Coupled Warm Pool Dynamics in the Indo-Pacific Ming Feng, Susan - PowerPoint PPT Presentation

Coupled Warm Pool Dynamics in the Indo-Pacific Ming Feng, Susan Wijffels, Andy Hsu, Anna Maggiorano, Gang Yang, Chris Chapman July 2020 CSHOR

Background: warm pool and its influences on global climate Asian monsoon Australian monsoon ENSO, IOD, MJO 2 | Warm pool project | Ming Feng

Goals of the project • To advance our knowledge of high-frequency air-sea coupling in the eastern Indian Ocean warm pool • To better understand roles of the Indonesian Throughflow and associated ocean circulation in influencing the heat and freshwater balance of the Indian Ocean • To work with international community on the design and implementation of the Indian Ocean observing system 3 | Warm pool project | Ming Feng

Highlights during 2019-2020 1. Successful meteorology and ocean profiling buoy operation off northwest Australia – BAMS publication 2. R/V Investigator voyage delivered valuable air-sea exchange datasets 3. Hemispheric asymmetry mode of global ocean heat content variability identified to better attribute greenhouse gas induced warming – paper in Nature Communications 4. (UNSW) Anna Maggiorano has finalised the 2013 northwest shelf marine heatwave manuscript; new progress from Gang Yang – PhD student working on Darwin Harbour 4 | WP Project | Ming Feng

Bailong Buoy deployment and retrieval Ian Darby Ryan Crossing Yongliang Duan November 2018 January 2020

CSHOR Field Measurement (2018-2019) 2 m wind Feng, Duan, Wijffels, Hsu … Yu 2020 BAMS

R/V Investigator voyage Oct-Nov 2019 Wire walker Triaxus CSHOR participants: Susan Wijffels Je-Yuan Hsu Anna Maggiorano 7 | Warm pool project | Ming Feng

Robust hemispheric asymmetry in global OHC change Observed ocean heat content (10 18 J/m) during 2005-2015 for (a) Northern Hemisphere and (b) Southern Hemisphere Southern Hemisphere Northern Saurabh Rathore Hemisphere 0-700 m 700-2000 m Southern Ocean Heat Content 5.12 ± 0.45 2.66 ± 0.19 Hemisphere trend (10 22 Northern J/decade) -0.74 ± 0.29 1.35 ± 0.14 Hemisphere

Distribution of the decadal trend of the ocean heat content (OHC) (10 22 J/decade) for the depth of 0-2000 m Rathore, Bindoff, Phillips, Feng 2020 Nature Communications

Weakening of Indian Ocean southward heat transport: contribution of Agulhas Current The weakened ITF heat transport is Windstress Transport (Sv) ITF AC (32S) overcompensated by the Indian curl (32S) Ocean meridional heat transport Historical run -15.3 -50.2 -35.0 reduction RCP8.5 run -10.7 -43.5 -32.8 Change 4.6 6.7 2.2 Ma, Feng, Lan, Hu, 2020 GRL

Publications • Ming Feng; Yongliang Duan; Susan Wijffels; Je-Yuan Hsu; Chao Li; Huiwu Wang; Yang Yang; Hong Shen; Jianjun Liu; Chunlin Ning; Weidong Yu (2020), Tracking air-sea exchange and upper ocean variability in the Indonesian-Australian Basin during the onset of the 2018-19 Australian summer monsoon, Bulletin of the American Meteorology Society, in press. • Rathore, S., N. L. Bindoff, H. E. Phillips, M. Feng (2020), Recent hemispheric asymmetry in global ocean warming induced by climate change and internal variability. Nature Communications, 11, 2383. • Ma, J., Feng, M., Lan, J. and Hu, D., 2020. Projected future changes of meridional heat transport and heat balance of the Indian Ocean. Geophysical Research Letters . 47. • Yuhong ZHANG; Yan Du; W.N.D.S JAYARATHNA; Qiwei SUN; Ying ZHANG; Fengchao YAO; Ming FENG, (2020). A prolonged high-salinity event in the Northern Arabian Sea during 2014-2017, Journal of Physical Oceanography, 50, 849-865. • Hu, S. Y. Zhang, M. Feng, Y. Du, J. Sprintall, F. Wang, D. Hu, Q. Xie, F. Chai (2019). Interanual to decadal variability of upper ocean salinity in the southern Indian Ocean and the role of the Indonesian Throughflow. Journal of Climate, 32(19), 6403-6421. • Cyriac, A., McPhaden, M. J., Phillips, H. E., Bindoff, N. L., & Feng, M. (2019). Seasonal evolution of the surface layer heat balance in the eastern subtropical Indian Ocean. Journal of Geophysical Research: Oceans , 124, 6459–6477. https://doi.org/10.1029/2018JC014559. • Hsu, J.Y. Hendon H., Feng M., Zhou, X. (2019) Magnitude and Phase of Diurnal SST Variations in the ACCESS-S1 model during the Suppressed Phase of the MJOs. Journal of Geophysical Research: Oceans , 124(12), 9553-9571.

