Knowing how incredible our deep seas are, famous French freediver Guillaume Nery is showcasing not one but three Philippine dive sites in a 12-minute video that compiles the most jaw-dropping underwater locations around the world. Some of the most amazing parts of the video include the limestone formations under Barracuda Lake in Coron, Palawan (2:16), an underwater shot in Coron filmed using an upside-down camera trick (5:50), and shots of Davao del Norte’s Sama-Bajau people, who can hunt underwater for as long as 13 minutes at depths of around 200 feet (6:14 mark). Filming started in April 2017 when Nery, along with his wife-slash-videographer Julie Gautier and photographer Franck Seguin, flew to some of the world’s under-the-radar dive spots.
They also filmed the Yonaguni Monument off the coast of Japan (0:44); the frozen Sonnanen Lake in Finland (3:59); and Cenote Angelita in Yucatán, Mexico (4:41). Freedivers hold their breath and go underwater for as long as they can without equipment.
Nery, who has broken the freediving world record four times, can dive to 125 meters (410 feet) below sea level.
Lowest Paris agreement target may temporarily be surpassed for first time between now and 2023
Global warming could temporarily hit 1.5C above pre-industrial levels for the first time between now and 2023, according to a long-term forecast by the Met Office.
Meteorologists said there was a 10% chance of a year in which the average temperature rise exceeds 1.5C, which is the lowest of the two Paris agreement targets set for the end of the century.
Until now, the hottest year on record was 2016, when the planet warmed 1.11C above pre-industrial levels, but the long-term trend is upward.
Man-made greenhouse gases in the atmosphere are adding 0.2C of warming each decade but the incline of temperature charts is jagged due to natural variation: hotter El Niño years zig above the average, while cooler La Ninã years zag below.
In the five-year forecast released on Wednesday, the Met Office highlights the first possibility of a natural El Niño combining with global warming to exceed the 1.5C mark.
Dr Doug Smith, Met Office research fellow, said: “A run of temperatures of 1C or above would increase the risk of a temporary excursion above the threshold of 1.5C above pre-industrial levels.
Predictions now suggest around a 10% chance of at least one year between 2019 and 2023 temporarily exceeding 1.5C.”
Climatologists stressed this did not mean the world had broken the Paris agreement 80 years ahead of schedule because international temperature targets are based on 30-year averages.
“Exceeding 1.5C in one given year does not mean that the 1.5C goal has been breached and can be redirected towards the bin,” said Joeri Rogelj, a lecturer at the Grantham Institute.
“The noise in the annual temperatures should not distract from the long-term trend.”
Although it would be an outlier, scientists said the first appearance in their long-term forecasts of such a “temporary excursion” was worrying, particularly for regions that are usually hard hit by extreme weather related to El Niño.
This includes western Australia, South America, south and west Africa, and the Indian monsoon belt.
NASA: the Global temperature anomalies from 1880 to 2017
They also noted that the probability of 1.5C years would steadily increase unless emissions were rapidly scaled back.
“It’s a warning that we’re getting close to that level,” Prof Adam Scaife, the head of long-range prediction at the Met Office, told the Guardian.
“We’re not saying there is a current risk of breaching the Paris agreement.
What we are saying is that for the first time, we are seeing a chance of a temporary rise of 1.5C due to a combination of global warming and natural climate variation.”
The Met Office said previous results had demonstrated the accuracy of such “decadal reports”, which cover the ground between short-term weather forecasts and long-range climate models.
Since 2014, the world has experienced the four hottest years since records began in 1850, but these highs are likely to be exceeded soon.
From now until 2023, the Met has 90% confidence that mean annual temperatures will range between 1.03C and 1.57C above pre-industrial levels.
The recent United Nations Intergovernmental Panel on Climate Change report on warming of 1.5C, highlighted the calamitous difference even a fraction of a degree above could make to coral reefs, Arctic ecosystems and hundreds of millions of lives.
