Phytoplankton Scales of Variability in the California Current System: 1. Interannual and Cross-Shelf Variability

In the California Current System, strong mesoscale variability associated with eddies and meanders of the coastal jet play an important role in the biological productivity of the area. To assess the dominant timescales of variability, a wavelet analysis is applied to almost nine years (October 1997 to July 2006) of 1-km-resolution, 5-day-averaged, Sea-viewing Wide Field-of-view Sensor (SeaWiFS) chlorophyll a (chl a) concentration data. The dominant periods of chlorophyll variance, and how these change in time, are quantified as a function of distance offshore. The maximum variance in chlorophyll occurs with a period of similar to 100-200 days. A seasonal cycle in the timing of peak variance is revealed, with maxima in spring/summer close to shore (20 km) and in autumn/winter 200 km offshore. Interannual variability in the magnitude of chlorophyll variance shows maxima in 1999, 2001, 2002, and 2005. There is a very strong out-of-phase correspondence between the time series of chlorophyll variance and the Pacific Decadal Oscillation (PDO) index. We hypothesize that positive PDO conditions, which reflect weak winds and poor upwelling conditions, result in reduced mesoscale variability in the coastal region, and a subsequent decrease in chlorophyll variance. Although the chlorophyll variance responds to basin-scale forcing, chlorophyll biomass does not necessarily correspond to the phase of the PDO, suggesting that it is influenced more by local-scale processes. The mesoscale variability in the system may be as important as the chl a biomass in determining the potential productivity of higher trophic levels.

The Effects of Social Anxiety on the Development of Romantic Relationships in Adolescence

The present study sought to investigate the ways in which social anxiety impedes the development of romantic relationships across adolescence. Previous research has demonstrated a natural progression for romantic associations during adolescence in which teens transition from same- to mixed-sex peer groups, and finally to dyadic relationships with romantic partners (Connolly, Furman, Konarski, 2000; Dunphy, 1963). This model of development was the basis for the present investigation. Social anxiety was examined in terms of how it impacted affiliations at the same- and mixed sex peer group levels, and ultimately the formation of romantic relationships. This project involved administering a series of questionnaires and rating scales to students enrolled in the 9th through \2l grades. Participants included 457 adolescents (196 males, 261 females) recruited from public high schools in the state of Maine. The questionnaires assessed social anxiety, peer acceptance, heterosocial competence, gender composition of adolescent peer networks, dating history, and relationship quality with significant others in the adolescent's life. Higher levels of social anxiety were expected to be associated with impairment at each of these three levels. Given the proposed developmental progression, the effects of anxiety were theorized to be most pronounced within the older cohort of adolescents. Moreover, gender was expected to affect the pattern of results. Social anxiety is most prevalent among females (LaGreca, 1998; LaGreca & Lopez, 1998), who are also thought to progress along the proposed developmental trajectory more quickly than their male counterparts. Therefore, social anxiety was expected to impact the females to a greater degree at each of the three levels. Correlation coefficients, multivariate analyses of variance, and regression analyses were used to evaluate the data. Overall, despite some discrepant findings, the results supported the hypotheses. Social anxiety was affiliated with problems in the same-sex peer group, the mixed-sex clique, and, for older adolescents, romantic relationships. As expected, social anxiety affected females the most at each level. There seems to be a maladaptive pathway that socially anxious teens are following that is markedly different than their non-anxious counterparts.