September 22 – Falling All Over The Place

Today’s factismal: Today is the first day of Fall, the twenty-second day of fall, and the fifty-third day of fall.

Well, Summer is over at last. Then again, according to some folks Summer has been done for quite some time. How can that be? It all has to do with people and our need to categorize things. The problem is that different groups of people can look at the same thing and break it apart in different ways. For example, today marks the first day of Fall for the astronomers. (Unless you are in the Southern Hemisphere, in which case, it is the first day of Spring.) For a meteorologist, today is the twenty-second day of Fall. And for folks who studied the classics, it is the middle of Fall!

It all started back in the days of the early Roman kings (about 2,700 years ago) when the calendar ran from late spring to early winter and then went silent for a couple of months. The Romans held various fertility and harvest festivals to celebrate the seasons, but the actual date when those were held slipped around a bit thanks to those missing two months. It wasn’t until Julius Caesar fixed the calendar that we started seeing folks who could say with any authority (a legion of armed men is authority, right?) that Summer was officially over and Fall had begun.

Visitors to the National Cherry Blossom Festival (My camera)

We no longer use the blooming of trees to determine the seasons – or do we? (My camera)

The interesting thing is that, while the various Roman provinces didn’t like the Romans very much (after all, what had Rome done for them other than the aqueducts, sanitation, roads, education, and the wine?), they loved the calendar because it made it easier for them to observe their religious rites and mark their seasons. And one of the most influential (at least in Europe) set of seasons was the one that modern pagans call “the Wheel of the Year”, which divided the year into four seasons (Spring, Summer, Winter, and Fall) and arranged them so that the middle of each season happened on an astronomically significant date. The middle of Winter would show up on December 20 (the Winter Solstice), the middle of Spring would occur on March 20 (the Vernal Equinox), the middle of Summer would be on June 20 (the Summer Solstice), and the middle of Fall would roll in on September 21 (the Autumnal Equinox). This method of timing the seasons lasted for more than 1,900 years; you can see its influence in things such as Shakespeare’s “Midsummer’s Night’s Dream” which takes place on the Summer solstice. And while the dates have slipped a bit due to the Earth’s wobble in its orbit, the basic idea remains and is celebrated in many countries.

But as we moved into the 20th century, we decided that those dates didn’t work well for us (mainly because there is nothing special to mark February first as the start of Spring). So we came up with a new system. Actually, we came up with two new systems. Around 1950, the meteorologists decided that the seasons would start on the first day of a specific month, so that each season was roughly the same length of time. Spring ran March, April, and May, Summer took up June, July, and August, Fall was September, October, and November, and Winter was December, January, and February. (These seasons are generally referred to as “meteorological spring” etc.)

M42 (Orion Nebula) Over Virginia (My camera)

The stars don’t set our calendar either – or do they? (My camera)

At about the same time, the astronomers decided that they weren’t going to let no stinking pagans decide when the seasons started based on obsolete astrological superstitions; instead, they’d start the seasons based on the stars. So the astronomers decreed that Spring would begin on the Vernal Equinox, Summer would come in on the Summer Solstice, Fall would commence on the Autumnal Equinox, and Winter would hold sway beginning on the Winter Solstice. That this effectively shifted the seasons by half a wavelength was irrelevant; it just made more sense to the astronomers.(These seasons are generally referred to as “astronomical spring” etc.)

The three seasonal calendars in use today

The three seasonal calendars in use today

So, as a result, we now have three different dates to start each season. Of course, Mama Nature is famous for not reading calendars (as anyone who has been caught in a May snowstorm can attest); she starts her seasons when she wants and marks it by changes in the plants and animals. And it turns out that there are a lot of scientists who are more interested in reading her calendar than man’s. If you would like to help them do so by recording when the leaves change color or the butterflies leave or the buds blossom in your area, then why not write a few pages in Nature’s Notebook?
https://www.usanpn.org/natures_notebook

September 15 – My Beautiful Balloon

Today’s factismal: The world’s first weather balloon was launched 112 years ago today.

Meteorologists in St. Louis, Missouri, have something to celebrate today. More than a century ago, they launched the very first weather balloon intended for use in weather reporting. Though scientists had been launching balloons with scientific instruments since 1896, this was the first balloon intended to be used specifically for predicting the weather. The balloon carried a recording thermometer and a pressure gauge in a small package that was recovered after the balloon burst in the stratosphere. Today, the National Weather Service launches balloons from 92 sites in the USA; they are just part of the more than 900 sites that launch twice a day (morning and evening) to get information.