Starting now, the report said emissions would have to be cut by 45% by 2030 to have any chance of holding to that level.
“Breaching 1.5C of global warming does indeed mean that we failed to limit warming to that ‘safe’ level, but not that our understanding of a safe level of climate change has suddenly changed and climate change should go unchecked,” said Rogelj, who was was a coordinating lead author on the UN report.
“Every tenth of a degree matters. So if 1.5C of global warming would be exceeded for whatever reason, this would be a call for steeper emissions reductions.”
NOAA’s Office of Coast Survey recently announced plans to change the U.S.
Army Corps of Engineers (USACE) maintained channel depth values on raster nautical chart products, which include paper nautical charts and the corresponding digital raster navigational charts (NOAA RNC®).
Minimum depths (also called controlling depths) are collected during periodic USACE sonar surveys of channels.
In the past, these depths were provided on raster charts, but controlling depths will now be replaced with the original channel design dredging depths used by the USACE (called project depths).
Standardizing depth presentation on these products will improve data consistency and overall safety.
Implementation begins in early 2019.
NOAA’s suite of electronic navigational charts (NOAA ENC®) are not affected by these changes.
Mariners are encouraged to use NOAA ENCs for critical safety information as these products are typically updated up to one month ahead of raster products.
Why the change?
The USACE makes the depth information from recent surveys publicly available on their website before NOAA nautical products are updated and published.
NOAA prioritizes making updates to ENC over RNC products.
This often results in RNC products not accurately reflecting the most current controlling depth values (as represented on NOAA ENC and the USACE website).
To eliminate inconsistencies among controlling depths, NOAA will only show project depths on raster chart products in the future.
The Initial implementation of this change will focus on deep draft shipping channels where the primary product used for navigation is the ENC. How will mariners be notified?
NOAA first publicized the concept of charting project depths in the National Charting Plan released in February 2017.
As the changes are made on individual charts, NOAA will include a note on each chart directing mariners to review the USACE website and use NOAA ENC to access the latest controlling depths.
Additionally, a statement drafted jointly by Coast Survey and the U.S.
Coast Guard (shown below) is being published weekly in the Coast Guard’s Local Notice to Mariners
NOAA recommends that mariners take advantage of the most recent chart updates by using the NOAA Electronic Navigational Chart (ENC) for navigation in U.S. waters. ENCs provide the most up to date information, whereas paper and raster nautical chart updates may be up to one month behind the corresponding ENC coverage. Over the next few years, mariners will see continued improvement in the extent and detail of ENC coverage, while there will be a reduction in RNC and paper chart coverage and service. ENCs will include routine changes between editions that are not published through notices to mariners. One significant change to the RNC and paper charts will be the removal of controlling (minimum) depth information from many maintained channels. Controlling channel depths will still be provided on ENCs.Comments or concerns can be addressed through ASSIST, NOAA’s Nautical Inquiry and Comment System. https://www.nauticalcharts.noaa.gov/customer-service/assist/
Project depths and controlling depths defined
Federally maintained channels are broken into a series of individually named sections called “reaches.” There are two different depths associated with each reach that are reported by the USACE, the project depth and the controlling depth.
Project depths are the original design dredging depths of a channel reach constructed by the USACE.
They may or may not be maintained by dredging after completion of the channel.
In other words, the actual depth of the channel may be shoaler than the project depth (for example, Reach B in image below).
Controlling depths, or minimum depths, are the least depths within the limits of a channel reach.
These depths are updated with each new USACE survey.
Minimum depths restrict the safe use of a channel to ships with drafts less than the minimum.
Example of a federally maintained channel with a project depth of 30 feet.
Reach A has a controlling depth of 32 feet and Reach B has a controlling depth of 28 feet.
Displaying project depths on raster charts
Controlling depths are depicted on raster chart products by channel tabulations, depth legends, and hydrography (individual depth soundings).
