Observation-based research on
atmospheric physical processes
Dr Jonathan P Taylor – Head of Observations Based Research
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Plus 48
staff at 3
locations
OBSERVATION BASED RESEARCH
Challenging our understanding of the Earth system
using high quality research observations.
Twinned with
Natural Enivronment Research Council
Founded: 1942
© Crown copyright Met Office
Population: 50
Contents
This presentation covers the following areas
• Recent science results
• Land surface temperature
• Fog
• Investment in Future Instrumentation
• Aerosol scattering and absorption
• Ice Nuclei Counter
• Conclusions
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Providing Understanding in to Land Surface
Temperature Anomalies
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Satellite retrievals of Land
Surface Temperature using IASI
DAY
NIGHT
This is data
for Arizona
but similar
situation
seen for
many semiarid regions
Stuart Newman
Is this a problem with the satellite
retrieval or the model background?
• Need an independent measure of land
surface temperature and emissivity
• Need to understand the state of the
atmosphere (temp and water vapour profiles,
wind speed etc.)
• SALSTICE campaign, Arizona May 2013.
• ARIES – airborne interferometer capable of
measuring thermal IR radiance at 4500
spectral intervals viewing in Nadir and Zenith
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Typical ARIES spectrum
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Stuart Newman
Airborne and Satellite Retrievals
of surface temperature
IASI 1D-Var retrieved T_skin
ARIES retrieved T_skin
Global model background T_skin
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Stuart Newman
What is happening with the energy budget?
Let’s look at 16 days of model and ground
based observations
Model is putting too much energy in
to the atmosphere and not enough
down in to the ground.
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Chawn Harlow
OBR Research in to Fog –
modelling and observations
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Fog research: Cardington Dewmeter
• Requirement to measure water
budget in fog
• MO Cardington have developed
lightweight micro-lysimeter
• Very sensitive: measures
deposition to 0.1 gm-2
• Accommodates variety of
different canopies (natural and
artificial)
• Autonomous operation possible
with stand alone logger
• Details in paper submitted to
BLM: Price and Clark (2013)
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• Understanding balance
between dew and fog
formation is key to radiation
fogs
• Evolution of deposition in
stratus fogs is key to visibility
forecasting
Large range in
deposition across
one airfield – Example data from Cardington dewmeters
classic radiation
night
Deposition turns to
evaporation as
cloud moves
overhead
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Fog Night
- deposition
increases as
fog thickens
- as fog
becomes
adiabatic
(thick)
deposition
decreases
Jeremy Price
Example of future fog research: the LANFEX
experiment
• LANFEX: Local And Non Local Fog EXperiement
• Experiment based at Cardington (homogeneous) and region of hills
(Shropshire, inhomogeneous)
• To study Local insitu processes forming radiation fog (Cardington)
• And non-local processes on formation and evolution (Shropshire)
• Shropshire: different orographic regions will be instrumented to
examine how the same mesoscale airmass evolves in different
closely located locations with different orography
• Is expected to elucidate more clearly the processes and
requirements for forming radiation fog, and its evolution
• New Cardington fog monitor weather stations are being built for this
purpose (12)
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under-forecast poor visibility
at Cardington
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Bernie Claxton
model error
obs–centric or model-centric
• Neural net driven by same observations as UKV
• UKV generates few occurrences of low visibility
• NN shows that even with same errors in input fields there is scope for improving
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Met Office
visibility
forecasts
Bernie Claxton
input error - forcing with obs
• Blue crosses –
UKV visibility
driven by model
inputs
• Green crosses
– UKV visibility
driven by
observations
• Red crosses –
NN driven by
observations
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UKV driven by
obs generates
false alarm cases
of fog
Bernie Claxton
Reducing the uncertainties in aerosol optical
properties
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Justin Langridge
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Understanding Ice Nuclei in the Atmosphere
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Met Office objectives
• The science plan requires us to investigate whether
incorporating aerosol-cloud interactions improves NWP. It also
requires the generation of parametrisations for aerosol-cloud
interactions in (coarser) climate models based on high
resolution models.
• The MetUM optionally has new microphysics with aerosol
interactions, eg. based on UKCA-mode (UK chemistry and
aerosol) with dust, sea-salt, biomass and anthropogenic
aerosols represented by mass and number prognostic
variables.
• Extensive and well-constrained case studies are required to
understand the aerosol-cloud interactions (using dynamically
simple cloud systems) and to show the sensitivity of model
evolution to IN and CCN.
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Saharan dust
and convective
clouds
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Key instrumentation.
Ice Nuclei
Counter
- Designed
- Built
- Operated
By OBR
scientists
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Richard Cotton
Summary
• OBR – using airborne and ground
observations to study LST
• OBR – making long term
measurements of fog formation
and challenging models
• OBR – Investing in state of the
art instrument development
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