YONG-SANG CHOI, MIT Postdoctoral Research Associate

 

 

 

 

 

 

 

 

CURRENT CONTACT POINT:

 

54-1726, Department of Earth, Atmospheric and Planetary Sciences, M.I.T.,
77 Massachusetts Ave., Cambridge, MA 02139 USA
Tel: (617) 253-7609, (617) 999-8595, Fax: (617) 253-6208
Email: ysc@mit.edu

 

AREAS OF EXPERTISE AND RESEARCH INTERESTS:

 

Ÿ          Global/regional climate physics

Ÿ          Satellite remote sensing of clouds and aerosols

Ÿ          Cloud radiation processes and feedbacks

 

My main research interest is the roles of atmospheric aerosol and cloud processes in the climate system.

To address scientific issues related with above I mainly analyze various satellite observations, and test climate models.

 

EDUCATION:

 

B.S. in both Earth Science Education and Statistics, February 2000, Seoul National University, Korea.

Ph.D. in Atmospheric Science, August 2007, Seoul National University, Korea.

Thesis title: Remote sensing of cloud properties from the satellite multispectral imagery and its application to study of cloud radiative effect.

 

APPOINTMENTS:

 

December 2008-Present.                Postdoctoral research associate at M.I.T. (Adviser: Prof. Richard S. Lindzen)

September 2007-November 2008.    Postdoctoral research associate at Seoul National University (Advisers: Profs. Chang-Hoi Ho and Rokjin J. Park)

 

AWARDS AND HONORS:

 

Korea Research Foundation grant, December 2008-November 2009.

Best Ph.D. thesis award of Korean Meteorological Society, October 2007.

Best Ph.D. thesis award of College of Natural Science at Seoul National University, August 2007.

 

TRAINING EXPERIENCES:

 

Visiting Research Assistant, Gothenburg University, Sweden, April 2006-March 2007 (Adviser: Prof. Deliang Chen).

Visiting Research Assistant, National Taiwan University, Taiwan, December 2004-February 2005 (Adviser: Prof. Ming-Dah Chou).

Visiting Research Assistant, National Central University, Taiwan, December 2003-January 2004 (Adviser: Prof. Chung-Hsiung Sui).

Intensive English Program, University of British Colombia, Canada, August-December 2002.

Service as an army officer (ROTC), March 2000-June 2002.

 

PUBLICATIONS:

 

1. Choi, Y.-S., C.-H. Ho, M.-H. Ahn, and Y.-S. Kim (2005), Enhancement of the consistency of MODIS thin cirrus with cloud phase by adding 1.6-¥ìm reflectance, International Journal of Remote Sensing, 26, 4669–4680. [pdf]

2. Choi, Y.-S., C.-H. Ho, and C.-H. Sui (2005), Different optical properties of high cloud in GMS and MODIS observations, Geophysical Research Letters, 32, L23823, doi:10.1029/2005GL024616. [pdf]

3. Oh, H.-R., Y.-S. Choi, C.-H. Ho, and M.-H. Ahn (2006), Development of sky cover retrieval algorithm for the Communication, Ocean and Meteorological Satellite (COMS) imagery, Journal of the Korean Meteorological Society, 42, 389–396. [pdf]

4. Choi, Y.-S., and C.-H. Ho (2006), Radiative effect of cirrus with different optical properties over the tropics in MODIS and CERES observations, Geophysical Research Letters, 33, L21811, doi:10.1029/2006GL027403, Editor¡¯s Highlight. [pdf]

5. Yoo, J.-M., M.-J. Jeong, K.-T. Lee, J. Kim, C.-H. Ho, M.-H. Ahn, Y. M. Hur, J.-E. Rhee, H.-L. Yoo, C.-Y. Chung, I.-C. Shin, Y.-S. Choi, Y.-M. Kim, Y.-G. Lee, J.-H. Lee, J.-M. Yoon, and W.-H. Lee (2007), Intercomparison of shortwave radiative transfer models for a Rayleigh atmosphere, The Journal of the Korean Earth Science Society, 28(3), 298–310 (in Korean). [pdf]

