ODINAFRICAGLOSS Sea Level Training Course

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ODINAFRICA/GLOSS Sea Level Training Course

• Regional Oceanography and Climate (West Africa)
• 13-24 November 2006, Oostende
• Angora AMAN

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• Recall why AMMA ?

Sahel Rainfall index



Humid
Dry
Indice pluviométrique Sahel

Niger à Malanville 106 km²
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• The Gulf of Guinea is very badly simulated in
  numerical models
• Pb with fluxes
• (eg wind stress, local air-sea
• interaction, convective heating over
• land of S. America and W. Africa)
• Pb with mixing processes
• - Pb with horizontal advection
• interactions with subsurface
• Pb with effect of waves

SST
Surface fluxes
Pb mostly in the GG
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WEST AFRICA CLIMATE

• Importance of the GG in the West Africa
  Climatology
• Principal source of the WV which is advected by
  the atmospheric circulation. It can constitute
  most of precipitations on the continent
• The SST in the GG is also one of the factors,
  with continental surface which conditions the
  intensity of the monsoon of West Africa.

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Atmospheric circulation (averaged
winds) Circulation atmosphérique (vents moyens)
Wauthy, 1983
January
July
April
October
Cersat, Année 2005
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(No Transcript)
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Annual cycle of precipitation / Cycle annuel des
précipitations
(Nicholson)
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PIRATA (needed for AMMA)
(Pilot Research moored Array in the Tropical
Atlantic) (1997 - 200??) (African Monsoon
Multidisciplinary Analyses)
Tripartite Programme as a contribution to
CLIVAR, GCOS and GOOS - FRANCE (IRD/LEGOS,
Météo-France) - BRESIL (INPE, DHN) - USA
(NOAA/PMEL)
PIRATA ATLAS buoys network in October 2005

• yearly dedicated cruises needed
• for replacement/deployment of mooorings

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PIRATA ATLAS buoys
Measured Parameters Atmosphere - wind
(direction, speed) - relative humidity -
air temperature - precipitation - incident
radiation Ocean - temperature (11 levels
from surface to 500m) - salinity (4 levels
0,20,40,120m) - pressure (at 300 500m)
- Daily averaged data transmitted in real time by
Argos - High frequency data (10mn) available
after servicing operations
Web sites http//www.pmel.noaa.gov/pirata/
http//www.brest.ird.fr/pirata/piratafr.html
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2 International program AMMA African Monsoon Mult
idisciplinary Analyses
What is AMMA?
2. A coordinated international effort

• Scientists from more than 25 agencies/institutions
  in more than 20 countries in Africa, Europe and
  the US are involved Algeria, Benin, Burkina
  Faso, Cameroon, Chad, Denmark, France, Germany,
  Ghana, Italy, Ivory Coast, Mali, Niger, Nigeria,
  Senegal, Spain, Togo, UK, US
• International Science and Implementation Working
  Groups are formed
• Endorsement received from WCRP (CLIVAR GEWEX),
  GCOS,
• French, UK USA funding agencies have declared
  support

2nd ODINAFRICA Seminar Ostende, April 24, 2006
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EGEE / AMMA cruises
French EGEE program gt 6 cruises, 2 per year in
2005, 2006 2007 ? interannual variability (Egée
1-gt6) intra-annual (Egée 3)
(Repeated sections at 10W, 3E Contribution
to PIRATA, ARGO (Coriolis), GODAE (Mercator).
opportunities for other programs as JGOF
(CO2, biogeochemistry)
Egée 1 trackline (June-July 2005) Egée 2
trackline (September 2005)
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EGEE
Measurements at São Tomé Island (0N, 6E)
Meteorological Station Tide gauge
1) Installation of a meteorological station in
October 2003 ONSET autonomous temperature
sensor in September 2005
 

• 2) Tide gauge maintained by IRD since 1980s.
• - Pressure, Atm. pressure SST SSS.
• Part of GLOOS.
• GPS positioned (in December 2002)

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SST annual evolution from in situ records
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Pointe Noire Cotonou- Tema - Abidjan
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Comparison Tabou - Lagos
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Comparison between in situ and satellite SST
measurements (Tema)
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Comparison between in situ and satellite SST
measurements (Tabou)
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Comparison between in situ and satellite SST
measurements (Abidjan)
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Comparison SST and SL (r 0.75)
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Comparison SST and SL (r0.93)
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SST and SL anomalies (San Pedro)
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ODINAFRICA CONTRIBUTION

• Information from African coast is needed to
  contribute to the global sea level monitoring
  network that understands the climate change.
  Better understanding on the futures of the GG.
• Contribution of ODINAFRICA to
• - the World Ocean Circulation Experiment (WOCE).
• Climate Variability (CLIVAR)
• African Multidisciplinary Monsoon Analysis (AMMA)
• GLOSS