scholarly journals Subsurface heat channel drove sea surface warming in the high‐latitude North Atlantic during the Mid‐Pleistocene Transition

2021 ◽  
Author(s):  
M. Carolina A. Catunda ◽  
André Bahr ◽  
Stefanie Kaboth‐Bahr ◽  
Xu Zhang ◽  
Nicholas P. Foukal ◽  
...  
Keyword(s):  
North Atlantic ◽  
High Latitude ◽  
Sea Surface ◽  
Surface Warming

Resolving Contrasting Regional Rainfall Responses to El Niño over Tropical Africa

2016 ◽  
Vol 29 (4) ◽  
pp. 1461-1476 ◽  
Author(s):  
Pradipta Parhi ◽  
Alessandra Giannini ◽  
Pierre Gentine ◽  
Upmanu Lall
Keyword(s):  
Water Vapor ◽  
Indian Ocean ◽  
North Atlantic ◽  
El Niño ◽  
Rainy Season ◽  
El Nino ◽  
Sea Surface ◽  
Eastern Africa ◽  
Surface Warming ◽  
Western Sahel

Abstract The evolution of El Niño can be separated into two phases—namely, growth and mature—depending on whether the regional sea surface temperature has adjusted to the tropospheric warming in the remote tropics (tropical regions away from the central and eastern tropical Pacific Ocean). The western Sahel’s main rainy season (July–September) is shown to be affected by the growth phase of El Niño through (i) a lack of neighboring North Atlantic sea surface warming, (ii) an absence of an atmospheric column water vapor anomaly over the North Atlantic and western Sahel, and (iii) higher atmospheric vertical stability over the western Sahel, resulting in the suppression of mean seasonal rainfall as well as number of wet days. In contrast, the short rainy season (October–December) of tropical eastern Africa is impacted by the mature phase of El Niño through (i) neighboring Indian Ocean sea surface warming, (ii) positive column water vapor anomalies over the Indian Ocean and tropical eastern Africa, and (iii) higher atmospheric vertical instability over tropical eastern Africa, leading to an increase in the mean seasonal rainfall as well as in the number of wet days. While the modulation of the frequency of wet days and seasonal mean accumulation is statistically significant, daily rainfall intensity (for days with rainfall > 1 mm day−1), whether mean, median, or extreme, does not show a significant response in either region. Hence, the variability in seasonal mean rainfall that can be attributed to the El Niño–Southern Oscillation phenomenon in both regions is likely due to changes in the frequency of rainfall.

A reconstruction of sea surface warming in the northern North Atlantic during MIS 3 ice-rafting events

2010 ◽  
Vol 29 (15-16) ◽  
pp. 1791-1800 ◽  
Author(s):  
Lukas Jonkers ◽  
Matthias Moros ◽  
Maarten A. Prins ◽  
Trond Dokken ◽  
Carin Andersson Dahl ◽  
...  
Keyword(s):  
North Atlantic ◽  
Sea Surface ◽  
Surface Warming ◽  
Mis 3 ◽  
Ice Rafting

Why Does Global Warming Weaken the Gulf Stream but Intensify the Kuroshio?

2019 ◽  
Vol 32 (21) ◽  
pp. 7437-7451 ◽  
Author(s):  
Changlin Chen ◽  
Guihua Wang ◽  
Shang-Ping Xie ◽  
Wei Liu
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
North Atlantic ◽  
North Pacific ◽  
Gulf Stream ◽  
Sea Surface ◽  
Surface Warming ◽  
The North ◽  
The Kuroshio ◽  
The North Pacific

ABSTRACT The Kuroshio and Gulf Stream, the subtropical western boundary currents of the North Pacific and North Atlantic, play important roles in meridional heat transport and ocean–atmosphere interaction processes. Using a multimodel ensemble of future projections, we show that a warmer climate intensifies the upper-layer Kuroshio, in contrast to the previously documented slowdown of the Gulf Stream. Our ocean general circulation model experiments show that the sea surface warming, not the wind change, is the dominant forcing that causes the upper-layer Kuroshio to intensify in a warming climate. Forced by the sea surface warming, ocean subduction and advection processes result in a stronger warming to the east of the Kuroshio than to the west, which increases the isopycnal slope across the Kuroshio, and hence intensifies the Kuroshio. In the North Atlantic, the Gulf Stream slows down as part of the Atlantic meridional overturning circulation (AMOC) response to surface salinity decrease in the high latitudes under global warming. The distinct responses of the Gulf Stream and Kuroshio to climate warming are accompanied by different regional patterns of sea level rise. While the sea level rise accelerates along the northeastern U.S. coast as the AMOC weakens, it remains close to the global mean rate along the East Asian coast as the intensifying Kuroshio is associated with the enhanced sea level rise offshore in the North Pacific subtropical gyre.

scholarly journals Dominant effect of relative tropical Atlantic warming on major hurricane occurrence

Science ◽  
2018 ◽  
Vol 362 (6416) ◽  
pp. 794-799 ◽  
Author(s):  
H. Murakami ◽  
E. Levin ◽  
T. L. Delworth ◽  
R. Gudgel ◽  
P.-C. Hsu
Keyword(s):  
North Atlantic ◽  
Warming Trend ◽  
Sea Surface ◽  
Global Ocean ◽  
Tropical Atlantic ◽  
Surface Warming ◽  
Key Factor ◽  
Resolution Model ◽  
Major Hurricane ◽  
Hurricane Activity

