scholarly journals Downslope Windstorms of San Diego County. Part I: A Case Study

2016 ◽  
Vol 144 (2) ◽  
pp. 529-552 ◽  
Author(s):  
Yang Cao ◽  
Robert G. Fovell
Keyword(s):  
San Diego ◽  
Wrf Model ◽  
San Diego County ◽  
Near Surface ◽  
Santa Ana ◽  
Forecast Bias ◽  
Downslope Windstorms ◽  
Wind Events ◽  
Downslope Flow

Abstract The “Santa Ana” wind is an offshore flow that affects Southern California periodically during the winter half of the year, typically between September and May. The winds can be locally gusty, particularly in the complex terrain of San Diego County, where the winds have characteristics of downslope windstorms. These winds can cause and/or rapidly spread wildfires, the threat of which is particularly acute during the autumn season before the onset of winter rains. San Diego’s largest fires, including the Cedar fire of 2003 and Witch Creek fire of 2007, occurred during Santa Ana wind events. A case study of downslope flow during a moderately intense Santa Ana event during mid-February 2013 is presented. Motivated by the need to forecast winds impinging on electrical lines, the authors make use of an exceptionally dense network of near-surface observations in San Diego County to calibrate and verify simulations made utilizing the Advanced Research version of the Weather Research and Forecasting (WRF) Model, which in turn is employed to augment the observations. Results demonstrate that this particular Santa Ana episode consists of two pulses separated by a protracted lull. During the first pulse, the downslope flow is characterized by a prominent hydraulic jumplike feature, while during the second one the flow possesses a clear temporal progression of winds downslope. WRF has skill in capturing the evolution and magnitude of the event at most locations, although most model configurations overpredict the observed sustained wind and the forecast bias is itself biased.

A Case Study of Planning

2001 ◽  
Author(s):  
Marlon Boarnet ◽  
Randall C. Crane
Keyword(s):  
United States ◽  
Land Use ◽  
Urban Areas ◽  
San Diego ◽  
The United States ◽  
San Diego County ◽  
Light Rail ◽  
Rail Transit ◽  
The South

The facts, figures, and inferences in chapter 7 regarding municipal behavior toward transit-oriented housing opportunities illustrate many points. Still, there is much that even a careful statistical analysis might miss or misunderstand. For that reason, we also explored what we could learn by talking to real planners about these issues. The case of San Diego is interesting and useful for several reasons. First, the San Diego Trolley is the oldest of the current generation of light rail projects in the United States. Unlike many newer systems, the age of San Diego’s rail transit (the South Line opened in 1981) allows time for land use planning to respond to the fixed investment. Second, the San Diego system is no stranger to modern transit-based planning ideas. The San Diego City Council approved a land-use plan for their stations that includes many of the ideas promoted by transit-oriented development (TOD) advocates (City of San Diego, 1992). Third, the light rail transit (LRT) authority in San Diego County, the Metropolitan Transit Development Board (MTDB), is often regarded as one of the more successful municipal LRT agencies. The initial parts of the MTDB rail transit system were constructed strictly with state and local funds, using readily available, relatively low-cost technology (Demoro and Harder, 1989, p. 6). Portions of San Diego’s system have high fare-box recovery rates, including the South Line, which in its early years recovered as much as 90 percent of operating costs at the fare box (Gómez-Ibáñez, 1985). All of these factors make San Diego potentially a “best-case” example of TOD implementation. When generalizing from this case study, it is important to remember that the transit station area development process in San Diego is likely better developed than in many other urban areas in the United States. The results from San Diego County can illustrate general issues that, if they have not already been encountered, might soon become important in other urban areas with rail transit systems. Also, given San Diego County’s longer history of both LRT and TOD when compared with most other regions, any barriers identified in San Diego County might be even more important elsewhere.

Racial geographies and the challenges of day labor formalization: a case study from San Diego County

2008 ◽  
Vol 25 (3) ◽  
pp. 223-244 ◽  
Author(s):  
Sean M. Crotty ◽  
Fernando J. Bosco
Keyword(s):  
San Diego ◽  
San Diego County ◽  
Day Labor

FREE SOIL, UNFREE LABOR

2004 ◽  
Vol 73 (3) ◽  
pp. 349-390 ◽  
Author(s):  
M. MAGLIARI
Keyword(s):  
Civil War ◽  
Native Americans ◽  
San Diego ◽  
Free State ◽  
San Diego County ◽  
Chattel Slavery ◽  
Indian Act ◽  
Unfree Labor ◽  
The Government

Although it prohibited chattel slavery, California permitted the virtual enslavement of Native Americans under the 1850 Act for the Government and Protection of Indians. Scholars have described some of the key components of the Indian Act, but none has provided a systematic examination of the law's labor provisions or examined how individual employers actually used the law. This article does both by offering a careful survey of the Indian Act, followed by a detailed case study focusing on Cave Couts, the owner of Rancho Guajome in San Diego County. The Couts example reveals that the 1850 Act did not simply legalize the exploitation of Indians as prisoners and indentured "apprentices." Perhaps more importantly, it also preserved the system of debt peonage that had �ourished in California under Mexican rule. Not until after the Civil War did California become a truly free state.

