Michael Ghil

Last updated
Michael Ghil
Born(1944-06-10)June 10, 1944
Budapest, Hungary
NationalityAmerican, Israeli
Alma mater Technion – Israel Institute of Technology, Courant Institute of Mathematical Sciences
Known for Boolean Delay Equations, Climate Dynamics, Data Assimilation, El Niño-Southern Oscillation, Singular Spectrum Analysis
AwardsAPS Fellow (2022)
A. Wegener Medal (2012)
L. F. Richardson Medal (2004)
Scientific career
FieldsClimate Science
Institutions UCLA, École normale supérieure
Thesis  (1975)
Doctoral advisor Peter Lax
Notable students Hervé Le Treut

Michael Ghil (born 10 June 1944 in Budapest, Hungary) [1] is an American and European mathematician and physicist, focusing on the climate sciences and their interdisciplinary aspects. He is a founder of theoretical climate dynamics, as well as of advanced data assimilation methodology. [1] He has systematically applied dynamical systems theory to planetary-scale flows, both atmospheric and oceanic. Ghil has used these methods to proceed from simple flows with high temporal regularity and spatial symmetry to the observed flows, with their complex behavior in space and time. His studies of climate variability on many time scales have used a full hierarchy of models, from the simplest ‘toy’ models all the way to atmospheric, oceanic and coupled general circulation models. [2] Recently, Ghil has also worked on modeling and data analysis in population dynamics, macroeconomics, and the climate–economy–biosphere system.

Contents

He is currently a Distinguished Research Professor at the University of California, Los Angeles and a Distinguished Professor Emeritus at the École Normale Supérieure, Paris. [3]

Early life and education

Ghil spent his childhood in Romania before moving to Israel. [4] He studied Mechanical Engineering at the Technion–Israel Institute of Technology, Haifa, Israel from where he received his B.Sc. in August 1966, and his M.Sc. in June 1971. He studied mathematics at the Courant Institute of Mathematical Sciences, New York University, New York from where he received a Master's in February 1973 and a Ph.D. in June 1975, under the supervision of Peter Lax (Abel Prize 2005). [4] His doctoral dissertation title was “A Nonlinear Parabolic Equation with Applications to Climate Theory". [5]

Career

Ghil was affiliated with the Courant Institute of Mathematical Sciences, from September 1971 until May 1987, first as a Research Assistant (1971–1975) and then as a Research Professor (1982–1987), via intermediate appointments. While in New York, he was a NAS/NRC Research Associate at the NASA Goddard Institute for Space Studies, New York from August 1975 to September 1976. [4]

In 1985 Ghil was appointed a full professor of Climate Dynamics at the Department of Atmospheric Sciences at the University of California, Los Angeles, where he also served as a chairman of the same Department from September 1988 to June 1992. From July 1994 until June 2003 he was appointed Distinguished Professor of Climate Dynamics at UCLA, as well as the Director of the Institute of Geophysics & Planetary Physics, UCLA, from July 1992 until June 2003. He served as the Director of the Environmental Research & Teaching Institute (CERES-ERTI), of École Normale Supérieure in Paris from November 2002 until September 2010 and as a Head of the Geosciences Department of ENS from July 2003 until December 2009, where he was also a Distinguished Professor of Geosciences from September 2002 until September 2012. [4]

Since October 2003 until today, he is a Distinguished Research Professor of Atmospheric and Oceanic Sciences at the University of California, Los Angeles. He is also a Distinguished Professor Emeritus at École Normale Supérieure, Paris from September 2012. [6] [7]

Research

Ghil has played an important role in the foundations of modern theoretical climate dynamics. [8] [9] During the late 1970s, he worked in the application of dynamical systems theory to problems of the climate sciences. Starting from the work of Budyko [10] and Sellers, [11] Ghil proposed a 1D Energy Balance Model able to provide a succinct but essentially correct description of the climate system. [12] Ghil's analysis complemented the ones by Budyko and Sellers and played a key role for understanding the multistability of the Earth system, which features competing snowball and warm states. Paleoclimatological evidence that the Earth had indeed experienced snowball episodes in the Pre-Cambrian emerged in the 1990s. [13] Energy balance models like Ghil's, once supplemented with stochastic forcings (along the direction of Hasselmann’s programme) led to the discovery of phenomena like stochastic resonance. [14]