Here are a few examples of how depiction of channel depths will change on raster charts:
Channel tabulation to project depth legend:
Depth legend to project depth legend:
Hydrography to project depth legend:
Controlling depth channel tabulation to project tabulation:
Project Depth Note:
The following note will be added to raster charts as controlling depths are replaced with project depths:
PROJECT DEPTHS
Channel legends and tabulations, where indicated, reflect the U.S. Army Corps of Engineers (USACE) project depths. The channel may be significantly shoaler, particularly at the edges. For detailed channel information and minimum depths as reported by USACE, use NOAA Electronic Navigational Charts. USACE surveys and channel condition reports are available at http://navigation.usace.army.mil/Survey/Hydro.
The change from showing – often outdated – controlling depths to showing channel project depths on raster nautical chart products, such as paper nautical charts and RNCs, will provide greater clarity and safety for mariners.
The project depths shown on raster charts will give users an idea of the original channel design dimensions.
The up-to-date controlling (minimum) depths provided on NOAA ENCs and on the USACE website (referenced on raster chart products) will give users the latest information on the safe depth in which ships may transit through federally maintained channels.
Comments or concerns about these changes can be addressed through NOAA ASSIST.
Publicly available multibeam data included in the Global Multi-Resolution Topography Synthesis covers only about 8 percent of the seafloor, (unshaded areas), although coverage is higher over continental margins and plate boundaries.
Credit: image from the Global Multi-Resolution Topography Synthesis,
For creating the most comprehensive global map of the ocean floor, Dr.David Sandwell received the Charles A. Whitten Medal, sponsored by the American Geophysical Union (AGU).
Sandwell, a geophysicist at Scripps Institution of Oceanography, accepted the award at the AGU Fall Meeting in December 2018.
Named after scientist Charles A. Whitten, the medal is given to honor "outstanding achievement in research on the form and dynamics of the Earth and planets."
Since the 1990s, sponsored by the Office of Naval Research (ONR), Sandwell has combined satellite data with acoustic depth measurements to develop a detailed, accurate map of the sea floor--painting a vivid tapestry of the deepest, least explored parts of the ocean.
The map catalogues thousands of previously unidentified underwater mountains, trenches, physical undersea connections between South America and Africa, and extinct ridges that spread the sea floor in the Gulf of Mexico.
"Dr. Sandwell's groundbreaking work provides the first high-resolution map of the ocean floor," said Dr. Tom Drake, head of ONR's Ocean Battlespace and Expeditionary Access Department.
"This has opened new research areas for oceanography, marine geology and geophysics--critical topics for the U.S. Navy."
About 8 percent of the seafloor has been mapped to 100-meter resolution like this.
Source: GeoMapApp
Sandwell's work relies on satellite altimetry (radar) to measure small bumps and dips on the ocean surface, which point to large-scale features on the ocean floor.
For example, undersea mountains are huge enough to exert gravitational pulls that gather water in a bump on the sea surface.
In contrast, massive cracks and rifts on the ocean floor have less gravitational attraction, resulting in a dip on the surface.
For utmost accuracy, Sandwell blends satellite measurements with traditional sonar soundings from manned research ships.
This enables him to compare the topography of the sea surface with that of the sea floor and form a complete map of the bottom.
Sandwell created multiple versions of his map over the last two decades.
He unveiled the first in 1997, based on marine gravitational data gathered by the Navy's GEOSAT Earth-observation satellite.
In 2014, he improved the original map by adding data from additional satellites operated by the National Aeronautics and Space Administration (NASA) and the European Space Agency.
"Dr. Sandwell's map is like a smart phone that improves with each new model," said Dr.
Reginald Beach, who sponsors Sandwell's work for ONR's Ocean Battlespace and Expeditionary Access Department.
"Each version teaches us more about the topography of the ocean bottom, which is crucial to safe navigation for the Navy."
Sandwell is now updating the 2014 map with information gathered by another pair of satellites run by NASA and the French space agency, CNES.
Other data comes from sonar soundings compiled by Australia, during that nation's participation in an international effort to scour the southern Indian Ocean in search of the wreckage of Malaysian Airways Flight 370--which disappeared in 2014.
