Apr 30, 2024
I gave a CISL Seminar today at NCAR introducing the new Python DA software NEDAS.
NEDAS provides a light-weight Python solution for implementing ensemble data assimilation methods for geophysical models. Thanks to its modular and scalable design, a wide range of ensemble assimilation algorithms become feasible for large-dimensional models. NEDAS provides a collection of state-of-the-art algorithms from existing research software using two main strategies: (1) serial assimilation where observations are used one at a time to update the model state iteratively, (2) batch assimilation where observations are in a local analysis for each model state. One can test new algorithmic ideas in NEDAS and compare them with existing methods early-on before committing resources to full implementation in a real operational setting. In this talk, I’ll describe the architectural design of NEDAS, highlight some new algorithmic ideas, and show some computational benchmarks as a guidance for picking the right algorithm in different application scenarios.
Here are my presentation slides, and here is a recording of the seminar:
Oct 16, 2023
Today I attended ISDA 2023 in Bologna, Italy. I showed a poster on the stress-test of multiscale alignment ensemble filter on a idealized vortex model.
May 2, 2023
I showed some preliminary results on assimilating sea ice deformation features at the EnKF Workshop in Norheimsund. The challenge of assimilating deformation is that they are spatial gradients of the velocity fields, and therefore are related to the model sea ice velocity nonlinearly. I used a 1D example to illustrate the effect of nonlinear position errors on the assimilation. Here are the presentation slides.
Mar 21, 2023
I attended a sea ice data assimilation workshop ICCWG-DA-11 in Oslo this week. This is my first time in a conference with sea ice experts and I learned new information from ice remote sensing and model rheologies. There are many cool presentations on the topic of improving sea ice forecasts, especially for the short timescales.
I showed some neXtSIM model forecasts and evaluation of sea ice predictability across scales in this poster. I also included an initial proof-of-concept for assimilating sea ice deformation from SAR imagery that can potentially improve the smaller-scale details of the model simulated sea ice.
Jan 20, 2023
Check out this ISDA online session: Non-Gaussian Data Assimilation where several new approaches in dealing with nonlinearity and non-Gaussian error distributions are discussed.
May 30, 2022
The 2022 EnKF Workshop takes place in a hybrid form. Locally, we took a boat trip from Bergen to Balestrand, while our colleagues joined online. In the workshop, I gave a talk on my work of developing DA methodology for the challenging sea ice forecast problems.
May 10, 2022
Postponed by COVID for a year, it finally took place. Today feels like a normal group meeting day again back in Penn State with us honoring Fuqing's contributions to the tropical meteorology community. We told stories about Fuqing and their impact on our research lives, it was enjoyable time with my academic sisters and brothers.
Sep 29, 2021
I gave a talk at the 2nd workshop on Artificial Intelligence and Data Science for the Arctic, AIDingArctic, about my work on correcting position errors in sea ice linear kinematic features.
May 12, 2021
The 34th AMS Conference on Hurricanes and Tropical Meteorology has been postponed for a year, and finally took place this week. I presented my research on reducing position errors in hurricane prediction. Yet another application scenario for the MSA method.
Apr 27, 2021
Check out my presentation at EGU21 General Assembly, session NP5.1 on data assimilation and machine learning. Assimilating sea ice deformation observations
Mar 10, 2021
Today I gave a Meteo Colloquium at Penn State. I shared my experiences in developing DA method, how I borrowed ideas from other disciplines, how I tested new DA methods in real application problems, and my vision for the future of the Earth system science from a DA research perspective.
Jan 14, 2021
Check out another talk given by my colleague Tammy Weckwerth at AMS annual meetings. This talk summarizes the work on assimilating MicroPulse Differential absorption lidar (MPD) data to improve forecasts of mesoscale convective systems, a project I participated during my NCAR postdoc.
Jan 13, 2021
This week the 101st AMS annual meetings took place, we had a new virtual format this year, everyone recorded their talk at home and had a round of lightning talks and Q/A in each session. I co-chaired a DA methodology session in the conference on IOAS-AOLS, and talked about my recent progress in applying the MSA method in two scenarios: hurricane forecasts and sea ice forecasts.
Aug 1, 2020
Today I start working as a researcher in NERSC, the Nansen Environmental and Remote Sensing Center in Bergen, Norway. Due to the COVID-19 pandemic, I am still physically in the US and working remotely. I am working on introducing a multiscale data assimilation method for sea-ice modeling and regional climate prediction.
Jan 13, 2020
This week marks the centennial for the American Meteorological Society and the annual meetings are held in Boston. It is my first time chairing a session this year! The session is called "Advances in ensemble DA methods for highly nonlinear and large dimensional systems", where we had speakers showcasing their new developments in data assimilation methodology that meets the challenges in ever increasing complexity of prediction systems. I also gave a talk on my newly developed multiscale ensemble filtering framework, here is a recording:
Sep 21, 2019
I just finished a three-week trip in China. I visited atmospheric science departments in several universities in Beijing, Shanghai, Nanjing, and Guangzhou, and talked to researchers from many different backgrounds. I showed my recent work on multiscale alignment method, and received a lot of feedback and suggestions, I really enjoyed all the discussion!
