West African Monsoon Region of Analysis

Total West African Monsoon Region of analysis: 15o W – 10o E, 5o N – 20o N

Sub-Sahel Region of analysis: 15o W – 10o E, 7.5o N – 15o N

Coastal Region of analysis: 15o W – 10o E, 5o N – 7.5o N

Precipitation Patterns

Precipitation intensity (mm/day), averaged over 15o W – 10o E (WAM)

Sub-Sahel

Coastal

Inter-annual Precipitation

trmm data

merra

Precipitation intensity (mm/day), averaged monthly over : 15o W – 10o E, and 5o N – 20o N (WAM) 15o W – 10o E, and 7.5o N – 15o N (Sahel Area) 15o W – 10o E, and 5o N – 7.5o N (Coastal Area)

era-interim

gpcp

Inter-annual Precipitation

Precipitation intensity (mm/day), averaged monthly over 15o W – 10o E, and 5o N – 20o N (WAM), for the years 1999 – 2005.

Precipitation intensity (mm/day), averaged over summer months, over 15o W – 10o E, and 5o N – 20o N (WAM), for the years 1999 – 2005.

trmm data merra era-interim

Inter-annual Precipitation Trends

trmm data merra era-interim

May

June

gpcp

test

July

August

September

May-June

July-September

Precipitation intensity (mm/day), averaged yearly over : 15o W – 10o E, and 5o N – 20o N (WAM) 15o W – 10o E, and 7.5o N – 15o N (Sub-Sahel Area) 15o W – 10o E, and 5o N – 7.5o N (Coastal Area)

for the years 1998 – 2007 for trmm, 1999 – 2005 for merra and era-interim, and 1997 – 2007 for gpcp.

May-September

TRMM Regional Precipitation 1999 (maximum rainfall) 2005 (minimum rainfall) Difference (1999-2005)

Spring:

Spring (April-May-June) and summer (July-August-September) precipitation (and their difference) averaged over the WAM

Summer:

TRMM Regional Precipitation

1999 2000 2001 2002

Spring (April-May-June) and summer (July-August-September) precipitation averaged over the WAM

Summer:

Spring:

TRMM Regional Precipitation

2003 2004 2005

Spring (April-May-June) and summer (July-August-September) precipitation averaged over the WAM

Summer:

Spring:

Merra Precipitation & Associated Winds 1999 (maximum rainfall) 2000 (minimum rainfall) Difference (1999 – 2000)

Spring:

Spring (April-May-June) and summer (July-August-September) precipitation and winds at 925 hPa and 700 hPa, (and their difference) averaged over the WAM

Summer:

Test page

Era-Interim Precipitation & Associated Winds 1999 (maximum rainfall) 2002 (minimum rainfall) Difference (1999 – 2002)

Spring:

Spring (April-May-June) and summer (July-August-September) precipitation and winds at 925 hPa and 700 hPa, (and their difference) averaged over the WAM

Summer:

Inter-annual Relative Humidity

Vertically averaged relative humidity, averaged monthly over 15o W – 10o E, and 5o N – 20o N (WAM), for the years 1999 – 2005.

Vertically averaged relative humidity, averaged over summer months, over 15o W – 10o E, and 5o N – 20o N (WAM), for the years 1999 – 2005.

merra era-interim

Merra Relative Humidity & Associated Winds 1999 (maximum precipitation) 2000 (minimum precipitation) Difference (1999 – 2000)

Spring:

Spring (April-May-June) and summer (July-August-September) vertically averaged relative humidity and winds at 925 hPa and 700 hPa (and their difference), averaged over the WAM

Summer:

Era-Interim Relative Humidity & Associated Winds 1999 (maximum precipitation) 2002 (minimum precipitation) Difference (1999 – 2002)

Spring:

Spring (April-May-June) and summer (July-August-September) vertically averaged relative humidity and winds at 925 hPa and 700 hPa (and their difference), averaged over the WAM

Summer:

1999 (maximum precipitation) 2000 (minimum precipitation) Difference (1999 – 2000)

Merra Relative Humidity & Meridional-Vertical Circulation

Merra Relative Humidity & Longitudinal-Vertical Circulation

Longitudinal-vertical circulation and relative humidity in summer (July-August-September) (and their difference), all averaged over 5o N – 20o N.

Meridional-vertical circulation and relative humidity in summer (July-August-September) (and their difference), all averaged over 15o W – 10o E.

Merra Relative Humidity & Associated Meridional-Vertical Circulation

1999 2000 2001 2002

Merra Relative Humidity & Associated Longitudinal-Vertical Circulation

1999 2000 2001 2002

Longitudinal-vertical circulation and relative humidity in summer (July-August-September), all averaged over 5o N – 20o N.

Meridional-vertical circulation and relative humidity in summer (July-August-September), all averaged over 15o W – 10o E.

