Wang, Pao-Kuan王寳貫

Research Interests

Prof. Pao-Kuan Wang has made outstanding contributions to the field of atmospheric science in the areas of (1) cloud physics, (2) cloud dynamics, (3) aerosol physics, and (4) historical climatology.

The research by the Intergovernmental Panel for Climate Change (IPCC) points out that the factor of clouds and aerosol is the source of largest uncertainty in the prediction of future climate using climate models because of the huge influence of cloud factor on atmospheric radiation, and it is difficult to predict clouds accurately. Prof. Wang research specialty is precisely the key field that can minimize this uncertainty

Prof. Pao-Kuan Wang is an international pioneer who created the research field of deep convective impact of the stratosphere-troposphere exchange. His recent achievement is the discovery of gravity wave breaking mechanism at the top of thunderstorm clouds. Normally the stability of the stratosphere will suppress the upward transport of tropospheric materials, but Prof. Wang found that the strong updrafts in the thunderstorm will excite internal gravity waves and, under suitable conditions, wave breaking may occur. The breaking waves can penetrate the tropopause and at the same time transport water vapor and ice into the stratosphere.  This research has been published in the Journal of Geophysical Research (Wang, 2003).

Representative Publications

Pao K. Wang, K. Y. Cheng, M. Setvak and C. K. Wang, (2016): The origin of the gullwing-shaped cirrus above an Argentinian thunderstorm as seen in CALIPSO images. J. Geophys. Res. Atmos, 121, doi:10.1002/2015JD024111.

K. Y. Cheng, P. K. Wang and T. Hashino, (2015): A Numerical Study on the Attitudes and Aerodynamics of Freely Falling Hexagonal Ice Plates. J. Atmos. Sci., 72, 3685-3698.

Pao K. Wang, (2013): Physics and Dynamics of Clouds and Precipitation. Cambridge University Press, 467pp.

Pao K. Wang, Shih-Hao Su., M. Setvak, H. M. Lin and R. Rabin, (2010): Ship wave signature at the cloud top of deep convective storms, Atmos. Res. 97, 294-302.

Pao K.Wang, M. Setvak, W. Lyons, W. Schmid and H. M. Lin, (2009): Further evidence of deep convective vertical transport of water vapor through the tropopause, Atmos. Res., 94, 400-408.

Pao K. Wang, (2007): The thermodynamic structure atop a penetrating convective Thunderstorm. Atmos. Res., 83, 254-262.

Pao K. Wang, (2003): Moisture Plumes above Thunderstorm Anvils and Their Contributions to Cross Tropopause Transport of Water Vapor in Midlatitudes. J. Geophys. Res., 108(D6), 4194, doi: 10.1029/2003JD002581, 2003.

M. Winkler and Pao K. Wang, (1994): The Late-Quaternary Vegetation and Climate of China, Wright et al., eds, Univ. of Minnesota Press, 221-264.

P. K. Wang, S. N. Grover and H. R. Pruppacher, (1978): On the Effect of Electric Charges on the Scavenging of Aerosol Particles by Clouds and Small Raindrops. J. Atmos. Sci., 35, 1735-1743.

P. K. Wang and H. R. Pruppacher, (1977a): Acceleration to Terminal Velocity of Cloud and Raindrops. J. Appl. Meteor., 16, 275-280.

Highlights

Prof. Wang has been studying cloud microphysics for a long time, especially the quantitative studies of the diffusion growth and collision growth of ice particles (ice crystals, snowflakes, graupel, hail) in clouds. He utilized precise numerical fluid dynamical models to determine the flow fields around falling ice particles and used these fields to calculate the ice particle growth rates due to absorption of water vapor (diffusion growth) and that due to collision with supercooled droplets to form graupel and hail. These are data of fundamental significance to atmospheric science. In addition, Prof. Wang had performed precise measurements of the acceleration of raindrops falling in air and the results have been used widely in atmospheric, forestry, and agricultural sciences. The above research results have been summarized in two books he authored (Wang, 2001; Wang, 2013). Prof. Wang also authored “Cloud Physics” (1997) which is the only cloud physics book in Chinese language published in Taiwan and is widely adopted as a textbook by atmospheric science departments.

In the field of aerosol physics, Prof. Wang constructed the first accurate mathematical model for precipitation scavenging of aerosol particles and also performed experimental measurements to prove quantitatively the existence of the Greenfield gap—a range of aerosol size about 0.1-1 µm where particles are hard to be removed by cloud and precipitation process (Wang, 1978). This research is especially significant in addressing the question will anthropogenic aerosol particles cause climatic change? The results of this work have been incorporated into many numerical atmospheric chemistry and climate models.

Prof. Wang also utilized ancient Chinese historical documents, such as the Records of Five Elements and Records of Disasters and Abnormalities in official histories, local records, and imperial court documents (e.g., Clear and Rain Records, Records of Rain, Snow and Grain Price) to reconstruct the climatic conditions in the historical time in China. He also compiled proxy climate data (such as microfossils in sedimentary cores, pollen assemblages, other marine geological data) to form paleoclimate series and inferred the climatic change in China during the Holocene (Winkler and Wang, 1994). This work is widely used by climate researchers.

Aside from formal research papers, Prof. Wang also authored a number of popular science books such as Heaven and Earth (popular astronomy and geophysics, received Ten Best Books Award, China Times, 1996), Insights (popular history of physical science, received Gold Caldron good book award, Government Information Office, 2002), Big World from a Small Dust (received Gold Caldron good book award, Government Information Office, 2005), that have been used by many schools as references in earth science. He thus has contributed substantially to the popular science education in Taiwan.

