Re: @ZLabe@fediscience.org

It was an unbelievable year for global climate.

As data is released in the first two weeks of January, you are going to be hearing all about these new climate change records. Apologies for all my graphs in advance!! 😬

See the spiral animation produced by NASA at: https://svs.gsfc.nasa.gov/5190/

https://fediscience.org/@ZLabe/111676637022642331

Hey folks. I recently had a discussion with an acquaintance where we disagreed about the functions of media luna, specifically about the collective and dispersive impacts on surface water flow. Looking for papers or other writings about them seems to all point back to this document (PDF warning) with data that they work but not how they work. What follows is my understanding of the process, and any information that improves my understanding is greatly appreciated.

With "horns up", sheet flow slows as it encounters the obstruction - during the early parts of a precipitation event or flow event, this will cause the water to enter the root and unsaturated zones of the soil profile. The water that does not percolate into the soil continues to move at 90° to contour around the rest of the obstruction's parts while also moving downward due to gravity. As the soil moves towards its capacity for stored water, the percentage flowing through the media luna increases. The pressure from the water on the upslope side of the media luna causes the flow to disperse through the obstruction, the convex shape of which causes additional lateral movement of the water as it makes its way downslope. My intuition is that the additional resistance towards the center of the structure is part of the cause, along with an evenly distributed lower pressure gradient along the convex face.

With "horns down", the upslope water slowing capacity is similar (I would expect the water retention properties to be strongest when installed with stream banks to either side) but due to the concave nature of the shape there is a greater amount of surface area directing the flow of water towards the geometric center of the shape through the same physical processes noted above - gravity and pressure differentials. I am not strong in maths and am unsure of how greatly the pressure differential affects the water's course, but I expect that value is nonzero.

I have a sneaking suspicion that my friend was considering the upslope behavior of a less-porous obstruction while I was considering the downslope behavior of a more-porous obstruction, causing them to think I had the collection/dispersion effects backwards. I'm well practiced at being wrong though, so it's a possibility that I'm open to even if I'm not enthusiastic about it.

Thoughts?

Researchers from China have confirmed the existence of an approximately 8.5-year Inner Core Wobble (ICW) in both polar motion and length-of-day variations, revealing a static tilt of about 0.17 degrees between the Earth's inner core and mantle, challenging traditional assumptions and providing insights into the Earth's internal dynamics and density distribution.

The findings of the study are published in Nature Communications.

Scientific research in Antarctica has played a key role in many important discoveries of the past century. But it has also come at a considerable cost to the environment.

Science in Antarctica is typically based at one of the 77 research stations. While their role is to support science, their isolation means they need to provide the infrastructure of a town.

As well as the local impacts of these stations, the Antarctic environment is facing massive challenges from external pressures such as climate change. The loss of sea ice could mean some of the continent's most iconic wildlife face extinction this century. For example, the early melting of sea ice recently led to complete breeding failure at several emperor penguin colonies.

So how can we keep doing research in Antarctica while minimizing our impact on the environment? This question led to our new research published in the Journal of Environmental Management.