Jun 6, 2019
Today I gave a seminar talk in the Mesoscale & Microscale Meteorology Laboratory on the multiscale data assimilation and prediction problem that I have been working on. In the talk I also introduced a "multiscale alignment" method that I recently developed. Check out this video recording of my presentation:
Dec 16, 2018
This week I attended the AGU 2018 fall meeting in Washington D.C. and gave a presentation in the Advances in Data Assimilation session in Nonlinear Geophysics. Right afterwards, I joined the Second ADAPT Symposium at Penn State. It's nice to meet old friends and get to know new students in the department. It surely was an intense week!Aug 14, 2018
Today I attend the Rocky Mountain Fluid Mechanics Research Symposium at CU Boulder, and enjoyed the interaction with a diverse group of researchers.
Aug 3, 2018
This week I participate in the JCSDA Summer Colloquium on Satellite Data Assimilation held in Bozeman, Montana. The colloquium was an interesting collection of topics related to satellite data and data assimilation.
Jun 4, 2018
Today I start my postdoc at the National Center for Atmospheric Research Advanced Study Program, where I will be exploring data assimilation methods for multiscale system prediction problems.
May 6, 2018
Commencement ceremony at Penn State! Dr. Dave Stensrud walked with me, we were both delighted.
Apr 28, 2018
Today I successfully defended my PhD thesis titled "Ensemble data assimilation for the analysis and prediction of multiscale tropical weather systems".
Apr 17, 2018
This week I am at Jacksonville, Florida again for the 33rd AMS Conference on Hurricanes and Tropical Meteorology (I attended the 30th Conference six years ago at the same location, this place hasn't changed at all). Today I gave a talk on my work on tropical weather predictability and satellite data assimilation, check out this recording:
Apr 11, 2018
I am honored to receive the Al and Betty Blackadar Scholarship from the Department of Meteorology and Atmospheric Science at Pennsylvania State University.
Jan 9, 2018
At the 22nd AMS IOAS-AOLS Conference I gave a presentation titled "On the selection of localization radius in ensemble filtering for multiscale quasigeostrophic dynamics". Check out the recording of this presentation:
This talk later won the Best Student Presentation Award! I'm very happy and a Big Thank You to both Fuqing and Jeff for supporting this project!
Jan 8, 2018
This week I attended the AMS annual meetings in Austin, my first presentation is a poster about tropical wave predictability in the 6MJO Poster Session.
Jan 25, 2017
On my way back to Penn State from NCAR visit, this week I am at the 97th AMS annual meeting in Seattle. Today I gave a talk on my tropical multiscale predictability work in the Second Symposium on Multiscale Atmospheric Predictability.
Oct 17, 2016
Today I start my three-month visit to the National Center for Atmospheric Research, to work with Jeff Anderson on multiscale localization problems in ensemble data assimilation.
May 27, 2016
The 7th EnKF DA Workshop, held in Penn State Toftrees Resort, ends today. I am very excited to show my preliminary findings from the tropical weather predictability study, and received a lot of suggestions and positive feedback.
Jun 30, 2015
Today I attended the 27th Weather Analysis and Forecasting and 23rd Numerical Weather Prediction joint conference. I gave a talk on my recent work on comparing various hybrid data assimilation methods.
May 22, 2014
The 6th EnKF DA Workshop was held in Beaver Hollow Resort, Buffalo, New York this week. I learned a lot from this workshop and got to know many data assimilation scientists.
Jun 20, 2013
I attended the 19th AMS Conference on AOFD and gave a poster presentation on simulated and observed equatorial waves and diurnal variations during DYNAMO.
Aug 15, 2012
Today I join Dr. Fuqing Zhang's research group at Department of Meteorology, Pennsylvania State University, and start my doctoral program in pursuit of a PhD in meteorology.
Jun 1, 2012
I graduated and got a M.S. Degree in Meteorology from Peking University. Here is a picture of me and my advisor Qinghong Zhang.
Apr 18, 2012
I presented my work on tropical cyclone structural changes in response to ambient moisture variations at the 30th AMS Conference on Hurricanes and Tropical Meteorology.
Aug 29, 2011
Today marks the end of the Summer School on High Impact Convective-scale Weather held at Peking University. Drs. Robert Houze, Richard Johnson, Fuqing Zhang, Paul Markowski, Matthew Parker, and David Schultz offered an awesome series of lectures with unique insights to convective-scale weather research. By the end, I even got some encouraging words and autographs on my notebook!
Mar 8, 2011
My first international conference attendance! I presented my work on tropical cyclone on the 8th International Conference on MCSs and High-Impact Weather (ICMCS-VIII) in Nagoya, Japan.
Dec 17, 2010
I attended the Winter School on Hurricane Dynamics in Nanjing University. Dr. Yuqing Wang gave a comprehensive overview of hurricane theories and dynamics, and I learned a lot!