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A New Fire Initialization Method For Operational Coupled Fire-Atmosphere Models: Assimilation Of Infrared Perimeters And Satellite Detections, Kathleen Nicole Clough
A New Fire Initialization Method For Operational Coupled Fire-Atmosphere Models: Assimilation Of Infrared Perimeters And Satellite Detections, Kathleen Nicole Clough
Master's Theses
For coupled fire-atmosphere forecast models, such as WRF-SFIRE, the method used to initialize wildfire within the model can greatly impact meteorological, fire, and smoke extent forecasts. A well-constructed ignition process must be integrated within models to assure the atmospheric component of the model is not destabilized by excessive heat flux released during ignition and realistic fire-induced atmospheric circulation is established. Two ignition methods are tested on the 2020 Creek fire. Analyses indicate a gradual perimeter ignition with selective “masking”, fuel removal, provides the best results in terms of resolving the fire-induced vertical circulation and fire spread, and is thus preferred …
Observational Analysis And Modeling Of The "B" Regional Dust Storm On Mars, Courtney Marylou Batterson
Observational Analysis And Modeling Of The "B" Regional Dust Storm On Mars, Courtney Marylou Batterson
Master's Theses
The annually-recurring, regional B storm on Mars occurs at the highest southernlatitudes in years lacking a global dust storm (GDS), and produces warm temperatures (> 200 K) at 50 Pa over the south pole. Observations of the B storm are limited due to the lack of in-situ data in the polar regions of Mars, and reproducing polar phenomena using traditional latitude-longitude grid models is difficult because of the increasingly small grid spacing at the poles. The development of the new NASA Ames Mars Global Climate Model (MGCM), which has a finite-volume dynamical core, a uniform cubed-sphere grid, and several of …
Fire Weather Associated With The 2019 Northern California Public Safety Power Shutoff Events, Scott Purdy
Fire Weather Associated With The 2019 Northern California Public Safety Power Shutoff Events, Scott Purdy
Master's Theses
Recent high impact wildfire events across California have piloted the implementation of grid de-energization by utilities across the state. The largest utility, Pacific Gas and Electric (PG&E), deployed this tactic on seven separate occasions during 2019, four of which occurred in October. This recent ploy has been established in the wake of many deadly wildfires such as the 2018 Camp Fire as an ignition mitigation tactic. Conditions such as the state of the fuels, meteorological conditions, and the consequent fire danger were evaluated as the primary triggers for the October de-energizations. It was determined that the fuels were critically dry …
Observations And Simulations Of Fire Weather Phenomena Across Scales, Matthew James Brewer
Observations And Simulations Of Fire Weather Phenomena Across Scales, Matthew James Brewer
Master's Theses
The need for a better understanding of wildfires and how the atmosphere affects them provided the motivation for this work. The November 2018 Camp Fire quickly became the deadliest and most destructive wildfire in California history. In chapter 1, we investigate the contribution of meteorological conditions and a downslope windstorm event that occurred during the 2018 Camp Fire. Results show that this event was associated with mid-level and surface synoptic scale processes which created conditions favorable for a North wind event. Sustained surface winds between 3–6 m s-1 were observed with gusts of over 25 m s-1. The meteorological conditions …
Evaluating Tropical Tropospheric Ozone And Water Vapor In Merra-2, Era-Interim, And Cam-Chem Using Aircraft Observations From The Western Pacific, Kathryn Steinmann
Evaluating Tropical Tropospheric Ozone And Water Vapor In Merra-2, Era-Interim, And Cam-Chem Using Aircraft Observations From The Western Pacific, Kathryn Steinmann
Master's Theses
Tropospheric ozone (O3) negatively is a greenhouse gas, affecting global climate. To improve climate predictions, the behavior of O3 and the mechanisms affecting its distribution must be understood and accurately represented in model simulations. This study evaluates O3 and water vapor (H2O) observations from the Convective Transport of Active Species in the Tropics (CONTRAST) campaign with data from the National Center for Atmospheric Research’s (NCAR) Community Atmospheric Model with Chemistry (CAM-Chem), the Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2), and the European Centre for Medium-Range Weather Forecast (ECMWF) Re-Analysis-Interim (ERA-Interim). In the tropical middle troposphere, CAM-Chem shows …
Comparisons Of Upper Tropospheric Ozone At A Coastal And Urban Site And The Impact Of Local Surface Emissions, Chloe Anne Gore
Comparisons Of Upper Tropospheric Ozone At A Coastal And Urban Site And The Impact Of Local Surface Emissions, Chloe Anne Gore
Master's Theses
This study quantified the impact of urban emission sources on the enhancement of ozone (O3) in the troposphere using data from simultaneous ozonesonde launches at Half Moon Bay (HMB), CA and San Jose (SJ), CA on eleven dates in July and August 2018. The urban O3 enhancement in the SJ vertical profile was derived by subtracting out HMB, which represents baseline O3, from the SJ profile. This enhancement was averaged into 1 km layers and statistically analyzed with surface emission concentration data from three locations in SJ, however this did not reveal any discernable trends between the surface and O3 …
Asian Long-Range Transport In Relation To Atmospheric Rivers In Northern California, Catherine Liu
Asian Long-Range Transport In Relation To Atmospheric Rivers In Northern California, Catherine Liu
Master's Theses
The study investigated the effect of aerosol long-range transport on precipitation over northern California during atmospheric river (AR) events in the 2017 cold season (January-April). ARs in 2017 were among the strongest to date and the intense precipitation associated with the ARs resulted in flooding, destruction of property, and contamination of water supplies. The aerosol optical depth (AOD) from Moderate Resolution Imaging Spectroradiometer (MODIS) data showed Asian dust traveling across the northern Pacific Ocean along with AR events. Aerosol measurements in California, provided by the Interagency Monitoring of Protected Visual Environments (IMPROVE), showed that more Asian dust tends to be …