The shoaling of nutrient-enriched subsurface waters as a mechanism to sustain primary productivity off Central Baja California during El Niño winters

Abstract. This study aims at establishing past variations of the main oceanographic and climatic features in the Central Chilean coast, using recent sedimentary records of a transitional semi-arid ecosystem susceptible to environmental forcing conditions. Coquimbo (30° S) region is characterized by dry summers and short rainfall periods during winter. The relatively wet-winter climate results from the interactions between the southern westerly winds and the South Pacific Anticyclone (SPA); in summer, the SPA moves southwards while in winter it returns to the north, allowing the passage of storm fronts. This semi-arid zone is strongly affected by variations associated with El Niño-Southern Oscillation (ENSO), caused by seasonal latitudinal changes in the SPA that produce high variability and precipitation in Chilean mid-latitudes. Sediment cores were retrieved in two bays, Guanaqueros and Tongoy, for geochemical analyses including: sensitive redox trace elements, biogenic opal, total organic carbon (TOC), diatoms, stable isotopes of organic carbon and nitrogen. The results suggest a main dry phase of high primary productivity concomitant with high fluxes of organic compounds to the bottom and suboxic-anoxic conditions in the sediments. This period reached a maximum at cal BC ~ 4500, followed by a continuous increase in wet conditions, low primary productivity and a more oxygenated environment towards the present, being remarkably stronger in the last 2000 years. We suggest that this might be associated with greater El Niño frequencies or similar conditions that increase precipitation, concomitantly with the introduction of oxygenated waters to coastal zones by the propagation of equatorial origin waves.

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ESTIMACIÓN DE LA PRODUCTIVIDAD PRIMARIA DURANTE OTOÑO-INVIERNO EN LA BAHÍA DE LA PAZ, B.C.S., MÉXICO

CICIMAR Oceánides ◽

10.37543/oceanides.v23i1-2.44 ◽

2008 ◽

Vol 23 (1-2) ◽

pp. 45

Author(s):

G. Verdugo-Díaz ◽

M. O. Albáñez-Lucero ◽

R. Cervantes Duarte

Keyword(s):

Chlorophyll A ◽

Primary Productivity ◽

El Niño ◽

Gulf Of California ◽

El Nino ◽

Cold Season ◽

Maximum Temperature ◽

La Paz ◽

Average Maximum ◽

Average Maximum Temperature

Se analizó la variabilidad de la productividad primaria en Bahía de La Paz, durante noviembre de 1997 y 2000, enero de 1998 y febrero de 2001. Se identificó Agua del Golfo de California en mayor proporción; Agua Superficial Ecuatorial y Agua Subsuperficial Subtropical. En noviembre de 1997 se registró el valor promedio máximo de temperatura (~27.62 °C) y en febrero el valor mínimo (~19.16 °C). El índice de Simpson (Ö) indicó que durante noviembre de 1997 (~286.6 J m-3) la columna de agua presentó mayor estratificación, mientras que en noviembre de 1998 (~60.4 J m-3) y febrero de 2001 (~94.5 J m-3) se encontró mezclada. En noviembre de 1997 se registraron bajos valores de nitratos (~1.52 µM), nitritos (~0.04 µM) y clorofila a (~0.44 mg Cla m-3). En febrero de 2001 se registraron valores mayores de nitratos (~7.46 µM), nitritos (~0.76 µM) y clorofila a (~1.07 mg Cla m-3). La productividad primaria superficial e integrada presentaron sus promedios máximos en noviembre de 2000 (~5.09 mg C m-3 h-1 y 75.54. mg m-2 h-1) y mínimos en noviembre de 1997 (~2.93 mg C m-3 h-1 y ~55.29 mg m-2 h-1), respectivamente. De acuerdo a investigaciones anteriores, los valores reportados de productividad son característicos de la temporada fría de la bahía con excepción de noviembre de 1997, que presentó influencia de El Niño. Primary productivity stimation during autumm-winter in Bahía de La Paz, B.C.S., Mexico We analyzed the variability of primary productivity in Bahía de La Paz during November 1997 and 2000, January 1998 and February 2001. Water was identified in the Gulf of California in higher proportion; Surface Water and Water Subsuperficial Equatorial Subtropical. In November 1997 we saw the average maximum temperature (~ 27.62 ° C) in February and the lowest value (~ 19.16 ° C). The index of Simpson (Ö) indicated that during November 1997 (~ 286.6 J-3 m) column of water with greater stratification, while in November 1998 (~ 60.4 m J-3) and February 2001 (~ 94.5 J m-3) was mixed. In November 1997 there were low values of nitrate (~ 1.52 µM), nitrites (~ 0.04 µM) and chlorophyll a (Cla ~ 0.44 mg m-3). In February 2001, there were larger values of nitrate (~ 7.46 µM), nitrites (~ 0.76 µM) and chlorophyll a (Cla ~ 1.07 mg m-3). The primary productivity and integrated surface presented their highest averages in November 2000 (C ~ 5.09 mg m-3 h-1 and 75.54. mg m-2 h-1) and minimum in November 1997 (C ~ 2.93 mg m-3 h-1 and ~ 55.29 mg m-2 h-1), respectively. According to previous research, reported productivity values are characteristic of the cold season of the bay with exception of November 1997, which showed influence of El Niño.

