**Academic Profile:**

- 2013 - present: Faculty at ICTS-TIFR
- 2007-2013: Faculty at TIFR Centre for Applicable Mathematics, Bangalore
- 2007: Postdoc at the Mathematical Sciences Research Institute (MSRI), Berkeley
- 2005-2006: Postdoc at the Statistical and Applied Mathematical Sciences Institute (SAMSI) and Dept. of Mathematics, U. North Carolina Chapel Hill
- Ph.D. in Physics: University of Texas at Austin (2004), Supervisor - Phil Morrison
- M.Sc.(Integrated) in Physics: Indian Institute of Technology (IIT) Kanpur (1996)

**Research Interests:** (updated approx. mid-2015)

Dynamical systems and their applications to physical problems have been the unifying themes of my research. One of the areas of great interest to me is that of data assimilation - the incorporation of noisy observations of a system into an incomplete dynamical model of that system. This problem is pertinent to a variety of applications, including weather and climate prediction. I work on applications of Bayesian Markov Chain Monte Carlo (MCMC) sampling methods to data assimilation and on understanding the interplay between nonlinearity and statistics in these problems, and in particular, in the Lagrangian data assimilation problem.

My other research interests are in Hamiltonian systems, specially, periodic orbit bifurcation phenomena and breakup of invariant circles in nontwist systems, such as the meandering jet of the gulf stream in the Atlantic ocean, and applications of renormalization group methods in these problems.

**Publications: **(updated approx. mid-2015)

__Submitted:__

- Madhuresh, S. Vadlamani, A. Apte, "Contraction rates for Bayesian inverse problems," arxiv:1412.8016
- A. Apte, D. Auroux, M. Ramaswamy, "Observers for compressible Navier-Stokes equation," arxiv:1503:05259
- K.S. Gurumoorthy, C. Grudzien, A. Apte, A. Carrassi, C.K.R.T. Jones, "Rank deficiency of Kalman error covariance matrices in linear perfect model," arxiv:1503:05029

