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 A spatio-temporal reconstruction of sea-surface temperatures in the North Atlantic during Dansgaard-Oeschger events 5–8

2017 ◽  
pp. 1-36
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 ◽  
Sea Surface Temperatures ◽  
Proxy Data ◽  
The North ◽  
Surface Temperatures ◽  
Temperature Reconstructions

Here we establish a spatio-temporal evolution of the sea-surface temperatures in the North Atlantic over Dansgaard Oeschger (DO) events 5–8 (c. 30–40 ka) 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. Our results are robust to uncertainties in the age models of the proxy data, the number of available temperature reconstructions, and over a range of climate models.

Cooling and freshening of the eastern equatorial Pacific over the last 2000 years

2020 ◽  
Author(s):  
Gerald Rustic ◽  
Athanasios Koutavas ◽  
Thomas Marchitto
Keyword(s):  
Stable Isotope ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Equatorial Pacific ◽  
Sea Surface ◽  
Eastern Pacific ◽  
Ice Age ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
Eastern Equatorial Pacific

<p>Sea surface temperatures in the eastern equatorial Pacific exert powerful influence on the climate beyond the tropics through strong atmosphere-ocean coupling. Records of eastern Pacific sea surface temperatures are of vital importance for identifying the linkages between short-term climate variability and long-term climate trends. Here we reconstruct eastern equatorial Pacific sea surface temperature and salinity from paired trace metal and stable isotope analyses in foraminifera from a sediment core near the Galápagos Islands. Sea surface temperatures are correlated with reconstructed Northern and Southern hemisphere temperature records suggesting a common origin. We propose that this temperature signal originates in the extra-tropics and is transmitted to the eastern Pacific surface via its source waters. We find exceptions to this cooling during the Little Ice Age and during the last century, where notable sea surface temperature increases are observed. We calculate δ<sup>18</sup>O<sub>sw </sub>from paired stable isotope and trace element analyses and derive salinity, which reveals a significant trend toward fresher surface waters in the eastern equatorial Pacific. The overall trend toward cooler and fresher sea surface conditions is consistent with longer-term trends from both the Eastern and Western Pacific.</p>

scholarly journals Relationship between Holocene climate variations over southern Greenland and eastern Baffin Island and synoptic circulation pattern

2009 ◽  
Vol 5 (3) ◽  
pp. 347-359 ◽  
Author(s):  
B. Fréchette ◽  
A. de Vernal
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
North Atlantic ◽  
Surface Air Temperature ◽  
Sea Surface ◽  
Baffin Island ◽  
North Atlantic Current ◽  
Climate Trends ◽  
Temperature Reconstructions ◽  
Southwest Greenland

Abstract. Lake pollen records from southwest Greenland and eastern Baffin Island show strong regionalism in climate trends of the last 7000 cal years. July surface air temperature reconstructions from pollen indicate larger amplitude cooling in southwest Greenland (>3.0°C) than in eastern Baffin Island (<1.0°C). This west-east gradient in climate change is consistent with August sea-surface temperature reconstructions from dinocyst records that indicate decreasing temperature and/or strength of the North Atlantic Current to the east during the Holocene while the eastern Canadian margins under the Labrador Current influence display slight warming. Complementary to air and sea-surface temperature records, the lake pollen data led to reconstruct increased cloudiness in southern Greenland, which points to increasing cyclonic activity since 7000 cal years BP west of Greenland. Together, the terrestrial and marine records of the northwest North Atlantic therefore suggest a shift from a dominant NAO+ during the early-mid Holocene to dominant NAO- in the late Holocene.

scholarly journals Influence of Upwelling in the Southern Waters of Java on CO2 Concentration in Kototabang, Agam District West

2020 ◽  
Vol 5 (1) ◽  
pp. 8
Author(s):  
Martono Martono ◽  
Fanny Aditya Putri
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Chlorophyll A ◽  
Descriptive Analysis ◽  
Co2 Concentration ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Chlorophyll A Concentration ◽  
Surface Temperatures

