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Meeting 3 January, 26th 2009

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mm/day of occurrence of TCs. North Atlantic basin. Definition : TCPE ... IFS = Integrated Forecast System **ECMWF = European Medium Range Weather Forecast ... – PowerPoint PPT presentation

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Title: Meeting 3 January, 26th 2009


1
Cyclonic precipitation Simulated Observed
Anne Sophie Daloz (Météo-France -CNRS) 2nd
International Summit on Hurricanes and Climate
Supervisor Frank Roux (CNRS- LA)? Co-Supervisor
Fabrice Chauvin (CNRM GAME Météo-France CNRS)?
2
Outline
  • Introduction
  • Why are we studying cyclonic precipitation ?
  • Review of the literature
  • Data and Methodology
  • NCEP 2, ARPEGE integrations
  • Tracking method for the model the
    observations
  • Definition of the Cyclonic precipitation,
    TCPE , TCGP
  • Results
  • - Cyclonic precipitation efficiency of the
    TCs
  • Conclusions Perspectives

TCPE Tropical Cyclonic Precipitation
Efficiency TCGP Tropical Cyclonic Generic
Precipitation TC Tropical Cyclone
3
Why Cyclonic precipitation ?
1. Introduction
  • The Intergovernmental on Climate Changes 4th
    Assessment Report (IPCC-AR4) reveals a lack of
    agreement about the possible evolution of the
    Tropical Cyclones ( TCs) behavior due to climate
    change in term of
  • Number Intensity
  • On the other hand, it seems that a consensus is
    appearing on the increase of tropical cyclonic
    precipitation.
  • In the North Atlantic basin, for the season 2008,
    the floods linked with the tropical cyclonic
    precipitation contributed to the loss of over 800
    lives.
  • The Réunion Island obtains all the world record
    of precipitation between 12 hours and 15 days
    due to the topography of the Island.
  • Ex TC Gamède 3329 mm in 72 hours (February,
    2007) .

4
The past studies …
1. Introduction
  • Lau, Zhou and Wu, 2008 Have Tropical Cyclones
    Been Feeding More Extreme Rainfall ?
  • - Extreme rain events defined in terms of
    percentile rainrate and TC-rain by rainfall
    associated with a named TC in the North Atlantic
    Basin.
  • - GPCP (1979-2005) and TRMM(1998-2005)
    rainfall data.
  • Study of the fractional contribution of TC-rain
    to total rain, the possible trend of the TC-rain.
  • Rodgers and Adler, 2001 Contribution of
    Tropical Cyclones to the North Atlantic
    Climatological Rainfall as Observed from
    Satellites
  • - Mean monthly rainfall within 444 km of the
    center of the North Atlantic TCs
  • - SSM/I- derived brightness temperatures
    (1987-98)
  • Study the impact of TC rainfall in altering
    geographical, seasonal and interannual
    distribution of total precipitation.

GPCP Global Precipitation Climatology
Project TRMM Tropical Rainfall Measuring
Mission
SSM/I Special Sensor Microwave Imager
5
Data Methodology
ARPEGE , NCEP 2 Cyclonic Precipitation Tracking
Methods
6
2. Data Methodology
NCEP 2 Reanalysis
  • NCEP-DOE Reanalysis 2 is an improved version of
    the NCEP Reanalysis I Model from NOAA.
  • Temporal resolution Daily
  • Spatial resolution of the global grid 1.875
    x 1.875
  • Time period 1979 2008
  • The choice of the reanalysis is explained by the
    time period covered.
  • More information on the internet site
  • ( http// www.cdc.noaa.gov/data/gridded/data.ncep.
    reanalysis2.html )

I
NCEP-DOE National Centers for Environmental
Predictions Department of Energy NOAA
National Oceanic and Atmospheric Administration
7
2. Data Methodology
NCEP 2 Tracking Method
  • Tracking with IBTrACS (Knapp et al., 2009)
  • IBTRaCS International Best Track Archive for
    Climate Stewardship from NOAAs NCDC .
  • Provides tropical cyclone best track data in a
    centralized location using 12 TCs datasets
  • Method An automated algorithm was developed to
    identify storms tracked by multiple centers in
    time and space.
  • Any observations at identical times within 111
    kilometers, were identified as identical storms.
  • More information on the internet site
  • http//www.ncdc.noaa.gov/oa/ibtracs

I
NOAA National Oceanic and Atmospheric
Administration NCDC National Climatic Data
Centers
8
2. Data Methodology
NCEP 2 Validation (1998-2006)
  • Cyclonic Precipitation (mm/year)
  • on the North Atlantic Basin.
  • Definition of cyclonic Precip Mean daily
    rainfall in 12x12 boxes around the center of
    each point of the TCs.
  • Good representation of the general
  • patterns
  • - lower values in the area on influence
  • of the Saharan air layer
  • - local maxima on the Gulf of Mexico
  • and the on the east side of the Caribbean
  • islands.

