using carbonyl sulfide to explore coastal fog and coast ... · using carbonyl sulfide to explore...

Using carbonyl sulfide to explore coastal fog and coast redwood interdependence Timothy W. Hilton 1 , Mary Whelan 2 , Joe Berry 3 , J. Elliott Campbell 1 1 University of California, Santa Cruz 2 University of California, Los Angeles 3 Department of Global Ecology, Carnegie Institution, Stanford, California, USA Coast redwoods (sequioa sempervirens): •are the tallest trees on Earth •grow in a narrow fog-shrouded band along the U.S. West Coast. •Little is know about coastal fog- redwood growth feedbacks. And coastal fog is declining with increasing temperature and coastal urbanization. photo: Scott Catron, 2003 Q1: Why carbonyl sulfide (OCS)? - large - cannot measure CO 2 GPP - large - cannot measure - small - can measure.. BUT NOT IN THE FOG! Forest image creator: DragonArt dragonartz.wordpress.com http://creativecommons.org/licenses/by-nc-sa/3.0/us/ photosynthesis respiration OCS CO 2 respiration CO 2 net ecosystem exchange Q2: Is there a redwood OCS signal? Preliminary flask samples from the field say "yes". Note larger OCS decline from coast to redwoods vs. coast to grassland! Figures: Campbell et al. (2017), JGR Biogeosci, 10.1002/2016JG003703 H1: stomata close (redwoods are "heaters") Q3: Can WRF-NOAH simulate land surface-fog interactions? fog decreases... latent heat gives way to sensible heat Experiment 1: make a vast swathe of North America urban: "the biggest hammer we can find" Experiment 2: remove all urbanization Experiment 3: urbanize the redwood groves: fog increases... sensible heat gives way to latent heat (at least near cities) coming up: •continuous redwood canopy [OCS] obs Q4: are these widespread changes meaningful? Offshore fog changes are not significant. Fog changes near redwood range are less likely noise but more work is needed! - + •implement redwood stomatal behavior in WRF-NOAH (or WRF- CLM?) latent heat flux (Wm -2 ) sensible heat flux (Wm -2 ) % of model hours foggy % of model hours foggy contact: [email protected] fog decreases... latent heat gives way to sensible heat (at least near redwoods) latent heat flux (Wm -2 ) sensible heat flux (Wm -2 ) latent heat flux (Wm -2 ) sensible heat flux (Wm -2 ) Our transport model (STEM) simulates the flask samples fairly well. % of model hours foggy H2: stomata stay open (redwoods are "coolers") the big Q: what do stomata do as fog dissipates? Our flask samples largely agree with NOAA/ESRL/GMD's nearby site (Mt. Sutro) significant at 95%

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Page 1: Using carbonyl sulfide to explore coastal fog and coast ... · Using carbonyl sulfide to explore coastal fog and coast redwood interdependence Timothy W. Hilton1, Mary Whelan2, Joe

Using carbonyl sulfide to explore coastal fog and coast redwood interdependence

Timothy W. Hilton1, Mary Whelan2, Joe Berry3, J. Elliott Campbell11University of California, Santa Cruz 2University of California, Los Angeles3Department of Global Ecology, Carnegie Institution, Stanford, California, USA

Coast redwoods (sequioa sempervirens): •are the tallest trees on Earth•grow in a narrow fog-shrouded band along the U.S. West Coast. •Little is know about coastal fog-redwood growth feedbacks. And coastal fog is declining with increasing temperature and coastal urbanization.

photo

: Sco

tt Catro

n, 2

Q1: Why carbonyl sulfide (OCS)?

- large- cannot measure

CO2 GPP- large- cannot measure

- small- can measure.. BUT NOT IN THE FOG!

Forest image creator: DragonArtdragonartz.wordpress.com

http://creativecommons.org/licenses/by-nc-sa/3.0/us/

photosynthesis respirationOCS CO2 respiration

CO2 net ecosystem exchange

Q2: Is there a redwood OCS signal?Preliminary flask samples from the field say "yes". Note larger OCS decline from coast toredwoods vs. coast to grassland!

Figures: Campbell et al. (2017), JGR Biogeosci, 10.1002/2016JG003703

H1: stomata close (redwoods are "heaters")

Q3: Can WRF-NOAH simulateland surface-fog interactions?

fog decreases... latent heat gives way to sensible heat

Experiment 1: make a vast swathe of North America urban: "the biggest hammer we can find"

Experiment 2: remove all urbanization

Experiment 3: urbanize the redwood groves:fog increases... sensible heat gives way to latent heat (at least near cities)

coming up:•continuous redwood canopy [OCS] obs

Q4: are these widespread changes meaningful?

Offshore fog changes are not significant. Fog changes near redwood range are less likely noise but more work is needed!

- +

•implement redwood stomatal behavior in WRF-NOAH (or WRF-CLM?)