Launching a weather balloon during World War II (Image courtesy NOAA)

Launching a weather balloon during World War II
(Image courtesy NOAA)

So why would they bother? Simply because we knew then as we know now that it isn’t enough to measure the temperature and pressure and other weather factors in just one place; if you want an accurate prediction of what is going to happen next, you need lots of data that goes up through the atmosphere as well as across the globe. And balloons do that! They can rise as far as 20 miles before they pop, and they will fly up to 125 miles away. Each year, some 75,000 instrument packages are sent up in weather balloons. And thanks to WiFi, we are getting more data than ever from them.

A modern weather balloon launch (Image courtesy NOAA)

A modern weather balloon launch
(Image courtesy NOAA)

But that’s still not enough to make the meteorologists happy. (That’s a meteorologist for you – always raining on our parade!) They want more data – and that’s where you come in! They have set up a group to record temperature, pressure, and (most importantly) precipitation. Known as CoCoRAHS, these folks feed valuable information to the meteorologists who use it to make better weather predictions. To learn more, float on over to:
http://www.cocorahs.org/

 

June 17 – In A Fog

Today’s Factismal: Fog is not considered to be precipitation by meteorologists.

If you’ve taken a fifth grade science course, then you’ve probably learned about the water cycle (or, if it was in a fancy school district, the hydrologic cycle). In this cycle, water evaporates from ocean, rivers, and lakes, goes high into the air to form clouds, and comes back down as rain and snow. It is a beautiful, simple model. And like most such things, it is too simple and not nearly beautiful enough.

When you ask a meteorologist about the hydrologic cycle, then you’ll get the full, juicy story. Water doesn’t just evaporate from lakes, rivers, and oceans; oh, no! It also comes out of plants that have sucked water up from the ground (sometimes from several hundred feet underground), used it during photosynthesis and then sweat it out as part of their temperature regulation in a process known as transpiration. Over the course of a year, a single large oak tree can “sweat” out enough water to fill two swimming pools! Transpiration from plants and evaporation from the soil itself may account for as much as 67% of all precipitation.

This fog is not precipitation (My camera)

This fog is not precipitation
(My camera)

OK, you say; so the water sources are a bit more varied than we thought. But at least we know what precipitation is. However, this turns out to be another of those places where non-scientists and scientists use terms differently. To a meteorologist, it is only precipitation if the air becomes so saturated in water vapor that the water comes out and condenses around a small particle (that’s the “precipitate” part) and then (here’s the tricky part) falls under gravity. If the water drops are too small to fall, as they are in mists and fogs, then it technically isn’t precipitation even if it is on the ground (e.g., dew). But if it falls and evaporates on the way down, it is precipitation even though it stays in the air; meteorologists call this type of precipitation “virga”.

Virga falling from a cloud in Florida (My camera)

Virga falling from a cloud in Florida
(My camera)

And the hydrologic cycle gets more interesting still once we consider all of the types of precipitation that we can get. There’s virga and rain and hail and snow and sleet and graupel and drizzle, to name but the seven best known. And here’s the truly interesting part: meteorologists still have to rely on people on the ground to help them discover what kind of precipitation is falling where. Though some progress has been made in using radar to discriminate between the various types of precipitation, radars don’t see very well near the ground (all those pesky buildings get int he way). So they need observers to tell them what is falling where, be it thundersnow or nonaqueous rain.

The drizzle on Uluru is a form of precipitation (My camera)

The drizzle on Uluru is a form of precipitation
(My camera)

If you’d like to help, then why not download the National Severe Storms Laboratory’s free mPING (Meteorological Phenomena Identification Near the Ground) app? It is available on both Android and Apple devices. All you have to do is use the app to send a report whenever you see precipitation; the app will even help you decide what type of precipitation it is. To find out more, go to the National Severe Storms Laboratory mPING webpage:
http://mping.nssl.noaa.gov/

April 22 – Weathering The Climate

Today’s factismal: A 90 day weather forecast is useless but a 90 year climate forecast is useful.

If you’ve paid any attention to the fuss over climate change, then you know that one of the common arguments made by non-scientists is that long-term climate forecasts shouldn’t be trusted because we can’t get good weather forecasts more than ten days long. And the non-scientists are right on the last part; any group that claims to be able to forecast the weather more than ten days in advance is simply fooling themselves. But they are wrong on the first part; climate forecasts that extend for a century or more are probably fairly reliable. But why the difference?

