SOP Meeting, Toulouse, Nov. 2006 Instruments and data sets, Status & Highlights The 2006 Rainy Season over the GOURMA meso-site (Mali) E. Mougin, M. Arjounin, F. Baup, E. Ceschia, L. Diarra, V. Demarez P. derosnay, S. Guibert, C. Gruhier, F. Guichard, P. Hiernaux, M. Koité F. Lavenu, L. Kergoat, V. LeDantec, T.M. Mabilo, S. Mangiarotti M.N. Mulhaupt, O. Samain, J. Seghieri, N. Soumaguel, F. Timouk Photo: Doug Parker
GOURMA - 2006 Instruments and Data Sets
Gourma 2006: Status of Instruments, Rainfall stations Ekia (16.0 N) Bilantao (15.3 N) Nessouma (15.3 N) EVOLUTION OF RAIN GAUGES. MESO-SCALE. 30 28 25 20 20 Total = 28 stations 15 10 7 9 13 NATIONAL MANUAL CRX10 PLUVIO 91 5 Status Description Automatic raingauges 11 Automatic Stations 0 2002 2003 2004 2005 2006 2002 2003 2004 2005 2006 2005 2006 Start Location 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 Date Nessouma 2004 Bilantao 2004 Kelma 2006 Kirnya 2005 Kobou 2005 Bangui Mallam 2005 Ekia 2005 Tin tadeini 2005 In Zaket 2006 Agoufou mid slope 2002 Agoufou (down slope) 2005 Data capture : 95%
Gourma 2006: Status of Instruments, Meteorological stations Agoufou (15.3 N, 1.5 W) Bamba (17.1 N, 1.3 W) Status Description Automatic Weather stations 2005 2006 Start Location 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 Date Agoufou 2002 Bamba 2004 Data capture : 95%
Gourma 2006: Status of Instruments, SM stations Meso-scale Network Soil Moisture Station In Zaket 16.6 N Depth: 5cm 2.50m 2005 2006 Start Description Location 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 Date Automatic soil moisture Agoufou Upslope 2005 Agoufou mid slope 2006 Agoufou down slope 2005 Agoufou (sapflow) 2005 Bangui Mallam 2005 Kelma (lowland) 2005 Ekia 2005 In Zaket 2005 Bamba 2004 9 stations + 4 (Flux) Data capture: 94%
Gourma 2006: Status of Instruments, Flux stations Agoufou (15.3 N) Eguerit (15.5 N) Bamba (17.1 N) Kelma (15.2 N) Description Network of 4 flux stations 2 Sensible Heat 2 Sensible Heat CO 2 H 2 O Automatic Weather Stations CEH Status 2005 2006 Start Location 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 Date Bamba (HF)? 2005 Agoufou (CO2+HO2) H only H only 2005 Kelma (C02+HO2) H only 2005 Eguerit (HF) 2005 Bamba???????? 2005 Agoufou 2005 Kelma 2005 Eguerit 2005 Flux-2006: H only ( 50%) Met-2006: ( 20 to 40%)
Gourma 2006: Status of Instruments, Sapflow station (Agoufou) Sampled evergreen and deciduous trees January 2006 Sap flow measures provide an estimation of transpiration from trees Heated probe Reference probe 1- Combretum glutinosum 2- Balanites aegyptiacum 3- Acacia raddiana 4- Acacia senegalensis 2005 2006 Start Description location 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 Date Sap flow station Agoufou 2006 Acacia senegal 320 Agoufou " Acacia senegal 317 (dead) Agoufou " Acacia raddiana 318 Agoufou " Balanites aegyptiaca 316 Agoufou " Combretum glutinosum 315 Agoufou " Data capture: 98%
GOURMA 2006 Highlights
Gourma 2006: Rainfall LONG TERM VARIABILITY HOMBORI (15.3 N) 400 1950 ANOMALY (mm) 300 200 100 0-100 -200-300 1940 1970 1984 1994 2006 YEARS Long Term mean : 374 mm Hombori - 2006 : 370 mm
Gourma 2006: Rainfall Period 1950-1990 2005 2006 Seasons 440 mm 305 mm Late starting Observations 2006: 1. Late starting, but normal (Hombori) to exceeding rain (Agoufou) 2. High intra-seasonal variability (2006 / 2005)