*Published:*

- L. Slivinski, E.T. Spiller, and A. Apte, "A hybrid particle-ensemble Kalman filter for high dimensional Lagrangian data assimilation," Lecture Notes in Computer Science (accepted, 2014) pdf
- A. Apte, "An introduction to data assimilation," Proceedings of Emerging Trends in Applied Mathematics: International Conference (accepted, 2014) pdf
- L. Slivinski, E.T. Spiller, A. Apte, and Bjorn Sandstede, "A hybrid particle-ensemble Kalman filter for Lagrangian data assimilation," Monthly Weather Review, v.
**143**pp.195-211 (2015) / doi:10.1175/MWR-D-14-00051.1 / pdf - E.T. Spiller, A. Apte, C.K.R.T. Jones, "Assimilation of en route Lagrangian observations," Tellus A v.
**65**pp.20319 (2013) / doi:10.3402/tellusa.v65i0.20319 / pdf - A. Apte, C.K.R.T. Jones, "The impact of nonlinearity in Lagrangian data assimilation," Nonlinear Processes in Geosciences, v.
**20**pp.1-13 (2013) / doi:10.5194/npg-_20-_329-_2013 / pdf - Md. Nurujjaman, A. Apte, P. Vinayachandran, "Data assimilation using ensemble transform Kalman filter (ETKF) in ROMS model for Indian Ocean," European Physical Journal Special Topics v.
**222**pp.875-883 (2013) / doi:10.1140/epjst/e2013-_01890-_3 / pdf - Md. Nurujjaman, S. Shivamurthy, A. Apte, T. Singla, P. Parmananda, "Effect of discrete time observations on synchronization in Chua model and applications to data assimilation," Chaos v.
**22**, pp.023125 (2012) / doi:10.1063/1.4712591 / pdf - A. Apte, "Renormalization group operators for maps and universal scaling of universal scaling exponents," Physica D v.
**240**(No.3) pp.317-322 (February 2010) / doi:10.1016/j.physd.2010.09.005 / pdf - A. Apte, D. Auroux, Mythily Ramaswamy, "Variational data assimilation for discrete Burgers equation," Electronic Journal of Differential Equations, Conference v.
**19**pp.15-30 (2010) / Journal webpage / pdf - A. Apte, C.K.R.T. Jones, A. M. Stuart, and J. Voss, "Data Assimilation: Mathematical and Statistical Perspectives," Int. J. Numer. Methods in Fluids v.
**56**pp.1033-1046 (March 2008) / doi:10.1002/fld.1698 / pdf - A. Apte, C.K.R.T. Jones, and A. M. Stuart, "A Bayesian approach to Lagrangian data assimilation," Tellus A
**60**336-347 (March 2008) / doi:10.1111/j.1600-_0870.2007.00295.x / pdf - T.B. Krause, A. Apte, and P.J. Morrison "A unique approach to the Darwin approximation," Phys. Plasmas v.
**14**pp.102112 (October 2007) / doi:10.1063/1.2799346 / pdf - A. Apte, M. Hairer, A.M. Stuart, and J. Voss, "Sampling the posterior: an approach to non-Gaussian data assimilation," Physica D v.
**230**pp.50-64 (June 2007) / doi:10.1016/j.physd.2006.06.009 / pdf - K. Fuchss, A. Wurm, A. Apte, and P.J. Morrison, "Breakup of meanders and `outer' tori in the standard nontwist map," Chaos v.
**16**pp.033120 (September 2006) / doi:10.1063/1.2338026 / pdf - A. Apte, R. de la Llave, Emilia Petrisor, "Comment on 'Reconnection scenarios... ,' Chaos Solitons and Fractals Vol 14, 117-127 (2002)," Chaos Solitons and Fractals v.
**27**(No. 4) pp.1115-1116 (2006) / doi:10.1016/j.chaos.2004.12.018 / - A. Wurm, A. Apte, K. Fuchss and P.J. Morrison, "Separatrix Reconnection, and Meanders in the Standard Nontwist Map," Chaos v.
**15**pp.023108 (June 2005) / doi:10.1063/1.1915960 / pdf - A. Apte, R. de la Llave, N.P. Petrov, "Regularity of critical invariant circles of non-twist maps," Nonlinearity v.
**18**(No. 3) pp. 1173-1187 (May 2005) / doi:10.1088/0951-_7715/18/3/013 / pdf - A. Apte, A. Wurm, and P.J. Morrison, "Renormalization for breakup of invariant tori," Physica D v.
**200**(No. 1-2) pp. 47-59 (January 2005) / doi:10.1016/j.physd.2004.09.010 / pdf - A. Wurm, A. Apte, and P.J. Morrison, "On reconnection phenomena in the standard nontwist map," Brazilian Journal of Physics v.
**34**(No. 4B) pp. 1700-1706 (December 2004) / doi:10.1590/S0103-_97332004000800035 / pdf (13 MB!!) / pdf (low resolution figures - 1 MB) - A. Apte, A. Wurm, and P.J. Morrison, "Renormalization and destruction of 1/γ
^{2}tori in the standard nontwist map," Chaos v.**13**pp.421-433 (June 2003) / doi:10.1063/1.1555472 / pdf

__Non-refereed:__

- A. Apte, "Wave--mean-flow interaction in Oldroyd-B fluid," Proceedings of the 2003 Program in Geophysical Fluid Dynamics (link in new window) (June 16 - August 15, 2003), Woods Hole Oceanographic Institution, Woods Hole, MA 02543 USA / pdf
- Dissertation: "Numerical Studies of the Standard Nontwist Map and a Renormalization Group Framework for Breakup of Invariant Tori" / pdf (13MB, 143 pages) / pdf (13MB, but singlespacing, narrower margins, reduce it to 83 pages!)
- A. Apte, Ravi Nanjundiah, Vijay Chandru, Roddam Narasimha, Spenta Wadia, "Report of the ICTS program 'Scientific discovery through intensive exploration of data'," Submitted to the Scientific Advisory Committee to the Prime Minister of India, April 2011, and a shortened version to Current Science / SAC-PM Apr-2011 pp.91-98 / pdf
- Md. Nurujjaman, Amit Apte , P. N. Vinayachandran, A. B. Samaddar, "Implementation of Data Assimilation in ROMS model for Indian Ocean," Third International Conference on MetaComputing, December 2012, Bhubaneswar, India / pdf