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Full-Text Articles in Physical Sciences and Mathematics
Ice Nucleation Parameterization And Relative Humidity Distribution In Idealized Squall-Line Simulations, Minghui Diao, George Bryan, Hugh Morrison, Jorgen Jensen
Ice Nucleation Parameterization And Relative Humidity Distribution In Idealized Squall-Line Simulations, Minghui Diao, George Bryan, Hugh Morrison, Jorgen Jensen
Faculty Publications, Meteorology and Climate Science
Output from idealized simulations of a squall line are compared with in situ aircraft-based observations from the Deep Convective Clouds and Chemistry campaign. Relative humidity distributions around convection are compared between 1-Hz aircraft observations (≈250-m horizontal scale) and simulations using a double-moment bulk microphysics scheme at three horizontal grid spacings: Δx = 0.25, 1, and 4 km. The comparisons focus on the horizontal extent of ice supersaturated regions (ISSRs), the maximum and average relative humidity with respect to ice (RHi) in ISSRs, and the ice microphysical properties during cirrus cloud evolution, with simulations at 0.25 and 1 km providing better …
The Mean And Turbulent Properties Of A Wildfire Convective Plume, Neil Lareau, Craig Clements
The Mean And Turbulent Properties Of A Wildfire Convective Plume, Neil Lareau, Craig Clements
Faculty Publications, Meteorology and Climate Science
The time-mean and time-varying smoke and velocity structure of a wildfire convective plume is examined using a high-resolution scanning Doppler lidar. The mean plume is shown to exhibit the archetypal form of a bent-over plume in a crosswind, matching the well-established Briggs plume-rise equation. The plume cross section is approximately Gaussian and the plume radius increases linearly with height, consistent with plumerise theory. The Briggs plume-rise equation is subsequently inverted to estimate the mean fire-generated sensible heat flux, which is found to be 87 kW m22 . The mean radial velocity structure of the plume indicates flow convergence into the …
Direct Comparisons Of Ice Cloud Macro- And Microphysical Properties Simulated By The Community Atmosphere Model Version 5 With Hippo Aircraft Observations, Chenglai Wu, Xiaohong Liu, Minghui Diao, Kai Zhang, Andrew Gettelman, Zheng Lu, Joyce Penner, Zhaohui Lin
Direct Comparisons Of Ice Cloud Macro- And Microphysical Properties Simulated By The Community Atmosphere Model Version 5 With Hippo Aircraft Observations, Chenglai Wu, Xiaohong Liu, Minghui Diao, Kai Zhang, Andrew Gettelman, Zheng Lu, Joyce Penner, Zhaohui Lin
Faculty Publications, Meteorology and Climate Science
In this study we evaluate cloud properties simulated by the Community Atmosphere Model version 5 (CAM5) using in situ measurements from the HIAPER Pole-to-Pole Observations (HIPPO) campaign for the period of 2009 to 2011. The modeled wind and temperature are nudged towards reanalysis. Model results collocated with HIPPO flight tracks are directly compared with the observations, and model sensitivities to the representations of ice nucleation and growth are also examined. Generally, CAM5 is able to capture specific cloud systems in terms of vertical configuration and horizontal extension. In total, the model reproduces 79.8 % of observed cloud occurrences inside model …
Dynamical Conditions Of Ice Supersaturation And Ice Nucleation In Convective Systems: A Comparative Analysis Between In Situ Aircraft Observations And Wrf Simulations, John D'Alessandro, Minghui Diao, Chenglai Wu, Xiaohong Liu, Ming Chen, Hugh Morrison, Trude Eidhammer, Jorgen Jensen, Aaron Bansemer, Mark Zondlo, Joshua Digangi
Dynamical Conditions Of Ice Supersaturation And Ice Nucleation In Convective Systems: A Comparative Analysis Between In Situ Aircraft Observations And Wrf Simulations, John D'Alessandro, Minghui Diao, Chenglai Wu, Xiaohong Liu, Ming Chen, Hugh Morrison, Trude Eidhammer, Jorgen Jensen, Aaron Bansemer, Mark Zondlo, Joshua Digangi
Faculty Publications, Meteorology and Climate Science