Can private land conservation reduce wildfire risk to homes? A case study in San Diego County, California, USA

2017 ◽  
Vol 157 ◽  
pp. 161-169 ◽  
Author(s):  
Van Butsic ◽  
Alexandra D. Syphard ◽  
Jon E. Keeley ◽  
Avi Bar-Massada
Keyword(s):  
San Diego ◽  
Land Conservation ◽  
San Diego County ◽  
Private Land ◽  
Wildfire Risk ◽  
Private Land Conservation

scholarly journals The Implementation of a Mineral Dust Wet Deposition Scheme in the GOCART-AFWA Module of the WRF Model

2018 ◽  
Vol 10 (10) ◽  
pp. 1595 ◽  
Author(s):  
Konstantinos Tsarpalis ◽  
Anastasios Papadopoulos ◽  
Nikolaos Mihalopoulos ◽  
Christos Spyrou ◽  
Silas Michaelides ◽  
...  
Keyword(s):  
Wet Deposition ◽  
Large Scale ◽  
Eastern Mediterranean ◽  
Wrf Model ◽  
Saharan Dust ◽  
Near Surface ◽  
Dust Transport ◽  
Wet Scavenging ◽  
Aerosol Module

The principal objective of this study is to present and evaluate an advanced dust wet deposition scheme in the Weather and Research Forecasting model coupled with Chemistry (WRF-Chem). As far as the chemistry component is concerned, the Georgia Tech Goddard Global Ozone Chemistry Aerosol Radiation and Transport of the Air Force Weather Agency (GOCART-AFWA) module is applied, as it supports a binary scheme for dust emissions and transport. However, the GOCART-AFWA aerosol module does not incorporate a wet scavenging scheme, nor does it interact with cloud processes. The integration of a dust wet deposition scheme following Seinfeld and Pandis into the WRF-Chem model is assessed through a case study of large-scale Saharan dust transport over the Eastern Mediterranean that is characterized by severe wet deposition over Greece. An acceptable agreement was found between the calculated and measured near surface PM10 concentrations, as well as when model estimated atmospheric optical depth (AOD) was validated against the AERONET measurements, indicating the validity of our dust wet deposition scheme.

Increase in Pediatric Respiratory Visits Associated with Santa Ana Wind–Driven Wildfire Smoke and PM2.5 Levels in San Diego County

2020 ◽  
Vol 17 (3) ◽  
pp. 313-320 ◽  
Author(s):  
Sydney Leibel ◽  
Margaret Nguyen ◽  
William Brick ◽  
Jacob Parker ◽  
Sindana Ilango ◽  
...  
Keyword(s):  
San Diego ◽  
San Diego County ◽  
Santa Ana ◽  
Wildfire Smoke

scholarly journals An Analysis of Near-Surface Winds, Air Temperature, and Cyclone Activity in Terra Nova Bay, Antarctica, from 1993 to 2009

2011 ◽  
Vol 50 (3) ◽  
pp. 662-680 ◽  
Author(s):  
Shelley L. Knuth ◽  
John J. Cassano
Keyword(s):  
Ross Sea ◽  
Reanalysis Data ◽  
Strong Wind ◽  
Near Surface ◽  
Terra Nova Bay ◽  
Field Season ◽  
Terra Nova ◽  
Wind Events ◽  
Upper Level ◽  
Downslope Flow

Abstract In September 2009, the first unmanned aerial vehicles were flown over Terra Nova Bay, Antarctica, to collect information regarding air–sea interactions. Prior to the field season, wind and temperature data from a local automatic weather station (AWS) were collected from 1993 to 2007 and compared with an August–October 2006–08 satellite cyclone analysis to place the September 2009 observations into a broader context. AWS wind data revealed a strong tendency toward downslope flow in the region regardless of season, as the majority (55%) of winds were from the west to northwesterly directions. Most winds observed at the site were less than 20 m s−1, but 83% of the stronger winds were associated with downslope flow. Of 15 strong wind events (greater than 20 m s−1 for more than 10 h) evaluated during the cyclone analysis period, 100% occurred in the presence of a cyclone in the adjacent Ross Sea. Winter experienced the greatest number of strong wind events (68%), and summer had the least (4%). Most temperatures were between −15° and −25°C, with temperatures influenced by wind fluctuations. The cyclone analysis revealed that 64% of systems were comma shaped, and most cyclones (84%) within the Ross Sea were mesocyclones. A comparison of AWS data for Septembers 1993–2007 and September 2009 showed more strong wind events during 2009, while the cyclone analysis revealed a shift in cyclonic activity eastward. Reanalysis data comparing September 1993–2007 and September 2009 show an eastward shift in a deeper upper-level trough, indicating that September 2009 was an anomalous year.

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