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Efecto de la condición ENSO en la frecuencia e intensidad de los eventos de lluvia en la península de Baja California (1998-2012)

Revista Mexicana de Ciencias Agrícolas ◽

10.29312/remexca.v0i10.1034 ◽

2018 ◽

pp. 1923-1937

Author(s):

Víctor Manuel Rodríguez-Moreno ◽

José Ariel Ruíz-Corral ◽

Guillermo Medina-García ◽

José Saúl Padilla-Ramírez ◽

Thomas Gunter Kretzschmar

Keyword(s):

El Niño ◽

Baja California ◽

El Nino ◽

La Niña ◽

La Nina

La influencia de la condición ENSO en la frecuencia e intensidaddeloseventosdelluviaenlaprovinciafisiográfica Península de Baja California, se analizó conforme una serie histórica de 15 años de registros diarios de lluvia TRMM. La base de datos fue estratificada en siete categorías a intervalos de 5 mm; se consideraron los eventos extremos como >30 mm día-1. Se obtuvieron indicios de que la condición ENSO inf luye en la frecuencia e intensidad de los eventos de lluvia. Se observó una cierta simetría entre las condiciones ENSO- Neutro y ENSO-La Niña Débil, y ENSO-El Niño Débil con ENSO-La Niña Moderada, que ocasionan un aumento en la frecuencia de los eventos de lluvia y una disminución en los mismos, respectivamente. En cuanto a la intensidad de la lluvia, otras relaciones simétricas fueron entre la condición ENSO-Neutro y ENSO-El Niño Débil y asimétricas entre las condiciones ENSO-La Niña Moderada y ENSO-La Niña Fuerte. La intensidad de las lluvias fue mayor durante las condiciones Neutro y El Niño Débil y menor durante las condiciones La Niña Moderada y La Niña Fuerte. Estos resultados son importantes debido a que los cambios en la frecuencia e intensidad de los eventos extremos son la consecuencia más dramática de la variabilidad climática y que afectan directamente la funcionalidad de los ecosistemas, su conformación paisajística y las fronteras espaciales del uso del suelo. La relación entre la frecuencia de ocurrencia y la intensidad de los eventos extremos, la condición ENSO y la presencia de huracanes está aún bajo investigación.

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Assessing the distribution and variation characteristics of marine primary productivity in the coastal marine area of Vietnam South Centre

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/964/1/012011 ◽

2022 ◽

Vol 964 (1) ◽

pp. 012011

Author(s):

Nguyen Trinh Duc Hieu ◽

Nguyen Huu Huan ◽

Tran Thi Van ◽

Nguyen Phuong Lien

Keyword(s):

Primary Productivity ◽

El Niño ◽

El Nino ◽

Southern Oscillation ◽

Monsoon Season ◽

Marine Ecosystem ◽

Correlation Coefficients ◽

Northeast Monsoon ◽

Marine Area ◽

Coastal Marine

Abstract Primary production (PP) of phytoplankton plays an essential role in food web dynamics, biogeochemical cycles and marine fisheries. It is used as one of the basic information for evaluating marine ecosystems. In this paper, monthly composite PP data on a 4 km x 4 km grid for the period 2003-2020 was used to evaluate the distributional characteristics of PP in the coastal marine area of Vietnam South Centre. The statistical results show that the climatological average of PP in 18 years reached 449.2 mgC/m2/day, ranged from 272.1 to 14,205.4 mgC/m2/day. The PP has seasonal and spatial variations. In time, the lowest value of PP was in spring, and the highest was in winter; in space, PP tended to decrease from shore to offshore, PP was higher in coastal areas than in the open sea areas. During the northeast monsoon season, PP increased by more than 1000 mgC/m2/day in the coastal area. Meanwhile, in the southwest monsoon season, due to the ecological influence of the upwelling phenomenon, PP increased with a value greater than 1500 mgC/m2/day, distributed along the coastline of Ninh Thuan - Binh Thuan. Primary productivity positively correlated with chlorophyll content but negatively correlated with sea surface temperature with correlation coefficients of 0.9 and -0.6, respectively. There was a weak correlation between PP and ONI with correlation coefficients of -0.23. The temporal-spatial variation of PP was affected by the ENSO (El Niño-Southern Oscillation) phenomenon, the positive phase of ENSO (El Niño conditions) corresponded to lower PP, and the negative phase of ENSO (La Niña conditions) corresponded to higher PP. The research results from this paper can be used as a reference in marine ecosystem management.

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