Picture of the week: Raja Ampat impression (2)

Picture of sweetlips congregation, taken in December 2019 at Raja Ampat. With Nikon D7200, dual D161 strobes, Tokina 10-17.

Highlighted: Arctic hotspot of temprature rise.

The temperature at the Northern Pole has risen dramatically in the last century,  relative to more southern regions of our globe (see insert taken from today's Washington Post survey). This phenomenon is called polar amplification: any change in the net radiation balance tends to produce a larger change in temperature near the poles than the planetary average. One mechanism leading to the observed arctic amplification suggested by Jennifer Francis in Scientific American (2017) is water vapor.  "A lot more water vapor is being transported northward by big swings in the jet stream. That’s important because water vapor is a greenhouse gas just like carbon dioxide and methane. It traps heat in the atmosphere. That vapor also condenses as droplets we know as clouds, which themselves trap more heat. The vapor is a big part of the amplification story—a big reason the Arctic is warming faster than anywhere else'.

Highlighted: The tragedy of Undine

Mermaids and river nymphs have always mystified seamen, story stellers, and filmmakers. In Hans Cristian Andersens  story from 1836 the little mermaid falls in love with a prince that she saved from drowning. The sea-witch gives her legs to become a human to marry the Prince. The Prince however  falls in love with a human princess. Undine then seeks revenge by killing the prince and returns to the sea where she transforms into the foam of the sea.  In a  recent film remake of Undines story, German filmmaker Christian Petzold follows the general tragic line of the story where a young woman Undine works as a historian lecturing on Berlin's urban development. But when the man she loves, the industrial diver Christoph,  leaves her, the ancient myth catches up with her. Undine has to kill the man who betrays her and return to the water.

Higlighted: how our brains developed from creatures of the sea.

A large part of the octopus brain lies in it's arms

Creatures that live in the sea, even the Medusozoa (jellyfish) have nervous systems.  Two-thirds of the nerve cells in the even more complex nervous system of  the octopus  (a mollusk) are located in the nerve cords of its arms which makes the eight tentacles function as an extended brain (see insert). Godfrey-Smith the author of the best-selling recent book Metazoa writes about how our nervous system developed from our early ancestors the metazoans (organisms with multiple cells), probably from the cells of corals, sponges, and anemones that live in the sea. Each of these organisms has evolved into a form that is perfectly adapted to its environment. He describes a one-armed shrimp as follows: “Eighteen limbs and protrusions … a body like a Swiss Army knife.” In spite of missing a claw and being surrounded by bigger, mightier animals such as mollusks and sharks — “in the land of the limbless, the one-armed shrimp is king’. The body of common fishes functions as ‘one great ear’,  catching the smallest sounds propagated in the water enabling some species even to distinguish between different melodies. Knowledge of how 'primitive' biological systems have evolved would, in his view,  contribute more to the understanding of the human brain than that of the modern digital computer. 

 

Higlighted: Jellyfish propulsion trick

A recent study by Brad Gemmell and colleagues shows that the jellyfish Aurelia aurita uses  a vortex ring (called: stopping vortex), created underneath the animal during the previous swim cycle. The vortex ring (see blue circles in the cavity under the umbrella in the figure at the left,  nrs. 3 and 4) is critical for increasing propulsive performance.The jellyfish then pushes itself against a ‘wall of water',   like the wings of an aircraft using the runway during take-off.  The phenomenon of increased lift generated over static surfaces moving parallel to a solid boundary is termed ‘steady ground’ or ‘steady wall’ effect.

Higlighted: Cant you sleep? Try Oceanscapes

Sit back, relax, and witness the incredible life that exists at the surface of our blue planet. Fully immerse yourself in the ocean with this 10 hour loop. Ocean Surface: 10 Hours of relaxing Oceanscapes, set at scull screen.

  

Highlighted: E-book update

This ‘E-book’  contains an updated collection of around 80  blog articles from the last three years.  I here provide two separate content lists, a list in which the articles are ordered according to the five most often recurring themes, and a chronological list. A simple click on the title will hopefully guide you to the article of your choice. For download,  click  next to the  PDF icon below

E-booknew