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
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
Ref. 4387
- 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
Ref. 4413
- 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
Ref. 4242
- 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
Ref. 4062
- 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
Ref. 4215
- 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
Ref. 3984
- 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
Ref. 3748
- 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
Ref. 3771
- 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
Ref. 3542
- 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
Ref. 3552
- 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
Ref. 3532
- 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
Ref. 3478
- 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
Ref. 3379
- 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
Ref. 3441
- 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
Ref. 3067
- 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
Ref. 3044
- 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
Ref. 2970
- 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
Ref. 2791
- 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
Ref. 2850
- 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
Ref. 2856
- 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
Ref. 2862
- 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
Ref. 2893
- 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
Ref. 2690
- 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
Ref. 2689
- 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
Ref. 136
- 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
Ref. 248
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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