6. Park, M.-S., Y.-S. Choi, C.-H. Ho, C.-H. Sui, S.-K. Park, and M.-H. Ahn (2007), Regional cloud characteristics over the tropical northwestern Pacific as revealed by TRMM PR and TMI, Journal of Geophysical Research, 112, D05209, doi: 10.1029/2006JD007437. [pdf]

7. Choi, Y.-S., C.-H. Ho, M.-H. Ahn, and Y.-M. Kim (2007), An exploratory study of cloud remote sensing capabilities of the Communication, Ocean and Meteorological Satellite (COMS) imagery, International Journal of Remote Sensing, 28, 4715–4732. [pdf]

8. Gong, D.-Y., C.-H. Ho, D. Chen, Y. Qian, Y.-S. Choi, and J. Kim (2007), Weekly cycle of aerosol-meteorology interaction over China, Journal of Geophysical Research, 112, D22202, doi: 101029/2007JD008888. [pdf]

9. Ho, C.-H., M.-S. Park, Y.-S. Choi, and Y. N. Takayabu (2008), Diurnal cycle of summer rainfall over the South China Sea for active and inactive periods of intraseasonal oscillation, Geophysical Research Letters, 35, L03701, doi:10.1029/2007GL031962. [pdf]

10. Choi, Y.-S., C.-H. Ho, D. Chen, Y.-H. Noh, and C.-K. Song (2008), Spectral analysis of weekly variation in PM10 mass concentration and environment conditions over China, Atmospheric Environment, 42, 655–666. [pdf]

11. Choi, Y.-S., C.-H. Ho, D.-Y. Gong, R. J. Park, and J. Kim (2008), The impact of aerosols on the summer rainfall frequency in China, Journal of Applied Meteorology and Climatology, 47, 1802–1813. [pdf]

12. Choi, Y.-S., C.-H. Ho, B.-G. Kim, and S.-K. Hur (2008), Long-term variation in midweek/weekend cloudiness difference during summer in Korea, Atmospheric Environment, 42, 6726–6732. [pdf]

13. Choi, Y.-S., and C.-H. Ho (2009), Validation of the cloud property retrievals from the MTSAT-1R imagery using MODIS observations, International Journal of Remote Sensing, 30, 5935–5958. [pdf]

14. Choi, Y.-S., C.-H. Ho, D.-Y. Gong, J.-H. Jeong, and T.-W. Park (2009), Adaptive change in intra-winter distribution of relatively cold events to East Asian warming, Terrestrial, Atmospheric and Oceanic Sciences, 20(6), 807–816. [pdf]

15. Choi, Y.-S., R. J. Park, and C.-H. Ho (2009), Estimates of ground-level aerosol mass concentrations using a chemical transport model with MODIS aerosol optical observations over East Asia, Journal of Geophysical Research, 114, D04204, doi:10.1029/2008JD011041. [pdf]

16. Song, C.-K., C.-H. Ho, R. J. Park, Y.-S. Choi, J. Kim, D.-Y. Gong, and Y.-B. Lee (2009), Different seasonal cycle between PM10 mass concentration and MODIS aerosol optical depth over China, Asia-Pacific Journal of Atmospheric Sciences, 45, 33–43. [pdf]

17. Ho, C.-H., Y.-S. Choi, and S.-K. Hur (2009), Long-term changes in summer weekend effect over northeastern China and the connection with regional warming, Geophysical Research Letters, 36, L15706, doi:10.1029/2009GL039509. [pdf]

18. Lindzen, R. S., and Y.-S. Choi (2009), On the determination of climate feedbacks from ERBE data, Geophysical Research Letters, 36, L16705, doi:10.1029/2009GL039628. [pdf]

19. Choi, Y.-S., C.-H. Ho, H.-R. Oh, R. J. Park, and C.-K. Song (2009), Estimating Bulk Optical Properties of Aerosols over the western North Pacific using MODIS and CERES Measurements, Atmospheric Environment, 43, 5656–5660. [pdf]

20. Choi, Y.-S., C.-H. Ho, S.-W. Kim, and R. S. Lindzen (2009), Observational diagnosis of cloud phase in the winter Antarctic atmosphere for parameterizations in climate models, Advances in Atmospheric Sciences, in review.

