Most recent 40 articles: Ocean2Climate - Global Warming
 |
France’s floating ocean laboratory is a hub of international Arctic research collaboration - Ocean2Climate - Global Warming (Sep 14) |
|
Sep 14 · As of 2024, there are currently 70 permanent research stations from 29 countries scattered around the continent of Antarctica conducting important scientific research to better understand the Earth system and its changes due to human activity. In the Arctic, however, there are no such permanent research stations because there is no land in the Arctic. Largely funded by the French government, the Tara Ocean Foundation is building a new drifting laboratory that can host up to 18 crew members and can be stationed permanently over the Arctic. This floating laboratory is equipped with a self-propulsion system. So, it can navigate around the Arctic if needed. It also has an underwater ... Read more ...
|
|
|
|
The Labrador Current restricts the Arctic freshwater-induced weakening of the AMOC - Ocean2Climate - Global Warming (Sep 8) |
|
Sep 8 · The Labrador Sea is one of the main regions where the surface Atlantic water loses its heat to the atmosphere (thus gets heavier) and sinks into the deep ocean, producing what’s known as deep ocean convection that mainly drives the Atlantic Meridional Ocean Circulation (AMOC). It is also characterized by the Labrador Current, a strong cyclonic ocean circulation (i.e., anticlockwise) along the lateral boundaries. The Labrador Sea is constantly affected by Arctic freshwater (in both solid and liquid forms) from the north through Davis Strait and from the east by the West Greenland Current. The future projected increase in the Arctic freshwater flux should increase the buoyancy ... Read more ...
|
|
|
|
Geomagnetic correction of submarine cable measurement revealed no significant trend in the Gulf Stream transport since 1982 - Ocean2Climate - Global Warming (Sep 6) |
|
Sep 6 · The Florida Current (FC) refers to the Gulf Stream across the Florida Straits between Florida and the Bahamas. Its volume transport has been measured continuously since 1982 using submarine cables across the Florida Straits at 27°N by NOAA’s Atlantic Oceanographic and Meteorological Laboratory (AOML). A previous study (Piecuch and Beal, 2023) reported that the FC volume transport declined significantly by -1.2 ± 1.0 Sv in the past 40 years (since 1982). This statistically significant trend was presented as “the first unequivocal evidence for a recent multidecadal decline in this climate-relevant component of ocean circulation”. In a new study published in Nature ... Read more ...
|
|
|
|
Increasing ocean stratification intensifies sea surface temperature variability - Ocean2Climate - Global Warming (Aug 17) |
|
Aug 17 · As the surface ocean warms and polar ice sheets melt due to increasing anthropogenic greenhouse gases in the atmosphere, near-surface ocean stratification is increasing almost everywhere. In tropical and subtropical oceans, in particular, enhanced near-surface stratification inhibits the mixing between warmer surface water and cooler subsurface water, leading to a shallower surface mixed layer. In the spring and summer seasons, heating from the sea surface has to be stored in a shallower mixed layer. This means that sea surface temperature (SST) has to increase to compensate for the smaller heat container:
?SST = QNET/(DMIX+?DMIX) – QNET/DMIX.
Here QNET is the net ... Read more ...
|
|
|
|
Human-induced ozone depletion has acted to enhance the La Niña-like SST trend pattern - Ocean2Climate - Global Warming (Jul 24) |
|
Jul 24 · During the satellite era (1979-present), the tropical Pacific Ocean has warmed significantly less than the other tropical oceans in response to increasing greenhouse gases (GHGs). This La Niña-like warming trend in observations is in disagreement with the El Niño-like warming trend projected by the Coupled Model Intercomparison Project (CMIP) models for both the 20th and 21st century. It remains unresolved whether the La Niña-like sea surface temperature (SST) trend pattern during the satellite era is driven by either external forcing or internal variability. A new study published in npj Climate and Atmospheric Science (Chung et al., 2024) conducted a comprehensive analysis of ... Read more ...
|
|
|
|
Quad-State Tornado Outbreaks promoted by a long-lived PNA - Ocean2Climate - Global Warming (Jun 16) |
|
Jun 16 · On December 10, 2021, one of the most destructive winter tornado outbreaks developed in northeastern Arkansas. This tornado outbreak, later coined as the Quad-State Tornado Outbreaks by the news media, struck portions of the Ohio Valley, including Missouri, Illinois, Tennessee, and Kentucky, from December 10 to 11, 2021. According to the National Oceanic and Atmospheric Administration (NOAA; https://www.weather.gov/pah/December-10th-11th-2021-Tornado), the Quad-State Tornado Outbreaks resulted in 66 confirmed tornadoes, 89 fatalities, 672 injuries, and at least $3.9 billion in property damages.
