Meet the PCAPS SG: PCAPS SG member Phil Browne reflects on PCAPS and improving data assimilation in the polar regions
This month’s monthly SG member highlight features PCAPS SG member, Phil Browne, a scientist in the research department at the European Centre for Medium-Range Weather Forecasts (ECMWF). Phil has a background in data assimilation, which is an important focus in PCAPS. Phil reflects on his own role in PCAPS and how his work in PCAPS helps pave the way forward for improved data assimilation and observing systems in the polar regions.
My research at ECMWF focusses on improving Numerical Weather Prediction (NWP) by incorporating ocean and sea ice processes and observations into the assimilation and initialisation of the forecast models. I focus on coupled data assimilation methodology and the use of new observation types to improve our analysis of the Earth system state.
We have a new generation of the ocean and sea ice model which we are developing, not only for NWP, but also for reanalysis purposes. My work in the polar areas has focused on assimilation of satellite-based sea ice concentration information in the new model that has a more complex representation of the state of the sea ice.
I originally joined PCAPS as a representative of the World Meteorological Organization’s World Weather Research Programme (WWRP) Working Group on Data Assimilation and Observing Systems (DAOS). In September 2024, the group held an in-person meeting in Boulder, Colorado, in conjunction with the WMO WWRP Working Group on Predictability, Dynamics and Ensemble Forecasting (PDEF).
At this meeting, my role was reversed, where I was now representing PCAPS within the Working Group.
From PCAPS’ point of view, I had two main objectives for the Working Group meeting:
Share plans and promote the PCAPS project to the wider WWRP community
Get direction from the DAOS group about what a successful coupled data assimilation (DA) task team in PCAPS should look like
DAOS and PDEF members at the in-person and online meeting in Boulder, Colorado in September 2024, hosted by the Joint Center for Satellite Data Assimilation (JSCDA) at the University Corporation for Atmospheric Research (UCAR). Photo credits: WMO
On the first point, I presented the PCAPS project to both working groups, by delivering the same overview slides that PCAPS co-chair, Jørn Kristiansen, had presented at the WWRP Scientific Steering Committee meeting earlier in September. For many of the members of the working groups, this was their first opportunity to hear in-depth about PCAPS’ plans and to understand how they could engage with the project. We also heard similar overviews from the InPRHA and SAGE WWRP projects, albeit via online representatives, as they did not have members from either working group in the room.
PCAPS is in its initial stages; we are still defining the scope for the various strands of work that will be carried out. This means there is an opportunity for the broader community to help shape PCAPS’s goal. With that in mind, we are strongly encouraging interested people to register for the PCAPS mailing list. Via this communication channel, we will be issuing calls for people to join task teams, sharing news and updates, as well as providing updates on WWRP and PCAPS-endorsed projects.
Phil Browne in the weather room at ECMWF headquarters, Reading, England. Photo credits: ECMWF
I am currently the chair of an upcoming PCAPS task team - coupled DA. Based on input from the rest of the PCAPS steering group, we have settled on focusing on sea ice thickness assimilation in the task team. From a DA perspective, this is a challenging problem for which not all forecasting centres yet have the capacity to implement. From an observational perspective, there are many interesting aspects such as characterising the different errors from passive microwave observations (e.g. SMOS) that work well in thin ice regions, and altimeter derived observations (e.g. CryoSat-2) that work well in thicker ice areas.
Success of the coupled DA task team could feed through to better seasonal sea ice forecasts, given the long memory stored in the ice pack in the polar regions.
We will soon be seeking members to join the task team, which we will do via an open call for members. Check the PCAPS website regularly for updates and more information as the process evolves.
Thumbnail photo information: Staff photo of Phil. Photo credit: ECMWF