Weather Around The World, 3/22: Potholes; Water; Climate Change; High Tides; But No Tornadoes

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Home / Weather Around The World, 3/22: Potholes; Water; Climate Change; High Tides; But No Tornadoes
A pothole begins when rain seeps into the ground beneath the road or fills cracks in the road. Graphic courtesy of Tennessee Department of Transportation.

A pothole begins when rain seeps into the ground beneath the road or fills cracks in the road. Graphic courtesy of Tennessee Department of Transportation.

When the water freezes, the ice expands, creating a buckle in the road. When the water melts and drains, the road crumbles into the gap left behind. Graphic courtesy of Tennessee Department of Transportation.

When the water freezes, the ice expands, creating a buckle in the road. When the water melts and drains, the road crumbles into the gap left behind. Graphic courtesy of Tennessee Department of Transportation.

The news this week is as much political as meteorological.

The President and the Governor of Florida have much different views on climate change. Yesterday was the UN’s World Water Day. The English Channel crested with the solar eclipse. Spring brings potholes in roads — worse this year than most. And there has not been a single tornado in the US so far in March.

Let’s go Around The World.

Potholes Aplenty After Cold Winter

Makers and installers of automobile shock absorbers may applaud the fierce winter as potholes shake drivers’ nerves and rattle their brains. But where did the potholes come from?

Virtually all substances contract as they get colder because the molecules vibrate less, but water is different. Because of its unique shape, water reaches a minimum density at 36 degrees. It’s no big deal that it expands a little as it cools to freezing, but once frozen the expansion of the ice can break plumbing and destroy roadways.

Rainwater seeps under roads and into cracks, and when it freezes, the expanding ice buckles the road. The colder it gets, the more damage is done. When the water melts and drains, passing vehicles break the buckled asphalt and holes open up.

Yesterday Was World Water Day

In 1993, the United Nations proclaimed March 22 World Water Day, a day on which member states should plan for conservation and sensible use of water. Each year the date comes and goes with little fanfare and less progress on the main problems: Profligate use of water for everything from toilet-flushing and tooth-brushing to golf course watering and inefficient irrigation of crops.

As the world’s dietary preferences have changed, production of food has become more water-intensive. According to the UN, it takes:

  • 3,500 liters of water to grow a kilogram (2.2 pounds) of rice, but
  • 15,000 liters of water to grow two steaks.
The hydrologic cycle involves evaporation, condensation, precipitation, runoff, repeat. Graphic courtesy of NOAA.

The hydrologic cycle involves evaporation, condensation, precipitation, runoff, repeat. Graphic courtesy of NOAA.

The hydrologic cycle, in its simplest form, circulates water from the ocean to the atmosphere to the land and back to the ocean. Lakes, rivers, and aquifers store water on land, and human beings tap into these sources.

As the climate warms, the atmosphere will be able to hold more moisture and precipitation will likely increase. But this will not provide sufficient water for future use at the rate that current use is increasing.

Conservation and desalinization seem the only reasonable solutions to this problem.

Supermoon Brings Super Tides

You can be pretty certain that any eclipse will come at a time of very high and very low tides (spring tides). That’s because eclipses occur when the sun, moon, and earth are lined up and the gravitational forces of the sun and moon are pulling in the same direction on the earth’s oceans. At new moon, the sun and moon are on the same side of the earth; at full moon, they are on opposite sides. It makes no difference as far as the equations for the gravitational forces are concerned.

When an eclipse comes near the time of the moon’s perigee, its closest approach to the earth, the tugging is a little stronger and the highest and lowest tides occur. Last Friday’s eclipse of the sun came on the same day as perigee. As a result, huge tides visited places they don’t normally go. Crowds massed on the banks of the English Channel, where the tidal effects are amplified by the contour of the land masses. The tide was actually a few inches lower than expected, but spectacular nonetheless.

The actual tide can be higher or lower than the astronomical tide, which is the theoretical tide based only on gravitational forces. Anomalies of wind and atmospheric pressure affect the actual tidal height.

These are the average number of tornadoes by state from 1991 to 2010. So far this March: Zero. Graphic courtesy of NOAA.

This graphic shows the average number of tornadoes by state from 1991 to 2010. So far this March: Zero. Graphic courtesy of NOAA.

Tornado Season Off To A Slow Start

Since January 4, there have only been four tornadoes reported in the United States. This is an unprecedentedly low number. There have been none at all in March. This is the third consecutive March with tornado numbers far below the average of 78.

Tornado formation requires a flow of moist air near the surface. This has been present on several occasions this winter and early spring, as humid southerly winds surged out of the Gulf of Mexico. However, tornado formation also requires a dry flow from a different direction above the surface flow. This usually results from a westerly jet stream drying out as it crosses the Rockies, a feature which has been absent this year.

The dry air above saturated air creates conditional instability, a situation in which a lifted column of air overturns with violent results. The turning of wind with height, technically known as vertical wind shear, begins the cyclonic circulation that leads to a tornado.

Longer-term jet stream forecasts show no letup in the recent pattern of an undulating jet stream, which prevents the westerly flow necessary for tornadoes. Only a curmudgeonly climatologist could complain about the lack of tornadoes.

President Obama Orders Federal Government To Cut Greenhouse Gas Emissions

The President signed an executive order Thursday directing federal agencies to reduce carbon dioxide emissions by 40% from their 2008 levels within ten years. This was pursuant to a bilateral agreement recently reached with China.

Since the Federal Government accounts for less than one per cent of US emissions, this move has mainly symbolic value: It signals to the nations of the world that the US is serious about cutting the emissions that are warming the world. Hopefully politicians preparing for the possibly-last-chance-to-avoid-catstrophe meeting in Paris in December will respond in kind.

Florida Governor Allegedly Stifled Use Of Phrases ‘Climate Change’ And ‘Global Warming.’

Since 2011, employees of Florida’s Department of Environmental Management have been prohibited from using the terms ‘climate change’ and ‘global warming,’ according to a growing number of employees and ex-employees, including one who was suspended for violating the policy. The policy was never put into writing, but it was allegedly widely understood as a result of verbal exchanges. The Governor claims he had no involvement.

One way to win an argument is to deny your opponents the language with which to express their side. Though many Republican politicians now accept the reality of global warming, the Florida Governor is allegedly still living in the dark ages of scientific thought.

The Future Of The Planet

Climate change is the transcendent issue of our generation. But it in turn is transcended on short time scales by current pocketbook issues, the need of politicians to get re-elected, and the search for corporate quarterly profits. Will statesmanship and generosity towards our descendants prevail, or should those descendants expect to live in a much hotter world with uncertain and very likely unwelcome features of climate?

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