21. Choi, Y.-S., C.-H. Ho, J. Kim, and R. S. Lindzen (2009), Observations of spherical cloud droplets at very cold temperatures, Geophysical Research Letters, in review.

22. Choi, Y.-S., R. S. Lindzen, and C.-H. Ho (2009), Satellite-viewed influence of aerosols on cold-cloud albedo, Journal of Geophysical Research, in review.

23. Jeong, J.-H., C.-H. Ho, S.-J. Jeong, Y.-S. Choi, H. W. Linderholm, D. Chen (2009), Impact of urban warming on earlier spring flowering in Korea, International Journal of Climatology, in review.

 

PATENTS:

 

Ÿ         ¡°Method for retrieving cloud top temperature and pressure using 6.7 and 10.8 micro channels,¡± Y.-S. Choi, C.-H. Ho, M.-H. Ahn, and Y.-M. Kim (a registration number 0761936).

Ÿ         ¡°Method for retrieving cloud phase using a 6.7 micro channel,¡± Y.-S. Choi, C.-H. Ho, M.-H. Ahn, and Y.-M. Kim (a registration number 0740347).

Ÿ         ¡°Method for retrieving cloud optical thickness and effective particle radius using a 3.7 micro channel,¡± Y.-S. Choi, C.-H. Ho, M.-H. Ahn, and Y.-M. Kim (a registration number 0775654).

 

PRESENTATIONS:

 

Ÿ         ¡°On the observational determination of climate sensitivity¡±, Y.-S. Choi, MIT MASS Seminar, Boston, USA, September 2009 (Invited).

Ÿ         ¡°Observational determination of climate feedbacks from ERBE and CERES data¡±, R. S. Lindzen and Y.-S. Choi, Joint Program Science on the Science and Policy of Global Change Center for Global Change Science meeting, MIT, USA, September 2009 (Invited).

Ÿ         ¡°Detailed properties of clouds and aerosols from satellite data¡±, Y.-S. Choi, International Seminars on Planetary Emergencies, Erice, Italy, August 2009 (Invited).

Ÿ         ¡°Presence of supercooled clouds in very cold temperature ranges¡±, Y.-S. Choi, Gordon Research Conference: Radiation and climate, New London, USA, 2009.

Ÿ         ¡°Testing climate sensitivity using observations of the earth¡¯s radiation imbalance¡±, Y.-S. Choi, Seoul National University, Seoul, Korea, 2009 (Invited).

Ÿ         ¡°Presence of supercooled clouds in the very cold atmosphere¡±, Y.-S. Choi, MIT MASS Seminar, Boston, USA, 2009 (Invited).

Ÿ         ¡°Remote sensing of cloud properties and its application to climate studies¡±, Y.-S. Choi, McGill University, Montreal, Canada, 2009 (Invited).

Ÿ         ¡°Abundant supercooled clouds in the winter Antarctic atmosphere observed in MODIS and CALIOP measurements¡±, Y.-S. Choi, C.-H. Ho, and S.-W. Kim, Korean Meteorological Society Fall Conference, Daejeon, Korea, 2008.

Ÿ         ¡°Abundant supercooled clouds in the winter Antarctic atmosphere observed in MODIS and CALIOP measurements¡±, Y.-S. Choi, Seoul National University, Korea, 2008 (Invited).

Ÿ         ¡°Validation of cloud property retrievals from MTSAT-1R imagery using MODIS observations,¡± Y.-S. Choi, and C.-H. Ho, EUMETSAT Metrological Satellite Conference, Darmstadt, Germany, 2008.

Ÿ         ¡°A paradox of 50-year trend in midweek Korea summer cloudiness,¡± Y.-S. Choi, C.-H. Ho, B.-G. Kim, and S.-K. Ho, Asia Oceania Geosciences Society 5th Annual General Meeting, Busan, Korea, 2008.

