Recent Acceleration of Arabian Sea Warming Induced by the Atlantic‐Western Pacific Trans‐basin Multidecadal Variability

2019 ◽  
Vol 46 (3) ◽  
pp. 1662-1671 ◽  
Author(s):  
Cheng Sun ◽  
Jianping Li ◽  
Fred Kucharski ◽  
In‐Sik Kang ◽  
Fei‐Fei Jin ◽  
...  
2019 ◽  
Vol 54 (3-4) ◽  
pp. 1295-1313
Author(s):  
Yidan Xu ◽  
Jianping Li ◽  
Cheng Sun ◽  
Xiaopei Lin ◽  
Hailong Liu ◽  
...  

AbstractThe global mean surface air temperature (GMST) shows multidecadal variability over the period of 1910–2013, with an increasing trend. This study quantifies the contribution of hemispheric surface air temperature (SAT) variations and individual ocean sea surface temperature (SST) changes to the GMST multidecadal variability for 1910–2013. At the hemispheric scale, both the Goddard Institute for Space Studies (GISS) observations and the Community Earth System Model (CESM) Community Atmosphere Model 5.3 (CAM5.3) simulation indicate that the Northern Hemisphere (NH) favors the GMST multidecadal trend during periods of accelerated warming (1910–1945, 1975–1998) and cooling (1940–1975, 2001–2013), whereas the Southern Hemisphere (SH) slows the intensity of both warming and cooling processes. The contribution of the NH SAT variation to the GMST multidecadal trend is higher than that of the SH. We conduct six experiments with different ocean SST forcing, and find that all the oceans make positive contributions to the GMST multidecadal trend during rapid warming periods. However, only the Indian, North Atlantic, and western Pacific oceans make positive contributions to the GMST multidecadal trend between 1940 and 1975, whereas only the tropical Pacific and the North Pacific SSTs contribute to the GMST multidecadal trend between 2001 and 2013. The North Atlantic and western Pacific oceans have important impacts on modulating the GMST multidecadal trend across the entire 20th century. Each ocean makes different contributions to the SAT multidecadal trend of different continents during different periods.


2021 ◽  
Author(s):  
Xiaoshan Sun ◽  
Renguang Wu

AbstractThis study investigates the spatial scale dependence of relationship between turbulent surface heat flux (SHF) and sea surface temperature (SST) variations in the mid-latitude frontal zones, subtropical gyres, and tropical Indo-western Pacific region in winter and summer with daily observational data. A comparison of the SHF and SST/SST tendency correlation between 1° and 4° spatial scale displays a decrease of the positive SHF–SST correlation and an increase of the negative SHF–SST tendency correlation as the spatial scale increases in all the above regions. The lead–lag SHF and SST/SST tendency correlation at different spatial scales illustrates an obvious transition from the oceanic forcing to the atmospheric forcing in the western boundary currents (WBCs) and the Agulhas Return Current (ARC) in both winter and summer. The transition length scale is smaller in summer than in winter, around 2.6°–4.5° in winter and around 0.8°–1.3° in summer based on the OAFlux data. In the subtropical gyres and tropical Indo-western Pacific region, atmospheric forcing dominates up to 10° spatial scale with the magnitude of forcing increasing with the spatial scale in both winter and summer except for the Arabian Sea in summer. The Arabian Sea distinguishes from the other tropical regions in that the SST forcing dominates up to more than 10° spatial scale in summer with the magnitude of forcing decreasing slowly with the spatial scale increase.


2020 ◽  
Vol 50 (4) ◽  
pp. 1087-1115 ◽  
Author(s):  
Joseph M. D’Addezio ◽  
Gregg A. Jacobs ◽  
Max Yaremchuk ◽  
Innocent Souopgui

