A possible forcing mechanism for intra-seasonal rainfall distribution to bi-decadal climate variability is explored. The atmospheric response to external forcing is demonstrated at a daily and annual time scale by noting variation in the Southern Annular Mode (SAM) as a function of changing lunar tidal potential. The predictability of the SAM, and the subsequent rainfall response over north-eastern South Africa, is evaluated by using an index derived from lunar tidal as a predictor. At intra-seasonal time scales, it is shown that an increase in rainfall between years with lower predicted SAM and years with a higher predicted SAM occurs on very specific parts of the lunar synodic month, providing indications that intra-seasonal outlooks for rainfall by forecast models may benefit from the consideration of lunar cycle characteristics.
Reference:
Malherbe J, Landman, WA and Engelbrecht, FA. 2014. Can intraseasonal to decadal forecasts benefit from from consideration of lunar forcing? In: 30th Annual Conference of South African Society for Atmospheric Sciences (SASAS), Potchefstroom, 1-2 October 2014
Malherbe, J., Landman, W., & Engelbrecht, F. (2014). Can intraseasonal to decadal forecasts benefit from from consideration of lunar forcing?. SASAS. http://hdl.handle.net/10204/7903
Malherbe, Johan, WA Landman, and FA Engelbrecht. "Can intraseasonal to decadal forecasts benefit from from consideration of lunar forcing?." (2014): http://hdl.handle.net/10204/7903
Malherbe J, Landman W, Engelbrecht F, Can intraseasonal to decadal forecasts benefit from from consideration of lunar forcing?; SASAS; 2014. http://hdl.handle.net/10204/7903 .
30th Annual Conference of South African Society for Atmospheric Sciences (SASAS), Potchefstroom, 1-2 October 2014. This is the abstract of the conference proceedings. The definitive version of the work is published in the SASAS proceedings. Due to copyright restrictions, the attached PDF file only contains the abstract of the full text item. For access to the full text item, please consult the publisher's website.