Dr. Altug Aksoy Scientist Hurricane Research Division-- CIMAS phone: 979-234-2032 altug.aksoy@noaa.gov
NOAA's Atlantic Oceanographic and Meteorological Laboratory
4301 Rickenbacker Causeway
Miami, FL 33149
Professional InterestsDr. Aksoy has scientific interests in data assimilation, numerical weather prediction, and ensemble methods, and especially in their application to tropical and mesoscale meteorology, as well as remote sensing platforms such as radars, lidars, and satellites. He is jointly appointed at Hurricane Research Division and University of Miami's Cooperative Institute for Marine and Atmospheric Studies since 2008. He earned his Ph.D. degree from Texas A&M University Department of Atmospheric Sciences in 2005.
Dr. Aksoy is a member of the data assimilation group and is the main developer of the Hurricane Ensemble Data Assimilation System (HEDAS). This is an advanced data assimilation system designed to assimilate hurricane inner-core observations at the vortex and smaller scales. Observation platforms that are commonly utlized for this purpose include the tail Doppler radar, dropwindsondes, Stepped Frequency Microwave Scatterometer (SFMR), and in-situ flight-level sensors installed on the NOAA P-3 and G-IV and Air Force Reserve C-130 aircraft. HEDAS is designed as a state-of-the-art system to carry out research on new data assimilation techniques and to investigate the potential impacts of new observing platforms for hurricane applications. It utilizes an ensemble Kalman filter and is interfaced with NOAA's HWRF model. Using HEDAS, Dr. Aksoy is currently actively carrying out research in parameter estimation, radar data assimilation, and satellite data assimilation.
Dr. Aksoy is also actively involved in serving the atmospheric science community through his editor role for Monthly Weather Review (MWR) published by the American Meteorological Society. MWR is one of the most popular scientific journals in the areas of numerical weather prediction and data assimilation.
Current Research Projects- Vortex-scale data assimilation using HEDAS HEDAS is an ensemble Kalman filter data assimilation system.
- Investigation of HWRF model error associated with surface-layer and boundary-layer parameterizations to improve vortex-scale, ensemble-based data assimilation using HEDAS (externally funded by NOAA/HFIP)
- Hurricane OSSE
- Lagrangian model forecast of the transport and dispersion of toxic gases/particles over Istanbul by assimilating radar observed winds in a regional model (with Istanbul Technical University and The Scientific and Technological Research Council of Turkey)
Hightlighted Publications- Aksoy, A. Parameter estimation. In Encylopedia of Atmospheric Sciences (2nd edition), G.R. North, J. Pyle, and F. Zhang (eds.). Academic Press, Volume 4, 181-186, doi:10.1016/B978-0-12-382225-3.00494-1 2014
- Aksoy, A., S.D. Aberson, T. Vukicevic, K.J. Sellwood, S. Lorsolo, and X. Zhang. Assimilation of high-resolution tropical cyclone observations with an ensemble Kalman filter using NOAA/AOML/HRD’s HEDAS: Evaluation of the 2008-2011 vortex-scale analyses. Monthly Weather Review, 141(6):1842-1865, doi:10.1175/MWR-D-12-00194.1 2013
- Aksoy, A., D.C. Dowell, and C. Snyder. A multicase comparative assessment of the ensemble Kalman filter for assimilation of radar observations, Part I: Storm-scale analyses. Monthly Weather Review, 137(6):1805-1824, doi:10.1175/2009MWR3086.1 2009
Recently Published Peer-Reviewed Papers- Aksoy, A. A Monte Carlo approach to understanding the impacts of initial-condition uncertainty, model uncertainty, and simulation variability on the predictability of chaotic systems: Perspectives from the one-dimensional logistic map. Chaos, 34(1):011102, https://doi.org/10.1063/5.0181705 2024
