Annual Activity Summary
Ying-Hwa (Bill) Kuo
Director, COSMIC Program
1 May 2012 –30 April 2013
As the Director of the COSMIC Program, I continued to devote a significant portion of my time to the
execution and management of the program. My responsibilities included: (1) providing leadership and
management of the day-to-day operations of the COSMIC Program; (2) interfacing with sponsors (NSPO,
NARL and NSC in Taiwan, and U.S. funding agencies) on decisions regarding the future direction and
priorities of the program, funding and reporting; (3) interacting with our partners on the execution of the
program; (4) conducting research and promoting the scientific applications of COSMIC data; and (5)
representing COSMIC program in UCAR and UCP management. The COSMIC data collection, processing
and distribution continue to move forward smoothly, and we continue to provide strong support to the
research and operational communities. As of June 2013, COSMIC has over 2,000 registered users from 65
countries, and we maintain the provision of approximately 1,500 radio occultation soundings per day,
despite the gradual degradation of the satellite constellation. Five out of the six COSMIC-1 satellites are
still operating. The data are actively used by all major operational weather centers.
Major activities over the past year include the following:
I.
Planning and development of COSMIC-II
I worked with UCAR COSMIC team and senior management at UCAR, NOAA, NSF, NSC and NSPO on
the definition, planning and development of the COSMIC-II mission. On 15th February, Taiwan (NSPO and
NSC) and US sponsors (US Air Force and NOAA) made a commitment to move forward with the first
(tropical) constellation for COSMIC-2. In July 2012, NSPO selected Surrey U.K. to be their spacecraft
contractor. The planned launch for the first constellation is set for the first quarter of 2016. Even though
COSMIC-2 is moving forward, many challenges remain. Despite significant advocacy efforts from
COSMIC team and UCAR management, NOAA’s funding for ground-station operation and data
processing remains highly uncertain. Funding for the second constellation on the U.S. side has yet to be
identified. I led the UCAR COSMIC team to work with UCAR management, NOAA, US Air Force, NSF,
NSPO, and other US sponsors on development of the COSMIC-2 program, in particular, to define the role
and responsibility of the UCAR team in COSMIC-2, and to secure necessary funding for COSMIC-2 data
processing and mission science and engineering support at UCAR. Given the changing fiscal environment,
the role and responsibility of UCAR COSMIC team in COSMIC-2 may be expanded. This will be my goal
for the coming year.
II.
Support for COSMIC-1 operations and research from U.S. and Taiwan
I worked with Dr. Eric DeWeaver at NSF and Dr. Suzanne Hilding at NOAA to secure funding from the
U.S. agencies to support the continued operation of COSMIC-1. This involved with considerable
preparation for a funding proposal to be presented to the U.S. Interagency Working Group. At the COSMIC
Interagency Working Group meeting in January 2013 at AMS, U.S. agencies made the commitment to fund
UCAR COSMIC team for the continued operation of COSMIC-1. I also worked NSPO and NARL
(National Applied Research Laboratories, parent organization of NSPO) management to ensure the support
of $1M a year to UCAR for the continued operation of COSMIC-1. In addition, I served as the PI for
Taiwan’s CWB (Central Weather Bureau) and TTFRI (Taiwan Typhoon and Flood Research Institute)
projects (with annual budget of $800K) to support the development of regional data assimilation and
forecast system in Taiwan based on WRF, and to assess the impact of COSMIC on typhoon prediction.
Several proposals submitted to NASA ROSE call were selected for funding. I served as the PI for a Naval
Research Laboratory project to improve the assimilation of GPS radio occultation data into the Naval
global forecast system (annual budget of $400K). These funds provide support for COSMIC data
processing and research at UCAR.
III.
COSMIC research
In addition to promoting the scientific applications of COSMIC in various meetings and workshops, I
continue to conduct research in several areas:
i)
Improvement of ionospheric calibration of GPS RO retrieval
A major source of error in GPS RO retrieval in the stratosphere is the calibration of ionospheric effects.
The traditional method using linear combination of measurements from the two GPS frequency does not
cleanly remove ionospheric effects, mainly due to the significant differences in quality and accuracy of L1
and L2 measurements. The residual ionospheric effects then result in errors in the retrieved neutral
atmospheric bending. Tae-Kwon Wee and I have develop a new method that takes into consideration of the
quality of measurements from these two frequency, which results in significant improvement on the
retrieval of neutral atmosphere bending angle. Two paper summarizing this research have been submitted
to JGR and GRL. One has been accepted for publication, and the other still under review.
ii)
Impact of COSMIC data on typhoon prediction
On average, Taiwan is affected by 3~4 typhoons per year. Accurate prediction of typhoon track, intensity
and rainfall is a major challenge for Taiwan, due to complex topography. Improving the accuracy of
typhoon prediction is a major motivation for Taiwan to support COSMIC-1 and COSMIC-2 missions.