Merra Relative Humidity & Associated Meridional-Vertical Circulation

2003 2004 2005

Merra Relative Humidity & Associated Longitudinal-Vertical Circulation

2003 2004 2005

Meridional-vertical circulation and relative humidity in summer (July-August-September), all averaged over 15o W – 10o E.

Longitudinal-vertical circulation and relative humidity in summer (July-August-September), all averaged over 5o N – 20o N.

1999 (maximum precipitation) 2002 (minimum precipitation) Difference (1999 – 2002)

Era-Interim Relative Humidity & Meridional-Vertical Circulation

Era-Interim Relative Humidity & Longitudinal-Vertical Circulation

Longitudinal-vertical circulation and relative humidity in summer (July-August-September) (and their difference), all averaged over 5o N – 20o N.

Meridional-vertical circulation and relative humidity in summer (July-August-September) (and their difference), all averaged over 15o W – 10o E.

Era-Interim Relative Humidity & Associated Meridional-Vertical Circulation

1999 2000 2001 2002

Era-Interim Relative Humidity & Associated Longitudinal-Vertical Circulation

1999 2000 2001 2002

Longitudinal-vertical circulation and relative humidity in summer (July-August-September), all averaged over 5o N – 20o N, for 1000 hPa – 700 hPa

Meridional-vertical circulation and relative humidity in summer (July-August-September), all averaged over 15o W – 10o E.

Era-Interim Relative Humidity & Associated Meridional-Vertical Circulation

2003 2004 2005

Era-Interim Relative Humidity & Associated Longitudinal-Vertical Circulation

2003 2004 2005

Meridional-vertical circulation and relative humidity in summer (July-August-September), all averaged over 15o W – 10o E.

Longitudinal-vertical circulation and relative humidity in summer (July-August-September), all averaged over 5o N – 20o N, for 1000 hPa – 700 hPa

Merra Seasonal Cycle of Moisture Flux 1999 (maximum rainfall) 2000 (minimum rainfall) Difference (1999 – 2000)

Seasonal cycle of moisture flux (s-1) across 50 N (averaged over -150 W – 100 E), plotted as [v(dq/dy)] in row one, [q(dv/dy)] in row two, and [v(dq/dy) + q(dv/dy)] in row three.

Merra Seasonal Cycle of Moisture Flux 1999 (maximum rainfall) 2000 (minimum rainfall) Difference (1999 – 2000)

Seasonal cycle of moisture flux (s-1) (averaged over -150 W – 100 E), across the entire WAM in row one,Across the Sub-Sahel Area in row two, and across the Coastal Area in row three.

WAM:

Sub-Sahel:

Coastline:

Merra Seasonal Cycle of Moisture Flux

1999 (maximum rainfall) 2000 (minimum rainfall) Difference (1999 – 2000)

Seasonal cycle of moisture flux (s-1) across 50 N (averaged over -150 W – 100 E), plotted as v in row 1 and as q in row two.

Merra Seasonal Cycle of Moisture Flux

1999 (maximum rainfall) 2000 (minimum rainfall) Difference (1999 – 2000)

Seasonal cycle of moisture flux (s-1) across 50 N (averaged over -150 W – 100 E), plotted as dv/dy in row 1 and as dq/dy in row two.

Merra Seasonal Cycle of Moisture Flux 1999 2000 2001 2002

Seasonal cycle of moisture flux (s-1) across 50 N (averaged over -150 W – 100 E), plotted as [v(dq/dy)] in row one, [q(dv/dy)] in row two, and [v(dq/dy) + q(dv/dy)] in row three.

Merra Seasonal Cycle of Moisture Flux 2003 2004 2005

Seasonal cycle of moisture flux (s-1) across 50 N (averaged over -150 W – 100 E), plotted as [v(dq/dy)] in row one, [q(dv/dy)] in row two, and [v(dq/dy) + q(dv/dy)] in row three.

Era-Interim Seasonal Cycle of Moisture Convergence (g kg-1 day-1), averaged over the West African Monsoon Domain

Merra Seasonal Cycle of Moisture Convergence (g kg-1 day-1), averaged over the West African Monsoon Domain

Comparison of total moisture convergence cycles, and its components related to nonlatent and latent heating, respectively

plots in progress

Merra Seasonal Cycle of Moisture Convergence (g kg-1 day-1), averaged over the West African Monsoon Domain

non-latent heat adjusted for precipitation:

Merra Seasonal Cycle of Moisture Convergence (g kg-1 day-1), averaged over the West African Monsoon Domain

Comparison of total moisture convergence cycles, and its components related to nonlatent and latent heating, respectively

Merra Seasonal Cycle of Moisture Convergence (g kg-1 day-1), averaged over the WAM for 1999 and 2000

non-latent heat adjusted for precipitation:

Merra Seasonal Cycle of Moisture Convergence (g kg-1 day-1),) averaged over the WAM for 1999 and 2000

Comparison of 1999 (maximum precipitation) and 2000 (minimum precipitation) total moisture convergence cycles, and its components related to nonlatent and latent heating, respectively

Merra Seasonal Cycle of Moisture Convergence 1999 (maximum rainfall) 2000 (minimum rainfall) Difference (1999 – 2000)

Seasonal cycle of moisture convergence (g kg-1 day-1) averaged over 1000 hPa – 700 hPa in the WAM by total, nonlatent heat-divergent, and latent heat-divergent winds (and the difference). The contours represent associated precipitation values (mm/day).