50
9
2. Data Methodology
Cyclonic Precipitation (1987-1998)
10
2. Data Methodology
Percentage of TC Rain (1987-1998)
  • Definition TC Rain Cyclonic Precipitation
    / Total Precipitation x100

11
2. Data Methodology
TCPE TCs Efficiency (1987-1998)
  • Definition of the Eulerian view
  • Cyclonic Precipitation normalized by the number
    of occurrence of TCs.
  • TCPE could be a way of quantifying one kind of
    destructiveness of TCs.

12
2. Data Methodology
TCGP TCs Generic Rain
(1987-1998)
  • Definition of the Lagrangian view
  • Average of all the 12x12 boxes of cyclonic
    precipitation normalized by the number of day of
    TCs.

13
2. Data Methodology
ARPEGE Integrations
  • ARPEGE global - uniform
  • - 20th -21st century experiment
  • - T319 truncation with a collocation grid of
    0.5 (50 kms over the intertropical regions)
  • - 1979-88 climatological SSTs, (Reynolds and
    Smith , 1994) 2090-99 addition of the anomaly
    from scenario B2 (Météo-France)
  • ARPEGE - Climat rotated stretched
    configuration ( Courtier and Geylen , 1988)
  • - Pole of the grid located 60W 20N in the
    western Atlantic
  • - Equivalent resolution 50 kms over the
    Atlantic Basin and 310 kms at the opposite,
    stretching coefficient 2.5.
  • - Year to year variation of SSTs of the 1960 -
    89 observed patterns and for the future
    (2070-99), addition of the anomaly from scenario
    A2 (Hadley Center)

14
Tracking method
2. Data Methodology
  • Presentation of the method
  • - Method developed by Ayrault and Joly, 2000 to
    track mid latitude lows refined with the method
    of (Hodges , 1994) and relaxation from (Camargo
    and Zebiak, 2002).
  • Criterias (Bengsston et al., 2005 Chauvin and
    Royer, 2006)
  • - Mean Sea Level Pressure (MSLP) is a local
    minimum (considered therefore as the center of
    the system)?
  • - 850 hPa vorticity gt 14 x 10?5 s¹
  • - 850 hPa wind intensity gt 15 m. s¹
  • - Mean 700-300 hPa temperature anomaly gt 3 K
  • - 300 hPa temperature anomaly gt 850 hPa
    temperature anomaly
  • 850 hPa tangential wind gt 300 hPa tangential
    wind
  • Thresholds chosen non objectively to obtain
    around 10 TCs each year.

15
3.1 Results
  • Present
  • ARPEGE vs NCEP 2

16
Total Precipitation ( 1979-88)
3. 1 Results
  • North Atlantic basin
  • Realistic representation of the general patterns
  • - Lower values over region on influence of the
    Saharan air layer
  • - Higher precipitation on the ITCZ Region and
    the Gulf of Mexico
  • ARPEGE integrations overestimate the Northern
    part of the Gulf of Mexico.

17
3. 1 Results
  • Cyclonic Density ( 1979-88)
  • North Atlantic Basin
  • Definition
  • Cyclonic Density Number of point where we have
    an occurrence of a TC
  • Overestimate of both integrations
  • Not enough spread , it is too concentrated on
    the Gulf of Mexico

Sum over the 10 years
18
3. 1 Results
  • Cyclonic Precipitation ( 1979-88)
  • North Atlantic basin
  • Good representation of the general patterns
  • - Maxima on the Gulf of Mexico but
    overestimated.
  • - That could be a result of the higher
    resolution of the simulations.

19
3. 1 Results
Percentage of TC-Rain ( 1979-88)
  • North Atlantic Basin
  • Definition
  • Percentage of TC-Rain
  • Cyclonic PR / Total PR 100
  • 3 maximum
  • - Gulf of Mexico
  • - Eastern Florida
  • - West African coast (WAC)
  • Overestimate the maxima on the WAC
  • Underestimate the maxima on eastern Florida

20
3. 1 Results
  • TCPE ( 1979-88)
  • North Atlantic basin
  • Definition
  • TCPE
  • Cyclonic PR / Number of occurrence of TCs
  • NCEP 2 Maximum on
  • - the ITCZ region
  • - the Gulf of Mexico
  • ARPEGE represents the maximum but overestimate
    the central Atlantic region.

mm/day of occurrence of TCs
21
3. 1 Results
  • TCGP ( Generic Efficiency) ( 1979-88)

mm/day of occurrence of TCs
0
4
36
40
44
48
32
28
24
20
16
12
8
  • North Atlantic basin
  • Definition TCGP Cyclonic PR / Number of
    occurrence of TCs
  • Both simulations overestimate the maximum of
    TCGP.