Xingqin Fang and I developed a new probability matching method to improve typhoon rainfall forecast
based on a dual resolution ensemble prediction system. Using this system, we showed that the assimilation
of COSMIC GPS RO data contributed significantly to improvement in rainfall forecast of Typhoon
Morakot (2009), which produced nearly 3,000 mm of rainfall. A paper summarizing the new probability
matching method has been submitted to Monthly Weather Review and accepted for publication.
I have also been working with Hui Liu on assessing the impact of COSMIC data on other tropical cyclone
systems. We conducted cycling data assimilation experiments using the WRF/DART system on three
typhoons during the T-PARC experiment of 2008, including Typhoons Sinkalu, Jangmi, and Hagupit. We
found that COSMIC improved the 48-h track forecast by 25%. We are currently preparing a journal paper
to summarize these results.
iii)
Antarctic data assimilation
Antarctica presents unique challenges for numerical weather prediction as it has little traditional
meteorological observations and the satellite radiance retrieval do not work well because of ice cover. GPS
radio occultation provides valuable observations over Antarctica. I worked with Shu-Ya Chen and TaeKwon Wee on the impact of GPS RO data on the analysis and prediction of explosive cyclones over the
Southern Ocean, using the WRF-Var data assimilation system. The results show that GPS RO data can be
used to improve the forecasting of these cyclones. A manuscript has been prepared on this work, and will
be submitted in the near future.
IV.
Collaboration on missions of opportunity
Given the gradual degradation of the COSMIC-1 (currently, satellite #3 has stopped working), it is
important to find ways to maintain the number of GPS RO observations to support research and operations.
I have been work with NOAA and NSF to bring data from international research missions to be processed
by CDAAC (COSMIC Data Analysis and Archive Center), and made available to the community. We now
process and distribute GPS RO data from SAC-C (Argentine) and C/NOFF (Air Force) missions. We are
working with the Korea space agency (KASI) on their KOMSAT-5mission and Spain’s IEEE on the PAZ
mission. We are also collaborating with EUMETSAT to process the GPS RO data from the METOP GRAS
instruments. This effort will be expanded to other missions as opportunity arises. These international
collaborations will position UCAR COSMIC to be an international GNSS science and data center.
V.
COSMIC management, education and outreach
I continued to perform all routine COSMIC management duties. I organized the annual COSMIC retreat to
help set the future direction for the program. I worked with Eric DeWeaver (NSF) and Suzanne Hilding
(NOAA) on the organization of the COSMIC Interagency Working Group meeting, and with Eric
DeWeaver on the transfer of agency funds to UCAR. I led the organization of the FORMOSAT3/COSMIC-2 Data Users Workshop in the fall of 2012. I served as the International Program Chair for the
International Conference on GPS Radio Occultation, held in May 2013 in Taiwan. I chaired quarterly
COSMIC all-staff meetings. I oversaw staff reclassification processes. I supervised graduate students
(Chuan-Chi Tu, Matthias Trattler), and SOARS students (Ching-An Wang, Vanessa Almanza, and HsiaoChun Lin). I attended UCP Director’s meetings and worked with Hanne Mauriello and Emily CoBabeAmmann on UCP and UCAR management matters.
Refereed Publications
(a) New Work
Chen, S.-Y., T.-K. Wee, Y.-H. Kuo, and D. H. Bromwich, 2013: Impact assessment of GPS RO on a
rapidly developing cyclone over the Southern Ocean. Mon. Wea. Rev. (to be submitted).
Fang, X., and Y.-H. Kuo, 2013: Improving ensemble-based quantitative precipitation forecast for
topography-enhanced typhoon heavy rainfall over Taiwan with a modified probability-matching
technique. Mon. Wea. Rev. (in press)
Ho, S.-P., X. Yue , Z. Zeng, C. Ao, C.-Y. Huang, E. R. Kursinski, Y.-H. Kuo (2013a), Applications of
COSMIC Radio Occultation Data from the Troposphere to Ionosphere and Potential Impacts of
COSMIC-2 Data, BAMS (accepted)
Rao, A. S., C.-Y. Huang, S.-Y. Chen, and Y.-H. Kuo, 2013: An impact study of GPS radio occultation data
with different observation operators for the prediction of a severe rainfall event. SOLA.
(submitted).
Teng*, W.-H, C.-Y. Huang, S.-P. Ho, Y.-H. Kuo, and X.-J. Zhou (2013), Characteristics of Global
Precipitable Water in ENSO Events Revealed by COSMIC Measurements, J. Geophy. Research,
DOI: 10.1002/jgrd.5037.
Wee, T.-K., and Y.-H. Kuo, 2013: A noise-aware combination of dual-frequency measurements from GPS
radio occultation. J. Geophys. Res. (conditionally accepted).
