A method to transform a variable thermal regime to a physiologically equivalent effective temperature.
We present a method to characterize variable thermal regimes in terms of an equivalent or effective temperature. Our method is based on a first order exponential transformation of a time series of temperatures to yield an exponentially-weighted mean temperature characteristic of the regime and independent of any particular species or end point. The resulting effective temperature or exponential mean, Te¯, offers an improved method for summarizing mean temperature where biological response scales exponentially to temperature. The exponential mean allows growth under varying thermal regimes to be predicted using constant temperature models and offers a compact descriptor communicating the growth capacity of variable thermal regimes. The method combines mathematical simplicity with translatability to different Q10values without recourse to the underlining time series data. It also provides a quantitative baseline that improves on mean temperature by incorporating the effect of Jensen's inequality and it remains applicable at near zero temperatures where thermal sums lack accuracy.
Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8. Electronic address: charles_mitz@golder.com.
Charles
C
Mitz
Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8. Electronic address: cthome@nosm.ca.
Christopher
C
Thome
Bruce Power, PO Box 1540, 177 Tie Road, R.R.2, Tiverton, Ontario, Canada N0G 2T0. Electronic address: Jeroen.Thompson@brucepower.com.
Jeroen
J
Thompson
Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, Saskatchewan, Canada S4S 0A2. Electronic address: richard.manzon@uregina.ca.
Richard G
RG
Manzon
Department of Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1. Electronic address: joanna.wilson@mcmaster.ca.
Joanna Y
JY
Wilson
Bruce Power, PO Box 1540, 177 Tie Road, R.R.2, Tiverton, Ontario, Canada N0G 2T0; Northern Ontario School of Medicine, 935 Ramsey Lake Road, Sudbury, Ontario, Canada P3E 2C6. Electronic address: dboreham@nosm.ca.
Douglas R
DR
Boreham
D000465:Algorithms; D000818:Animals; D057231:Climate Change; D003198:Computer Simulation; D017753:Ecosystem; D008954:Models, Biological; D010473:Perciformes / Q000254:growth & development*; D012487:Salmonidae / Q000254:growth & development*; D013696:Temperature
Effective temperature; Jensen's inequality; Thermal sums; Variable thermal regime