A new study published in npj Climate and Atmospheric Science (Kim et al., 2024) ... Read more ...
|
|
|
|
Sustained ocean measurements at 34°S crucial for estimating the distance to an AMOC collapse - Ocean2Climate - Global Warming (Feb 10, 2024) |
|
Feb 10, 2024 · The Atlantic Meridional Overturning Circulation (AMOC) transports warm and salty upper ocean water to the subpolar North Atlantic where the upper ocean releases some heat to the atmosphere. Due to the surface cooling and the high salinity (i.e., salty), the upper ocean water becomes heavier and thus sinks down to the deep ocean and then is carried southward. However, if the ice-melting from Greenland, due to anthropogenic global warming, exceeds a critical level and continues for a long period, the associated freshwater from the ice melting will make the upper ocean much lighter reducing the sinking of the upper ocean water and thus the AMOC. The weakened AMOC in turn transports ... Read more ...
|
|
|
|
Is the AMOC shutting down soon? - Ocean2Climate - Global Warming (Jul 26, 2023) |
|
Jul 26, 2023 · The Atlantic Meridional Overturning Circulation (AMOC) is the Atlantic component of the global ocean conveyor belt, which is a large-scale ocean circulation system that connects the Arctic, Atlantic, Indian, and Pacific Oceans via the Southern Ocean. Predominantly driven by deep convection in the high-latitude North Atlantic Ocean, the AMOC carries heat, salt, carbon, and other biogeochemical elements along its paths, redistributing them between hemispheres and across ocean basins, and thus is a crucial component of the global heat, salt, and carbon balances. For instance, the AMOC-related sinking in the high-latitude North Atlantic accounts for approximately 25% of the ... Read more ...
|
|
|
|
Atlantic deep water is now warm enough to melt previously stable Greenland glacier - Ocean2Climate - Global Warming (Apr 23, 2023) |
|
Apr 23, 2023 · Ice sheet melting from Greenland’s glaciers accounts for an increasing proportion of global sea level rise, losing ~330 billion tonnes of ice per year during 2006-2018 (compared to ~120 billion tonnes of ice per year during 1901-1990). A new study published in Nature Communications examined recent changes at K.I.V Steenstrups Nordre Bræ (66.53°N, 34.57°W), a glacier in the southeast Greenland Ice Sheet that exhibited long-term stability since the cartographic records started in the late 1930s. The study found that Steenstrups retreated ~7?km, thinned ~20%, and doubled in ice discharge between 2018 and 2021. Due to this unprecedented change, Steenstrups is now placed in the top ... Read more ...
|
|
|
|
The Global Ocean Conveyer Belt is Reshaping from the Southern Ocean - Ocean2Climate - Global Warming (Mar 15, 2023) |
|
Mar 15, 2023 · As the surface ocean warms and polar ice sheets melt due to increasing anthropogenic greenhouse gases in the atmosphere, near-surface stratification is increasing almost everywhere, including the major deep water formation regions in the high-latitude North Atlantic and around Antarctica. As a result, the global Meridional Overturning Circulation (MOC), also known as the global ocean conveyor belt, is expected to change significantly with a risk of disrupting the global redistribution of ocean properties that sustains marine ecosystems, carbon cycle, sea-level, climate, and extreme weather. A growing number of observational studies based on repeated hydrographic sections are ... Read more ...
|
|
|
|
Antarctic Bottom Water (AABW) export pathways across the Southern Ocean - Ocean2Climate - Global Warming (Feb 12, 2023) |
|
Feb 12, 2023 · The Antarctic Bottom Water (AABW) is the densest water mass of the global ocean that covers about 30 ~ 40% of the global ocean volume with temperatures ranging from -0.8 to 2°C and salinities from 34.6 to 34.7 psu. It forms around Antarctica and spreads into the Southern Ocean and then into the Atlantic, Indian, and Pacific Oceans, feeding the lower cell of the global meridional overturning circulation. Repeated hydrographic sections across the Southern Ocean showed that a significant contraction of the AABW volume occurred between the 1980s and 2000s with a freshening and warming of AABW observed throughout the Southern Ocean. This is consistent with the future projected slowdown ... Read more ...