Wee, T-K., and Y.-H. Kuo, 2013: A variational combination of dual-frequency measurements from GPS
radio occultation. Geophys. Res. Lett. (submitted).
Yue, X., W. S. Schreiner, J. Braun,Y.-H. Kuo, and W. Wan, 2013, Observing System Simulation
Experiment (OSSE) stud on imaing the ionosphere by assimilating ground GNSS, LEO based
radio occultation and ocean reflection, and cross link. IEEE transaction on Geosceince and
Remote Sensing. (submitted).
Yue, X., W. S. Schreiner, Y.-H. Kuo, Q. Wu, Y. Deng, 2013: GNSS radio occultation nderived electron
density quality in high lattude and polar region: TIEGCM simulation and real data evaluation. J.
Atmos. and Sol.-Terr. Phys. (in press).
(b) Previously cited work
Hsiao, L.-F., D.-S. Chen, Y.-H. Kuo, Y.-R. Guo, T.-C. Yeh, J.-S. Hong, C.-T. Fong, C.-S. Lee, 2012:
Application of WRF 3DVAR to operational typhoon prediction in Taiwan: Impact of outer loop
and partial cycling. Wea. Forecasting, 27, 1249-1263.
Ho, S.-P., D. Hunt , A. Steiner , A. Mannucci , G. Kirchengast , H. Gleisner , S. Heise , A. von Engeln , C.
Marquardt , S. Sokolovskiy , W. Schreiner , B. Scherllin-Pirscher , C. Ao , J. Wickert , S.
Syndergaard , K. Lauritsen , S. Leroy , E.R. Kursinski , Y.-H. Kuo , U. Foelsche , T. Schmidt , M.
Gorbunov, 2012: Reproducibility of GPS radio occultation data for climate monitoring: Profile-toprofile inter-comparison of CHAMP climate records 2002 to 2008 from six data centers. J.
Geophys. Res., 117, D18111, doi:10.1029/2012JD017665.
Scherllin-Pirscher, B., C. Deser, S.-P. Ho, C. Chou, W. Randel, Y.-H. Kuo, 2012: The vertical and spatial
structure of ENSO in the upper troposphere and lower stratosphere from GPS radio occultation
measurements. Geophys. Res. Letters. 39, L20801, 6 PP., 2012, doi:10.1029/2012GL053071.
Steiner, A., D. Hunt , S.-P. Ho , G. Kirchengast , A. Mannucci , B. Scherllin-Pirscher , H. Gleisner , A. von
Engeln , T. Schmidt , C. Ao , S. Leroy , E.R. Kursinski , U. Foelsche , M. Gorbunov , S. Heise ,
Y.-H. Kuo , K. Lauritsen , C. Marquardt , C. Rocken , W. Schreiner , S. Sokolovskiy , S.
Syndergaard , J. Wickert, 2012: Quantification of structural uncertainty in climate data records
from GPS radio occultation. ACP doi:10.5194/acp-13-1469-2013.
Wang, M. Y.-M., G. T.-J. Chen, C.-C. Wang, Y.-H. Kuo, 2012: A case study of the cutoff process and
latent heating effect in an upper-level cold-core low during the Mei-Yu season in East Asia. Mon.
Wea. Rev. 140, 1725-1747.
Wee, T.-K., Y.-H. Kuo, D.-K. Lee, Z. Liu, W. Wang, S.-Y. Chen, 2012: Two overlooked biases of
Advanced Research WRF (ARW) model in geopotential height and temperature. Mon. Wea. Rev.
140, 3907-3918.
Yue, X., W. S. Schreiner, Y.-H. Kuo, 2012: A feasibility study of the radio occultation electron density
retrieval aided by a global ionospheric data assimilation model. J. Geophys. Res. 117, A08301,
doi: 10.1029/2011JA017446.
Yue, X., W. Schreiner , Y.-H. Kuo , D. Hunt , W. Wang , S. Solomon , A. Burns , D. Bilitza , J. Y. Liu ,
We. Wan, J. Wickert, 2012: Global 3-D ionospheric electron density reanalysis based on multisource data assimilation. J. Geophys. Res., 117, A09325, doi:10.1029/2012JA017968.
Yue, X., W. S. Schreiner, and Y.-H. Kuo, 2012: Evaluating the effect of the global ionospheric map on
aiding retrieval of radio occultation electron density profiles. GPS Solutions, doi: 10.1007/s10291012-0281-9.
Yue, X., W. S. Schreiner, C. Rocken, and Y.-H. Kuo, 2013: Validate the IRI2007 model by the COSMIC
slant TEC data during the extremely solar minimum of 2008. Advances in Space Research. 51
647-653.
Zeng, Z., S.-P. Ho, S. Sokolovskiy, and Y.-H. Kuo, 2012: Structural evolution of the Madden-Julian
Oscillation from COSMIC radio occultation data. J. Geophys. Res. 117, D22108,
doi:10.1029/2012JD017685.