Scientist (Eumetsat Fellow)Research Department, Earth System Assimilation Section, Microwave Radiance Observations Grouppage tabs Profile Summary: David Duncan works on maintaining and improving the usage of microwave sounder data assimilated at ECMWF. This includes the monitoring of current microwave sounders, as well as research into and implementation of next generation sensors into the data assimilation system. Increased utilisation of current sensors is also a focus, through greater use of all-sky assimilation and treatment of correlated observation errors. Professional interests: The global observing system Information content in satellite measurements Radiative transfer in clouds and precipitation Observation errors for satellite sensors Variational methods Career background: David earned his master's and doctoral degrees at Colorado State University in Fort Collins, Colorado working with Professor Chris Kummerow from 2010 to 2017. His PhD thesis was on the limits of one-dimensional variational retrievals of microwave imagers, with a focus on clouds and precipitation from the AMSR2 and GMI sensors. From 2017 to early 2019 David was a postdoctoral researcher at Chalmers University in Gothenburg, Sweden working with Professor Patrick Eriksson on clouds and precipitation as seen from active sensors and passive sensors from microwave to sub-millimetre wavelengths. David joined ECMWF in May 2019 as a EUMETSAT research fellow. Publications 2022 (May 2022) Assimilation of AMSU-A in All-sky Conditions, Monthly Weather Review n. 5, pp. 1023 - 1041. DOI: 10.1175/mwr-d-21-0273.1 Alan Geer, Katrin Lonitz, David Ian Duncan, Niels Bormann (April 2022) Improved surface treatment for all-sky microwave observations, ECMWF Technical Memoranda n. 894. DOI: 10.21957/zi7q6hau David Ian Duncan, Niels Bormann, Alan Geer (August 2022) All-sky Assimilation of AMSU-A Window Channels, EUMETSAT/ECMWF Fellowship Programme Research Report n. 59. DOI: 10.21957/daefm16p8 (February 2022) Synergistic radar and sub-millimeter radiometer retrievals of ice hydrometeors in mid-latitude frontal cloud systems, Atmospheric Measurement Techniques n. 3, pp. 677–699. DOI: 10.5194/amt-15-677-2022 Katrin Lonitz, Alan Geer, David Ian Duncan, Niels Bormann (April 2022) Developing an all-surface capability for all‑sky microwave radiances, ECMWF Newsletter, issue 171, pp. 23-27. DOI: 10.21957/ag94h613vk 2021David Ian Duncan, Niels Bormann, Alan Geer, Peter Weston (October 2021) Assimilation of AMSU-A in All-sky Conditions, EUMETSAT/ECMWF Fellowship Programme Research Report. DOI: 10.21957/b3qsdrf2l Linus Magnusson, Sharanya Majumdar, Rebecca Emerton, David Richardson, Magdalena A. Balmaseda, Calum Baugh, Peter Bechtold, Jean Bidlot, Antonino Bonanni, Massimo Bonavita, Niels Bormann, Andy Brown, Philip Browne, Hilda Carr, Mohamed Dahoui, Giovanna De Chiara, Michail Diamantakis, David Ian Duncan, Stephen English, Richard Forbes, Alan Geer, Thomas Haiden, Sean Healy, Timothy Hewson, Bruce Ingleby, Martin Janousek, Christian Kühnlein, Simon Lang, Sarah-Jane Lock, Tony McNally, Kristian S. Mogensen, Florian Pappenberger, Inna Polichtchouk, Fernando Prates, Christel Prudhomme, Florence Rabier, Patricia de Rosnay, Tiago Quintino, Michael Rennie (October 2021) Tropical cyclone activities at ECMWF, ECMWF Technical Memoranda n. 888. DOI: 10.21957/zzxzzygwv (August 2021) On the Addition of Microwave Sounders and Numerical Weather Prediction Skill, Quarterly Journal of the Royal Meteorological Society. DOI: 10.1002/qj.4149 (2021) Can machine learning correct microwave humidity radiances for the influence of clouds?, Atmospheric Measurement Techniques n. 4, pp. 2957–2979. DOI: 10.5194/amt-14-2957-2021 (March 2021) Dual-Polarization Deconvolution and Geophysical Retrievals from the Advanced Microwave Precipitation Radiometer during OLYMPEX/RADEX, Journal of Atmospheric and Oceanic Technology n. 3, pp. 607 - 628. (August 2021) Growing Operational Use of FY-3 Data in the ECMWF System, Advances in Atmospheric Sciences n. 8, pp. 1285–1298. DOI: 10.1007/s00376-020-0207-3 2020David Ian Duncan, Niels Bormann (September 2020) On the Addition of Microwave Sounders and NWP Skill, Including Assessment of FY-3D Sounders, EUMETSAT/ECMWF Fellowship Programme Research Report n. 55. DOI: 10.21957/iimhohmqt (August 2020) Synergistic radar and radiometer retrievals of ice hydrometeors, Atmospheric Measurement Techniques. DOI: 10.5194/amt-13-4219-2020 2019 (May 2019) On the distinctiveness of observed oceanic raindrop distributions, Atmospheric Chemistry and Physics. DOI: 10.5194/acp-19-6969-2019 (December 2019) An experimental 2D-Var retrieval using AMSR2, Atmospheric Measurement Techniques. DOI: 10.5194/amt-12-6341-2019 2018 (July 2018) Towards variational retrieval of warm rain from passive microwave observations, Atmospheric Measurement Techniques n. 7, pp. 4389–4411. DOI: 10.5194/amt-11-4389-2018 (2018) An update on global atmospheric ice estimates from satellite observations and reanalyses, Atmospheric Chemistry and Physics n. 15, pp. 11205–11219. DOI: 10.5194/acp-18-11205-2018 (August 2018) A neural network approach to estimate a posteriori distributions of Bayesian retrieval problems, Atmospheric Measurement Techniques n. 8, pp. 4627–4643. DOI: 10.5194/amt-11-4627-2018 2017David Ian Duncan, Christian D. Kummerow, Walter N. Meier (September 2017) An Integrated Examination of AMSR2 Products Over Ocean, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing n. 9, pp. 3963–3974. DOI: 10.1109/jstars.2017.2718535 (2017) Exploring The Limits Of Variational Passive Microwave Retrievals. 2016David I. Duncan, Christian D. Kummerow (June 2016) A 1DVAR retrieval applied to GMI: Algorithm description, validation, and sensitivities, Journal of Geophysical Research: Atmospheres n. 12, pp. 7415–7429. DOI: 10.1002/2016jd024808 2014David I. Duncan, Christian D. Kummerow, Gregory S. Elsaesser (March 2014) A Lagrangian Analysis of Deep Convective Systems and Their Local Environmental Effects, Journal of Climate n. 5, pp. 2072–2086. DOI: 10.1175/jcli-d-13-00285.1 2013 (2013) A Lagrangian perspective on deep convective tropical raining systems.