Pausata Francesco Salvatore Rocco

No Thumbnail Available
Last Name
Pausata
First Name
Francesco Salvatore Rocco
ORCID
0000-0001-5182-8420

Filters

2017 - 2019 1 2020 - 2023 1
1 1
2
Reset filters

Settings

Search Results

Now showing 1 - 2 of 2
  • Preprint
    Tropical cyclone activity enhanced by Sahara greening and reduced dust emissions during the African Humid Period
    ( 2017-05) Pausata, Francesco Salvatore Rocco ; Emanuel, Kerry A. ; Chiacchio, Marc ; Diro, Gulilat T. ; Zhang, Qiong ; Sushama, Laxmi ; Stager, J. Curt ; Donnelly, Jeffrey P.
    Tropical cyclones (TCs) can have devastating socioeconomic impacts. Understanding the nature and causes of their variability is of paramount importance for society. However, historical records of TCs are too short to fully characterize such changes and paleo-sediment archives of Holocene TC activity are temporally and geographically sparse. Thus it is of interest to apply physical modeling to understanding TC variability under different climate conditions. Here we investigate global TC activity during a warm climate state (mid-Holocene, 6,000 yr BP) characterized by increased boreal summer insolation, a vegetated Sahara, and reduced dust emissions. We analyze a set of sensitivity experiments in which not only solar insolation changes are varied but also vegetation and dust concentrations. Our results show that the greening of the Sahara and reduced dust loadings lead to more favorable conditions for tropical cyclone development compared to the orbital forcing alone. In particular, the strengthening of the West African Monsoon induced by the greening of the Sahara triggers a change in atmospheric circulation that affects the entire tropics. Furthermore, while previous studies suggest that stronger boreal summer insolation and warmer sea surface temperatures may actually lower TC activity in the Northern Hemisphere, accounting for the Sahara greening and its associated reduction in dust emissions leads instead to an increase of TC activity in both hemispheres, particularly over the Caribbean basin and east coast of North America. Our study highlights the importance of regional changes in land cover and dust concentrations in affecting the potential intensity and genesis of past TCs, and suggests that both factors may have appreciable influence on TC activity in a future warmer climate.
  • Article
    Sensitivity of northwest Australian tropical cyclone activity to ITCZ migration since 500 CE
    (American Association for the Advancement of Science, 2023-01) Denniston, Rhawn F. ; Ummenhofer, Caroline C. ; Emanuel, Kerry ; Ingrosso, Roberto ; Pausata, Francesco S. R. ; Wanamaker, Alan D. ; Lachniet, Matthew S. ; Carr, Kenneth T. ; Asmerom, Yemane ; Polyak, Victor J. ; Nott, Jonathan ; Zhang, Wei ; Villarini, Gabriele ; Cugley, John ; Brooks, Darren ; Woods, David ; Humphreys, William F.
    Tropical cyclones (TCs) regularly form in association with the intertropical convergence zone (ITCZ), and thus, its positioning has implications for global TC activity. While the poleward extent of the ITCZ has varied markedly over past centuries, the sensitivity with which TCs responded remains poorly understood from the proxy record, particularly in the Southern Hemisphere. Here, we present a high-resolution, composite stalagmite record of ITCZ migrations over tropical Australia for the past 1500 years. When integrated with a TC reconstruction from the Australian subtropics, this time series, along with downscaled climate model simulations, provides an unprecedented examination of the dependence of subtropical TC activity on meridional shifts in the ITCZ. TCs tracked the ITCZ at multidecadal to centennial scales, with a more southward position enhancing TC-derived rainfall in the subtropics. TCs may play an increasingly important role in Western Australia's moisture budgets as subtropical aridity increases due to anthropogenic warming.