Here we explore factors potentially linked to the enhanced major hurricane activity in the Atlantic Ocean during 2017. Using a suite of high-resolution model experiments, we show that the increase in 2017 major hurricanes was not primarily caused by La Niña conditions in the Pacific Ocean but rather triggered mainly by pronounced warm sea surface conditions in the tropical North Atlantic. Further, we superimpose a similar pattern of North Atlantic surface warming on data for long-term increasing sea surface temperature (a product of increases in greenhouse gas concentrations and decreases in aerosols) to show that this warming trend will likely lead to even higher numbers of major hurricanes in the future. The key factor controlling Atlantic major hurricane activity appears to be the degree to which the tropical Atlantic warms relative to the rest of the global ocean.

scholarly journals Trends in cyclones in the high‐latitude North Atlantic during 1979–2016

2019 ◽  
Vol 146 (727) ◽  
pp. 762-779 ◽  
Author(s):  
S. Wickström ◽  
M. O. Jonassen ◽  
T. Vihma ◽  
P. Uotila
Keyword(s):  
North Atlantic ◽  
High Latitude

scholarly journals A spatiotemporal reconstruction of sea-surface temperatures in the North Atlantic during Dansgaard–Oeschger events 5–8

2018 ◽  
Vol 14 (6) ◽  
pp. 901-922 ◽  
Author(s):  
Mari F. Jensen ◽  
Aleksi Nummelin ◽  
Søren B. Nielsen ◽  
Henrik Sadatzki ◽  
Evangeline Sessford ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
North Atlantic ◽  
General Circulation ◽  
Sea Surface ◽  
Reconstruction Method ◽  
Sea Surface Temperatures ◽  
Proxy Data ◽  
Surface Temperatures ◽  
Temperature Reconstructions

Abstract. Here, we establish a spatiotemporal evolution of the sea-surface temperatures in the North Atlantic over Dansgaard–Oeschger (DO) events 5–8 (approximately 30–40 kyr) using the proxy surrogate reconstruction method. Proxy data suggest a large variability in North Atlantic sea-surface temperatures during the DO events of the last glacial period. However, proxy data availability is limited and cannot provide a full spatial picture of the oceanic changes. Therefore, we combine fully coupled, general circulation model simulations with planktic foraminifera based sea-surface temperature reconstructions to obtain a broader spatial picture of the ocean state during DO events 5–8. The resulting spatial sea-surface temperature patterns agree over a number of different general circulation models and simulations. We find that sea-surface temperature variability over the DO events is characterized by colder conditions in the subpolar North Atlantic during stadials than during interstadials, and the variability is linked to changes in the Atlantic Meridional Overturning circulation and in the sea-ice cover. Forced simulations are needed to capture the strength of the temperature variability and to reconstruct the variability in other climatic records not directly linked to the sea-surface temperature reconstructions. This is the first time the proxy surrogate reconstruction method has been applied to oceanic variability during MIS3. Our results remain robust, even when age uncertainties of proxy data, the number of available temperature reconstructions, and different climate models are considered. However, we also highlight shortcomings of the methodology that should be addressed in future implementations.

scholarly journals Space-Time Sea Surface pCO2 Estimation in the North Atlantic Based on CatBoost

2021 ◽  
Vol 13 (14) ◽  
pp. 2805
Author(s):  
Hongwei Sun ◽  
Junyu He ◽  
Yihui Chen ◽  
Boyu Zhao
Keyword(s):  
North Atlantic ◽  
Function Analysis ◽  
Biological Activities ◽  
Mixed Layer Depth ◽  
Sea Surface ◽  
Coefficient Of Determination ◽  
Mean Bias Error ◽  
Bias Error ◽  
The North ◽  
The North Atlantic

Sea surface partial pressure of CO2 (pCO2) is a critical parameter in the quantification of air–sea CO2 flux, which plays an important role in calculating the global carbon budget and ocean acidification. In this study, we used chlorophyll-a concentration (Chla), sea surface temperature (SST), dissolved and particulate detrital matter absorption coefficient (Adg), the diffuse attenuation coefficient of downwelling irradiance at 490 nm (Kd) and mixed layer depth (MLD) as input data for retrieving the sea surface pCO2 in the North Atlantic based on a remote sensing empirical approach with the Categorical Boosting (CatBoost) algorithm. The results showed that the root mean square error (RMSE) is 8.25 μatm, the mean bias error (MAE) is 4.92 μatm and the coefficient of determination (R2) can reach 0.946 in the validation set. Subsequently, the proposed algorithm was applied to the sea surface pCO2 in the North Atlantic Ocean during 2003–2020. It can be found that the North Atlantic sea surface pCO2 has a clear trend with latitude variations and have strong seasonal changes. Furthermore, through variance analysis and EOF (empirical orthogonal function) analysis, the sea surface pCO2 in this area is mainly affected by sea temperature and salinity, while it can also be influenced by biological activities in some sub-regions.

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