The Cryospheric Science Group of the Interdisciplinary Centre on Climate Change (IC3) is pleased to welcome Dr. Niina Luus, of the Dublin Institute of Technology, to present her research at our seminar this month. Her presentation is entitled:
“Arctic photosynthesis captured by satellite-observed solar-induced chlorophyll fluorescence”
ABSTRACT
Arctic regions are predicted to warm disproportionately over time due to climate change, potentially resulting in increased emissions of carbon dioxide (CO2) from thawing permafrost. Accurately monitoring the rate at which CO2 is exchanged between the land surface and the atmosphere is therefore critically important. Model estimates of the Arctic carbon cycle have typically indicated that Arctic vegetation takes up as much if not more carbon than the land surface releases each year, but the length of the growing season and total amount of carbon taken up by tundra vegetation has been overestimated due to reliance on visible and infrared satellite observations to estimate the quantity and health of vegetation. Novel satellite observations instead allow the rate of photosynthesis to be more accurately quantified according to solar-induced fluorescence (SIF) released by chlorophyll receptors during photosynthesis. By estimating photosynthesis according to SIF and photosyntetically active radiation, and respiration according to temperature, improved accuracy is attained in estimating the seasonal cycle of CO2 net uptake and release. Insights can then be gained into the environmental drivers of Arctic net ecosystem CO2 exchange, and the role of warmer air temperatures in increasing net CO2 efflux.