AbstractWe analyze high-resolution (1 km) simulations of the western Pacific, Gulf of Mexico, and Arabian Sea to understand submesoscale eddy dynamics. A mask based on the Okubo–Weiss parameter isolates small-scale eddies, and we further classify those with |ζ/f| ≥ 1 as being submesoscale eddies. Cyclonic submesoscale eddies exhibit a vertical depth structure in which temperature anomalies from the large-scale background are negative. Peak density anomalies associated with cyclonic submesoscale eddies are found at a depth approximately twice the mixed layer depth (MLD). Within anticyclonic submesoscale eddies, temperature anomalies are positive and have peak density anomalies at the MLD. The depth–depth covariance structure for the cyclonic and anticyclonic submesoscale eddies have maxima over a shallow region near the surface and weak off diagonal elements. The observed vertical structure suggests that submesoscale eddies have a shallower depth profile and smaller vertical correlation scales when compared to the mesoscale phenomenon. We test a two-dimensional submesoscale eddy dynamical balance. Compared to a geostrophic dynamical balance using only pressure gradient and Coriolis force, including velocity tendency and advection produces lower errors by about 20%. In regions with strong tides and associated internal waves (western Pacific and Arabian Sea), using the mixed layer integrated small-scale steric height within the dynamical equations produces the lowest magnitude errors. In areas with weak tides (Gulf of Mexico), using small-scale sea surface height (SSH) produces the lowest magnitude errors. Recovering a submesoscale eddy with the correct magnitude and rotation requires integration of small-scale specific volume anomalies well below the mixed layer.


Zootaxa ◽  
2020 ◽  
Vol 4819 (2) ◽  
pp. 364-374
Author(s):  
ALEC B. M. MOORE ◽  
PETER R. LAST ◽  
GAVIN J.P. NAYLOR

A new stingray, Hemitrygon yemenensis sp. nov., is described from old preserved material collected on the Arabian Sea coast of eastern Yemen. Consistent with other members of the genus, H. yemenensis sp. nov. is a small dasyatid (males mature at ~22 cm disc width), but it is the only Hemitrygon known to occur outside the western Pacific and eastern Indian Oceans. Hemitrygon yemenensis sp. nov. most closely resembles H. bennetti, but H. yemenensis is separable based on several characters including a longer and more narrowly pointed snout, shorter tail, and a longer disc and head. Hemitrygon yemenensis is unknown to science beyond the two type specimens collected nearly 120 years ago.


2011 ◽  
Vol 24 (12) ◽  
pp. 2949-2962 ◽  
Author(s):  
Anantha Aiyyer ◽  
Chris Thorncroft

Abstract Spatiotemporal patterns of tropics-wide vertical shear variability are extracted after separating a 58-yr data record into high-frequency (HF, periods of 1.5–8 yr) and low-frequency (LF, periods greater than 8 yr) components. The HF vertical shear variability is dominated by circulation anomalies associated with the El Niño–Southern Oscillation (ENSO). The LF variability is primarily contained in two multidecadal patterns and a near-decadal pattern. The multidecadal modes are strongest within the tropical Atlantic and are correlated with Sahel precipitation and interhemispheric sea surface temperature (SST) anomalies. The results suggest that the multidecadal variability of vertical shear over the Atlantic is linked to atmospheric circulation anomalies forced by the variability in Sahel precipitation. The decadal mode is strongest within the central Pacific and is correlated with Pacific decadal oscillation (PDO)-like SST anomalies. The circulation associated with this anomalous shear pattern appears to be consistent with the atmospheric response to the PDO-related diabatic heating anomaly over the central Pacific. The relationship between vertical shear and seasonal tropical cyclone activity, as defined by the accumulated cyclone energy (ACE), is examined for the Atlantic, eastern Pacific, and western Pacific Oceans. The results show that global modes of vertical shear and seasonal average ACE are not consistently related in all three regions. It is only in the Atlantic Ocean that seasonal ACE is most consistently limited by vertical shear. This calls into question the utility of vertical shear as an independent predictor of seasonal tropical cyclone activity, particularly over the western Pacific Ocean.


Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
N Ebrahimi ◽  
M Moein ◽  
S Moein

2014 ◽  
Vol 73 (1) ◽  
pp. 51-67 ◽  
Author(s):  
A Jain ◽  
M Bandekar ◽  
J Gomes ◽  
D Shenoy ◽  
RM Meena ◽  
...  

2012 ◽  
Vol 2 (6) ◽  
pp. 271-272
Author(s):  
Sudhir Pal Singh Rawat ◽  
◽  
Dr. Arnab Das ◽  
Dr. H.G.Virani Dr. H.G.Virani ◽  
Dr. Y.K.Somayajulu Dr. Y.K.Somayajulu

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