On the Role of the Saharan Air Layer in the 2015 Puerto Rico Drought

TitleOn the Role of the Saharan Air Layer in the 2015 Puerto Rico Drought
Publication TypeConference Paper
Year of Publication2016
AuthorsRamseyer, CA, Mote, TL, Miller, PW
Conference Name113th Annual Meeting of the American Association of Geographers. April 5–9, 2017, Boston, MA.
PublisherAmerican Association of Geographers (AAG)
Conference LocationBoston, MA
Accession NumberLUQ.1371
Other Numbers1371
AbstractThe Puerto Rico drought of 2015 led to water rationing throughout the eastern side of the island including San Juan. Additionally, the drought caused extensive changes to the biota and biogeochemistry in the El Yunque National Forest. We examine the drought of 2015 in northeastern Puerto Rico in comparison to the available historical record, with particular attention to 1994. In addition to examining precipitation, we examined key atmospheric variables that are strongly associated to precipitation variability, including wind shear, atmospheric moisture and pressure, and aerosols (specifically dust). Results indicate the critical role of the Saharan Air Layer (SAL) on the drought, particularly in the strengthening of the trade wind inversion. This work makes use of two unique tools that are only recently available to the research community. The DayMet 1-km daily precipitation product is used to assess the timing and magnitude of the drought in the complex topography of eastern Puerto Rico. Additionally, the experimental Gálvez-Davison Index (GDI) is used to understand the impact of SAL intrusions on precipitation. This index has been used in the operational community to forecast convective precipitation in Puerto Rico, and components of the index are well suited to capture the effect of the hot, dry air intrusions above the trade wind inversion. We believe this is the first application of the GDI to examine the impact of the SAL on precipitation.