Applied introduction of main procedures of spatio-temporal analysis of the bio-optical component of chlorophyll-a in the southern Caspian Sea

Abstract The wind and current are two physical forces that strongly influence the biogeochemistry in coastal waters. Both of these forces could enhance the Chlorophyll-a (Chl-a) concentration through the upwelling process. Here we examine the contribution of the wind and current to the Chl-a variability in the South Java upwelling system in terms of wind stress and bottom stress respectively using satellite-derived and reanalysis data from 2002 to 2017. Ten longitudinally cells were used for further analysis. A long-term Chl-a shows a strong longitudinal gradient of Chl-a with the highest value on the shelf. Seasonal and Inter-annual Chl-a analysis shows the evidence of the monsoonal winds and other forcing effects relevant to the previous studies. Wind stress (τwx ) has a strong seasonal variation which is upwelling- favorable during southeast monsoon coincide with higher Chl-a suggesting wind as the main forces during that time, while bottom stress (τbx ) has more complicated variations, but it’s seen that τwx mostly downwelling-favorable or eastward circulations. There were about 39.92- 52.94% of positive Chl anomalous events generated by the combination of upwelling- favourable τwx and downwelling-favorable τbx , higher than other combinations. In terms of Oceanographic drivers, the wind has a higher effect on enhancing Chl-a through a negative correlation. τwx leads the Chl-a anomalies by about 15 – 24 days with a correlation coefficient of more than 0.6.

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Seasonal Variation of Chlorophyll and Carotenoids in Leaves of Hancornia speciosa in Three Central Areas of the Cerrado of the State of Tocantins, Brazil

Journal of Agricultural Science ◽

10.5539/jas.v10n3p344 ◽

2018 ◽

Vol 10 (3) ◽

pp. 344

Author(s):

Rafael J. de Oliveira ◽

José Expedito C. da Silva ◽

Davi B. das Chagas

Keyword(s):

Seasonal Variation ◽

Chlorophyll A ◽

Temporal Analysis ◽

Chlorophyll B ◽

Total Chlorophyll ◽

Dry Period ◽

Rainy Period ◽

Significant Difference ◽

Spatio Temporal ◽

Hancornia Speciosa

This study aimed to evaluate the seasonal variation in concentrations of chlorophyll a, b, total chlorophyll and carotenoids in leaves of Hancornia speciosa, Gomes, during the periods of the year, relating them to the main phenological events, periods (rainy, dry and transitions) and populations evaluated. The survey was performed in three sites and the spatio-temporal analysis divided into four periods (rainy, rainy-drytransition, dry and dry-rainy transition), with 10 replicates (matrix plants). The data were collected in average intervals of 33 days from October 2014 to April 2017. The extraction and calculation of the chlorophyll and carotenoid contents of the leaves were expressed in mg/g DM, according to the equations of Arnon (1949) and Lichtenthaler (1987). There was a significant difference between the periods and sites analyzed for all pigments and their relationships. There was a greater amount of chlorophyll a than chlorophyll b; this difference was greater in the dry period. In the rainy period, we found a greater amount of total chlorophyll, carotenoids and total chlorophyll/carotenoid ratio. The behavior for the species follows that already observed for deciduous plants, closely related to water availability.

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