<p>Absorption of atmospheric CO<sub>2</sub> by the sea through two processes, namely solubility pumps and biological pumps. This study aims to determine the effect of upwelling in the southern waters of Java on atmospheric CO<sub>2</sub> concentrations in Kototabang. The data used are in situ CO<sub>2</sub> concentration, sea surface temperature and chlorophyll-a concentration from 2004-2016. The method used was descriptive analysis. The results showed that upwelling that occurred during JJA-SON caused a decrease in sea surface temperature to 26.8 °C and 27.1 °C respectively, as well as an increase chlorophyll-a concentration to 2.03 mg/m<sup>3</sup> and 2.19 mg/m<sup>3</sup>. In both seasons CO<sub>2</sub> concentration in Kototabang dropped to 385.8 ppm and 385.4 ppm. Meanwhile, when there was no upwelling during DJF-MAM, sea surface temperatures rose to 28.8 °C and 29.0 °C, and chlorophyll-a concentration dropped to 0.32 mg/m<sup>3</sup> and 0.54 mg/m<sup>3</sup>. CO<sub>2</sub> concentration in DJF and MAM increased to 386.3 ppm and 386.5 ppm. Based on these results it is known that when upwelling occurs, CO<sub>2</sub> concentration decrease and vice versa.</p>

scholarly journals Holocene trends in the foraminifer record from the Norwegian Sea and the North Atlantic Ocean

2009 ◽  
Vol 5 (4) ◽  
pp. 2081-2113 ◽  
Author(s):  
C. Andersson ◽  
F. S. R. Pausata ◽  
E. Jansen ◽  
B. Risebrobakken ◽  
R. J. Telford
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Sea Surface ◽  
Norwegian Sea ◽  
The North ◽  
Temperature Reconstructions ◽  
The North Atlantic ◽  
Temperature Records

Abstract. The early to mid-Holocene thermal optimum is a well-known feature in a wide variety of paleoclimate archives from the Northern Hemisphere. Reconstructed summer temperature anomalies from across northern Europe show a clear maximum around 6 ka. For the marine realm, Holocene trends in sea-surface temperature reconstructions for the North Atlantic and Norwegian Sea do not exhibit a consistent pattern of early to mid-Holocene warmth. Sea-surface temperature records based on alkenones and diatoms generally show the existence of a warm early to mid-Holocene optimum. In contrast, several foraminifer and radiolarian based temperature records from the North Atlantic and Norwegian Sea show a cool mid-Holocene anomaly and a trend towards warmer temperatures in the late Holocene. In this paper, we revisit the foraminifer record from the Vøring Plateau in the Norwegian Sea. We also compare this record with published foraminifer based temperature reconstructions from the North Atlantic and with modelled (CCSM3) upper ocean temperatures. Model results indicate that while the seasonal summer warming of the sea-surface was stronger during the mid-Holocene, sub-surface depths experienced a cooling. This hydrographic setting can explain the discrepancies between the Holocene trends exhibited by phytoplankton and zooplankton based temperature proxy records.

scholarly journals The timescale and extent of thermal expansion of the global ocean due to climate change

Ocean Science ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 179-184 ◽  
Author(s):  
S. Marčelja
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Temperature Variation ◽  
Sea Level ◽  
Heat Content ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
The Past ◽  
Surface Temperatures

Abstract. With recently improved instrumental accuracy, the change in the heat content of the oceans and the corresponding contribution to the change of the sea level can be determined from in situ measurements of temperature variation with depth. Nevertheless, it would be favourable if the same changes could be evaluated from just the sea surface temperatures because the past record could then be reconstructed and future scenarios explored. Using a single column model we show that the average change in the heat content of the oceans and the corresponding contribution to a global change in the sea level can be evaluated from the past sea surface temperatures. The calculation is based on the time-dependent diffusion equation with the known fixed average upwelling velocity and eddy diffusivity, as determined from the steady-state limit. In this limit, the model reduces to the 1966 Munk profile of the potential temperature variation as a function of depth. There are no adjustable parameters in the calculation and the results are in good agreement with the estimates obtained from the in situ data. The method allows us to obtain relevant timescales and average temperature profiles. The evaluation of the thermosteric sea level change is extended back to the beginning of accurate sea surface temperature records. The changes in sea surface temperature from 1880 until the present time are estimated to have produced a thermosteric sea level rise of 35 mm. Application to future IPCC scenarios gives results similar to the average prediction of more complex climate models.