Throughout the 1980s and 1990s Ghil contributed to the development of data assimilation techniques in meteorology and oceanography, [15] and to the theory of low-frequency variability of the atmosphere (with a special emphasis on the study of blocking), as well as to the understanding of large-scale ocean dynamics. He introduced the use of advanced spectral methods for the analysis of chaotic geophysical time series, [16] and most prominently the singular-spectrum analysis technique (SSA). [17] [18] In the 2000s, he extended his studies of the El Niño-Southern Oscillation phenomenon (ENSO) using Boolean delay and delay differential equations, [19] and worked on the statistics and dynamics of extreme events. Recently, Ghil proposed the pullback attractor as a mathematical framework able to encompass the random and time-dependent nature of the climate system. Another area of research has been the development of data-driven methods for reconstructing the surrogate dynamics of partially observed systems. [20] Additionally, he has contributed to data analysis and modeling in macroeconomics and population dynamics, as well as to coupled climate-economy-biosphere modeling. [21]

Honors and awards

Publications

A selection of books and papers is given below.

Selected books

Selected papers

Theory of Climate Dynamics and Climate Variability

Paleoclimate

Data assimilation

Blockings

Dynamical Systems Theory

Macroeconomics & coupled climate-macroeconomics

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References

  1. 1 2 Cushman-Roisin, Benoit; Beckers, Jean-Marie (2011-01-01), Cushman-Roisin, Benoit; Beckers, Jean-Marie (eds.), "Chapter 22 - Data Assimilation", International Geophysics, Introduction to Geophysical Fluid Dynamics, Academic Press, vol. 101, pp. 725–760, doi:10.1016/b978-0-12-088759-0.00022-5, ISBN   9780120887590 , retrieved 2022-07-01
  2. 1 2 "Michael Ghil". European Geosciences Union (EGU). Retrieved 2022-01-03.
  3. ↑ "Michael Ghil" (PDF). Retrieved 7 July 2020.
  4. 1 2 3 4 "Courant Newsletters | NYU Courant". cims.nyu.edu (Fall 2011 ed.). pp. 4–5. Retrieved 2022-01-04.
  5. ↑ "Michael Ghil - The Mathematics Genealogy Project". www.genealogy.math.ndsu.nodak.edu. Retrieved 2021-12-16.
  6. ↑ "Michael Ghil". dept.atmos.ucla.edu. Retrieved 2022-01-04.
  7. ↑ "GHIL, Michael - Centre de formation sur l'environnement et la société". www.environnement.ens.fr (in French). Retrieved 2022-01-04.
  8. ↑ "The Climate Modelling Primer, 4th Edition | Wiley". Wiley.com. Retrieved 2022-07-01.
  9. ↑ Chown, Marcus (2004-02-28). "Chaotic heavens". New Scientist. Retrieved 2023-05-21.
  10. ↑ Budyko, M. I. (1969-01-01). "The effect of solar radiation variations on the climate of the Earth". Tellus. 21 (5): 611–619. Bibcode:1969Tell...21..611B. doi: 10.3402/tellusa.v21i5.10109 . ISSN   0040-2826.
  11. ↑ Sellers, William D. (1969-06-01). "A Global Climatic Model Based on the Energy Balance of the Earth-Atmosphere System". Journal of Applied Meteorology and Climatology. 8 (3): 392–400. Bibcode:1969JApMe...8..392S. doi: 10.1175/1520-0450(1969)008<0392:AGCMBO>2.0.CO;2 . ISSN   1520-0450.
  12. ↑ Ghil, Michael (1976-01-01). "Climate Stability for a Sellers-Type Model". Journal of the Atmospheric Sciences. 33 (1): 3–20. Bibcode:1976JAtS...33....3G. doi: 10.1175/1520-0469(1976)033<0003:CSFAST>2.0.CO;2 . ISSN   0022-4928.
