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Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Land processes and the global water cycle: Past
results and upcoming CMIP6 plans
Sonia I. Seneviratne1, Bart van den Hurk2, Gerhard Krinner3,
Hyungjun Kim4, Chris Derksen5, and Taikan Oki4
1Institute for Atmospheric and Climate Science, ETH Zurich, Switzerland
[email protected] 2KNMI, De Bilt, Netherlands 3LGGE, Grenoble, France 4University of Tokyo, Tokyo, Japan 5Environment Canada
Our common future under climate change, Paris, 7.7.2015
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Global water cycle
Terrestrial
Precipitation
(100%)
(Flux estimates: Oki and Kanae 2008, Science)
Terrestrial
Evapotranspiration
(60%)
Oceanic
Precipitation
(350%)
Oceanic
Evaporation
(390%) Streamflow
(40%)
Atmospheric
transport
(40%)
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Land water and energy balances
P E Rn lE
Water Energy
H
E=60%P lE=50-60%Rn
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Land water and energy balances
P E Rn lE
Water Energy
H
E=60%P lE=50-60%Rn
SWin a SWin
a variations due to
snow: ~0.4-0.5
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Soil moisture-evapotranspiration coupling
(Seneviratne et al. 2010, Earth Science Reviews)
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Land-climate interactions
Climate
Land processes
IMPACTS FEEDBACKS
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Outline
Land-temperature feedbacks
Land-precipitation feedbacks
Land controls on droughts
CMIP6 land modeling plans: LS3MIP experiment
Conclusions
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Land-temperature feedbacks
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
(Mueller and Seneviratne 2012, PNAS)
NHD: # hot days
SPI: Standardized Precipitation Index
Land-temperature feedbacks: Observations
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Soil moisture (point in Central Europe)
Impact of decadal
changes in soil
moisture (and
evapotranspiration)
on climate
First stage: 5 CMIP5
models (CESM, EC-
EARTH, GFDL, IPSL,
MPI-ESM)
GLACE-CMIP5 (“Global Land-
Atmosphere Coupled Experiment”)
(Seneviratne et al. 2013, GRL)
Effects of land evapotranspiration on climate change
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Linear increase of
temperature (up to 2ºC
additional warming) as a
function of change in
evapotranspiration
Substantial component of
warming in projections
(e.g. Mediterranean region:
20% of summer warming,
25% of warming of hot
extremes)
Effects of land evapotranspiration on climate change
(Seneviratne et al. 2013, GRL)
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Role of land vs oceans?
Variance difference (in %) when prescribing soil moisture (left)
or SST (right)
Interannual time scale, local warm season (warmest 3 months),
CESM simulations (ocean-land-atmosphere)
(Orth and Seneviratne, in preparation)
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Role of land vs oceans?
Variance difference (in %) when prescribing soil moisture (left)
or SST (right)
Interannual time scale, local warm season (warmest 3 months),
CESM simulations (ocean-land-atmosphere)
(Orth and Seneviratne, in preparation)
Similar effect of soil moisture and SSTs! Additive effects (not
feedbacks)
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Snow-climate feedbacks
Spread in snow albedo feedback
accounts for much of the CMIP5
spread in the 21st century
warming of Northern Hemisphere
land masses
(Qu and Hall 2014, Climate Dynamics)
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Outline
Land-temperature feedbacks
Land-precipitation feedbacks
Land controls on droughts
CMIP6 land modeling plans: LS3MIP experiment
Conclusions
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Soil moisture-precipitation feedbacks
Soil moisture - precipitation coupling strength (JJA) averaged across AGCMs
(Koster et al. 2004, Science)
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Sign of soil moisture-precipitation feedbacks
Some inconsistent results?
(Findell et al. 2011, Nature Geoscience)
(Taylor et al. 2012, Nature)
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Sign of soil moisture-precipitation feedbacks
(Guillod et al. 2015, Nature Communications)
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Sign of soil moisture-precipitation feedbacks
Using consistent data:
GLEAM evaporative
stress
CMORPH precipitation
(data gaps filled with
GPCP and ERA-
interim)
(Guillod et al. 2015, Nature Communications)
Implications for
climate change
projections?
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Soil moisture-precipitation feedbacks
(Martius et al. 2013, Quart. J. Roy. Met. Soc)
Model simulations of Pakistan 2010 floods with (left) and without (right)
evapotranspiration from land surface
Air masses spent 72 hours over land before raining out: Model suggests that 90%
and 60% of rainfall over Pakistan was originating from land (reevaporation)
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Outline
Land-temperature feedbacks
Land-precipitation feedbacks
Land controls on droughts
CMIP6 land modeling plans: LS3MIP experiment
Conclusions
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Trends in salinity in the oceans
(1950-2000): “dry” regions
become “drier”, “wet” regions
become “wetter” (DDWW)
(Durack et al. 2012, Science)
Validity of “dry gets drier, wet gets wetter” paradigm?
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
(Greve et al. 2014, Nature Geoscience)
Robust dryness trends on
land (1948-68 vs 1985-
2005)
the DDWW paradigm
does not apply on land!!
Trends in salinity in the oceans
(1950-2000): “dry” regions
become “drier”, “wet” regions
become “wetter” (DDWW)
(Durack et al. 2012, Science)
Validity of “dry gets drier, wet gets wetter” paradigm?
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
(Greve et al. 2014, Nature Geoscience;
Greve and Seneviratne 2015, GRL)
Different response
over land compared
to global and ocean
behaviour: Because
of soil moisture
limitation!
Validity of “dry gets drier, wet gets wetter” paradigm?
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Uncertainties of land datasets
(Greve et al. 2014, Nature Geoscience)
4 P datasets,
11 Ep datasets,
7 ET datasets
ET
P
Ep
Weighted errors
based on all
possible
combinations within
Budyko framework
Largest uncertainty
in ET! (related to
soil moisture
limitation and other
plant physiological
effects)
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Impact of human water use
Human impact
simulations
compared to
naturalized runoff
(1971-2000)
Climate impact
simulations for 2ºC
increase compared to
naturalized runoff
(Haddeland et al. 2013, PNAS)
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Outline
Land-temperature feedbacks
Land-precipitation feedbacks
Land controls on droughts
CMIP6 land modeling plans: LS3MIP experiment
Conclusions
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
LS3MIP: Overview and scientific goal
• Multi-model based reanalysis of land surface (from early 20th century)
• Explore land-atmosphere coupling and its impacts (for historical
climate trends and projections, water resources, predictability)
• Link patterns and trends of essential climate variables to model
properties and biases
Land Surface, Snow, and Soil moisture MIP (CMIP6)
Co-chairs: B. van den Hurk, G. Krinner, S. Seneviratne, H. Kim, C. Derksen, and T. Oki
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
“LandMIPs”
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Outline
Land-temperature feedbacks
Land-precipitation feedbacks
Land controls on droughts
CMIP6 land modeling plans: LS3MIP experiment
Conclusions
Sonia Seneviratne / IAC ETH Zurich 7.7.2015 Our common future under climate change
Conclusions
• Land hydrology (soil moisture, snow) substantially
affects the water cycle on land, as well as temperatures
• Large remaining uncertainties, necessity to better
quantify underlying causes for model spread
• The Land Surface, Snow and Soil Moisture MIP
(LS3MIP) will provide for the first time a systematic
evaluation of land water cycle processes and feedbacks
in the CMIP context