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The Saharan Air Layer (SAL) is a hot, dry, and dust‐laden feature that advects large concentrations of dust across the Atlantic annually to destination regions in the Americas and Caribbean. However, recent work has suggested the SAL may be a contributing factor to high‐impact drought in the Caribbean basin. While the SAL's characteristic dust loadings have been the focus of much previous research, fewer efforts have holistically engaged the co‐evolution of the dust plume, its associated convective environment, and resultant rainfall in Caribbean islands. This study employs a self‐organizing map (SOM) classification to identify the common trans‐Atlantic dust transport typologies associated with the SAL during June and July 1981–2020. Using the column‐integrated dust flux, termed integrated dust transport (IDT), from MERRA‐2 reanalysis as a SAL proxy, the SOM resolved two common patterns which resembled trans‐Atlantic SAL outbreaks. During these events, the convective environment associated with the SAL, as inferred by the Gálvez‐Davison Index, becomes less conducive to precipitation as the SAL migrates further away from the west African coast. Simultaneously, days with IDT patterns grouped to the SAL outbreak typologies demonstrate island‐wide negative precipitation anomalies in Puerto Rico. The SOM's most distinctive SAL outbreak pattern has experienced a statistically significant increase during the 40‐year study period, becoming roughly 10% more frequent over that time. These results are relevant for both climate scientists and water managers wishing to better anticipate Caribbean droughts on both the long and short terms.
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Recurring Trans-Atlantic Dust Pathways during June-July
These data represent a self-organizing map (SOM) classification of all trans-Atlantic integrated dust fluxes (IDT) between June-July 1981-2020 as presented in: Miller, P. W., and C. Ramseyer, In press: The relationship between the Saharan Air Layer, convective environmental conditions, and precipitation in Puerto Rico. Journal of Geophysical Research: Atmospheres. Each daily IDT field is paired to one of 12 discrete pathways in idt_bmus_junjul.csv. The mean composite IDT over the tropical North Atlantic for each of these 12 patterns, as well as the mean composite Galvez-Davison Index (ERS_idt_node_gdi_1981_2020_junjul.nc) and mean composite precipitation over Puerto Rico (ERS_idt_node_prcp_1981_2020_junjul.nc) for the same node-date pairings are also provided. See the above-referenced manuscript for more details.
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- Award ID(s):
- 2236655
- PAR ID:
- 10526219
- Publisher / Repository:
- Zenodo
- Date Published:
- Format(s):
- Medium: X
- Right(s):
- Creative Commons Attribution 4.0 International
- Sponsoring Org:
- National Science Foundation
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