Occurrence frequency and dynamical conditions of ice supersaturation (ISS, where relative humidity with respect to ice (RHi) > 100%) are examined in the upper troposphere around convective activity. Comparisons are conducted between in situ airborne observations and the Weather Research and Forecasting model simulations using four double‐moment microphysical schemes at temperatures ≤ −40°C. All four schemes capture both clear‐sky and in‐cloud ISS conditions. However, the clear‐sky (in‐cloud) ISS conditions are completely (significantly) limited to the RHi thresholds of the Cooper parameterization. In all of the simulations, ISS occurrence frequencies are higher by ~3–4 orders of magnitude at higher updraft speeds ( …
Assessment Of An Atmospheric Transport Model For Annual Inverse Estimates Of California Greenhouse Gas Emissions, Justin Bagley, Seongeun Jeong, Xinguang Cui, Sally Newman, Jingsong Zhang, Chad Priest, Mixtli Campos-Pineda, Arlyn Andrews, Laura Bianco, Matthew Lloyd, Neil Lareau, Craig Clements, Marc Fischer
Assessment Of An Atmospheric Transport Model For Annual Inverse Estimates Of California Greenhouse Gas Emissions, Justin Bagley, Seongeun Jeong, Xinguang Cui, Sally Newman, Jingsong Zhang, Chad Priest, Mixtli Campos-Pineda, Arlyn Andrews, Laura Bianco, Matthew Lloyd, Neil Lareau, Craig Clements, Marc Fischer
Faculty Publications, Meteorology and Climate Science
Atmospheric inverse estimates of gas emissions depend on transport model predictions, hence driving a need to assess uncertainties in the transport model. In this study we assess the uncertainty in WRF-STILT (Weather Research and Forecasting and Stochastic Time-Inverted Lagrangian Transport) model predictions using a combination of meteorological and carbon monoxide (CO) measurements. WRF configurations were selected to minimize meteorological biases using meteorological measurements of winds and boundary layer depths from surface stations and radar wind profiler sites across California. We compare model predictions with CO measurements from four tower sites in California from June 2013 through May 2014 to assess …
Estimating Methane Emissions From Biological And Fossil-Fuel Sources In The San Francisco Bay Area, Seongeun Jeong, Xinguang Cui, Donald Blake, Ben Miller, Stephen Montzka, Arlyn Andrews, Abhinav Guha, Philip Martien, Ray Bambha, Brian Lafranchi, Hope Michelsen, Craig Clements, Pierre Glaize, Marc Fischer
Estimating Methane Emissions From Biological And Fossil-Fuel Sources In The San Francisco Bay Area, Seongeun Jeong, Xinguang Cui, Donald Blake, Ben Miller, Stephen Montzka, Arlyn Andrews, Abhinav Guha, Philip Martien, Ray Bambha, Brian Lafranchi, Hope Michelsen, Craig Clements, Pierre Glaize, Marc Fischer
Faculty Publications, Meteorology and Climate Science
We present the first sector-specific analysis of methane (CH4) emissions from the San Francisco Bay Area (SFBA) using CH4 and volatile organic compound (VOC) measurements from six sites during September – December 2015. We apply a hierarchical Bayesian inversion to separate the biological from fossil-fuel (natural gas and petroleum) sources using the measurements of CH4 and selected VOCs, a source-specific 1 km CH4 emission model, and an atmospheric transport model. We estimate that SFBA CH4 emissions are 166–289 Gg CH4/yr (at 95% confidence), 1.3–2.3 times higher than a recent inventory with much of the underestimation from landfill. Including the VOCs, …
Extending Flood Forecasting Lead Time In A Large Watershed By Coupling Wrf Qpf With A Distributed Hydrological Model, Ji Li, Yangbo Chen, Huanyu Wang, Jianming Qin, Jie Li, Sen Chiao
Extending Flood Forecasting Lead Time In A Large Watershed By Coupling Wrf Qpf With A Distributed Hydrological Model, Ji Li, Yangbo Chen, Huanyu Wang, Jianming Qin, Jie Li, Sen Chiao
Faculty Publications, Meteorology and Climate Science
Long lead time flood forecasting is very important for large watershed flood mitigation as it provides more time for flood warning and emergency responses. The latest numerical weather forecast model could provide 1–15-day quantitative precipitation forecasting products in grid format, and by coupling this product with a distributed hydrological model could produce long lead time watershed flood forecasting products. This paper studied the feasibility of coupling the Liuxihe model with the Weather Research and Forecasting quantitative precipitation forecast (WRF QPF) for large watershed flood forecasting in southern China. The QPF of WRF products has three lead times, including 24, 48 …