Bahamas WLP update in the Marine GeoGarage

14 charts have been updated since the last release :

• B12   Abaco Chart
• B28   Ab- Sandy Pt.
• B35   Ab-Foxown
• B155   Ab- Gorda Cay
• B156   Ab- Mores Island
• B161   Abaco, Western Bight
• B165   Ab- Allens-Pen Area
• B171   Ab- West End Rocks
• B185   Abacoight - Redshanks Cay
• B186   Abacoight - Burrows & Water Cay
• B187   Ab- Normans Castle
• B188   Ab- Basin Harbour Cay
• B189   Ab- Point of Bank Anchorage
• B222   Ab- Schooner Bay

Today, 295 charts for Bahamas (from WLP) are published on the Marine GeoGarage

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

Méditerranean sea-surface temperature

Sea-surface temperature in the Mediterranean Sea from January 2011 to May 2012
as measured by multiple Earth-observation missions.

From The Guardian

New research attributes the surface warming slowdown to accelerating trade winds mixing more heat into the oceans

  

  Research looking at the effects of Pacific Ocean cycles has been gradually piecing together the puzzle explaining why the rise of global surface temperatures has slowed over the past 10 to 15 years.
A new study just published in Nature Climate Change, led by Matthew England at the University of New South Wales, adds yet another piece to the puzzle by examining the influence of Pacific trade winds.

Pacific trade winds

While the rate of surface temperature warming has slowed in recent years, several studies have shown that the warming of the planet as a whole has not.
This suggests that the slowed surface warming is not due as much to external factors like decreased solar activity or more pollutants in the atmosphere blocking sunlight, but more due to internal factors shifting the heat into the oceans.
In particular, the rate at which the deep oceans have warmed over the past 10 to 15 years is unprecedented in the past half century.

Research led by Masahiro Watanabe of the Japanese Atmosphere and Ocean Research Institute suggests this is mainly due to more efficient transfer of heat to the deep oceans.
Consistent with model simulations led by Gerald Meehl, Watanabe finds that we sometimes expect "hiatus decades" to occur, when surface air temperatures don't warm because more heat is transferred to the deep ocean layers.
A paper published last year by Yu Kosaka and Shang-Ping Xie from the Scripps Institution of Oceanography found that accounting for the changes in Pacific Ocean surface temperatures allowed their model to reproduce the slowed global surface warming over the past 10 to 15 years.
However, the mechanism causing these Pacific Ocean changes has remained elusive.

The new study published by Matthew England's team helps explain how and why more heat is being funneled into the deeper ocean layers.
The study indicates that a dramatic acceleration in equatorial trade winds, associated with a negative phase of a cycle called the Interdecadal Pacific Oscillation (IPO) has invigorated the circulation of the Pacific Ocean.
This has caused more heat from the surface to be mixed down into deeper ocean layers, while bringing cooler waters to the surface.
The combination of these two processes cools global surface temperatures.
Like the rate at which heat is accumulating in the deep oceans, the recent strengthening of the trade winds is unprecedented, as the bottom frame in the figure below shows.

Top frame: Global surface temperature anomalies.

Bottom frame: Pacific wind stress anomalies. From England et al. (2014).

Not only is this acceleration of trade winds unprecedented, but it also far exceeds anything captured by climate models.
Hence they have difficulty reproducing the recent slowdown in surface warming.
The catch is that oscillations eventually change phases, so as England notes, the strengthened trade winds and faster rate of ocean heat accumulation are only temporary.

"the heat uptake is by no means permanent: when the trade wind strength returns to normal - as it inevitably will - our research suggests heat will quickly accumulate in the atmosphere. So global temperatures look set to rise rapidly out of the hiatus, returning to the levels projected within as little as a decade."

The study estimates that by shifting more heat into the oceans, the strengthening trade winds can account for 0.1–0.2°C cooling of surface temperatures over the past 10 to 15 years. This would account for most of the slowed rate of warming, especially when combined with a recent study showing that the global surface warming slowdown is not as large as previously thought. The lead author of that paper, Kevin Cowtan said of this study,

"I think Professor England has uncovered the biggest piece in the puzzle of recent temperature trends"

In the figure below, the England study compares observed surface temperature changes (black and grey) with IPCC model projections (red), and projections made by models that incorporate these changes in trade winds (green and blue). The models including trade winds can reproduce the surface warming slowdown. However, once the IPO cycle shifts and winds return to previous levels, the models see an accelerated warming at the surface, and temperatures start to catch back up to the IPCC model projections.