- Sellwood, K.J., J.A. Sippel, and A. Aksoy. Assimilation of Coyote small uncrewed aircraft system observations in Hurricane Maria (2017) using operational HWRF. Weather and Forecasting, 38(6):901-919, https://doi.org/10.1175/WAF-D-22-0214.1 2023
- Aksoy, A., J.J. Cione, B.A. Dahl, and P.D. Reasor. Tropical cyclone data assimilation with Coyote uncrewed aircraft system observations, very frequent cycling, and a new online quality control technique. Monthly Weather Review, 150(4):797-829, https://doi.org/10.1175/MWR-D-21-0124.1 2022
- Aksoy, A. A Monte Carlo approach to understanding the impacts of initial-condition uncertainty, model uncertainty, and simulation variability on the predictability of chaotic systems: Perspectives from the one-dimensional logistic map. Chaos, 34(1):011102, https://doi.org/10.1063/5.0181705 2024
- Poyer, A., W. Komaromi, S. Gopalakrishnan, L. Wolf, F. Marks, G. Alaka Jr., J. Anderson, V. Tallapragada, M. Brennan, A. Mehra, X. Zhang, Z. Zhang, A. Hazelton, D.A. Zelinsky, J.L. Franklin, A. Aksoy, C. Alexander, M. Bender, L. Bernardet, M. Biswas, J. Cangialosi, M. DeMaria, R. Dunlap, M. Ek, G. Eosco, L. Gramer, L. Harris, J.S. Hilderbrand, E. Kalina, H.-S. Kim, P. Kucera, B. Liu, P. McCaslin, T. Marchok, J. Moskaitis, K. Musgrave, L. Nance, K. Newman, M. Onderlinde, W. Ramstrom, D. Rosen, J. Sims, J. Sippel, D. Stern, R. Torn, X. Wang, W. Wang, Y. Weng, B.C. Zachry, C. Zhang, M. Zhang, and L. Zhu. 2021-2022 HFIP R&D activities summary: Recent results and operational implementation. HFIP Technical Report, HFIP-2023-1, 73 pp., https://doi.org/10.25923/exgj-1n68 2023
- Sellwood, K.J., J.A. Sippel, and A. Aksoy. Assimilation of Coyote small uncrewed aircraft system observations in Hurricane Maria (2017) using operational HWRF. Weather and Forecasting, 38(6):901-919, https://doi.org/10.1175/WAF-D-22-0214.1 2023
- Aksoy, A., J.J. Cione, B.A. Dahl, and P.D. Reasor. Tropical cyclone data assimilation with Coyote uncrewed aircraft system observations, very frequent cycling, and a new online quality control technique. Monthly Weather Review, 150(4):797-829, https://doi.org/10.1175/MWR-D-21-0124.1 2022
- Christophersen, H., J.A. Sippel, A. Aksoy, and N.L. Baker. Recent advances for tropical cyclone data assimilation. Annals of the New York Academy of Sciences, 1517(1):25-43, https://doi.org/10.1111/nyas.14873 2022
- Zawislak, J., R.F. Rogers, S.D. Aberson, G.J. Alaka, G. Alvey, A. Aksoy, L. Bucci, J. Cione, N. Dorst, J. Dunion, M. Fischer, J. Gamache, S. Gopalakrishnan, A. Hazelton, H.M. Holbach, J. Kaplan, H. Leighton, F. Marks, S.T. Murillo, P. Reasor, K. Ryan, K. Sellwood, J.A. Sippel, and J.A. Zhang. Accomplishments of NOAA’S airborne hurricane field program and a broader future approach to forecast improvement. Bulletin of the American Meteorological Society, 103(2):E311-E338, https://doi.org/10.1175/BAMS-D-20-0174.1 2022
- Cione, J.J., G.H. Bryan, R. Dobosy, J.A. Zhang, G. de Boer, A. Aksoy, J.B. Wadler, E.A. Kalina, B.A. Dahl, K. Ryan, J. Neuhaus, E. Dumas, F.D. Marks, A.M. Farber, T. Hock, and X. Chen. Eye of the storm: Observing hurricanes with a small Unmanned Aircraft System. Bulletin of the American Meteorological Society, 101(2):E186-E205, https://doi.org/10.1175/BAMS-D-19-0169.1 2020
- Wick, G.A., J.P. Dunion, P.G. Black, J.R. Walker, R.D. Torn, A.C. Kren, A. Aksoy, H. Christophersen, L. Cucurull, B. Dahl, J.M. English, K. Friedman, T.R. Peevey, K. Sellwood, J.A. Sippel, V. Tallapragada, J. Taylor, H. Wang, R.E. Hood, and P. Hall. NOAA’s Sensing Hazards with Operational Unmanned Technology (SHOUT) Experiment: Observations and forecast impacts. Bulletin of the American Meteorological Society, 101(7):E698-E987, https://doi.org/10.1175/BAMS-D-18-0257.1 2020
