The Influence of Tropical Cyclones on Circulation, Moisture Transport, and Snow Accumulation at Kilimanjaro During the 2006-2007 Season
Tropical cyclones represent an important component of intraseasonal atmospheric variability in the southwest Indian Ocean, and their landfall can be devastating to coastal communities. However, little is known about their impact on precipitation in the high-elevation regions of East Africa. Here we combine in situ measurements from the summit of Kilimanjaro and subkilometer atmospheric modeling of the region to investigate the impact of these storms during the 2006-2007 cyclone season, which was characterized by anomalously positive snow accumulation at the summit coinciding with cyclone activity. Observations indicate that two storms are associated with snowfall amounts exceeding 10 cm per day, an amount representing 5% of the observed average annual total. Numerical simulations show that some tropical cyclones transport moisture directly to the region while others induce moisture transport from the continental interior. Our study suggests that these synoptic-scale phenomena have the potential to complicate the extraction of climate signals from glaciers.