edu.ucar.opensky::articles:24902 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T23:02:26.500733 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7pg1w7f Bay of Bengal intraseasonal oscillations and the 2018 monsoon onset 2021-10-01T00:00:00Z publication https://n2t.org/ark:/85065/d7pg1w7f https://doi.org/10.1175/BAMS-D-20-0113.1 Shroyer, E. author Tandon, A. author Sengupta, D. author Fernando, H. J. S. author Lucas, A. J. author Farrar, J. T. author Chattopadhyay, R. author De Szoeke, S. author Flatau, M. author Rydbeck, A. author Wijesekera, H. author McPhaden, M. author Seo, H. author Subramanian, A. author Venkatesan, R. author Joseph, J. author Ramsundaram, S. author Gordon, A. L. author Bohman, S. M. author Pérez, J. author Simoes-Sousa, I. T. author Jayne, S. R. author Todd, R. E. author Bhat, G. S. author Lankhorst, M. author Schlosser, T. author Adams, K. author Jinadasa, S. U. P. author Mathur, M. author Mohapatra, M. author Rama Rao, E. P. author Sahai, A. K. author Sharma, R. author Lee, C. author Rainville, L. author Cherian, Deepak author Cullen, K. author Centurioni, L. R. author Hormann, V. author MacKinnon, J. author Send, U. author Anutaliya, A. author Waterhouse, A. author Black, G. S. author Dehart, J. A. author Woods, K. M. author Creegan, E. author Levy, G. author Kantha, L. H. author Subrahmanyam, B. author UCAR/NCAR - Library publisher In 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 similar to 20-day research cruise was characterized by warm sea surface temperature (SST > 30 degrees 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 similar to 20 to 50 m), cooling SST (by similar to 1 degrees 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 degrees 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. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2021 American Meteorological Society (AMS). None eng geoscientificInformation