Early Highlights from the Propagation of Intraseasonal Tropical Oscillations (PISTON) Field Campaign

The Boreal Summer Intraseasonal Oscillation (BSISO) strongly modulates atmospheric circulation patterns, rainfall and the diurnal cycle over the waters of the W. Pacific and South China Sea. The BSISO is associated with active and break periods of the Asian Monsoon system, and has significant teleconnections to higher latitudes, as well as impacting tropical cyclones in the region. Timing, structure and propagation of the BSISO are poorly simulated in weather forecasting and climate models. PISTON (Propagation of Intraseasonal Tropical Oscillations) is a major field/modeling campaign to improve understanding of the BSISO, including atmospheric and ocean responses, ocean-atmosphere coupling and air-sea interaction. PISTON field observations will be made during the period from early August to mid-October 2018 in the western Pacific north of Palau, with additional observations planned for boreal summer 2019 west of Luzon, Philippines. The primary platform for the PISTON 2018 campaign is the R/V Thomas G. Thompson operated by the University of Washington, guided by a suite of numerical model simulations. Field observations include measurements of:

• convection by the Colorado State University’s SEA-POL C-band Doppler, polarimetric radar;
• The thermodynamic state of the atmosphere via continuous 3 hourly radiosonde launches (CSU);
• surface fluxes by NOAA’s Earth Systems Research Lab;
• aerosol backscatter and tenuous cloud layers using high spectral resolution Lidar observations operated by the University of Wisconsin;
• upper ocean structure and turbulence by Oregon State University;
• the spatial structure of the upper ocean using underway CTD by the Scripps Institute of Oceanography; and
• profiling SOLO II floats to examine spatial variability of the upper ocean diurnal cycle in the mixed layer (Scripps);

as well as

• long term (1 year) upper ocean responses using two moorings (Scripps).

In this presentation, just a couple of months after the end of the 2018 field campaign, a summary and highlights of the field campaign will be presented.

This presentation is on behalf of the PISTON science team. More details are available at onrpiston.colostate.edu.