Introduction of New Book:

New Book by Pao K. Wang:Motions of Ice Hydrometeors in the Atmosphere




The puffy white clouds floating in the blue sky often inspire a leisurely sentiment, yet they actually play a very important role in the earth’s atmosphere. The most familiar to the public is that they may produce rain or snow when they are thick enough, and may even produce thunderstorms that cause severe weather disasters. But relatively few realize that clouds also have huge impact on the long-term climate. This is due to the strong influence of clouds on radiation – be it short wave solar radiation or long wave terrestrial radiation. For example, low clouds tend to act more in reflecting solar visible lights whereas high clouds tend to act more in trapping terrestrial infrared radiation. Consequently, the amount of high clouds and low clouds impacts directly the reception or interception of radiation, and therefore influences the long-term climate. Thus, the cloud amount and how long clouds can exist in the atmosphere have decisive impact on the future trend of climate. In fact, the IPCC reports have identified the cloud factor (along with the cloud interaction with aerosol) as the single largest source of uncertainty when using climate models to predict future climate.

All clouds are ensembles of their constituent particles that may be water drops or ice particles or both. The size, concentration and life span of these particles therefore decide the development stage of the cloud and its longevity. But what controls the growth or dissipation of these particles? Aside from the humidity in the atmosphere, the most important factor is the motion state of these particles. The motions of particles decide on how they can collide and coalesce with each other. How fast they can grow by vapor diffusion or how fast they will evaporate. And diffusion growth and evaporation involve the release or absorption of latent heats which are the energy source driving the cloud dynamical process.

But particles in clouds are very complex – they have many different kinds with milliards of sizes and different shapes and properties, especially those of ice particles. That’s why research on the motion of ice articles has been an important subject of cloud physics. But difficulties in experiments and complexities in theoretical studies had impeded the progress in this aspect.

This book summaries the research results of our group in recent years utilizing the computational fluid dynamics (CFD) techniques to solve numerically the 3-D free fall motions of ice crystals, snowflakes, graupel and hailstones. This is the first time in the world that the detailed theoretical 3-D flow fields around the true freely falling ice particles are obtained. They simulate in great detail the possible motions of these particles, such as rotation, vibration, zigzag, tumbling and spiraling, and these motions all occur in appropriate conditions agreeing with experimental data. In addition, we also provide the ventilation coefficients which are necessary for accurately estimate the diffusion growth or evaporation rates. This book is important to researchers in atmospheric science, especially cloud physics, and may also be useful for fluid dynamicists who are interested in understanding the fluid mechanics of complex bodies.

Publisher webpage:https://www.springer.com/gp/book/9789813344303

Professional Experiences
  • Atmospheric Physicist (1978-1980), Adjunct Assistant Professor (1980), Atmospheric Science Dept., UCLA
  • Asst. Professor (1980-1984), Associate Professor (1984-1988), Professor (1988-date), Univ. of Wisconsin-Madison.
  • Chair, Department of Atmospheric and Oceanic Sciences, UW-Madison (1994-1997)
  • Chair, Air Resources Management Program, UW-Madison (1998-2002)
  • Chair, Fellowship Committee (Physical Sciences Division), UW-Madison (1997-2002)
  • Visiting Professor, Department of Atmospheric Science, UCLA (1988)
  • Chair, Cloud Physics Committee, American Meteorological Society (1991-1993)
  • Visiting Professor, Dept. of Atmospheric Physics, University of Mainz, Germany (Spring, 1993)
  • Visiting Professor, Atmospheric Science, National Taiwan University (Fall, 1993); Adjunct Professor (2013-date)
  • Professor (joint appoint.), Space and Remote Sensing Research, National Central University (2015-date)
  • Visiting Professor, Dept. of Earth, Atmospheric, and Planetary Sci., MIT     (1997)
  • Visiting Professor, Physics Department, University of Ferrara, Italy (2001)
  • Visiting Professor, Max-Planck Institute for Chemistry, Germany (2003)
  • Advisory Committee, Interaction of Cosmic and Atmospheric Particle Systems, European Space Agency, 2001-2009
  • Advisory Committee, Center for Marine Environmental Sciences, University of Bremen, Germany (2005-2011)
  • Consulting Editor, McGraw-Hill Encyclopedia of Science and Technology (2003-date)
  • Editor (Geophysics), Il Nuovo Cimento C (2009-2015)
  • Associate Editor, Atmospheric Research (2010-date)
  • Associate Editor, European Physical Journal Plus (2010-2015)
  • International Advisory Board, Terrestrial, Atmospheric and Oceanic Sciences (2011-2014)
  • Editorial advisory board, Versita Publishing (Environmental Studies) (2011-date)
  • President, Meteorological Society of ROC (2013-2017), Councilor, Chinese Geoscience Union (2013-date)
  • Distinguished Research Fellow and Director, Research Center for Environmental Changes, Academia Sinica (2013-2019); Distinguished Visiting Chair (2020-date)
 
 
Awards and Honors (in chronological order)
  • Samuel C. Johnson Distinguished Fellowship (US), 1992
  • Alexander von Humboldt Senior Research Award (Germany), 1993
  • Fellow, American Meteorological Society, 2005
  • Fellow, Meteorological Society of ROC, 2008
  • Ten Best Books, China Times (Heaven and Earth, Newton), 1996
  • Ta-You Wu Popular Science Good Book Award (Insights, Commonwealth), 2002
  • Gold Caldron Good Book Award, Government Information Office (Insights, Commonwealth), 2002
  • Gold Caldron Good Book Award, Government Information Office (Big World from a Small Dust, Rhythms), 2005
  • Academician, Academia Sinica, 2018
  • Ph.D.
    Atmospheric Sciences
    University of California-Los Angeles (1978)
  • M.S.
    Atmospheric Sciences
    University of California-Los Angeles (1975)
  • B.S.
    Atmospheric Sciences
    National Taiwan University (1971)
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