Australia made the sonar data publicly available in 2017.
In the search for MH370, Geoscience Australia applied a GIS solution to support the world’s largest marine survey, mapping the seafloor in greater detail than ever to provide scientific insights.
"Thanks to this new data, our map can provide greater information about the world's oceans," said Sandwell, "particularly the Southern Hemisphere, which includes the Indian Ocean and south Atlantic Ocean.
I'm grateful to ONR for its valuable support over the years, which has been crucial to creating the most accurate sea floor map possible."
AGU is a not-for-profit, scientific organization with nearly 60,000 members in 139 countries.
A new MIT study finds that over the coming decades climate change will affect the ocean’s color, intensifying its blue regions and its green ones.
Image: NASA Earth Observatory
Climate-driven changes in phytoplankton communities will intensify the blue and green regions of the world’s oceans.
Climate change is causing significant changes to phytoplankton in the world’s oceans, and a new MIT study finds that over the coming decades these changes will affect the ocean’s color, intensifying its blue regions and its green ones.
Satellites should detect these changes in hue, providing early warning of wide-scale changes to marine ecosystems.
Writing in Nature Communications, researchers report that they have developed a global model that simulates the growth and interaction of different species of phytoplankton, or algae, and how the mix of species in various locations will change as temperatures rise around the world.
The researchers also simulated the way phytoplankton absorb and reflect light, and how the ocean’s color changes as global warming affects the makeup of phytoplankton communities.
Current day Chl-a and its interannual variability.
Composite mean Chl-a (mg Chl m−3) for 1998–2015:
a model actual;
b model satellite-like derived (using an algorithm and the model RRS,);
c Ocean Colour Climate Change Initiative project (OC-CCI, v2) satellite derived. Interannual variability defined as the standard deviation of the annual mean composites (1998–2015):
d model actual;
e model satellite-like derived; f OC-CCI, v2 satellite derived. White areas are regions where model resolution is too coarse to capture the smaller seas, or where there is persistent ice cover.
Model actual Chl-a is the sum of the dynamic Chl-a for each phytoplankton type that is explicitly resolved in the model.
It is equivalent to the Chl-a that would be measured in situ.
This is distinct to satellite-derived Chl-a which is calculated via an algorithm derived from the reflected light measured by ocean colour satellite instruments
The researchers ran the model through the end of the 21st century and found that, by the year 2100, more than 50 percent of the world’s oceans will shift in color, due to climate change.
The study suggests that blue regions, such as the subtropics, will become even more blue, reflecting even less phytoplankton — and life in general — in those waters, compared with today.
Some regions that are greener today, such as near the poles, may turn even deeper green, as warmer temperatures brew up larger blooms of more diverse phytoplankton.
“The model suggests the changes won’t appear huge to the naked eye, and the ocean will still look like it has blue regions in the subtropics and greener regions near the equator and poles,” says lead author Stephanie Dutkiewicz, a principal research scientist at MIT’s Department of Earth, Atmospheric, and Planetary Sciences and the Joint Program on the Science and Policy of Global Change.
“That basic pattern will still be there. But it’ll be enough different that it will affect the rest of the food web that phytoplankton supports.”
Dutkiewicz’s co-authors include Oliver Jahn of MIT, Anna Hickman of the University of Southhampton, Stephanie Henson of the National Oceanography Centre Southampton, Claudie Beaulieu of the University of California at Santa Cruz, and Erwan Monier, former principal research scientist at the MIT Center for Global Change Science, and currently assistant professor at the University of California at Davis, in the Department of Land, Air and Water Resources. This research was supported, in part, by NASA and the Department of Energy.
The story of oceans and climate would not be complete until we explore the impact of weather and climate on marine life.
We also need to understand how ocean life, notably phytoplankton might modulate oceanic weather and climate, through their role in the global carbon cycle, and on the ocean heat budget. One way that phytoplankton influence the oceans is through heating.
