Co-oscillation of a fjord basin’s circulation with decade-long oceanographic, hydrologic, and climatic regimes: Puget Sound 1916-'87 [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Oceanographic, hydrologic, and climatic data collected during 1916-'87 in Puget Sound's Main Basin (~200 m x 5 km x 100 km) and approaches oscillate at low frequency between two regimes (I, II). The oscillation accounts for a large fraction of the interannual variability (41-75%) and the zero crossings between regimes span approximately a decade. ... The transition between regimes is accompanied by substantial changes in the horizontal pressure and density fields between the Pacific coast and the mixing zones leading to the Basin, as well as within the Basin itself.

Climatic effects on flood frequency: an example from southern Arizona

EXTRACT (SEE PDF FOR FULL ABSTRACT): After 1960, the Santa Cruz River at Tucson, Arizona, an ephemeral stream normally dominated by summer floods, experienced an apparent increased frequency of flooding coincident with an increased percentage of annual floods occurring in fall and winter. This shift reflects large-scale and low-frequency changes in the eastern Pacific Ocean, in part associated with El Niño-Southern Oscillation (ENSO) phenomena. ... Questions are raised about the validity of standard methods of flood-frequency analysis to estimate regulatory and designed floods.

El Niño-Southern Oscillation (ENSO) phenomena and forest fires in the southwestern United States

Fire statistics (area burned) and fire-scar chronologies from tree rings show reduced fire activity during El Niño-Southern Oscillation (ENSO) in forests of Arizona and New Mexico. This relationship probably stems from increased fuel moisture after a wet winter and spring, but also could involve climatic controls on lightning activity at the onset of the monsoon season.

Inter-decadal climate variability in the Southern Hemisphere: evidence from Tasmanian tree rings over the past three millennia

EXTRACT (SEE PDF FOR FULL ABSTRACT): The characterization of inter-decadal climate variability in the Southern Hemisphere is severely constrained by the shortness of the instrumental climate records. To help relieve this constraint, we have developed and analyzed a reconstruction of warm-season (November-April) temperatures from Tasmanian tree rings that now extends back to 800 BC. A detailed analysis of this reconstruction in the time and frequency domains indicates that much of the inter-decadal variability is principally confined to four frequency bands with mean periods of 31, 57, 77, and 200 years. ... In so doing, we show how a future greenhouse warming signal over Tasmania could be masked by these natural oscillations unless they are taken into account.

Household consumption pattern and buying behavior for fish in an area Mymensingh, Bangladesh

The study was conducted on 238 households in Bangladesh Agricultural University campus and its adjoining areas in Mymensingh. The household were divided into four groups based on their per capita income. Monthly expenditure on fish, income elasticity of demand and marginal propensity to consume were calculated. 'Weighted average' method was used to study the level of preference for fish by sex and age groups and frequency of its purchase. The per capita monthly expenditure on fish of overall households was found to be Tk. 178.83. The consumption increased considerably between and among the income groups rising from Tk. 63.95 in the lowest income group to Tk. 249.11 in the highest income group. Based on income elasticity the proportion of income spent on fish was found to be greater than the proportion of increase in income for lower middle and upper middle income groups. However, percent expenditure decreased from 8.15 in lowest to 5.49 in the highest income group. Female members between 20 and 40yrs had the highest preference for fish in general followed by male members of above 40 yrs. Children (0 to 8 yrs), on the other band, had the least preference for fish, Sing and Magur (Catfishes) were the most preferred fish species for each age and sex group. Rui, a carp, was the single most purchased fish while the introduced exotic fishes were the least bought. Freshness was found to be the most important factor followed by the appearance and taste perception that positively affected the fish purchase.

Population dynamics of killifish Aphanius dispar (Ruppel) in Sandspit area off Karachi

Growth and mortality parameters of Aphanius dispar a cyprinoides generally observed in the catches of near shore area were estimated from the length frequency data collected from Sandspit area of Karachi, using LFSA. The von Bertalanffy growth parameters were estimated as Loo=71.73 mm & K=L35/yr for Male Aphanius dispar and Loo=70.66 & K=l.41 for female. Total Mortality coefficient (Z) was estimated using Length converted catch curve which is equal to 2.12/yr, for male and for female 2.19/yr. Natural mortality (M) was estimated by Pauly's empirical formula: M=l.64/yr (male) and 1.70/yr (female). The species also displayed two cohorts a year.