Annual (grey bars) and a five-year running mean (black solid line) global surface temperature measurements. Climate model projections are shown in red.

The blue and green show results from an ocean and a coupled climate model adjusted by the trade-wind-induced surface cooling.

From England et al. (2014).

A consistent picture is emerging in the climate research; increases in the strength of trade winds force more heat to be mixed down into the ocean, leading to a temporary slowing of rising surface temperatures.
The next piece of the puzzle will involve explaining the cause of the dramatic, unprecedented trade wind acceleration.
The IPO cycle can explain about half of the wind changes, but climate scientists are still investigating other possible contributing factors.
In any case, England concludes that surface temperatures may rapidly warm when the IPO phase shifts again in the next decade or so, and it will eventually be as though the surface warming slowdown never occurred.

"We should be very clear: the current hiatus offers no comfort - we are just seeing another pause in [surface] warming before the next inevitable rise in global temperatures."

Links :

• The Guardian : Global warming 'pause' due to unusual trade winds in Pacific ocean, study finds
• ESA : Is global warming hiding underwater ?

Earth's magnetic field : lesson from ESA

An introduction to Earth's magnetic field: what it is, where it comes from and what it's used for.

Why it matters

Earth's magnetic field is continuously changing.

Magnetic north wanders, and every few hundred thousand years the polarity gradually flips, so that a compass would point south instead of north.

To learn more about Earth's magnetic field, the three Swarm satellites were launched on 22 November.

Like 3D compasses, they are measuring the strength and direction of the magnetic field.

Spider crabs vs. stingray

BBC Life - Creatures of the Deep

Huge stingray crashes a spider crab party

The motion of our oceans revealed: Hypnotic interactive globe reveals our planet’s powerful sea currents in real time

The detail is incredible.

A region that looks calm at first glance is seen as an active area of currents on closer inspection, using the mouse wheel to zoom in.

From DailyMail

• Created by Tokyo-based Cameron Beccario, users can drag the globe to their desired location and click to zoom in
• A region that looks calm at a first glance is seen as an active area of currents circling as the user moves closer in
• It follows an interactive global wind map, also created by Mr Beccario (see GeoGarage blog). Studied together, they reveal just how unpredictable our planet’s weather system can be.

If you’ve ever wanted to sail through the world’s powerful ocean currents, then take a look at this.

Created by Tokyo-based Cameron Beccario, this interactive globe shows the ocean currents in real time as they swirl around continents.
Users can drag the globe to their desired location and click on the spot they want to find out an ocean current in all its grandeur.

Fascinatingly, the globe gives viewers an insight into the five major ocean gyres, the large systems of rotating ocean currents, particularly those involved with large wind movements.
The five - located in the Indian Ocean and in the north and south of the Pacific and the Atlantic - are clearly visible and their affects can be traced throughout the world.

This globe shows the ocean currents in real time as they swirl around continents

Pictured here is the ocean current system close to the UK.

The colours in this map denote speed, with red the fastest at over 1 metre per second and blue showing a static state

 

 Fascinatingly, the globe gives viewers an insight into the major ocean gyres, the large systems of rotating ocean currents, particularly those involved with large wind movements

 
The map relies on data compiled by NOAA's Global Forecast System to update its global wind patterns every three hours, and OSCAR Earth and Space Research to update its ocean surface current patterns every five days.
Details are thin on the ground on the sparsely-designed website, created by software engineer Mr Beccario, but it describes itself as a 'visualisation of global weather conditions forecast by supercomputers'.

It follows an interactive global wind map, also created by Mr Beccario.
Studied together, they reveal just how unpredictable our planet’s weather system can be.
Ocean currents transport huge amounts of heat around the world, making them one of the most important driving forces of climate.
Perhaps the most striking example is the Gulf Stream, which makes northwest Europe milder than other regions at the same latitude.

The ocean currents map follows an interactive global wind map (pictured), also created by Mr Beccario.
Studied together, they reveal just how unpredictable our planet's weather system can be

The currents are generated from the forces acting upon the water like the Earth's rotation, the wind, the temperature and salinity differences and the gravitation of the moon.
The colours in this map denote speed, with red the fastest at over 1 metre per second and blue showing a static state.

Links :

• GeoGarage blog : Real-time world winds animated map 

The data visualization in this excerpt represents a high point in the Scientific Visualization Studio's work in recent years to show "flows" -- ocean currents, winds, the movement of glaciers.
Using data from sophisticated NASA models, the studio's visualizers have figured out how to illustrate the velocities of these natural phenomena.