Photosynthesis is quite inefficient, so much of the light absorbed by phytoplankton cells is released as heat.
Chlorophyll count
The ocean’s color depends on how sunlight interacts with whatever is in the water.
Water molecules alone absorb almost all sunlight except for the blue part of the spectrum, which is reflected back out.
Hence, relatively barren open-ocean regions appear as deep blue from space.
If there are any organisms in the ocean, they can absorb and reflect different wavelengths of light, depending on their individual properties.
Phytoplankton, for instance, contain chlorophyll, a pigment which absorbs mostly in the blue portions of sunlight to produce carbon for photosynthesis, and less in the green portions.
As a result, more green light is reflected back out of the ocean, giving algae-rich regions a greenish hue.
Since the late 1990s, satellites have taken continuous measurements of the ocean’s color.
Scientists have used these measurements to derive the amount of chlorophyll, and by extension, phytoplankton, in a given ocean region.
But Dutkiewicz says chlorophyll doesn’t necessarily reflect the sensitive signal of climate change.
Any significant swings in chlorophyll could very well be due to global warming, but they could also be due to “natural variability” — normal, periodic upticks in chlorophyll due to natural, weather-related phenomena.
“An El Niño or La Niña event will throw up a very large change in chlorophyll because it’s changing the amount of nutrients that are coming into the system,” Dutkiewicz says.
“Because of these big, natural changes that happen every few years, it’s hard to see if things are changing due to climate change, if you’re just looking at chlorophyll.”
In this extra video, Dr Michelle Gierach from NASA JPL outlines how models can be used to assess phytoplankton biodiversity, and how future satellite missions will lead to better monitoring of coral health, biodiversity and potentially even phytoplankton species.
Modeling ocean light
Instead of looking to derived estimates of chlorophyll, the team wondered whether they could see a clear signal of climate change’s effect on phytoplankton by looking at satellite measurements of reflected light alone.
The group tweaked a computer model that it has used in the past to predict phytoplankton changes with rising temperatures and ocean acidification.
This model takes information about phytoplankton, such as what they consume and how they grow, and incorporates this information into a physical model that simulates the ocean’s currents and mixing.
This time around, the researchers added a new element to the model, that has not been included in other ocean modeling techniques: the ability to estimate the specific wavelengths of light that are absorbed and reflected by the ocean, depending on the amount and type of organisms in a given region.
“Sunlight will come into the ocean, and anything that’s in the ocean will absorb it, like chlorophyll,” Dutkiewicz says.
“Other things will absorb or scatter it, like something with a hard shell. So it’s a complicated process, how light is reflected back out of the ocean to give it its color.”
When the group compared results of their model to actual measurements of reflected light that satellites had taken in the past, they found the two agreed well enough that the model could be used to predict the ocean’s color as environmental conditions change in the future.
“The nice thing about this model is, we can use it as a laboratory, a place where we can experiment, to see how our planet is going to change,” Dutkiewicz says.
Marine diatom cells (Rhizosolenia setigera), which are an important group of phytoplankton.
Photograph: Karl Bruun/AP
A signal in blues and greens
As the researchers cranked up global temperatures in the model, by up to 3 degrees Celsius by 2100 — what most scientists predict will occur under a business-as-usual scenario of relatively no action to reduce greenhouse gases — they found that wavelengths of light in the blue/green waveband responded the fastest.
What’s more, Dutkiewicz observed that this blue/green waveband showed a very clear signal, or shift, due specifically to climate change, taking place much earlier than what scientists have previously found when they looked to chlorophyll, which they projected would exhibit a climate-driven change by 2055.
“Chlorophyll is changing, but you can’t really see it because of its incredible natural variability,” Dutkiewicz says.
“But you can see a significant, climate-related shift in some of these wavebands, in the signal being sent out to the satellites.
So that’s where we should be looking in satellite measurements, for a real signal of change.”