Ÿ         ¡°Surface aerosol mass concentrations over East Asia from GEOS-Chem simulation scaled by MODIS aerosol optical property observation,¡± Y.-S. Choi, R. J. Park, and C.-H. Ho, Korean Meteorological Society Spring Conference, Seoul, 2008.

Ÿ         ¡°How do human activities affect the climate system? –On aerosol-meteorology interaction in East Asia,¡± Y.-S. Choi, Luncheon Seminar at School of Earth and Environmental Sciences, Seoul National University, Seoul, 2007 (Invited).

Ÿ         ¡°Radiative effect of cirrus with different optical properties over the tropics in MODIS and CERES observations,¡± Y.-S. Choi, Korea Meteorological Administration, Seoul, 2007 (Invited).

Ÿ         ¡°Examination of ground-level PM2.5 and PM10 using MODIS aerosol optical observations over East Asia,¡± Y.-S. Choi, R. J. Park, and J.-I. Jeong, American Geophysical Union Fall Meeting, San Fransisco, 2007.

Ÿ         ¡°The impact of aerosols on the summer rainfall frequency in China,¡± Y.-S. Choi, C.-H. Ho, D.-Y. Gong, R. J. Park, and J. Kim, Korean Meteorological Society Fall Conference, Seoul, 2007.

Ÿ         ¡°Weekly cycle of aerosol-meteorology interaction over China,¡± Y.-S. Choi, D.-Y. Gong, C.-H. Ho, and J. Kim, The 5th Climate Change Conference, Seoul, 2007.

Ÿ         ¡°Radiative effect of cirrus with different optical properties over the Tropics,¡± Y.-S. Choi, and C.-H. Ho, The Fourth International Ocean-Atmosphere Conference (COAA2007), Qingdao, 2007.

Ÿ         ¡°Retrieval of cloud properties using COMS imagery,¡± Y.-S. Choi, C.-H. Ho,  M.-H. Ahn, and Y.-M. Kim, EUMETSAT Metrological Satellite Conference, Helsinki, 2006.

Ÿ         ¡°Different optical properties of high cloud in GMS and MODIS observations,¡± Y.-S. Choi, and C.-H. Ho, GAC-C2 Conference, Gothenburg, 2006.

Ÿ         ¡°Different optical properties of high cloud in GMS and MODIS Observations,¡± Y.-S. Choi, C.-H. Ho, and C.-H. Sui, The 5th International Symposium on Asian Monsoon System, Yongpyong, 2005.

Ÿ         ¡°Perspective of COMS cloud analysis algorithm: high semi-transparent and multi-layer Clouds,¡± Y.-S. Choi, C.-H. Ho, and Y.-M. Kim, Korean Meteorological Society Spring Conference, Kangnung, 2005.

Ÿ         ¡°Cloud analysis algorithm by using 5 channels in COMS,¡± Y.-S. Choi, and C.-H. Ho, Korean Meteorological Society Fall Conference, Kongju, 2004.

Ÿ         ¡°Enhancement of the consistency of MODIS thin cirrus with cloud phase by adding 0.6- and 1.6 mm reflectances,¡± Y.-S. Choi, and C.-H. Ho, International Radiation Symposium, Busan, 2004.

Ÿ         ¡°Improvement of MODIS thin cirrus detection: Preliminary study using NIR 1.6-¥ìm reflectance,¡± Y.-S. Choi, and C.-H. Ho, The 2004 EUMETSAT Meteorological Satellite Conference, Prague, 2004.

Ÿ         ¡°Improvement of MODIS thin cirrus detection: Preliminary study using NIR 1.6-¥ìm reflectance,¡± Y.-S. Choi, and C.-H. Ho, Korean Meteorological Society Spring Conference, Seoul, 2004.

Ÿ         ¡°Comparative studies of cloud retrieval algorithm between MODIS/Terra and SEVIRI/MSG,¡± Y.-S. Choi, and C.-H. Ho, Korean Meteorological Society Fall Conference, Seoul, 2003.