|
|
|
|
Nearshore sea ice shield Antarctic ice shelves from the damaging impact of ocean waves - Ocean2Climate - Global Warming (May 10, 2022) |
|
May 10, 2022 · The Larsen ice shelves extend along the east coast of the Antarctic Peninsula over the northwest part of the Weddell Sea. From north to south, these segments are called the Larsen A, B, C, and D, bordered by Filchner–Ronne Ice Shelf south of the Weddell Sea. In 1995, the Larsen A ice shelf completely disintegrated, followed by a partial break-up of the Larsen B in 2002. The Larsen C ice shelf, the largest in the region and the fourth-largest ice shelf in Antarctica, has already shown a sign of break-up process starting around 2016 and 2017. The break-up of Larsen A and B ice shelves has been attributed to regional atmospheric warming and ocean-driven basal melting. In a new study ... Read more ...
|
|
|
|
North Atlantic zonal winds will shift northward and become more extreme in the future - Ocean2Climate - Global Warming (Apr 24, 2022) |
|
Apr 24, 2022 · The warming response of the upper atmosphere is much stronger in the tropics due to higher water vapor content and frequent deep tropical convection that maintains the atmosphere column well-mixed. As a result, the zonal jet strength, which is largely proportional to the meridional gradient of atmosphere temperature via “thermal wind relationship” is projected to increase in the future. However, due to the influence of Arctic amplification, the lower atmospheric zonal wind may not follow the increasing trend in the upper atmosphere. In fact, some studies argue that the polar jet may actually weaken in the future largely due to Arctic amplification increasing the ... Read more ...
|
|
|
|
Why climate models are unable to reproduce the observed Antarctic sea-ice expansion - Ocean2Climate - Global Warming (Apr 14, 2022) |
|
Apr 14, 2022 · Antarctic sea-ice has expanded over the period of continuous satellite monitoring, which seemingly contradicts ongoing global warming resulting from increasing concentrations of greenhouse gases. A variety of hypotheses have been proposed to explain the observed Antarctic sea-ice expansion and corresponding model–observation discrepancy, but the issue remains unresolved. In a new study published in Nature Climate Change, an international team of scientists led by Eui-Seok Chung at the Korea Polar Research Institute in South Korea shows that Antarctic sea ice has expanded since the late 1970s due to ocean surface cooling associated with multidecadal variability in the Southern Ocean ... Read more ...
|
|
|
|
Sea-ice retreat may invigorate the weakening Atlantic Meridional Overturning Circulation - Ocean2Climate - Global Warming (Apr 09, 2022) |
|
Apr 09, 2022 · Due to rapidly rising air temperature over the Arctic and subarctic regions, the ocean-to-air turbulent (i.e., sensible and latent) heat flux over the Greenland, Iceland, and Norwegian Seas (GINS) has diminished (i.e., less cooling of the surface ocean) steadily during the satellite period (i.e., since the 1970s). This may lead to a reduction of deep ocean convection in the region, and thus a slowdown of the Atlantic Meridional Overturning Circulation (AMOC). However, a new study published in Nature Communications argues exactly the opposite is happening. The study analyzed the ocean-to-air turbulence heat flux along the major boundary currents in the GINS (i.e., the East Greenland ... Read more ...
|
|
|
|
Future El Niño events will develop faster and persist longer - Ocean2Climate - Global Warming (Apr 08, 2022) |
|
Apr 08, 2022 · Previous studies based on the climate models participating in the Coupled Model Intercomparison Project (CMIP) have suggested an increase in the frequency of extreme El Niño events in the 21st Century in response to increasing greenhouse gases. Several studies have attributed these shifts in El Niño frequency and amplitude to the projected changes in the tropical Pacific mean state. In a new study published in Nature Communications, a team of scientists led by Hosmay Lopez at NOAA’s Atlantic Oceanographic and Meteorological Laboratory (AOML) investigated the seasonal evolution of El Niño events in the 21st century. The highlight of the major findings is that El Niño is ... Read more ...
