Transcript vocals-uk - HiGEM

VOCALS-UK
John Constable ‘Cloud Study’ 1822
Len Shaffrey and Thomas Toniazzo
Walker Institute, University of Reading
The South East Pacific
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The South East Pacific (SEP) region is a tightly coupled
system involving poorly understood interactions
between the ocean, the atmosphere, and the land.
The SEP region and other upwelling regions are poorly
represented in coupled climate models.
Why is the SEP so important? It has a huge impact on
the climate of the Pacific basin and its variability.
HadCM3 Experiments:
The Importance of the SEP
Interannual standard
deviation of SSTs in
HadCM3 control run.
Standard deviation
of SSTs in a run
where the SST
anomalies in the SEP
region are relaxed to
the monthly SST
climatology of the
coupled model.
HadCM3 Experiments: The Role
of the Andes
HadCM3 Control
HadCM3 Displaced Andes
HadCM3 SST errors
against HadISST.
10m wind errors
against ERA-40.
SEP surface wind
errors in HadCM3
appear to
determined by the
orography. A need
for higher
resolution?
VOCALS
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VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) is an
international project to understand the climate of the SEP.
VOCALS-REX is an international field experiment designed to
better understand physical and chemical processes central to
the climate system of the SEP region.
VOCALS
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The aim of VOCALS-MOD is to understand the processes that
determine the climate of the SEP in coupled oceanatmosphere models and how the representation of those
processes can be improved.
Understanding how resolution can improve the upwelling
regions is one of the central objectives of VOCALS-MOD.
The VOCALS-MOD
modelling strategy.
A high resolution oceanatmosphere regional
coupled model. The
regional model is then
upscaled to the global
model.
VOCALS
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A consortium bid was submitted to NERC for a UK
contribution to the VOCALS field experiment and
modelling project.
The ambition of VOCALS-UK is to reduce uncertainties in
current and future climate projections, especially those
associated with marine stratocumulus and coupled
ocean atmosphere processes.
Using a high resolution global coupled climate model
(HiGEM) to study the SEP region would dovetail nicely
with the main VOCALS modelling effort.
HiGEM1.2 minus
HadGEM1.2 annual mean
1.5m temperature
difference (colours), 10m
wind differences (vectors).
HiGEM1.2 minus
HadGEM1.2 annual mean
1.5m temperature
difference (colours), 10m
wind differences (vectors)
and total cloud differences
(contour interval=0.1).
VOCALS-UK
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If the submission is successful we are planning to:
Assess systematic model biases in the SEP and in the
wider tropical Pacific and the effect of increased
resolution in the atmosphere and in the ocean
components, particularly in the simulation of the
oceanic heat budget.
Explore the sensitivity of the SEP region to large-scale
processes (orographic forcing, air-sea interaction, and
cloud radiative feedbacks) using HiGEM and HadGEM
Use NWP techniques with NuGAM to analyse the growth
of model errors compared to reanalysis and
observational campaign data, especially those related
with the interaction between the MBL and the cloud
cover.
VOCALS-UK




If the submission is successful we are planning to:
Assess systematic model biases in the SEP and in the
wider tropical Pacific and the effect of increased
resolution in the atmosphere and in the ocean
components, particularly in the simulation of the
oceanic heat budget.
Explore the sensitivity of the SEP region to large-scale
processes (orographic forcing, air-sea interaction, and
cloud radiative feedbacks) using HiGEM and HadGEM
Use NWP techniques with NuGAM to analyse the growth
of model errors compared to reanalysis and
observational campaign data, especially those related
with the interaction between the MBL and the cloud
cover.
Ocean Heat Budget in
the SEP
Mesoscale eddy variability (Right: snapshot from
ROMS) is important for oceanic heat budget of the
SEP (Below: October eddy and mean temperature
advection at 13oS in HiGEM)
Eddy temperature advection
(interval 10-8K day-1)
Mean temperature advection
(interval 10-8K day-1)
Latitude
Latitude