Gourma 2006: Total Rainfall Gourma meso-site Strong North-South gradient : 2 mm/km 7.5 Hombori super-site 15.5 BAMBA (mm) 17 OURMA-RHAROUS 6.5 TINT 16 HEKYA 5.5 DIMA AGOUFOU HOMBORI KYNIA 15 480 460 440 420 400 380 360 340 320 300 280 260 240 220 200 180 160 140 120 100 15.45 15.4 15.35 15.3 15.25 15.2 15.15 15.1 15.05 NESS HOMBORI DARA KILM GOUN SEBA TARA BILA KELM DARI DOUN AGOUFOU EBAN (mm) 500 490 480 470 460 450 440 430 420 410 400 390 380 370 360 350 340 330 320 310 300 290 KOBOU 15-1.8-1.75-1.7-1.65-1.6-1.55-1.5-1.45-1.4-1.35-1.3 4.5-2 -1.5-1 High local variability : 60%
Gourma 2006: Soil moisture AMSR Supersite Averaged Soil Moisture Product August 8 Sept. 17
Gourma 2006: Surface Radiative Budget Net radiation = LW -LW + SW -SW Agoufou 2006 Rainy season: Strong increase after mid-july 2006 Period 2002-2005 High interannual variability with stronger increase of Rnet for wet years (2003, 2005) compared to dry years (2002, 2004) 2005 2004 Jul Aug Wet Year Dry Year
Gourma 2006: Surface Radiative Budget Albedo = SW / SW Jul Aug Agoufou 2006 Rainy season: Strong decrease after mid-july 2006 Period 2002-2005 High interannual variability with stronger decrease for wet years (2003, 2005) compared to dry years (2002, 2004) 2005 Jun Jul Aug Wet Year Dry Year 2004
Gourma 2006: Tethered Balloon in the CBL Convective Boundary Layer growth August 19 9h 17h Virtual potential Temperature (θv) vs pressure CBL rather low, following significant rainfall over a well vegetated area. Data capture: August 12-31
Gourma 2006: Seasonal change of vegetation, Hombori JULY -2006: desperately seeking green vegetation Super-site overflight Hombori: July 28, 2006 Field survey Hombori: July 17, 2006
Gourma 2006: Interannual change of vegetation, Agoufou GRASSLAND 2005 2006 Soil Moisture June 06 May 29 July 17 LAI July 15 August 19 DOY August 20
Gourma 2006: Interannual change of vegetation, Kelma 2005 2006 ACACIA FOREST August 02 LAI July 24 August 30 August 21 DOY September 19 September 20
Gourma 2006: Surface fluxes, Kelma 1 m 3 /m 3 Rain Soil moisture mm 20 Acacia Forest site 0,9 0,8 Rain Soil Water content -50 cm 18 16 0,7 Soil Water content -10 cm 14 0,6 12 0,5 10 0,4 8 0,3 6 0,2 4 0,1 2 0 10-Jul 15-Jul 20-Jul 25-Jul 30-Jul 4-Aug 9-Aug 0 900 800 700 600 500 400 300 200 100 0-100 W/ m² Sensible Heat Fluxes Net Radiation ma x Flooded Sensible Heat Flux 10-Jul 15-Jul 20-Jul 25-Jul 30-Jul 4-Aug 9-Aug
Gourma 2005: Inter-sites variation, H fluxes 800 700 W/m² Grassland 600 Rnet max 500 400 Sensible Heat Flux 300 200 100 0-100 1-juin 11-juin 21-juin 1-juil. 11-juil. 21-juil. 31-juil. 10-août 20-août 30-août Erosion surface
Gourma 2006: Sapflow fluxes from trees, Agoufou Seasonal variation 2006 0.30 flux de s eve HV (-5cm) 40 Flux (mv) 0.25 0.20 0.15 35 30 25 TDR (mv) Strong seasonal variation dependent on leaf phenology and Soil Moisture Content in the root zone 0.10 0.05 0.00 Soil Moisture 110 130 150 170 190 210 230 20 15 Daily variation jours 0.25 Water stress 120 232 174 0.20 Strong daily variation dependent on SWC flux (mv) 0.15 0.10 0.05 No Water stress 0.00 7h 17h 100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 heure
Gourma 2006: Summary Rainy season Late starting, followed by heavy rains from mid-july to mid-august (60% of total rainfall) and finally normal to exceeding total rainfall Surface Radiative properties (Net radiation): typical of wet year (2005, 2003) Late starting of vegetation (trees and herbs) but fast growth and finally a total cover close to that observed in 2005 (even better for trees) Instruments and Data Sets Operational network : Data collection >95% (rainfall, soil moisture, vegetation) Flux stations : 50%, complemented by sap flow measurements on trees.