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Zheng Liu

Research Associate

Email

liuzheng@apl.washington.edu

Phone

206-543-5626

Department Affiliation

Polar Science Center

Education

B.E. Mechanical Engineering, University of Science & Technology of China, 2004

M.S. Atmospheric Sciences, University of Washington, 2008

Ph. D. Atmospheric Sciences, University of Washington, 2012

Publications

2000-present and while at APL-UW

Observations and modeling of atmospheric profiles in the arctic seasonal ice zone

Liu, Z., A. Schweiger, and R. Lindsay, "Observations and modeling of atmospheric profiles in the arctic seasonal ice zone," Mon. Wea. Rev., 143, 39-53, doi:, 2015.

More Info

1 Jan 2015

The authors use the Polar Weather Research and Forecasting (WRF) Model to simulate atmospheric conditions during the Seasonal Ice Zone Reconnaissance Survey (SIZRS) in the summer of 2013 over the Beaufort Sea. With the SIZRS dropsonde data, the performance of WRF simulations and two forcing datasets is evaluated: the Interim ECMWF Re-Analysis (ERA-Interim) and the Global Forecast System (GFS) analysis. General features of observed mean profiles, such as low-level temperature inversion, low-level jet (LLJ), and specific humidity inversion are reproduced by all three models. A near-surface warm bias and a low-level moist bias are found in ERA-Interim. WRF significantly improves the mean LLJ, with a lower and stronger jet and a larger turning angle than the forcing. The improvement in the mean LLJ is likely related to the lower values of the boundary layer diffusion in WRF than in ERA-Interim and GFS, which also explains the lower near-surface temperature in WRF than the forcing. The relative humidity profiles have large differences between the observations, the ERA-Interim, and the GFS. The WRF simulated relative humidity closely resembles the forcings, suggesting the need to obtain more and better-calibrated humidity data in this region. The authors find that the sea ice concentrations in the ECMWF model are sometimes significantly underestimated due to an inappropriate thresholding mechanism. This thresholding affects both ERA-Interim and the ECMWF operational model. The scale of impact of this issue on the atmospheric boundary layer in the marginal ice zone is still unknown.

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center
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