Since heaving changes are so important, we compute isopycnal depth displacement (in σ0 space) as area average for SODA, ORAS4, ECDA, and EN4 for the North Atlantic as decadal averages referenced to the first common decade, 1961 1970.
In addition, this study uses satellite altimetry data to estimate variations in the Lake Chad water levels, and further employs relevant climate teleconnection indices (El-Niño Southern Oscillation-ENSO, Atlantic Multi-decadal Oscillation-AMO, and Atlantic Meridional Mode-AMM) to examine their links to the observed drought temporal patterns over the basin.
These cycles may be associated with the stratospheric Quasi-Biennial Oscillation (QBO), the El-Nino Southern Oscillation (ENSO); the sunspot cycles and the Atlantic Multi-Decadal Oscillation (AMO) sea surface temperature, respectively.
We hypothesized that temporal annual or seasonal changes in discharge could be explained by variations in extreme phases of the Atlantic Multi-decadal Oscillation (AMO index, SST: Sea Surface Temperature anomalies) and the North Atlantic Oscillation (NAO index, SLP: Sea-Level Pressure anomalies) up to three seasons in advance.
The variability may be rooted in (i) natural internal processes within the climate system, e.g., El Niño/La Niña or the multi-decadal Atlantic Oscillation (internal variability) or (ii) in natural or anthropogenic external influences (external variability), e.g., aerosol contents and the equivalent radiative forcing due to GHG emissions.
The utilization of newer acoustic Doppler methods are described, as well as the emerging field of geographic flow pattern analysis tied to large-scale temporal change in meteorological patterns (Atlantic Multidecadal Oscillation, Pacific Decadal Oscillation, and El Niño Southern Oscillation) that affect hydrographs on decadal or multidecadal intervals.
The individual and coupled impacts of the El Niño-Southern Niño-SouthernENSOscillation DENSOal Oscillation (Pacifictlantic MultiDecadal Oscillation (AMO), and North Atlantic Oscillation (NAO) on baseflow were quantified.
They found that a northward shift of the warm ocean current known as the Gulf Stream hit the New England coast at the same time that two decade-long ocean climate cycles, the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation, entered a warmer phase, turning the heat up even further.
In addition to ENSO, other global climate factors (such as the stratospheric Quasi-Biennial Oscillation, Pacific Decadal Oscillation (PDO), North Atlantic Oscillation, Arctic Oscillation, Antarctic Oscillation, the northern hemisphere oscillation, long-wave radiation equatorial Pacific, etc).
This study was conducted to establish the individual and coupled impacts of the El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO) on streamflow in the Apalachicola Chattahoochee Flint (ACF) river basin.
