27 No embe 2025 | 10:00
Clima e
Co ee
Capo ondi e al. (2024)
Mo i a ion Ma ine hea wa es can be biological game change s
1
We nbe g e al. (2016)
Mo i a ion Ye no all ma ine hea wa es a e ha m ul
2
F eds on e al. (2023)
Role o compound e en s?
Le G ix e al. (2023)
Mo i a ion Compound e en s a e o en associa ed wi h se e e impac s
3
Capo ondi e al. (2024)
Mo i a ion Compound e en s a e o en associa ed wi h se e e impac s
4
G ube , Boyd, F öliche , Vog (2021)
Yea s
Hea wa e
Low oxygen
High acidi y
Hea wa e
Low oxygen Hea wa e
Hea wa e
Low oxygen
Hea wa e
Hea wa e
High acidi y
The ‘Blob’
A ea a ec ed (%)
Resea ch ques ions
1. Whe e do ma ine hea wa es, high acidi y and low oxygen ex eme e en s
end o co-occu ?
2. How can we explain hei compound e en equency pa e ns?
3. How will hey e ol e unde clima e change?
5
Me hods
•Model: GFDL-ESM2M-LE (15 ensemble membe s;
1891-2100 ollowing RCP8.5; daily-mean ou pu )
•Obse a ions: NOAA OISST, MOBO-DIC, GOBAI-O2
•Ecosys em s esso s: high T (MHW), high H+ (OAX), low
O2 (LOX)
•De ini ion o ex emes: seasonally a ying 90 h o
10 h pe cen ile h eshold
•Focus on mul i a ia e compound e en s, i.e., ex eme
e en s on he same day and loca ion. Top 2000 m
6
MHW-OAX-LOX
Resul s
mo e equen han expec edless equen han expec ed
P esen -day dis ibu ion o compound ex eme e en s
7
MHW-OAX-LOX
Resul s
mo e equen han expec edless equen han expec ed
MHW-OAX-LOX
P esen -day dis ibu ion o compound ex eme e en s
8
MHW-OAX MHW-LOX OAX-LOX
Mean + Va iabili y
+ Dependence
Unde a ixed baseline:
S onges inc ease a he sea su ace o all compound e en ypes.
In 2100 a su ace (RCP8.5): Compound MHW-OAX, MHW-LOX and OAX-LOX e en s
occu in mo e han 80% o days
Resul s His o ical and u u e changes in compound e en equency
Fixed
13
Resul s
25
Mean + Va iabili y + Dependence
Va iabili y + Dependence
Dependence
MHW-OAX MHW-LOX OAX-LOX
His o ical and u u e changes in compound e en equency
Fixed
Shi ing-mean
Fully-adap ing
14
Resul s
25
Mean + Va iabili y + Dependence
Va iabili y + Dependence
Dependence
MHW-OAX MHW-LOX OAX-LOX
His o ical and u u e changes in compound e en equency
Mos o he equency inc ease is d i en
by long- e m mean shi s in T, H+ and O2
Shi ing-mean
Fully-adap ing Fixed
14
Resul s
In some egions, subsu ace MHW-OAX
e en s do no inc ease o e en dec ease
Complexi ies in how wa ming and
acidi ica ion un old in he ocean in e io .
25
MHW-OAX MHW-LOX OAX-LOX
His o ical and u u e changes in compound e en equency
Shi ing-mean
Fully-adap ing Fixed
*
*617m
15
MHW-OAX-LOX
2°C wa ming
98%
Unde ixed p eindus ial baseline
Resul s
98% o op 2000m exposed o
ex eme/compound e en s unde 2°C
Unde shi ing baseline
MHW-OAX-LOX
Unde a ixed p eindus ial baseline
30%
His o ical and u u e changes in compound e en equency
16
MHW-OAX-LOX
2°C wa ming
98%
Unde ixed p eindus ial baseline
Resul s
98% o op 2000m exposed o
ex eme/compound e en s unde 2°C
Unde shi ing baseline
MHW-OAX-LOX
98%
Unde a ixed p eindus ial baseline
30%
98% o global ocean olume down o 2000m will
be exposed o an ex eme/compound e en
unde 2°C wa ming.
His o ical and u u e changes in compound e en equency
16
MHW-OAX-LOX
2°C wa ming
98%
Unde ixed p eindus ial baseline
Resul s
98% o op 2000m exposed o
ex eme/compound e en s unde 2°C
Unde shi ing baseline
MHW-OAX-LOX
98%
Unde a shi ing baseline
30%
Unde a ixed p eindus ial baseline
His o ical and u u e changes in compound e en equency
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•Ex eme condi ions in T, H+ and O2 equen ly
coincide a he sea su ace and in la ge pa s o
he subsu ace ocean.
•Subsu ace compound e en s a e o en linked
o e ical wa e mass shi s.
•The p ojec ed ise in compound e en s unde
clima e change occu s in mos o he global
ocean down o 2000 m.
Take-home messages
Densi y anomaly (kg/m3)
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