scholarly journals The Combined QBO and ENSO Influence on Tropical Cyclone Activity over the North Atlantic Ocean

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1588
Author(s):  
Alejandro Jaramillo ◽  
Christian Dominguez ◽  
Graciela Raga ◽  
Arturo I. Quintanar

The Quasi-Biennal Oscillation (QBO) and the El Niño-Southern Oscillation (ENSO) largely modulate the zonal wind in the tropics. Previous studies showed that QBO phases produce changes in deep convection through an increase/decrease in the tropopause height over the tropics and subtropics. This study investigates the combined effects of QBO and ENSO on tropical cyclone activity by modulating tropopause height. We found that tropopause height increases over the Gulf of Mexico, the Caribbean region, and the Western North Atlantic Ocean during La Niña + QBOW, allowing deeper tropical convection to develop over those regions. As a consequence, TC activity over those regions is not only increased in number but also enhanced in intensity. Conversely, during El Niño + QBOE, most deep tropical convection is inhibited over those same regions due to the decrease in tropopause height over the subtropics. We conclude that QBO effects on TCs and deep convection should be studied in combination with ENSO. Additional comparative studies using long record data at high vertical resolution are needed to fully understand to what extent QBO interacts with ENSO in the lower tropical stratosphere and upper tropical troposphere.

2010 ◽  
Vol 02 (04) ◽  
pp. 463-508 ◽  
Author(s):  
T. YAN ◽  
L. J. PIETRAFESA ◽  
D. A. DICKEY ◽  
S. BAO ◽  
N. E. HUANG ◽  
...  

Atmospheric and oceanic climate factors and conditions play a crucial role in modulating seasonal/annual tropical cyclone activity in the North Atlantic Ocean Basin. In the following, correlations between North Atlantic tropical cyclone activity including frequency of occurrence and pathways are explored, with special emphasis on hurricanes. The value of two-dimensional and three-dimensional data sets representing climate patterns is investigated. Finally, the diagnostic study of historical tropical cyclone and hurricane temporal and spatial variability and relationships to climate factors lead to a statistical prognostic forecast, made in April, 2010, of the 2010 tropical cyclone and hurricane season. This forecast is tested both retrospectively and presently and is shown to be quite accurate. Knowing the probability of the frequency of occurrence, i.e. the numbers of named storms to form in general and the number of hurricanes (NHs) that are likely to form, is important for many societal sectors. However, the reliable forecasts of probable pathways of predicted events, specifically the likely NH land falls along the coastlines of the United States, should have great potential value to emergency planners, the insurance industry, and the public. The forecast provided in this study makes such a prognostication. As the 2010 hurricane season has progressed, an update of the goodness of the forecast is shown to be quite accurate in numbers of named events, hurricanes, major hurricanes (MHs), and landfalls. The mathematical and statistical methodology used in this study, which could be coupled to next generation "empirical modal decomposition," suggests that this may signal a new era in the future of tropical cyclone forecasting, including the reliable prognostication of numbers of events, intensities of events, and the pathways of those events. The ability to reliably predict the probability and location of land falls of these destructive events would be very powerful indeed.


2018 ◽  
Author(s):  
Manon Tonnard ◽  
Hélène Planquette ◽  
Andrew R. Bowie ◽  
Pier van der Merwe ◽  
Morgane Gallinari ◽  
...  

Abstract. Dissolved Fe (DFe) samples from the GEOVIDE voyage (GEOTRACES GA01, May–June 2014) in the North Atlantic Ocean were analysed using a SeaFAST-picoTM coupled to an Element XR HR-ICP-MS and provided interesting insights on the Fe sources in this area. Overall, DFe concentrations ranged from 0.09 ± 0.01 nmol L−1 to 7.8 ± 0.5 nmol L−1. Elevated DFe concentrations were observed above the Iberian, Greenland and Newfoundland Margins likely due to riverine inputs from the Tagus River, meteoric water inputs and sedimentary inputs. Air-sea interactions were suspected to be responsible for the increase in DFe concentrations within subsurface waters of the Irminger Sea due to deep convection occurring the previous winter, that provided iron-to-nitrate ratios sufficient to sustain phytoplankton growth. Increasing DFe concentrations along the flow path of the Labrador Sea Water were attributed to sedimentary inputs from the Newfoundland Margin. Bottom waters from the Irminger Sea displayed high DFe concentrations likely due to the dissolution of Fe-rich particles from the Denmark Strait Overflow Water and the Polar Intermediate Water. Finally, the nepheloid layers were found to act as either a source or a sink of DFe depending on the nature of particles.


2014 ◽  
Vol 27 (21) ◽  
pp. 8055-8069 ◽  
Author(s):  
Timothy E. LaRow ◽  
Lydia Stefanova ◽  
Chana Seitz

Abstract The effects on early and late twenty-first-century North Atlantic tropical cyclone statistics resulting from imposing the patterns of maximum/minimum phases of the observed Atlantic multidecadal oscillation (AMO) onto projected sea surface temperatures (SSTs) from two climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) are examined using a 100-km resolution global atmospheric model. By imposing the observed maximum positive and negative phases of the AMO onto two CMIP5 SST projections from the representative concentration pathway (RCP) 4.5 scenario, this study places bounds on future North Atlantic tropical cyclone activity during the early (2020–39) and late (2080–99) twenty-first century. Averaging over both time periods and both AMO phases, the mean named tropical cyclones (NTCs) count increases by 35% when compared to simulations using observed SSTs from 1982 to 2009. The positive AMO simulations produce approximately a 68% increase in mean NTC count, while the negative AMO simulations are statistically indistinguishable from the mean NTC count determined from the 1995–2009 simulations—a period of observed positive AMO phase. Examination of the tropical cyclone track densities shows a statistically significant increase in the tracks along the East Coast of the United States in the future simulations compared to the models’ 1982–2009 climate simulations. The increase occurs regardless of AMO phase, although the negative phase produces higher track densities. The maximum wind speeds increase by 6%, in agreement with other climate change studies. Finally, the NTC-related precipitation is found to increase (approximately by 13%) compared to the 1982–2009 simulations.


2008 ◽  
Vol 2 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Kjetil Våge ◽  
Robert S. Pickart ◽  
Virginie Thierry ◽  
Gilles Reverdin ◽  
Craig M. Lee ◽  
...  

2017 ◽  
Vol 44 (3) ◽  
pp. 1439-1447 ◽  
Author(s):  
A. Piron ◽  
V. Thierry ◽  
H. Mercier ◽  
G. Caniaux

2010 ◽  
Vol 23 (21) ◽  
pp. 5810-5825 ◽  
Author(s):  
Suzana J. Camargo ◽  
Adam H. Sobel

Abstract The statistical relationship between the quasi-biennial oscillation (QBO) and tropical cyclone (TC) activity is explored, with a focus on the North Atlantic. Although there is a statistically significant relationship between the QBO and TCs in the Atlantic from the 1950s to the 1980s, as found by previous studies, that relationship is no longer present in later years. Several possibilities for this change are explored, including the interaction with ENSO, volcanoes, QBO decadal variability, and interactions with solar forcing. None provides a completely satisfying explanation. In the other basins, the relationship is weaker than in the Atlantic, even in the early record.


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