WC (1963). “Long-wave radiation from clear skies.” Quarterly Journal of the Royal Meteorological Society, 89, 339-348.

Wong LT, Chow WK (2001). “Solar radiation model.” Applied Energy, 69(3), 191-224. ISSN 0306-2619, doi:10.1016/S0306-2619(01)00012-5 , https://www.sciencedirect.com/science/article/pii/S0306261901000125.

Examples

  Tb_grasshopper(T_a       = 25, 
                 T_g       = 25,      
                 u         = 0.4, 
                 H         = 400, 
                 K_t       = 0.7, 
                 psi       = 30, 
                 l         = 0.02, 
                 Acondfact = 0.25, 
                 z         = 0.001, 
                 abs       = 0.7, 
                 r_g       = 0.3)
#> [1] 25.03167