How winds and river discharge affect circulation in a mesotidal estuary, San Francisco Bay, USA

Previous studies suggest importance of wind forcing on salt intrusion length and salt flux in river-dominated microtidal estuaries (with tidal range < 2 m). In this study, we investigate the role of wind forcing on salt intrusion in a mesotidal estuary, San Francisco Bay (SFB), with tidal ranges between 2 m and 4 m, through an open-source model of high transferability, the Semi-implicit Cross-scale Hydroscience Integrated System Model (SCHISM). Meanwhile, we investigate circulation and salinity variation of San Francisco Bay. The model’s performance in hydrodynamics at tidal, spring/neap and seasonal time scales is validated through model-observation comparisons. Through realistically forced and process-oriented experiments, we demonstrate that spring/neap tides can cause fortnightly variations in salinity and currents by modulating vertical mixing and stratification; and seasonal variability of circulation in North Bay is determined by change of river discharge and modified by winds, while in South Bay it is dominated by wind-driven flows. Furthermore, we revealed the role of wind on X2 (the distance from the Golden Gate Bridge to the 2-PSU isohaline at the bottom). The model results show that X2 is primarily influenced by river flow and proportional to river flow to the ¼ power. Meanwhile, wind plays a secondary role in modifying X2 by increasing X2 from 0 to 5 km during low discharge period, while spring/neap tide modulation on X2 is negligible but important for salt balance in sub-regions downstream of X2.

Differential Effects of Race/Ethnicity and Social Vulnerability on COVID-19 Positivity, Hospitalization, and Death in the San Francisco Bay Area

BACKGROUND: Higher COVID-19 incidence and morbidity have been amply documented for US Black and Hispanic populations but not as clearly for other racial and ethnic groups. Efforts to elucidate the mechanisms underlying racial health disparities can be confounded by the relationship between race/ethnicity and socioeconomic status. OBJECTIVE: Examine race/ethnicity and social vulnerability effects on COVID-19 outcomes in the San Francisco Bay Area, an ethnically and socioeconomically diverse region. DESIGN: Retrospective cohort study. SETTING: Geocoded patient records from the University of California, San Francisco Health system between January 1, 2020 to December 31, 2020. PATIENTS: Patients who underwent polymerase chain reaction testing for COVID-19. EXPOSURES: Race/ethnicity and Social Vulnerability Index (SVI). MAIN MEASURES: COVID-19 test frequency, positivity, hospitalization rates, and mortality. KEY RESULTS: Higher social vulnerability, but not race/ethnicity, was associated with less frequent testing yet a higher likelihood of testing positive. Asian hospitalization rates (11.5\%) were double that of White patients (5.4\%) and exceeded the rates for Black (9.3\%) and Hispanic (6.9\%) groups. A modest relationship between higher hospitalization rates and increasing social vulnerability was evident only for White individuals. The Hispanic group had the lowest mean age at death and thus highest years of expected life lost due to COVID-19. CONCLUSIONS: COVID-19 outcomes were not consistently explained by greater socioeconomic vulnerability. Asian individuals showed disproportionately high rates of hospitalization regardless of socioeconomic status. Study of the San Francisco Bay Area population not only provides valuable insights into the differential contributions of race/ethnicity and social determinants of health to COVID-19 outcomes but also emphasizes that all racial groups have experienced the toll of the pandemic, albeit in different ways and to varying degrees.

‘Don't educate them out of educating themselves’: A conversation with Al Wunder

Al Wunder's biography, in his own words: I had four lucky breaks that precipitated my becoming a teacher of improvised movement theatre. Between the ages of eight and fourteen I broke my right leg four different times. In 1962, I began modern dance classes with Alwin Nikolais as a physical therapy. His choreography and improvisation sections of class inspired me to teach and perform professionally. I spent eight years studying, teaching, choreographing, and performing with Nikolais.1970 saw me move to the San Francisco Bay area where I opened a dance studio teaching Nikolais dance technique and improvisation. In 1971, I joined forces with Terry Sendgraff and Ruth Zaporah creating The Berkeley Dance Theater &amp; Gymnasium. My focus was to create a way to teach dance technique through improvisation. I met my Australian wife, Lynden Nicholls, in 1981 when she came to study Motivity at Terry’s studio in Berkeley. In 1982, I moved to Melbourne, Australia where Lynden and I set up a dance studio. My focus changed from teaching dance technique improvisationally to teaching improvised movement theatre performance.Over the next thirty years I developed a pedagogy that inspired professional and non-professional performers to create improvised movement theatre pieces. In 2006, I self-published a book, The Wonder of Improvisation. In 2017, a documentary was made by Michelle Dunn, The Wonder of Improvisation. In 2021, a book was written by Hilary Elliott and published by Routledge, The Motional Improvisation of Al Wunder.

Factors associated with emerging multimodal transportation behavior in the San Francisco Bay Area

This paper identifies the influence of demographic, local transportation environment, and individual preferences for transportation attributes on multimodal transportation behavior in an urban environment with emergent transportation mode availability. Multimodality is the use of more than one mode of transportation during a given timeframe. Multimodality has been considered a key component of sustainable and efficient transportation systems, as this travel behavior can represent a shift away from personal vehicle use to more sustainable transportation modes, especially in urban environments with diverse transportation systems and emergent shared transportation alternatives (e.g., carsharing, ridehailing, bike sharing). However, it is unclear what factors contribute towards people being more likely to exhibit multimodal transportation behavior in modern urban environments. We assessed commuting behavior based on a survey administered in the San Francisco Bay Area according to whether residents commuted (i) exclusively by vehicle, (ii) by a mix of vehicle and non-vehicle modes, or (iii) exclusively by non-vehicle modes. A classification tree approach identified correlations between commuting classes and demographic variables, preferences for transportation attributes, and location-based information. The characterization of commuting styles could inform regional transportation policy and design that aims to reduce vehicle use by identifying the demographic, preference, and location-based considerations correlated with each commuting style.