M

1
Météo-France EUROSIP contribution present,
future and sensitivity experiments

• Jean-François Guérémy
• Michel Déqué, Jean-Philippe Piedelievre, Lauriane
  Batté

2
Outlook

• Present EUROPSIP Syst3
• - Components
• - Some products
• Future EUROPSIP Syst4
• - Components and first tests
• Sensitivity experiments and specific studies
• - l91 versus l31 in the frame of EUROPSIP Syst3
• - Predictability of regimes and heavy
  precipitation events
• - Skill sore over Africa

3
EUROPSIP Syst3

• Operational international project
• Multi-model seasonal forecast (CNRM, ECMWF,
  UKMO)
• model
• ARPEGE-Climat V4 Tl63l91 OASIS V2.4 OPA V8.2
  (ORCA 2 grid)
• Since May 2008
• forecast set-up
• - Ocean ICs MERCATOR, Kalman filter analysis
  including altimetry, SST and (T,S) in situ data
• Atmospheric ICs ECMWF analyses
• - 41 members (8 lagged atmospheric ICs combined
  to 5 lagged ocean ICs), each month (starting the
  first) for 7month run
• - Hindcasts from 1979 (11 members)

4
EUROPSIP Syst3 product examples

• Hydrology reservoir management in Mali
• Energy heating management in western Europe
• JFM forecast

5
Manantali Dam
Water release management in September-October
function of the August seasonal forecast
6
heating management in western Europe

• Seasonal cumulation 18C (Tn Tx)

7
JFM forecast
8
Toward EUROPSIP Syst4operational mid 2012

• Model
• ARPEGE-Climat V5 Tl127l31 OASIS V3 NEMO V3.2
  (GELATO ice, ORCA 1)
• (new radiation and soil schemes - SURFEX)
• IPCC set-up (climate projections and decadal
  forecasts)
• Preliminary tests without SURFEX and GELATO
• Similar scores compared to EUROSIP Syst3

44 years (NDJF and MJJA) 9 members Month 2-4
seasonal average Anomaly correlations
9
Toward EUROPSIP Syst4operational mid 2012

• Initial Conditions
• Possibly, nudging or anomaly nudging in coupled
  mode toward atmospheric analyses (ECMWF), ocean
  analyses (MERCATOR, from a ¼ analysis) and
  possibly soil analyses (MF).
• Initial and/or in-run perturbations taken from
  analysis departure terms (stochastic term).

10
l91 versus l31 in the frame of EUROPSIP Syst3

• Time period 1979-2007, EUROPSIP Syst3 l31 and
  l91

11
Predictability of regimes and heavy precipitation
events (MEDUP french project)

• National research project Seasonal forecast of
  weather regime and heavy precipitation event
  occurrence (from 01/2008 to 12/2010) (CNRM,
  IPSL, LTHE)
• Time period 1960-2001 ENSEMBLES EU project
  (42 years)
• Sensitivity tests 3 models ENS_MF, ENS_CEP
  and
• Pro_Tl127l62 (CNRM model with a new atmospheric
  physics turbulence, convection and microphysics)

12

• Precipitation biases (/CMAP), coupled simulations

DJF

JJA
Standard Tl63l31
Pronostique (convection Guérémy) Tl127l62
Guérémy 2011, accepted in Tellus
13

• Teleconnections SON
• (similar to Guérémy et al. 2005, Tellus)

Composites of T2m anomalies for the years
during which the occurrence of Heavy
Precipitating Events (HPE) over South-East of
France was greater than the mean 1 standard
deviation (1960-2001).
Pro_ Tl127l62
ERA40
ENS_MF
ENS_CEP
Years 1960, 1963, 1964, 1968, 1977, 1994,
1995 gt 7 HPE per year
14

• Teleconnections SON

Composites of 200 hPa Velocity Potential
anomalies for the years during which the
occurrence of Heavy Precipitating Events (HPE)
over South-East of France was greater than the
mean 1 standard deviation (1960-2001).
Pro_ Tl127l62
ERA40
ENS_MF
ENS_CEP
15

• Teleconnections SON

Composites of Z500 anomalies for the years
during which the occurrence of Heavy
Precipitating Events (HPE) over South-East of
France was greater than the mean 1 standard
deviation (1960-2001).
Pro_ Tl127l62
ERA40
ENS_MF
ENS_CEP
16

• Regimes (stream function ?, velocity potential ?)
  200hPa
• ERA40, SON

1 2 3 4 5 6
?
?
17
Predictability of (?, ?)200 regime
occurrencerelationship to heavy precipitation
events, SON
ENS_MF ENS_CEP Pro_Tl127l62
Regime 1 0.45 0.38 0.41
Regime 2 0.17 0.30 0.28
Regime 3 0.12 -0.11 -0.11
Regime 4 -0.09 0.39 0.05
Regime 5 0.19 0.13 -0.08
Regime 6 0.49 0.23 0.39
Association HPE (177 over 42 years) / regimes (?,
?)200
Correlation regime occurrence / ERA40
18
Predictability of Z500 regime occurrencerelations
hip to heavy precipitation events, SON
NAO- Atlantic trough NAO
Atlantic ridge 1 2
3 4
ENS_MF ENS_CEP Pro_Tl127 l62
Regime 1 0.06 -0.05 0.08
Regime 2 -0.02 0.00 0.00
Regime 3 -0.07 -0.04 0.27
Regime 4 0.24 0.06 0.31
Association HPE (177 over 42 years) / regimes Z500
Correlation regime occurrence / ERA40
19
Predictability of heavy precipitation events
(HPE)from analogues, SON
Following Clark and Déqué (2003, QJRMS),
analogues (for each member of the ensemble) are
chosen in the model hindcasts according to a
minimum distance in terms of (?, ?)200 regime
occurrence. The result is a distribution of
analogue years. From this distribution,
forecasted HPE occurrence (larger than mean 1
std) is calculated and compared to the observed
occurrence of the considered year.
ENS_MF ENS_CEP Pro_Tl127l62
Occurrence correlation -0.07 -0.13 0.23
From the analogues
ENS_MF ENS_CEP Pro_Tl127l62
Occurrence correlation 0.00 0.09 0.21
Model forcasted HPE occurrence
20
Skill sore over Africa

• RPSS (Ranked probability skill score) computed
  for precipitation deciles over the 1960-2005
  period (ENSEMBLES), for West Africa in JJA and
  South Africa in DJF GPCC is the reference.
  Results from a multi-model (5 out of 9) this
  muti-model provides greater scores than 0, where
  most of individual model gives no information.

Batte 2010, accepted in Tellus
21
Bathymetry ORCA2 and ORCA1

• ORCA2 (182149)
  ORCA1 (362292)

22
Scores over DJF, observed SST mode
Std phys (Tl63l31) Pro phys (Tl63l31) Pro phys(Tl63l91)
ACC T850 Trop 0.52 0.52 0.56
ACC T850 NH 0.25 0.31 0.31
ACC Z500 NH 0.25 0.29 0.33
Standard physics, left Prognostic physics,
right (31 levels top, 91 levels bottom) ? Pro91
gt Pro31gt Std31