|
|
|
|
New aircraft-based observations confirm the role of the Southern Ocean as a significant carbon sink - Ocean2Climate - Global Warming (Jan 03, 2022) |
|
Jan 03, 2022 · Ship-based CO2 flux estimates of the contemporary air-sea flux of CO2 showed that the Southern Ocean (south of 35oS) plays an important role as a significant carbon sink, with a net uptake at the rate of -0.8 ~ -1.0 Pg C/year (Takahashi et al., 2009; Landschützer et al., 2014) largely consistent with climate model-based estimates (e.g., Nevison et al., 2016). However, a recent study based on measurements from biogeochemical profiling floats estimated a much smaller net CO2 uptake rate of -0.08 Pg C/year for the Southern Ocean south of 35oS (Gray et al., 2018). This is because ship-based CO2 flux estimates underestimate CO2 outgassing in the poorly observed area around Antarctica ... Read more ...
|
|
|
|
Increasing river alkalinity slows ocean acidification in river-dominated ocean margins - Ocean2Climate - Global Warming (Dec 20, 2021) |
|
Dec 20, 2021 · Although ocean acidification (OA) is mainly driven by the ocean uptake of anthropogenic carbon dioxide from the atmosphere, multiple factors including changes in ocean temperature, biological processes, and river discharge influence its temporal progression. In a new paper accepted in the Geophysical Research Letters, a team of researchers from the Northern Gulf Institute of the Mississippi State University, and NOAA’s Atlantic Oceanographic and Meteorological Laboratory used a regional ocean-biogeochemical model to describe historical OA trends across the Gulf of Mexico (GoM) and identify the main drivers of its spatial variability. This study showed that changes in river ... Read more ...
|
|
|
|
Arctic Ocean is experiencing dramatic weight loss due to increasing freshwater storage - Ocean2Climate - Global Warming (Nov 30, 2021) |
|
Nov 30, 2021 · The freshwater cycle in the Earth System is a delicate balance between the net loss (i.e., evaporation > precipitation) in the warm tropical-subtropical oceans, the net gain (i.e., precipitation > evaporation) in the cold polar oceans, and the net poleward transport by the atmosphere. These processes maintain the tropical-subtropical oceans salty and the polar oceans fresh. In return, the ocean transports the freshwater equatorward, thereby closing the freshwater budget. A significant change in one of these components may result in a disruption in the global freshwater cycle, potentially leading to regional drought, flooding, and changes in the global ... Read more ...
|
|
|
|
Zooplanktons eat microplastics? Yes, they do and it may reshape the global ocean-biogeochemistry - Ocean2Climate - Global Warming (Apr 21, 2021) |
|
Apr 21, 2021 · Plastics are now widely distributed in the global ocean, serving as a new and serious contaminant for marine ecosystems. For instance, ingestion of small plastic detritus ( 0.1 µm ~ 5 mm), “microplastics” by fish, mussels and seabirds has been widely reported. A recent study (Cole et al., 2013) used fluorescence bioimaging techniques to show that microplastics are also ingested by a wide range of zooplanktons commonly found in the northeast Atlantic Ocean. Of course, there is no nutrient values in microplastics. So, the consumption of microplastics negatively impact zooplankton health. It also make them less hungry, and thus decreases their feeding of phytoplankton species such as ... Read more ...
|
|
|
|
Why does the Arctic temperature rise faster in the cold season? - Ocean2Climate - Global Warming (Dec 17, 2020) |
|
Dec 17, 2020 · The Arctic warming response to increasing greenhouse gas is substantially greater than the rest of the globe. It has been suggested that this phenomenon, commonly referred to as Arctic amplification, and its peak in boreal fall and winter result primarily from the so-called lapse-rate feedback, which is associated with the vertical structure of tropospheric warming, rather than from the sea-ice albedo feedback, which operates mainly in boreal summer. However, future climate model projections show consistently that an overall reduction of sea-ice in the Arctic region leads to a gradual weakening of Arctic amplification, thereby implying a key role for sea-ice albedo feedback. To ... Read more ...
|
|
|
|
Increasing influence of warm and salty Atlantic water on the cold season Arctic sea ice melting - Ocean2Climate - Global Warming (Sep 21, 2020) |
|
Sep 21, 2020 · The Arctic Ocean in the upper 100 - 200 m is typically characterized by a cold and fresh surface mixed layer and a layer of rapidly increasing salinity with depth, as known as halocline, separating the surface mixed layer from the warm and salty Atlantic water at depth. Due to large vertical density gradient and static stability of the halocline water, the surface mixed layer is mostly isolated from the influence of warm and salty intermediate-depth water originating from the North Atlantic Ocean. A new study published in the Journal of Climate analyzed mooring date in the eastern Eurasian Basin (77 - 80oN and 125 - 142oE) during 2003-2018 to report a gradual weakening of the ... Read more ...
