The Tropical Pacific Observing System (TPOS 2020) project is a broad community effort to rethink and redesign the next-generation sustained observing system in the tropical Pacific. Gaining full benefit from our diverse assemblage of in situ instruments, with increasing satellite capabilities, requires integration through data assimilation in process-realistic Earth system models. In order to foster the communication and collaboration among the observational, modeling, and data assimilation communities, a workshop on Bridging Sustained Observations & Data Assimilation for TPOS 2020 is being held on May, 1-3, 2018 in Boulder, CO, USA. Results of the workshop will identify feasible and fundable recommendations, including process studies, that would advance the development of model parameterizations and data assimilation techniques so the tropical Pacific observing system can meet the needs of monitoring, prediction, and research for the next decades.

Applications & abstract submission close on February 23, 2018.

Objectives

Specifically, the workshop will:

• Communicate and discuss the TPOS 2020 operational requirements for predicting atmosphere-ocean conditions on timescales from hours to centuries (with a primary focus on subseasonal to decadal);
• Identify the key observations (including new platforms) to obtain the Essential Ocean Variables necessary to constrain numerical ocean and coupled Earth system models, and to promote advancement of data assimilation systems;
• Define and develop in situ process studies that would point most clearly to particular model improvements, and specify the path to those improvements, beginning with those identified in the TPOS 2020 First Report;
• Identify and define the modeling and data assimilation research needed to meet the observational goals defined by TPOS 2020; and
• Facilitate collaboration to design, conduct and evaluate observing system simulation experiments (OSSEs).

Participants
The workshop will bring together the community of scientists involved in process studies, model improvement (including parameterization development), data assimilation, operational prediction, and the TPOS 2020 community (including leadership and observational experts). Meeting participation will be limited to about 80 participants selected through a brief online application process. Limited travel support is available for early career scientists. The Organizing Committee (see below) with review all materials and make its decisions in March.

Format
The workshop will focus the meeting's objectives with a day of invited synthesis talks on the present state of understanding and ideas for improvement. The remainder of the workshop will include integrated poster, discussion, and breakout sessions. This workshop is designed to stay highly targeted on (a) plans for TPOS 2020 to date, (b) model development needs and the role of observational guidance, and (c) data assimilation needs and input. Breakout sessions, which will be targeted discussions with minimal presentations, will increase intermixing amongst these different groups that do not normally have opportunities to interact all in one place. Attendees wishing to present a poster should submit an abstract through the application page.

Outcomes
A key outcome of the workshop is the interaction and information exchange that will help shape the TPOS 2020 effort. The organizing committee expects the workshop participants to provide input for new directions that will lead to improved monitoring and modeling of the TPOS system and its role in understanding Pacific variability.

Specific outputs from the proposed workshop will include:

• A workshop report with specific recommendations, including for integration into OceanObs19 strategic plans, to address the workshop objectives. These will define key analyses to be performed by the community, potential in situ process studies, and modeling studies in the Pacific.
• Participant input to help inform the TPOS 2020 Steering Committee and Task Teams in their development of the second TPOS 2020 report.
• A Variations edition or journal article capturing the workshop highlights and recommendations.

Scientific Organizing Committee
Kris Karnauskas (U. Colorado, Boulder; Co-Chair)
Billy Kessler (NOAA Pacific Marine Environmental Lab; Co-Chair)
Craig Bishop (Naval Research Lab)
Meghan Cronin (NOAA Pacific Marine Environmental Lab)
Maria Flatau (Naval Research Lab)
Samson Hagos (Pacific Northwest National Lab)
Steve Penny (NOAA NCEP; U. Maryland)
Janet Sprintall (Scripps Institution of Oceanography)
Sam Stevenson (U. California, Santa Barabara)
Aneesh Subramanian (Scripps Institution of Oceanography)

Program Organizing Committee
Mike Patterson (US CLIVAR)
Jill Reisdorf (UCAR)
Kristan Uhlenbrock (US CLIVAR)