Salinity variations in the Indo-Pacific warm pool 2011–2017 minus 2004–2010 (contour: temperature) Hu et al. 2019 J. Climate Zhang et al. 2020 JPO Ying Zhang

Mixed layer processes 1m resolution model is necessary to Collaboration with U. Tas and NOAA to better capture the strong diurnal warming understand air-sea heat flux in the SE IO RAMA Cyriac et al. 2019 JGR Hsu et al. 2019 JGR Confirmed with BoM ACCESS coupled model 13 |

Modelling the 2013 marine heatwave Maggiorano et al. submitted

Wave effects on sediment dynamics in Darwin Harbour during monsoon season Gang Yang and Wang 2020 ECSS, accepted Wang

Publications • Beal, L. M., Vialard, J., Roxy, M. K. and lead authors (including Feng, M, Sloyan B) 2019: Executive Summary. IndOOS-2: A roadmap to sustained observations of the Indian Ocean for 2020-2030. CLIVAR-4/2019, GOOS-237, 8 pp. https://doi.org/10.36071/clivar.rp.4-1.2019. • Beal, L. M., Vialard, J., Roxy, M. K. and lead authors (including Feng, M., Sloyan, B) 2019: Full Report. IndOOS-2: A roadmap to sustained observations of the Indian Ocean for 2020-2030. CLIVAR-4/2019, GOOS-237, 206 pp. https://doi.org/10.36071/clivar.rp.4.2019. • Beal, L.M., Vialard, J., Roxy, M.K., Li, J., Andres, M., Annamalai, H., Feng, M ., Han, W., Hood, R., Lee, T., Lengaigne, M., Lumpkin, R., Masumoto, Y., McPhaden, M.J., Ravichandran, M., Shinoda, T., Sloyan, B.M ., Strutton, P.G., Subramanian, A.C., Tozuka, T., Ummenhofer, C.C., Unnikrishnan, A.S., Wiggert, J., Yu, L., Cheng, L., Desbruyères, D.G., Parvathi, V. (2020). A roadmap to IndOOS-2: Better observations of the rapidly warming Indian Ocean. Bulletin of the American Meteorological Society . DOI: 10.1175/BAMS-D-19-0209.1. 16 | Warm pool project | Ming Feng

Beal et al. 2020

Year 4 plan • Continue to analyse 2018-19 profiling float data and Bailong buoy time series, and improve understanding of the large-scale climate drivers of coupled ocean-atmosphere dynamics in the Indonesian-Australian Basin • Quality control of the R/V Investigator cruise data for the Years of Maritime Continent program (collaboration with WHOI) • Contribute to International Indian Ocean Expedition-2 (IIOE-2) research and review publications • Improved assessment on the influences of the Indo-Pacific warm pool on Australian rainfall variability and predictability (U. Tas PhD student) • Finalise publication on the 2013 northwest shelf marine heatwave event Warm pool project | Ming Feng 18 |

Severe TC Riley Yongliang Duan Severe TC Veronica Severe TC Wallace Weidong Yu Monsoon Onset Tropical Cyclones Bailong buoy observations over the whole year

Coupled process in the Indonesian-Australian Basin Chris Chapman • Develop composites of MJO events from oceanography and meteorology data and model output (iHESP or ACCESS) • Identify links between the "deep" oceanography and the onset/breakdown/detouring of the MJO • Is MJO onset favored by deep thermocline anomalies? • What’s the influence of the Pacific coming through the ITF? 20 | Warm pool project | Ming Feng

Rapid foundation SST Warming Captured by ALAMO Floats during the Suppressed Phase of the MJO Je-Yuan Hsu, National Taiwan University Ming Feng and Susan Wijffels Centre for Southern Hemisphere Oceans Research (CSHOR)

Temperature and Salinity on ALAMO Floats • Vertical resolution ≤ 1 m in the upper 50 m • Temperature measurements at ~ 0.1-0.2 m-depth used as SST

Barrier Layer Salinity-driven Barrier Layer: • Lukas and Lindstrom (1991) first report the barrier layer due to the salinity stratification • The salinity-driven barrier layer can inhibit turbulent mixing Temperature-driven Barrier Layer: Thick DWL should be regarded as a barrier • layer , because high stratification in DWL also prevents nighttime mixing for eroding restratified upper ocean BL However, the 1-D ROMS model with KPP or • other turbulent closure mixing scheme cannot simulate the thick DWL (not shown)

Thank you CSHOR Ming Feng Senior Principal Research Scientist t +61 8 9333 6512 e ming.feng@csiro.au w https://cshor.csiro.au/