scholarly journals Studi Pendahuluan Variasi Suhu Permukaan Laut dan Sebaran Aerosol di Laut Sawu

2021 ◽  
Vol 1 (2) ◽  
pp. 9-15
Author(s):  
Ashari Wicaksono ◽  
Nike Ika Nuzula
Keyword(s):  
Numerical Model ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Low Temperatures ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
Aerosol Distribution ◽  
Preliminary Study

Research related to aerosols in Indonesia is still very minimal compared to sea surface temperature parameters and other oceanographic parameters. This study is a preliminary study that aims to determine the variation in aerosol distribution and its influence by variations in sea surface temperatures in the areas crossed by Arlindo, especially the savu sea. Savu sea surrounded by Flores islands (Sumba Regency, Kupang Regency, and Manggarai Regency) has a variation of SPL from 22 - 30 °C, where in the wetar strait, ombai strait, and sumba strait in the northwest part of sawu often occur low temperatures. While the value of aerosol spread is ranging from 0 - 0.3. Thus, a numerical model is needed that can help in analyzing the results that currently exist.

scholarly journals The timescale and extent of thermal expansion of the oceans due to climate change

2009 ◽  
Vol 6 (3) ◽  
pp. 2975-2992
Author(s):  
S. Marčelja
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Temperature Variation ◽  
Sea Level ◽  
Heat Content ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
The Past ◽  
Surface Temperatures

Abstract. With recently improved instrumental accuracy, the change in the heat content of the oceans and the corresponding contribution to the change of the sea level can be determined from in situ measurements of temperature variation with depth. Nevertheless, it would be favourable if the same changes could be evaluated from just the sea surface temperatures because the record could then be extended into the past and projected into the future. We show here that the average change in the heat content of the oceans and the corresponding contribution to a change in the sea level can be evaluated from the past sea surface temperatures. The calculation is based on the time-dependent diffusion equation with constant upwelling velocity and has no adjustable parameters. In the steady-state limit it recovers the well-known profile of the potential temperature variation as a function of depth. The results are in good agreement with the estimates obtained from the in situ data, even though most of the warming occurs in the upper 1000 m. The method allows us to obtain relevant timescales and average temperature profiles. The evaluation of the thermosteric sea level change is extended back to the beginning of accurate sea surface temperature records in 1880. The changes in sea surface temperature from 1880 until the present time led to a thermosteric sea level rise of 3 cm and to a commitment for a future rise of 5 cm.

scholarly journals Holocene trends in the foraminifer record from the Norwegian Sea and the North Atlantic Ocean

2010 ◽  
Vol 6 (2) ◽  
pp. 179-193 ◽  
Author(s):  
C. Andersson ◽  
F. S. R. Pausata ◽  
E. Jansen ◽  
B. Risebrobakken ◽  
R. J. Telford
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Sea Surface ◽  
Norwegian Sea ◽  
The North ◽  
Temperature Reconstructions ◽  
The North Atlantic ◽  
Temperature Records

Abstract. The early to mid-Holocene thermal optimum is a well-known feature in a wide variety of paleoclimate archives from the Northern Hemisphere. Reconstructed summer temperature anomalies from across northern Europe show a clear maximum around 6000 years before present (6 ka). For the marine realm, Holocene trends in sea-surface temperature reconstructions for the North Atlantic and Norwegian Sea do not exhibit a consistent pattern of early to mid-Holocene warmth. Sea-surface temperature records based on alkenones and diatoms generally show the existence of a warm early to mid-Holocene optimum. In contrast, several foraminifer and radiolarian based temperature records from the North Atlantic and Norwegian Sea show a cool mid-Holocene anomaly and a trend towards warmer temperatures in the late Holocene. In this paper, we revisit the foraminifer record from the Vøring Plateau in the Norwegian Sea. We also compare this record with published foraminifer based temperature reconstructions from the North Atlantic and with modelled (CCSM3) upper ocean temperatures. Model results indicate that while the seasonal summer warming of the sea-surface was stronger during the mid-Holocene, sub-surface depths experienced a cooling. This hydrographic setting can explain the discrepancies between the Holocene trends exhibited by phytoplankton and zooplankton based temperature proxy records.

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