Spring ami(d)st

The weather is driven by the movement and transfer of energy, embodied in the form of low pressure systems. There, warm air surges northward with the warm front ahead the storm and cold air dives south behind it to be warmed again. At this time of the year, the warm is slowly winning the seasonal battle, driving further and further north. Yes, the cold fights back but any gain is soon lost. That's not to say it doesn't put up a fight. On Tuesday, we were able to witness the transition in action in the form of dense fog.

Around noon, very dense fog suddenly developed, shrouding the campus in a ghostly mist. Warm air can hold more water vapor than cold air. This warm air cooled as it contacted the cooler air at the surface since cold air is dense and therefore hard to dislodge. When the air cannot hold any more water vapor, it condenses into liquid, and suddenly the water is visible. This process generally happens high in the atmosphere, forming clouds. Fog is basically a ground level cloud. Normally, air cools as one increases in altitude. In the case of fog temperatures near the surface are cooler than the upper levels. This is called an inversion. This often happens in valleys where the mountains physically prevent warm winds from mixing the cold air out. This results in the weird thing where one can stand on the summit of a mountain in the sun but meanwhile the valley below is cool and foggy. This could have been the case since we are located on the slope of an ancient glacial valley. In this case, another explanation could be that a cold front was pressing in from the North, feeding cold, dry air, which was being channeled down the valley. This dry air eventually caused the fog to dissipate (evaporate). While the cold won out this time, its victory won't last long. Eventually the warmth will win out.

Well this tree fell, not sure if it made a sound...

Why do peoplc care if a falling tree made a noise? One should be asking why the tree fell in the first place.  What I found interesting about this tree was that it fell with no warning, on a calm day. There was no way one could predict the failure of the tree. However, upon further analysis there are several factors that could have led to the failure of the tree.

Upon examining the rootball (or lack thereof), it's obvious that this once handsome red oak suffered from major root issues. Instead of uprooting which is characteristic of trees that still have some semblance of a healthy root system, every root just snapped.

Let's have a closer look. Clearly this tree has been having some issues for a while. The white substance is fungus. Whether it was pathogenic or was just an opportunistic fungus is hard to determine. It it no doubt contributed to the decline in the structural integrity of the roots.

Another contributing factor could be the the severe drought that we had last year. Since trees are such large organisms, they respond on a longer timescale. In short, it takes longer for them to show stress or die. The drought could have stressed the tree and the wet winter allowed for the roots to rot out enough for the tree to fall. Another possible factor is recent road construction. If one looks back at the first photo, the pavement closest to the tree is darker which means that it is newer. What happened under the pavement is unknown but if they did any digging it would have affected the tree. Fortunately this tree fell on a closed road at a quiet part of the day, only causing damage to the wooden railing. Although this tree has fallen, it is my hope that another one will be able to take advantage of the hole in the canopy. Normally, the fallen tree would be home to insects and animals for decades as it decays but seeing that it is blocking a road, it probably will be removed soon.

Wildlife at Cornell: Big Red the red-tailed hawk

The other day I came out of plant science to go to dinner like any other day and while I was unlocking my bike noticed a man standing 50 feet alone behind me looking up at the plant science building and seemed to be talking to someone else. Slightly perplexed, I hopped on my bike, glanced back to the building and seeing nothing amiss, prepared to leave. I didn't get far before finding a woman also staring at the building from another vantage point. Turns out that they were looking a red-tailed hawk perched on top of plant science. She told me that her name was Big Red, that her mate (Ezra) had recently passed away, and that she had not been seen on the Ag quad for a while although her nest was nearby. After a few minutes of admiring the bird perched calmly on the roof, I was on my way back to the hubbub of a freshman dining hall. 

Here's an incredibly high quality photo of Big Red surveying the Ag Quad on top of Plant Science.

In this urban environment, most of the animals have adapted to life in proximity to humans and Big Red is no different. Her nest is located on Fernow Hall, as opposed to a tree in a more "natural" setting. Human activities have opened up nearby woodlands giving her places to hunt the healthy squirrel and rabbit population that is no doubt benefiting off our activities such as the lush lawns and food scraps. In a way the wildlife here is not even truly wild; they have all experienced the human hand in some way. We watch Big Red's nest with webcams. Ezra was euthanized after being brought in with a severe wing fracture and identified by his tag number. What we have here are the organisms that can tolerate or take advantage of the changes that we bring about.

Big Red back at her nest courtesy of the Cornell Lab of Orinthology's Cornell Hawks twitter account.