|
|
|
|
What caused the abrupt reduction of the South Indian Ocean heat & sea level in 2014–2016 and the ensuing quick recovery? - Ocean2Climate - Global Warming (Sep 04, 2020) |
|
Sep 04, 2020 · A decade-long increase of the basin-wide sea level and heat content in the subtropical southern Indian Ocean (SIO) during 2004â??2013 ended abruptly, immediately following the onset of the strong 2014â??2016 El Niño. Interestingly, this unprecedented drop of the SIO heat quickly recovered during the weak 2017â??2018 La Niña. A study recently published in Science Advances used observations and model simulations to explore what caused the abrupt reduction and recovery of the SIO heat and sea level during 2014-2018.
The interannual-to-decadal variability of heat content and sea level in the SIO is strongly influenced by its connection with the Pacific and large-scale climatic ... Read more ...
|
|
|
|
Accelerated warming of the Antarctic interior caused by moist air intrusion from the Weddell Sea - Ocean2Climate - Global Warming (Jun 30, 2020) |
|
Jun 30, 2020 · In a new study published in Nature Climate Change, Clem and colleagues reported that the South Pole has experienced a record-high warming of 1.81?±?1.02°C during the last 30 years, three times larger than the global average. They used observational records to show that the recent warming of the South Pole, which started around 2000 following the downward shift of Interdecadal Pacific Oscillation (IPO), is largely caused by the increased transport of warm and moist air from the Weddell Sea to the Antarctic interior. They further used a series of climate model simulations to suggest that the recent increase in sea surface temperatures in the western tropical Pacific, which is directly ... Read more ...
|
|
|
|
Compensating change in the Indo-Pacific MOC in response to the Atlantic MOC slowdown - Ocean2Climate - Global Warming (Jun 25, 2020) |
|
Jun 25, 2020 · The climate model simulations forced with increasing anthropogenic greenhouse gases consistently project a robust decline of the Atlantic Meridional Overturning Circulation (MOC) and a strengthening of the Southern Hemisphere westerly winds, which may in turn result in an increase in the Southern Ocean MOC. In a research article recently accepted in the Journal of Physical Oceanography, a team of scientists from California Institute of Technology and Scripps Institution of Oceanography carried out a series of ocean and climate model experiments to show that the future declines of the Atlantic MOC and associated northward ocean heat transport may be compensated by the slowdown of the ... Read more ...
|
|
|
|
While the warming of northern hemisphere oceans almost stalled, the southern hemisphere oceans are heating up - Ocean to Climate - Ocean2Climate - Global Warming (Apr 25, 2020) |
|
Apr 25, 2020 · Observations from Argo floats and satellite shows that the rate of global ocean warming during 2005-2015 is largely consistent with the climate simulations under the increasing greenhouse gas concentration. However, during that period, the southern hemisphere oceans have absorbed up to 98% of the net global ocean heat gain, while the warming of northern hemisphere oceans almost stalled. Some studies suggested that this asymmetric warming of the global ocean is due to natural decadal variability. Others suggested that the higher concentrations of anthropogenic aerosols in the northern hemisphere caused the radiative cooling of the northern hemisphere. A study recently published in ... Read more ...
|
|
|
|
Future Arctic and Antarctic sea-ice losses slow down the subtropical Pacific shallow overturning cell and enhance the tropical warming - Ocean to Climate - Ocean2Climate - Global Warming (Apr 20, 2020) |
|
Apr 20, 2020 · Under the high emission scenario for the future (RCP 8.5), a nearly ice-free Arctic Ocean (i.e., sea-ice extent less than 10-6 km2 for at least five consecutive years) in northern summer is likely before 2050. A decrease in Antarctic sea-ice extent is also expected during the 21st century, but at a slower rate with large uncertainty. However, it is not entirely clear how the tropical atmosphere and ocean respond to the future Arctic and Antarctic sea-ice losses. A study recently published in Nature Geoscience (England et al., 2020) investigated this question by performing a series of fully coupled climate model experiments with two sets of sea-ice concentration map, one for the ... Read more ...
|
|
|