- Christophersen, H., A. Aksoy, J. Dunion, and S. Aberson. Composite impact of Global Hawk unmanned aircraft dropwindsondes on tropical cyclone analyses and forecasts. Monthly Weather Review, 146(7):2297-2314, https://doi.org/10.1175/MWR-D-17-0304.1 2018
- Christopherson, H., R. Atlas, A. Aksoy, and J. Dunion. Combined use of satellite observations and Global Hawk unmanned aircraft dropwindsondes for improved tropical cyclone analyses and forecasts. Weather and Forecasting, 33(4):1021-1031, https://doi.org/10.1175/WAF-D-17-0167.1 2018
- Steward, J.L., J.E. Roman, A. Lamas Davina, and A. Aksoy. Parallel direct solution of the covariance-localized ensemble square root Kalman filter equations with matrix functions. Monthly Weather Review, 146(9):2819-2836, https://doi.org/10.1175/MWR-D-18-0022.1 2018
- Aksoy, A., J.A. Zhang, B.W. Klotz, E.W. Uhlhorn, and J.J. Cione. Axisymmetric initialization of the atmosphere and ocean for idealized coupled hurricane simulations. Journal of Advances in Modeling Earth Systems, 9(7):2672-2695, https://doi.org/10.1002/2017MS000977 2017
- Christophersen, H., A. Aksoy, P. Dunion, and K. Sellwood. The impact of NASA Global Hawk unmanned aircraft dropwindsonde observations on tropical cyclone track, intensity and structure: Case studies. Monthly Weather Review, 145(5):1817-1830, https://doi.org/10.1175/MWR-D-16-0332.1 2017
- Steward, J.L., A. Aksoy, and Z.S. Haddad. Parallel direct solution of the Ensemble Square-Root Kalman Filter equations with observation principal components. Journal of Atmospheric and Oceanic Technology, 34(9):1867-1884, https://doi.org/10.1175/JTECH-D-16-0140.1 2017
- Aberson, S.D., A. Aksoy, K.J. Sellwood, T. Vukicevic, and X. Zhang. Assimilation of high-resolution tropical cyclone observations with an ensemble Kalman filter using HEDAS: Evaluation of 2008-2011 HWRF forecasts. Monthly Weather Review, 143(2):511-523, https://doi.org/10.1175/MWR-D-14-00138.1 2015
- Aksoy, A. Parameter estimation. In Encylopedia of Atmospheric Sciences (2nd edition), G.R. North, J. Pyle, and F. Zhang (eds.). Academic Press, Volume 4, 181-186, https://doi.org/10.1016/B978-0-12-382225-3.00494-1 2014
- Gall, R., F. Toepfer, F. Marks, E.N. Rappaport, A. Aksoy, S. Aberson, J.W. Bao, M. Bender, S. Benjamin, L. Bernardet, M. Biswas, B. Brown, J. Cangialosi, C. Davis, M. DeMaria, J. Doyle, M. Fiorino, J. Franklin, I. Ginis, S. Gopalakrishnan, T. Hamill, R. Hodur, H.S. Kim, J. Knaff, T. Krishnamurti, P. Kucera, Y. Kwon, W. Lapenta, N. Lett, S. Lord, T. Marchok, E. Mifflin, M. Morin, K. Musgrave, L. Nance, C. Reynolds, V. Tallapragada, H. Tolman, R. Torn, G. Vandenberghe, T. Vukicevic, X. Wang, Y. Weng, J. Whittaker, R. Yablonsky, D.-L. Zhang, F. Zhang, J. Zhang, X. Zhang, and D.A. Delinsky. Hurricane Forecast Improvement Project: 2013 HFIP R&D activities summary—Recent results and operational implementation. HFIP Technical Report, HFIP2014-2, 50 pp., 2014
- Aksoy, A. Storm-relative observations in tropical cyclone data assimilation with an ensemble Kalman filter. Monthly Weather Review, 141(2):506-522, https://doi.org/10.1175/MWR-D-12-00094.1 2013
- Aksoy, A., S.D. Aberson, T. Vukicevic, K.J. Sellwood, S. Lorsolo, and X. Zhang. Assimilation of high-resolution tropical cyclone observations with an ensemble Kalman filter using NOAA/AOML/HRD’s HEDAS: Evaluation of the 2008-2011 vortex-scale analyses. Monthly Weather Review, 141(6):1842-1865, https://doi.org/10.1175/MWR-D-12-00194.1 2013
- Lorsolo, S., J. Gamache, and A. Aksoy. Evaluation of the Hurricane Research Division Doppler radar analysis software using synthetic data. Journal of Atmospheric and Oceanic Technology, 30(6):1055-1071, https://doi.org/10.1175/JTECH-D-12-00161.1 2013