Though plankton can't be seen from space, NASA's SeaWIFS satellite can image the chlorophyll found in phytoplankton. Since the fall of 1997, NASA satellites have continuously and globally observed all plant life at the surface of the land and ocean. Satellites measured land and ocean life from space as early as the 1970s. But it wasn't until the launch of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) in 1997 that the space agency began what is now a continuous, global view of both land and ocean life. This video was created with data from satellites including SeaWiFS, and instruments including the NASA/NOAA Visible Infrared Imaging Radiometer Suite and the Moderate Resolution Imaging Spectroradiometer. On land, vegetation appears on a scale from brown (low vegetation) to dark green (lots of vegetation); at the ocean surface, phytoplankton are indicated on a scale from purple (low) to yellow (high). In the Northern Hemisphere, ecosystems wake up in the spring, taking in carbon dioxide and exhaling oxygen as they sprout leaves — and a fleet of Earth-observing satellites tracks the spread of the newly green vegetation. Meanwhile, in the oceans, microscopic plants drift through the sunlit surface waters and bloom into billions of carbon dioxide-absorbing organisms — and light-detecting instruments on satellites map the swirls of their color. The space-based view of life allows scientists to monitor crop, forest and fisheries health around the globe. Observations from space help determine agricultural production globally, and are used in famine early warning detection. But the space agency's scientists have also discovered long-term changes across continents and ocean basins. As NASA begins its third decade of global ocean and land measurements, these discoveries point to important questions about how ecosystems will respond to a changing climate and broad-scale changes in human interaction with the land. The climate is warming fastest in Arctic regions, and the impacts on land are visible from space as well. The tundra of Western Alaska, Quebec and elsewhere is turning greener as shrubs extend their reach northwards. And as concentrations of carbon dioxide in the atmosphere continue to rise and warm the climate, NASA's global understanding of plant life will play a critical role in monitoring carbon as it moves through the Earth system. Expanding these observations to the rest of the globe, the scientists could track the impact on plants of rainy and dry seasons in Africa, see the springtime blooms in North America, and the after-effects of wildfires in forests worldwide. The grasslands of Senegal, for example, undergo drastic seasonal changes. Grasses and shrubs flourish during the rainy season from June to November, then dry up when the rain stops. With early weather satellite data in the 1970s and '80s, NASA Goddard scientist Compton Tucker was able to see that greening and die-back from space, measuring the chlorophyll in the plants below. He developed a way of comparing satellite data from two wavelengths, which gives a quantitative measurement of this greenness called the Normalized Difference Vegetation Index. But land is only part of the story. At the base of the ocean’s food web are phytoplankton — tiny organisms that, like land plants, turn water and carbon dioxide into sugar and oxygen, aided by the right combination of nutrients and sunlight. Recent studies of ocean life have shown that a long-term trend of rising sea surface temperatures is causing ocean regions known as “biological deserts” to expand. These regions of low phytoplankton growth occur in the center of large, slow-moving currents called gyres. The next step for NASA scientists is actually looking at the process of photosynthesis from space. When plants undergo that chemical process, some of the absorbed energy fluoresces faintly back, notes Joanna Joiner, a NASA Goddard research scientist. With satellites that detect signals in the very specific wavelengths of this fluorescence, and a fine-tuned analysis technique that blocks out background signals, Joiner and her colleagues can see where and when plants start converting sunlight into sugars. Earth is still the only planet we know of with life - the one thing that, so far, makes Earth unique among the thousands of other planets we've discovered. With that in mind, our habitable home world seems evermore fragile and beautiful when considering the vastness of unlivable space.
According to their model, climate change is already changing the makeup of phytoplankton, and by extension, the color of the oceans.
By the end of the century, our blue planet may look visibly altered.
“There will be a noticeable difference in the color of 50 percent of the ocean by the end of the 21st century,” Dutkiewicz says.
“It could be potentially quite serious. Different types of phytoplankton absorb light differently, and if climate change shifts one community of phytoplankton to another, that will also change the types of food webs they can support.“
