Hawaiian Winter Precipitation Variability during Central Pacific (CP) and Eastern Pacific (EP) El Niño Events
Mr. Bo-Yi Lu
Ph.D. Candidate
Department of Atmospheric Sciences, S.O.E.S.T.
University of Hawaii at Manoa
Seminar Date: Wednesday, October 16, 2019
Refreshments: 3:00pm at MSB courtyard
Cookies, Coffee & Tea Provided
Seminar Time: 3:30pm
Location: Marine Sciences Building, MSB 100
Abstract:
The large-scale atmospheric circulation of the North Pacific associated with two types of El Niño – the eastern Pacific (EP) and the central Pacific (CP) – is studies in relation to Hawaii winter rainfall. The eastern and central equatorial Pacific undergo active heating and convection during EP El Niño winters. The local Hadley circulation is enhanced and upper-level westerly jet stream of the North Pacific is elongated eastward. Owing to the impact from both phenomena, stronger anomalous descending motion and divergence anomalies occur near Hawaii. The anomalously strong sinking motion near Hawaii, the anomalous moisture flux divergence over the subtropical North Pacific, and reduction of easterly trade winds, characteristics of EP winters, are all unfavorable for winter rainfall in Hawaii. As a result of this strong and robust signal, dry conditions prevail in Hawaii and the standard deviation of winter rainfall during EP winters is smaller than the climatology.
In contrast, for CP winters, the maximum ocean heating is weaker and shifted westward to near the dateline. The subtropical jet stream retreats westward and the anomalously sinking motion near Hawaii is variable and generally weaker during CP winters. Although the anomalous moisture flux divergence still exists over the subtropical North
Pacific, its magnitude is much weaker relative to EP winters. Without strong forcing, rainfall in the Hawaiian Islands during CP winters is close to the long-term mean, except for a slightly drying on Kauai. The spread of rainfall from one CP event to another is also larger compared to the climatology.
Event Sponsor
SOEST Atmospheric Sciences, Mānoa Campus
More Information
(808) 956-8775, SEE FLYER (PDF)
Wednesday, October 16 |
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| 7:00am |
2019 Future Focus Conference Hawaii Convention Center
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| 10:00am |
Bookstore National Student Day - Free Giveaways! Mānoa Campus, Manoa Bookstore
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| 12:00pm |
Orientation: Crown Prince Akihito Scholarship 2020-21 Mānoa Campus, Moore Hall 319 (Tokioka Room), 1890 East-West Rd.
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| 12:00pm |
Architecture Final Oral Mānoa Campus, ARCH 214
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| 12:00pm |
To ‘Leave’ or to ‘Move’: Experiences of Citizenship along the Border Mānoa Campus, Burns Hall 2118
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| 12:30pm |
Theatre Final Oral Mānoa Campus, KT 101
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| 12:45pm |
Food Drop @ the Campus Center Courtyard Mānoa Campus, Campus Center Courtyard
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| 1:00pm |
Career Day Mānoa Campus, Campus Center Ballroom
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| 1:00pm |
Learning Styles & Study Skills Workshop Honolulu Campus, Building 7, Room 309
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| 3:00pm |
LGBTQ+ Student Coffee Hour Mānoa Campus, ZOOM ID: 202 052 344
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| 3:00pm |
UH Manoa Sustainability Council Mānoa Campus, HIG 210
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| 3:30pm |
Atmospheric Sciences Seminar Mānoa Campus, Marine Sciences Building, MSB 100
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| 4:00pm |
Na'au Checks: a Kukakuka group Mānoa Campus, Queen Lili'uokalani Center #412
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| 4:30pm |
SAPFB Town Hall Mānoa Campus, Campus Center 203C
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| 4:30pm |
Maunakea Talk Story with ALU Mānoa Campus, Bale/ Manoa Gardens
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| 5:00pm |
Family Pau Hana Mānoa Campus, Manoa Gardens/ Ba-Le
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| 5:00pm |
Health Professionals Panel Mānoa Campus, Kuykendall Hall, Room 210
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