  13. ↑ Hoffman, Paul F.; Kaufman, Alan J.; Halverson, Galen P.; Schrag, Daniel P. (1998-08-28). "A Neoproterozoic Snowball Earth". Science. 281 (5381): 1342–1346. Bibcode:1998Sci...281.1342H. doi:10.1126/science.281.5381.1342. PMID   9721097. S2CID   13046760.
  14. ↑ Benzi, R; Sutera, A; Vulpiani, A (1981-11-01). "The mechanism of stochastic resonance". Journal of Physics A: Mathematical and General. 14 (11): L453–L457. Bibcode:1981JPhA...14L.453B. doi: 10.1088/0305-4470/14/11/006 . ISSN   0305-4470. S2CID   123005407.
  15. ↑ Ghil, Michael; Malanotte-Rizzoli, Paola (1991), Data Assimilation in Meteorology and Oceanography, Advances in Geophysics, vol. 33, Elsevier, pp. 141–266, doi:10.1016/s0065-2687(08)60442-2, ISBN   9780120188338 , retrieved 2021-12-16
  16. ↑ Ghil, M.; Vautard, R. (March 1991). "Interdecadal oscillations and the warming trend in global temperature time series". Nature. 350 (6316): 324–327. Bibcode:1991Natur.350..324G. doi:10.1038/350324a0. ISSN   1476-4687. S2CID   4241857.
  17. ↑ Vautard, Robert; Yiou, Pascal; Ghil, Michael (1992-09-15). "Singular-spectrum analysis: A toolkit for short, noisy chaotic signals". Physica D: Nonlinear Phenomena. 58 (1): 95–126. Bibcode:1992PhyD...58...95V. doi:10.1016/0167-2789(92)90103-T. ISSN   0167-2789.
  18. ↑ Ghil, M.; Allen, M. R.; Dettinger, M. D.; Ide, K.; Kondrashov, D.; Mann, M. E.; Robertson, A. W.; Saunders, A.; Tian, Y.; Varadi, F.; Yiou, P. (2002). "Advanced Spectral Methods for Climatic Time Series". Reviews of Geophysics. 40 (1): 3–1–3–41. Bibcode:2002RvGeo..40.1003G. doi:10.1029/2000RG000092. ISSN   1944-9208. S2CID   6765204.
  19. ↑ Zaliapin, Ilya; Keilis-Borok, Vladimir; Ghil, Michael (2003-05-01). "A Boolean Delay Equation Model of Colliding Cascades. Part II: Prediction of Critical Transitions". Journal of Statistical Physics. 111 (3): 839–861. doi:10.1023/A:1022802432590. ISSN   1572-9613. S2CID   118736384.
  20. ↑ Santos Gutiérrez, Manuel; Lucarini, Valerio; Chekroun, Mickaël D.; Ghil, Michael (2021-05-01). "Reduced-order models for coupled dynamical systems: Data-driven methods and the Koopman operator". Chaos: An Interdisciplinary Journal of Nonlinear Science. 31 (5): 053116. arXiv: 2012.01068 . Bibcode:2021Chaos..31e3116S. doi:10.1063/5.0039496. ISSN   1054-1500. PMID   34240957. S2CID   235303689.
  21. ↑ Hallegatte, Stéphane; Ghil, Michael (December 2008). "Natural disasters impacting a macroeconomic model with endogenous dynamics". Ecological Economics. 68 (1–2): 582–592. doi:10.1016/j.ecolecon.2008.05.022.
  22. ↑ "APS Fellow Archive". aps.org. Retrieved 2022-12-10.
  23. ↑ "Michael Ghil got elected as an Honorary Member of the Hungarian Academy of Sciences". dept.atmos.ucla.edu. Retrieved 2022-01-03.
  24. ↑ "Ed Lorenz Lecture | AGU". www.agu.org. Retrieved 2022-01-03.
  25. ↑ "Oeaw Members Detail". www.oeaw.ac.at. Retrieved 2022-01-03.
  26. ↑ "Michael Ghil". European Geosciences Union (EGU). Retrieved 2022-01-03.
  27. ↑ Simion @Yonescat, Florin. "Honorary Fellowship (A)". The Royal Astronomical Society. Retrieved 2022-01-03.
  28. ↑ "Academy of Europe: Ghil Michael". www.ae-info.org. Retrieved 2022-01-03.
  29. ↑ Anonymous (1995). "1995 AGU Fellows". Eos, Transactions American Geophysical Union. 76 (35): 348–349. Bibcode:1995EOSTr..76..348.. doi:10.1029/95eo00213. ISSN   0096-3941.
  30. ↑ "John Simon Guggenheim Foundation | Michael Ghil" . Retrieved 2022-01-03.
  31. ↑ "List of Fellows". American Meteorological Society. Retrieved 2022-01-03.
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