He received a B.S. in Physics from Utah State University and a M.S. and Ph.D. in Geophysics from the University of Washington. Dr. Walden's research interests include polar meteorology and remote sensing of the polar atmosphere. He has also worked on understanding climate change in the western U.S. He has conducted eight field experiments in Antarctica and the Arctic, including a current deployment at Summit Station, Greenland as part of NSF’s Arctic Observing Network. Dr. Walden served on NASA’s Validation Team for the Atmospheric Infrared Sounder (AIRS) from 2001 to 2008. He is currently on the Steering Committee for the International Arctic Systems for Observing the Atmosphere (IASOA) and is leading the Surface Radiation Working Group. At Washington State University, Dr. Walden teaches courses in atmospheric radiative transfer, remote sensing, and fluid mechanics.
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His recent foci are on mixed-phase clouds and atmospheric forcing of Arctic sea-ice and ice sheets. Most of this work entails combining measurements from sophisticated suites of ground-based remote sensors to characterize detailed cloud microphysical, radiative, and dynamical properties, as well as related features of the atmospheric structure and surface properties. Recent efforts have worked to link these detailed observations with process modeling to further elucidate processes responsible for cloud phase partitioning and maintenance. Matthew has been engaged in Arctic research for his whole career, getting his start at the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment on an ice breaker in 1997. Since that time, Matthew has been involved in numerous observational activities in Alaska, northern Canada, Greenland, and the central Arctic sea ice. He is currently championing a new activity called MOSAiC (the Multi-disciplinary drifting Observatory for the Study of Arctic Climate), that will involve year-round, inter-disciplinary measurements from a drifting ship within the Arctic ice pack. Matthew's research support comes from the National Science Foundation, Department of Energy, and National Oceanic and Atmospheric Administration. Matthew oversees the ICECAPS cloud radar, POSS, radiosondes, hotplate, and sodar, as well as the data management and archival system.
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In particular, Dave works with state-of-the-art remote sensors such as an automated water vapor and aerosol Raman lidar, Doppler lidar, Atmospheric Emitted Radiance Interferometer, multi-frequency microwave radiometer, and millimeter-wave cloud radar in his research. Dave utilizes observations from these and other more traditional instruments, typically in synergistic fashion, to gain insight into such topics as evolution of the boundary layer's turbulent structure; shallow convective cloud processes; the interaction between clouds, aerosols, radiation, precipitation, and the thermodynamic environment in the boundary layer; mixed-phase clouds; radiative transfer in the atmosphere; and other topics. Additionally, Dave has led and been involved with numerous feild campaigns, such as M-PACE, RHUBC-I and II, prior to ICECAPS. Dave is the instrument lead for the MPL, the HATPRO and HF MWRs, and the ceilometer as well as developing the retrievals for the PWV and LWP values.
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Currently, not much is known about changes in cloud amount, cloud type, or precipitation, and the international community is in dire need of climatologically relevant cloud and precipitation observations to gain a better understanding of the processes involved in climate change and of how human activities influence these processes. Remote sensing observations of the Earth system can in part serve as a means of understanding these complex processes. Indeed, such observations have already become a crucial input to numerical weather prediction models and also provide comprehensive data sets to study climate. Ralf's research combines the development of instrumentation and algorithms, the analysis of remote sensing observations observations, and the development of new models and methods to simulate atmospheric radiative transfer. Ralf has added a MASC instrument to the ICECAPS suite in 2014 to observe and characterize ice habits and particle size distributions.
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