Technical note: Novel estimates of the leaf relative uptake rate of carbonyl sulfide from optimality theory

[摘要] In order to estimate the gross primary productivity (GPP)of terrestrial ecosystems from the canopy uptake of carbonyl sulfide (COS),leaf relative uptake rate (LRU) of COS with respect to carbon dioxideneeds to be known a priori. Currently, the variability of LRU between plantspecies in different biomes of the world is poorly understood, making thechoice of an appropriate LRU uncertain and hampering further progresstowards developing COS as a tracer of GPP. Here we propose a novel approachfor estimating light-saturated LRU based on plant optimality principles,validate it against in situ leaf gas exchange measurements and provide globalmonthly climatological estimates. The global vegetation season averagesimulated LRUs fall into the 95 % range of 0.68–1.58 and are thus lowerthan most other published global estimates. We advocate for these LRU estimatesto be adopted by global modellers in order to test to what degree these arecompatible with our current understanding of the sources and sinks in theglobal COS budget.

[学科分类] 大气科学