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Award Detail

Doing Business As Name:University of Hawaii
  • Alison D Nugent
  • (808) 956-2878
Award Date:06/06/2019
Estimated Total Award Amount: $ 336,587
Funds Obligated to Date: $ 336,587
  • FY 2019=$336,587
Start Date:08/01/2019
End Date:07/31/2022
Transaction Type:Grant
Awarding Agency Code:4900
Funding Agency Code:4900
CFDA Number:47.050
Primary Program Source:040100 NSF RESEARCH & RELATED ACTIVIT
Award Title or Description:Collaborative Research: Topographic Influences on Extreme Warm-Season Precipitation
Federal Award ID Number:1854443
DUNS ID:965088057
Parent DUNS ID:009438664
Program:Physical & Dynamic Meteorology
Program Officer:
  • Chungu Lu
  • (703) 292-7110

Awardee Location

Street:2440 Campus Road, Box 368
Awardee Cong. District:01

Primary Place of Performance

Organization Name:University of Hawaii
Street:2525 Correa Rd., HIG 333
Cong. District:01

Abstract at Time of Award

Extreme rainfall affects millions of people globally, yet our understanding and forecast skill of this high-impact weather phenomenon is limited. The Prediction of Rainfall Extremes Campaign in the Pacific (PRECIP, May-August 2020) field campaign aims to improve understanding of the multi-scale processes important for generating extreme rainfall in the moisture-rich environment of Taiwan and the western North Pacific. The overarching PRECIP hypothesis is that extreme rainfall results from an optimal combination of multi-scale ingredients in a moisture-rich environment, but different key ingredients and processes lead to strong vertical forcing and high rainfall intensity, strong horizontal forcing and long duration, or a mixture of both intense and sustained precipitation. Intellectual Merit: This project focuses on orographic influences on extreme rainfall, using a unique combination of radar and radiosonde observations on both sides of Taiwan's Central Mountain Range (CMR) to determine the role of steep terrain in enhancing both intensity and duration of rainfall through a combination of thermodynamic, dynamic, kinematic, and microphysical processes. The overall hypothesis is that terrain enhances both intensity and duration of extreme rainfall through increasing the magnitude of ingredients needed to produce heavy rainfall. In addition to promoting lifting and concentrating moisture, terrain modifies rainfall intensity and duration through changes in microphysical processes. In the subtropical environment of Taiwan, efficient warm-rain processes can produce high intensity convective rainfall, while ice-based processes become increasingly important for long-duration events dominated by stratiform precipitation. Additionally, results from TiMREX 2008 suggest that upslope tilting of relatively shallow convection along Taiwan's CMR can promote growth of precipitation-sized ice. Subsequent cold-pool generation leads to continuous growth of cells upstream and prolongs the duration of rainfall events along the CMR. PRECIP offers the opportunity to further explore the role of terrain, including the influence on microphysical processes, in producing extreme rainfall for a wide variety of events, both on the western slopes and along the data-sparse east coast of Taiwan. To test the above hypotheses, the study will use a combination of PRECIP data from multi-frequency dual-polarization Doppler radars (S-PolKa, SEA-POL), radiosondes, and models to explore terrain-influenced processes for diurnally-forced convection, mesoscale convective systems embedded within the Meiyu front, and tropical cyclones. Broader Impacts: An important broader goal of this investigation is to determine which of the key ingredients and processes identified for Taiwan extreme rainfall events are also relevant to orographic precipitation in other environments or locations. The team of three early-career female scientists brings a wealth of knowledge of observational field projects and terrain-influenced precipitation studies spanning a variety of global regimes, including warm-season rainfall in the Sierra Madre Occidentals, CMR, Andes, Rockies, and Himalayas, typical trade-wind flow, a tropical cyclone passing over Dominica, and cold-season rainfall over the Olympics. PRECIP will give an opportunity to investigate a wide variety of rain-producing events, both the windward and leeward sides of the mountain range. The findings from this project will have the potential to provide an updated understanding of extreme rainfall globally by building off an ingredients-based framework through unprecedented data collected in a wide variety of heavy rain events. This project is jointly funded by the Established Program to Stimulate Competitive Research (EPSCoR) and PREEVENTS, Prediction of and Resilience against Extreme Events program. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

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