1. ECMWF IFS Rnet (net radiation) Met station Agoufou, 1.5W,15.3N MJJA 2005 weaker seasonal dynamic of Rnet in the model (MJJA mean values rather close) * IFS Rnet larger in May, smaller during the monsoon * also, less day to day variability (just a bit of caution, not exactly same time sampling/smoothing here, + maybe effect of 1 point versus ~(40 km)**2 area) decomposition in SW, LW, up & down fluxes, next slides seasonal dynamics explained mostly by upward fluxes monsoon trends (both SW and LW) more differences between IFS and Met station in 2005 (these plots) than in 2004 (dry year) because of weaker seasonal dynamics of measured radiative fluxes for dry years 24-h avg values 3-day running mean Observations provided by the CESBIO team: Mougin, Timouk, Kergoat et al

2. Rnet SWnet ECMWF IFS Rnet SW cloud forcing clear sky SW net LWnet -20-LW cloud forcing clear sky LW net LWnet SWnet Met station Agoufou, 1.5W,15.3N MJJA 2005 24-h avg values 3-day running mean

3. SW down LW down SW up LW up Met station Agoufou, 1.5W,15.3N MJJA 2005 day of year 2005 ECMWF IFS 24-h avg values 3-day running mean

4. Jun Jul Aug Sep Met station Agoufou 1.5W,15.3N 2002, Rnet This slide and next ones for 2003 to 2006 illustrate interannual variability and show how the differences between years take place mostly during daytime

5. Jun Jul Aug Sep Met station Agoufou 1.5W,15.3N 2003, Rnet

6. Jun Jul Aug Sep Met station Agoufou 1.5W,15.3N 2004, Rnet

7. Jun Jul Aug Sep Met station Agoufou 1.5W,15.3N 2005, Rnet

8. Jun Jul Aug Sep Met station Agoufou 1.5W,15.3N 2006, Rnet

9. variations along latitude (North Sahel) weel, with 2 met stations only, 15.3N & 17N, in 2004 interannual variability with 2004 and 2005, met station at 15.3N note: there is a meaningful seasonal variation of albedo in the IFS, in terms of shape but it is less than 0.02 in amplitude – I have just drawn a line to indicate the avg value in the IFS.

10. 2004 Bamba, 1.5W, 17.0N 0.4 Albedo ECMWF ~ 0.38 Rnet ECMWF IFS Rnet Met station

11. 2004 Agoufou 1.5W, 15.3N 0.4 Albedo ECMWF ~ 0.27 Rnet ECMWF IFS Rnet Met station

12. 2005 Agoufou 1.5W, 15.3N Albedo ECMWF ~ 0.28 Rnet ECMWF IFS Rnet Met station

13. Cloud cover and rainfall in the IFS Sahel, 2 next slides an example with 1 met station 15.3N, in 2004 24-h average values, except rainfall: 24-h cumulative (also shown, surface heat fluxes H and LE) ok I made them with 24h starting each day something like 6 or 9 hours after the model start, i.e. Possibly a bit early with respect to spin-uo-down but it may be less of a pb at this latitude (?) then a slide showing some characteristics of the measured rainfall overall, in the IFS it does not seem to me that there is a clear underestimation of rainfall events but there is an underestimation of rainfall per rainfall event (I base this argument on more than these examples of course) the stratiform rainfall being negligible in the IFS does not seems wrong to me

15. note: simulated stratiform rainfall negligible

16. composite precipitation events Agoufou 2002,2003,2005,2006 from met station, for Jun Jul Aug Sep, other colours=other months duration Range of fluctuations

17. OBS ECMWF IFS LWnet+cstA,SWnet+cstB Rnet Distinct interannual signatures of Rnet in OBS & ECMWF IFS, qualitatively similar LW & SW differences for wet (2003) versus dry (2004) monsoon seasons but the sum LW+SW reflect the quantitative differences SWnet LWnet