West African Monsoon

Model 1 Forcing Run Analysis


Precipitation

Figure 26a Figure 26b
Normalized black carbon anomaly top tercel and bottom tercel from the forcing run timeseries are referenced with grid normalized precipitation anomalies.  The corresponding precipitation in the bottom tercels and top tercels are averaged then subtracted to attain composite.  Precipitation in units of mm/day, bc in units of g/m2.
Seasonal cycle of the difference composite calculated in Figure 26a for the WAM region..
   
Figure 29a Figure 29b
Normalized black carbon anomaly top tercel and bottom tercel from the forcing run timeseries are referenced with grid normalized black carbon anomalies.  The corresponding black carbon in the bottom tercels and top tercels are averaged then subtracted to attain composite.
Seasonal cycle of the difference composite calculated in Figure 29a for the WAM region.
 
   
Rain change due to black carbon. 

where c is the correlation coefficient of the normalized anomaly (grid rain vs. domain mean bc), σrain is the grid point standard deviation of rain, σbc is the grid point standard deviation of bc, and bcmean is the grid point mean of bc.  Units are in mm/day.

Percent rain change due to black carbon.

where δrain is previously calculated for each grid point (see left) and rain is mean rain at the grid point.

 

   
Black carbon and precipitation mean with seasonal cycle removed.  Top and bottom black carbon tercels are displayed.

 

Correlation Analysis

   
Figure 32a Figure 32b
240 month correlation between black carbon and precipitation normalized anomalies.  Values are calculated grid by grid.  White lines represent 99% and 95% confidence.
240 month correlation between black carbon and precipitation normalized anomalies.  Values are calculated by precipitation grid vs. black carbon domain mean.  White lines represent 99% and 95% confidence.
   
   

Figure 32e

240 month correlation between precipitation and black carbon normalized anomalies for the WAM region.