Merra Seasonal Cycle of Moisture Convergence

1999 2000 2001 2002

Seasonal cycle of moisture convergence (g kg-1 day-1) averaged over 1000 hPa – 700 hPa in the WAM by total, nonlatent heat-divergent, and latent heat-divergent winds. The contours represent associated precipitation values (mm/day).

Merra Seasonal Cycle of Moisture Convergence

2003 2004 2005

Seasonal cycle of moisture convergence (g kg-1 day-1) averaged over 1000 hPa – 700 hPa in the WAM by total, nonlatent heat-divergent, and latent heat-divergent winds. The contours represent associated precipitation values (mm/day).

Era-Interim Seasonal Cycle of Moisture Convergence 1999 (maximum rainfall) 2002 (minimum rainfall) Difference (1999 – 2000)

Seasonal cycle of moisture convergence (g kg-1 day-1) averaged over 1000 hPa – 700 hPa in the WAM by total, nonlatent heat-divergent, and latent heat-divergent winds (and the difference). The contours represent associated precipitation values (mm/day).

Era-Interim Seasonal Cycle of Moisture Convergence 1999 (maximum rainfall) 2000 2001

Seasonal cycle of moisture convergence (g kg-1 day-1) averaged over 1000 hPa – 700 hPa in the WAM by total, nonlatent heat-divergent, and latent heat-divergent winds (and the difference). The contours represent associated precipitation values (mm/day).

2002 (minimum rainfall) 2003 2004 2005

Merra Meridional-Vertical Circulation

1999 (maximum precipitation) 2000 (minimum precipitation) (1999-2000)

Meridional-vertical circulation, its divergent and non-divergent components, and their moisture convergence in summer (July-August-September), all averaged over 15o W – 10o E. Column 3 represents the difference between 1999 and 2000 values (the years

of maximum and minimum precipitation, respectively). The solid line marks the coast line.

Merra Meridional-Vertical Circulation 1999 (maximum precipitation) 2000 (minimum precipitation) (1999-2000)

As above, for pressure levels 1000 hPa – 700 hPa

Merra Meridional-Vertical Circulation

1999 (maximum precipitation) 2000 (minimum precipitation) (1999-2000)

Divergent meridional-vertical circulation, its nonlatent and latent heating components, and their moisture convergence in summer (July-August-September), all averaged over 15o W – 10o E. Column 3 represents the difference between 1999 and 2000 values (the

years of maximum and minimum precipitation, respectively). The solid line marks the coast line.

Merra Meridional-Vertical Circulation 1999 (maximum precipitation) 2000 (minimum precipitation) (1999-2000)

As above, for pressure levels 700 hPa – 1000 hPa

Merra Longitudinal-Vertical Circulation

1999 (maximum precipitation) 2000 (minimum precipitation) (1999 – 2000)

Longitudinal-veritcal circulation, its divergent and non-divergent components, and their moisture convergence in summer (July-August-September), all averaged over 15o W – 10o E. Column three represents the difference between 1999 and 2000 values (the

years of maximum and minimum precipitation, respectively).

Merra Longitudinal-Vertical Circulation 1999 (maximum precipitation) 2000 (minimum precipitation) (1999 – 2000)

As above, for pressure levels 700 hPa – 1000 hPa

Divergent longitudinal-vertical circulation, its nonlatent and latent heating components, and their moisture convergence in summer (July-August-September), all averaged over 15o W – 10o E. Column three represents the difference between 1999 and 2000

values (the years of maximum and minimum precipitation, respectively).

Merra Longitudinal-Vertical Circulation

1999 (maximum precipitation) 2000 (minimum precipitation) (1999 – 2000)

As above, for pressure levels 700 hPa – 1000 hPa

Merra Longitudinal-Vertical Circulation 1999 (maximum precipitation) 2000 (minimum precipitation) (1999 – 2000)

Merra Spring Nonlatent-Heating vs. Summer Latent-Heating

Summer (July-August-September) latent heating plotted against spring (April-May-June) nonlatent heating over the WAM

April May June

July, August, and September latent heating plotted against April, May, and June nonlatent-heating, respectively, over the WAM

Merra Spring Nonlatent-Heating vs. Summer Precipitation

Summer (July-August-September) latent heating plotted against spring (April-May-June) precipitation over the WAM

April May June

July, August, and September precipitation plotted against April, May, and June nonlatent-heating, respectively, over the WAM