Lab members in December 2013

We have more rapid changes in my lab than the quarterly updates. Africa Perianez (fourth from left) of German Weather Service (DWD) is visiting from Thursday, December 5 to Friday 13, 2013. We started collaborations on theoretical developments of localization methods and other topics in ensemble data assimilation. Also, Ms. Yukie Komori (second from right) is our new assistant. This picture includes everyone in the lab except for some Visiting Researchers, Drs. Juan Ruiz, Shu-Chih Yang, and Masahiro Sawada.

A multi-scale localization method was developed

We developed a new approach to error-covariance localization that considers multi-scale structure of the forecast error covariance in ensemble data assimilation methods. We found that this new approach is practical and very effective in improving accuracy of ensemble data assimilation.

With higher-resolution models, we tend to have more sampling noise in the shorter range due to limited ensemble size. This limits the use of observation data only in a limited range even though the data should impact a larger area. The figure above illustrates how the proposed multi-scale localization works. The patterns indicate what impact the observation data at the star point have. We mix the shorter-range impact (top left) with the longer-range impact (bottom left) to obtain a hybrid of both (right). This way, we preserve more structure in the shorter range, while we still include impact on an extended area using the smoothed error covariance (or smoothed ensemble perturbations). For more details, please refer to our recent publications:

• Miyoshi, T. and K. Kondo, 2013: A multi-scale localization approach to an ensemble Kalman filter. SOLA, 9, 170-173. doi:10.2151/sola.2013-038
• Kondo, K., T. Miyoshi and H. L. Tanaka, 2013: Parameter sensitivities of the dual-localization approach in the local ensemble transform Kalman filter SOLA, 9, 174-177. doi:10.2151/sola.2013-039

Lab members for 2013 fourth quarter

Team photo as of November 7, 2013 at the welcome party in Kachoen. We are expanding. Seven members are in the picture, and there are four more visiting members not in the picture. New members include Dr. Hazuki Arakida (front left), Mr. Marimo Ohhigashi (back, second from left), and Ms. Rie Deguchi (front right).

RIKEN-Kyoto University Joint Workshop on Data Assimilation

On August 9, 2013, we had the first RIKEN-Kyoto University Joint Workshop on Data Assimilation in RIKEN AICS, Kobe, Japan. The workshop webpage is available only in Japanese, since we intended to exchange ideas among Japanese scientists in both sides.

Data assimilation requires interdisciplinary developments based on statistics and applied mathematics, and it is essential to make a productive collaboration between mathematicians and scientists in application fields. Fortunately, I got to know Professor Sakajo a few years ago in Sapporo, and since then we have been exchanging ideas. Recently I moved from Maryland to Kobe, and Professor Sakajo also moved from Sapporo to Kyoto. We now have this geographical advantage, and try to make our collaborations more active and productive. This is the first workshop to have mathematicians from Professor Sakajo's group and scientists in my group get together, exchange ideas and have active discussions.

We are planning the second workshop in Kyoto in March 18-20, with a prestigious invited speaker Professor Brian Hunt from the University of Maryland.

Two new members

We have two new members starting on August 1, 2013. Professor Shu-Chih Yang (right) is a professor in Taiwanese National Central University and is visiting my lab until mid September as a Visiting Scientist. Dr. Koji Terasaki (left) joined my lab as a Postdoctoral Researcher.

Lab members for 2013 second quarter

Team photo as of May 29, 2013. Prof. Shinichiro Shima (left) from the University of Hyogo and Dr. Masahiro Sawada (second from right) from the University of Tokyo just started in May as visiting scientists. Also, Ms. Naomi Tamura (right), an assistant to the DA team is in the picture, and another assistant Ms. Yuri Iida was very kind and took this nice picture. Dr. Shigenori Otsuka (second from left), myself (third from left), and Keiichi Kondo (third from right) are also in the picture.

Thank you, wonderful visitors!

On Monday, February 25, the day before the Data Assimilation Workshop, four visitors visited my lab. Professor Eugenia Kalnay (third from left) is my former adviser and came a long way from the East Coast of the US. Professor Shu-Chih Yang (third from right) is my former classmate and one of my best friends, coming from Taiwan. Dr. Ji-Sun Kang (second from right) was a colleague until last December in Maryland but moved to Korea recently. Guo-Yuan Lien (left) is a student in Maryland. We enjoyed seeing each other and had fruitful scientific discussions. All four visitors attended the Data Assimilation Workshop, and Eugenia and Guo-Yuan attended the AICS symposium on Thursday and Friday, and spent the whole week. I am very grateful to the four wonderful visitors and hope they enjoyed their stay in Kobe.

AICS International Workshop on Data Assimilation

AICS International Workshop on Data Assimilation took place at RIKEN Advanced Institute for Computational Science (AICS), Kobe, Japan on February 26-27, 2013. We had total 48 enthusiastic and serious participants from many parts of Japan and other countries including the US, Germany, Taiwan, Korea, and Argentina. Following the opening address by the AICS Director Professor Kimihiko Hirao, Professor Eugenia Kalnay of the University of Maryland presented the wonderful Keynote. We had full of exciting, thought-provoking talks during 1.5 days, with several very interesting posters. I was very happy and rewarded to hear that many attendees expressed how they enjoyed the workshop.

I would like to acknowledge the science committee composed of distinguished scientists Drs. Tadashi Tsuyuki, Nobumasa Komori, Takeshi Enomoto, Toshiki Iwasaki, and myself. I would also like to thank Keiichi Kondo, Shigenori Otsuka, Juan Ruiz, and Yukiko Hayakawa who helped the planning and organization of the workshop. Finally and most importantly, enthusiasm and cooperation of all of the participants was crucial for the success of this workshop. I would like to thank everyone who helped make this workshop most successful and fruitful.

Lab members for 2013 first quarter

This is the first photo of our team. We have four members in team for 2013 first quarter. Dr. Juan Ruiz (left) is a visiting scientist from the University of Buenos Aires, Argentina, and will stay until the end of March. Keiichi Kondo (second from left) is a student trainee from the University of Tsukuba. Dr. Shigenori Otsuka (right) is a postdoctoral researcher.

Shipment arrived after about 50 days trip from Maryland

Finally, my books and staff from my office and home arrived to my new office and home in Kobe. I shipped on December 20, so it took about 50 days. Many of my books traveled back and forth between Japan and Maryland, and this was the second time. The books are getting dirtier, that tells the history. It gets harder to get rid of them.

As I said in the previous post, we have a very nice view of Akashi bridge from our office. Today I took a photo of the nice view. We can see the sunset just above the Awaji island (left side of the picture). If I get a chance, I will take another shot.

Miyoshi Lab has moved to Kobe, Japan

Greetings from Kobe, Japan.

My lab was born in the University of Maryland, College Park, but moved permanently to Kobe, Japan as of January 1, 2013. Data Assimilation Research Team was launched on October 1, 2012, and now has 4 members including myself. We are looking for more members, if anyone is interested in working with us on exciting data assimilation research in Kobe, please contact me (Takemasa Miyoshi).

RIKEN Advanced Institute for Computational Science (AICS) is located in the port island, within 15 minutes by train (Port Liner) from downtown Kobe (Sannomiya Station). The view from my new lab is simply amazing, a wide ocean view with the beautiful Akashi Bridge and Awaji island. We are facing to the west, and can see very beautiful sunset in the early evening. Kobe is known for its port, and we can find many boats and ships coming and going. With this new wonderful environment, we refresh ourselves and work on exciting research on data assimilation with the 10-Peta-Flops K computer.