22
3.2 Results
Futur ARPEGE
23
3. 2 Results
Percentage of TC-Rain
PRESENT
FUTURE

24
3. 2 Results
TCPE ( Cyclonic Efficiency)
PRESENT
FUTURE
mm/day of occurrence of TCs
25
3. 2 Results
TCGP ( Generic Efficiency)
ARPEGE SST Reynolds
ARPEGE SST IV
PRESENT
FUTURE
26
Conclusions and perspectives
Conclusions Perspectives
  • Conclusions
  • - Derive the precipitation efficiency of TCs
    could be a good way of quantifying one kind of
    destructiveness due to TCs and evaluate the
    models (e.g. next IPCC report ).
  • - ARPEGE seems to overestimate the efficiency,
    that could be a result of its higher resolution
    in comparison with NCEP2.
  • - Adding SST anomalies (future), ARPEGE
    integrations produce a diminution of the fraction
    of cyclonic precipitation but an increase of the
    efficiency of TCs.
  • Perspectives
  • Perform ARPEGE integration in a Ocean -
    Atmosphere coupling configuration.
  • Transpose the study over South Indian Ocean,
    region known for high precipitation rates.

27
References
  • Lau and Zhou, 2008 Have tropical cyclones been
    feeding more extreme rainfall? J. of Geophysical
    Research. Revised September 2008.
  • Rodgers and Adler, 2001 Contribution of Tropical
    Cyclones to the North Atlantic Climatological
    Rainfall as Observed Satellites. J. of Applied
    Meteo. 40 1785-1800.
  • Chauvin and Royer, 2006 Response of
    hurricane-type vortices to global warming. Clim
    Dym. DOI 10.1007/s00382-006-0135-7
  • Geleyn et al, 1995 Atmospheric parameterization
    schemes in Météo-Frances Arpege NWP model. In
    Proceedings of the ECMWF seminar parameterization
    of sub-grid scale physical processes, 5-9 Sept
    1994, ECMWF, Reading, pp 385-402. (description of
    the physics of the model)?
  • Douville, 2003 Assessing the influence of soil
    moisture on seasonal climate variability with
    AGCMS. J. Clim 1044-1066.( description of the
    ISBA scheme)?
  • Ayrault and Joly, 2000 Une nouvelle topologie
    des dépresions météorologiques classification
    des phases de maturation. Compte-rendus à
    lAcadémie des Sciences, Sciences de la Terre et
    des planètes 330 167-172. (tracking mid-latitude
    lows)?
  • Bengtsson et al. 1982 Simulation of
    hurricane-type vortices in a general circulation
    model. Tellus 34 440-457.
  • Bengtsson et al. 1995 Hurricanes-type vortices
    in a general circulation model. Tellus
    47A175-195.
  • Gray 1975 Tropical cyclone genesis. Department
    of Atmospheric Science Paper, No. 234, Colorado
    State University, Fort Collins, CO, p121.
  • Louis et al. ,1981 A short history of the
    operational PBL-parameterization at ECMWF. In
    ECMWF workshop planetary boundary layer
    parameterization, 25-27 Nov 1981, ECMWF, Reading,
    UK, pp 59-80.
  • Ricard and Royer, 1993 A statistical could
    scheme for use in an AGCM. Ann. Geophys
    111095-1115.
  • Bougeault, 1985 A simple parameterization of the
    large-scale effects of cumulus convection. Mon
    Weather Rev 1132108-2121.
  • Morcrette, 1990 Impact of changes to the
    radiation transfer parameterizations plus cloud
    optical properties in the ECMWF model. Mon
    Weather Rev 118847-873.
  • Noilhan and Planton , 1989 A simple
    parameterization of land surfaces processes for
    meteorological models. Mon Weather Rev
    1171095-1115.
  • NCEP-DEO-AMIP-II Reanalysis (R-2) M.Kanamitsu,
    W. Ebisuzaki, J. Woolen, s-K Yang, J.J. Hnilo, M.
    Fiorino, and G. L. Potter. 1631-1643, Nov 2002,
    Bul. of the Atmos. Met. Soc.

28
ARPEGE Schemes
  • ARPEGE-Climat model originate from ARPEGE - IFS
    numerical weather prediction model developed
    jointly by Météo-France and ECMWF .
  • Spectral atmospheric model with
  • - hybrid s-pressure vertical coordinate
  • - 2 time level semi-lagrangian numerical
    integration scheme with a 30 min time-step
  • - Turbulence scheme of (Louis et al. ,1981)
  • - Statistical cloud scheme of Ricard and Royer,
    1993
  • - Mass-flux convective scheme with Kuo Type
    closure of Bougeault, 1985
  • - Radiative scheme derived from Morcrette, 1990
    activated every 3 hours
  • More details can be found in Geleyn et al. 1995
  • - The interaction soil biosphere atmosphere
    ISBA land surface scheme ( Noilhan and Planton ,
    1989, Douville , 2003)

IFS Integrated Forecast System ECMWF
European Medium Range Weather Forecast
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