- Rogers, R.F., S.D. Aberson, A. Aksoy, B. Annane, M. Black, J.J. Cione, N. Dorst, J. Dunion, J.F. Gamache, S.B. Goldenberg, S.G. Gopalakrishnan, J. Kaplan, B.W. Klotz, S. Lorsolo, F.D. Marks, S.T. Murillo, M.D. Powell, P.D. Reasor, K.J. Sellwood, E.W. Uhlhorn, T. Vukicevic, J.A. Zhang, and X. Zhang. NOAA’s Hurricane Intensity Forecasting Experiment (IFEX): A progress report. Bulletin of the American Meteorological Society, 94(6):859-882, https://doi.org/10.1175/BAMS-D-12-00089 2013
- Vukicevic, T., A. Aksoy, P. Reasor, S. Aberson, K. Sellwood, and F. Marks. Joint impact of forecast tendency and state error biases in Ensemble Kalman Filter data assimilation of inner-core tropical cyclone observations. Monthly Weather Review, 141(9):2992-3006, https://doi.org/10.1175/MWR-D-12-00211.1 2013
- Aksoy, A., S. Lorsolo, T. Vukicevic, K.J. Sellwood, S.D. Aberson, and F. Zhang. The HWRF Hurricane Ensemble Data Assimilation System (HEDAS) for high-resolution data: The impact of airborne Doppler radar observations in an OSSE. Monthly Weather Review, 140(6):1843-1862, https://doi.org/10.1175/MWR-D-11-00212.1 2012
- Lorsolo, S., and A. Aksoy. Wavenumber analysis of azimuthally-distributed data: Assessing maximum allowable gap size. Monthly Weather Review, 140(6):1945-1956, https://doi.org/10.1175/MWR-D-11-00219.1 2012
- Aksoy, A., D.C. Dowell, and C. Snyder. A multicase comparative assessment of the ensemble Kalman filter for assimilation of radar observations, Part II: Short-range ensemble forecasts. Monthly Weather Review, 138(4):1273-1292, https://doi.org/10.1175/2009MWR3086.1 2010
- Aksoy, A., D.C. Dowell, and C. Snyder. A multicase comparative assessment of the ensemble Kalman filter for assimilation of radar observations, Part I: Storm-scale analyses. Monthly Weather Review, 137(6):1805-1824, https://doi.org/10.1175/2009MWR3086.1 2009
Recent Presentations- Aksoy, A., H. Christophersen, B. Dahl, K. J. Sellwood, and S. D. Aberson, 2017: Advances in Tropical Cyclone Vortex-Scale Data Assimilation using NOAA's Hurricane Ensemble Data Assimilation System (HEDAS) and Hurricane WRF (HWRF) Model. The Third Symposium on High Performance Computing for Weather, Water, and Climate, January 2017, Seattle, Washington, American Meteorological Society. Click here for the recorded presentation on the AMS website.
- Aksoy, A., J. J. Cione, B. Dahl, K. Ryan, H. Christophersen, and R. Atlas, 2017: Evaluating the Impact of Hurricane Observations from the Unmanned Coyote Aircraft in Observing System Simulation Experiments. The 21st Conference on Integrated Observing and Assimilation Systems for the Atmosphere, Oceans, and Land Surface, January 2017, Seattle, Washington, American Meteorological Society. Click here for the recorded presentation on the AMS website.
- Aksoy, A., 2016: An Overview of the Tropical Cyclone Data Assimilation Activities at NOAA’s Hurricane Research Division. The 7th EnKF Data Assimilation Workshop, 23-27 May 2016, State College, Pennsylvania. Click here for the workshop webpage.
Awards and Honors | | | | | | | 2012 | | Certificate of Recognition | | U.S. Department of Commerce NOAA/AOML
| | | 2011 | | Monthly Weather Review Editor’s Award | | American Meteorological Society
| | | 2011 | | Group Achievement Award to Genesis and Rapid Intensification Processes | | NASA
| | | 2011 | | Certificate of Recognition | | U.S. Department of Commerce NOAA/AOML
| | | 2003 | | College of Geosciences Graduate Excellence Scholarship | | Texas A&M University
| | | 2002 | | Mr./Mrs. Kenneth P. Pike Fellowship | | Texas A&M University
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