Bay of Bengal Intraseasonal Oscillations and the 2018 Monsoon Onset

Author:

Shroyer Emily1,Tandon Amit2,Sengupta Debasis3,Fernando Harindra J. S.4,Lucas Andrew J.5,Farrar J. Thomas6,Chattopadhyay Rajib7,de Szoeke Simon1,Flatau Maria8,Rydbeck Adam9,Wijesekera Hemantha9,McPhaden Michael10,Seo Hyodae6,Subramanian Aneesh11,Venkatesan R12,Joseph Jossia12,Ramsundaram S.12,Gordon Arnold L.13,Bohman Shannon M.13,Pérez Jaynise4,Simoes-Sousa Iury T.2,Jayne Steven R.6,Todd Robert E.6,Bhat G. S.3,Lankhorst Matthias5,Schlosser Tamara5,Adams Katherine14,Jinadasa S. U. P15,Mathur Manikandan16,Mohapatra M.17,Rama Rao E. Pattabhi18,Sahai A. K.7,Sharma Rashmi19,Lee Craig20,Rainville Luc20,Cherian Deepak1,Cullen Kerstin1,Centurioni Luca R.5,Hormann Verena5,MacKinnon Jennifer5,Send Uwe5,Anutaliya Arachaporn5,Waterhouse Amy5,Black Garrett S.21,Dehart Jeremy A.21,Woods Kaitlyn M.21,Creegan Edward22,Levy Gad23,Kantha Lakshmi H.11,Subrahmanyam Bulusu24

Affiliation:

1. College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, Oregon

2. University of Massachusetts Dartmouth, Dartmouth, Massachusetts

3. Indian Institute of Science, Bengaluru, India

4. University of Notre Dame, Notre Dame, Indiana

5. Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California

6. Woods Hole Oceanographic Institution, Woods Hole, Massachusetts

7. Indian Institute of Tropical Meteorology, Pune, India

8. U.S. Naval Research Laboratory, Monterey, California

9. U.S. Naval Research Laboratory, Stennis Space Center, Mississippi

10. NOAA/Pacific Marine Environmental Laboratory, Seattle, Washington

11. University of Colorado Boulder, Boulder, Colorado

12. National Institute of Ocean Technology, Chennai, India

13. Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York

14. Naval Information Warfare Center Pacific, San Diego, California

15. Ocean University of Sri Lanka, Colombo, Sri Lanka

16. Indian Institute of Technology Madras, Chennai, India

17. India Meteorological Department, New Delhi, India

18. Indian National Centre for Ocean Information Services, Hyderabad, India

19. Space Applications Centre, Indian Space Research Organisation, Ahmedabad, India

20. Applied Physics Laboratory, University of Washington, Seattle, Washington

21. 53rd Weather Reconnaissance Squadron, U.S. Air Force, Biloxi, Mississippi

22. DEVCOM Army Research Laboratory, Adelphi, Maryland

23. NorthWest Research Associates, Redmond, Washington

24. University of South Carolina, Columbia, South Carolina

Abstract

AbstractIn the Bay of Bengal, the warm, dry boreal spring concludes with the onset of the summer monsoon and accompanying southwesterly winds, heavy rains, and variable air–sea fluxes. Here, we summarize the 2018 monsoon onset using observations collected through the multinational Monsoon Intraseasonal Oscillations in the Bay of Bengal (MISO-BoB) program between the United States, India, and Sri Lanka. MISO-BoB aims to improve understanding of monsoon intraseasonal variability, and the 2018 field effort captured the coupled air–sea response during a transition from active-to-break conditions in the central BoB. The active phase of the ∼20-day research cruise was characterized by warm sea surface temperature (SST > 30°C), cold atmospheric outflows with intermittent heavy rainfall, and increasing winds (from 2 to 15 m s−1). Accumulated rainfall exceeded 200 mm with 90% of precipitation occurring during the first week. The following break period was both dry and clear, with persistent 10–12 m s−1 wind and evaporation of 0.2 mm h−1. The evolving environmental state included a deepening ocean mixed layer (from ∼20 to 50 m), cooling SST (by ∼1°C), and warming/drying of the lower to midtroposphere. Local atmospheric development was consistent with phasing of the large-scale intraseasonal oscillation. The upper ocean stores significant heat in the BoB, enough to maintain SST above 29°C despite cooling by surface fluxes and ocean mixing. Comparison with reanalysis indicates biases in air–sea fluxes, which may be related to overly cool prescribed SST. Resolution of such biases offers a path toward improved forecasting of transition periods in the monsoon.

Publisher

American Meteorological Society

Subject

Atmospheric Science

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3