Publication Abstracts

Druyan 1998

Druyan, L.M., 1998: The role of synoptic systems in the interannual variability of Sahel rainfall. Meteorol. Atmos. Phys., 65, 55-75, doi:10.1007/BF01030269.

Components of the June-September climate over the Sahel are investigated in simulations with the GCM of the NASA/Goddard Institute for Space Studies, forced by SST observed during 1987 and 1988. The study analyzes the role of the synoptic patterns in determining precipitation differences between the two seasons, with special attention given to African wave disturbances (AWD). Emphasis is placed on deducing the characteristics of individual systems which may be missed by spectral and/or composite analyses. Results are derived from time-longitude cross-sections and spatial distributions of daily and weekly averages of key climatological variables. Despite the overall rainier season, rainless AWD are more prevalent in the simulations corresponding to June-September 1988 forcing than for 1987. Daily precipitation is shown to be highly correlated with mid-tropospheric vorticity, near surface convergence and 200 mb divergence. August daily rainfall was somewaht better correlated with implied large scale vertical motion for 1988 forcing, emphasizing the dominance of broad circulation influences during that summer. While significant rainfall variability is attributed to AWD, quasi-stationary mechanisms cannot be ignored. In these simulations, upper tropospheric divergence modulated by changes in the Tropical Easterly Jet serves to both intensify the rainfall triggered by AWD and to sustain broader rainfall patterns during events of "massive uplift".

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BibTeX Citation

  author={Druyan, L. M.},
  title={The role of synoptic systems in the interannual variability of Sahel rainfall},
  journal={Meteorol. Atmos. Phys.},

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RIS Citation

ID  - dr04000r
AU  - Druyan, L. M.
PY  - 1998
TI  - The role of synoptic systems in the interannual variability of Sahel rainfall
JA  - Meteorol. Atmos. Phys.
VL  - 65
SP  - 55
EP  - 75
DO  - 10.1007/BF01030269
ER  -

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