An example of weather data that is being collected to help us understand climate (Image courtesy NOAA)

An example of weather data that is being collected to help us understand climate
(Image courtesy NOAA)

The reason that meteorologists can’t predict long-term weather but climatologists can predict long-term climate is because the climatologists cheat. They use a trick that is common in science. It is used in geophysics to help locate oil and gas. It is used in economics to compare GDPs. And it is used in biology to help sequence DNA. The trick is this: by looking at a lot of examples instead of just one, random variations that we call noise average out and the signal is left behind.

A simple example of this is traffic. If I asked you to predict how long it would take you to drive to the grocery store ten miles from your house today, you could probably give me a good estimate. You know what the weather is like and what the traffic is like and if your car needs gas. But if I asked you to predict how long it would take you to drive to the same grocery store two weeks from now, you would probably give me a bad estimate because you wouldn’t know any of the things you need to know to make the prediction. But if I asked you to tell me how long it would take you to drive from California to Maine, you could give me a fairly good estimate no matter when I wanted you to start. That’s because all of those variables average out over the much longer distance so that you can see the underlying pattern.

The daily high and low temperatures at Will Rodgers International Airport

The daily high and low temperatures at Will Rodgers International Airport

Let’s see how that works in practice. We’ll start with the daily maximum and minimum temperatures recorded at one spot. Since I live in Oklahoma City, I’ll use the Will Rodgers International Airport and I’ll pull the data from the National Climatic Data Center (free to the public!). When we plot that data up, we get the chart above. Can you see a pattern? Probably not, because of all of the various things that affect a temperature reading, from cloudiness to el Nino to wind speed.

Converting to monthly averages gets rid of some of the noise

Converting to monthly averages gets rid of some of the noise

So let’s see what happens when we take some of that variation out by looking at the monthly average high and low temperatures. A lot of the daily noise is removed but it is still pretty hard to see if there’s a pattern there or not.

A clear pattern has begun to show up bit there are still some strong local effects

A clear pattern has begun to show up bit there are still some strong local effects

So let’s move the the annual average of the maximum and minimum temperatures. The averaging removes even more of the short-term effects so that a clear long-term pattern is visible. The temperatures, both high and low, tended to be lower in the 1950s than they are now. But what can we do to make things even more obvious?

The global average shows the same trend but much less influence from local factors

The global average shows the same trend but much less influence from local factors

Climatologists use two tricks. First, instead of relying on one spot on the globe, they average values taken from all over. That removes local influences; as a result, the variations are much smaller. That’s why the Will Rodgers curve in the plot above swings from 58°F to 64°F but the global curve only shifts from 56°F to 59°F. (That’s also why a change of just 3.5°F worries so many climatologists; it means much larger changes in many cities.) The second trick is actually the first one – instead of looking at annual averages, they prefer five-year averages.

Spencer's annotated climate chart showing exactly the same results as NASA (Image courtesy Roy Spencer)

Spencer’s annotated climate chart showing exactly the same results as NASA
(Image courtesy Roy Spencer)

And when the data is looked at using those two simple tricks, it becomes clear that the globe is warming thanks to the amount of CO2 that has been added to the atmosphere by man. (Even skeptics like Spencer and Watts agree with this; they just disagree on what happens next.) Our contribution is 100 times greater than that of volcanoes and fifty times greater than that of wildfires; as for the oceans, they absorb ten times more CO2 than they emit, making them net sinks. To put it as simply as possible, teh world is getting warmer and it is our doing.

A comparison of the CO2 emissions from various sources.

A comparison of the CO2 emissions from various sources.

So this Earth Day, why not do something about it? Check the pressure in your tires. If we all drove on properly inflated tires, we’d save 1,250,000,000 gallons of gasoline each year! That means we’d have $2,500,000,000 more to spend on things other than gasoline (like food). Check the insulation in your attic. By doubling the amount of insulation, you could save $112 per year! And check your light bulbs. By switching just one 40 watt bulb to an LED, you could save $4 per year!

You may have noticed the common theme there – doing things to reduce our CO2 emissions is the same as doing things to save us money. For once we can save our planet and make money doing it. So what are you waiting for? Go celebrate Earth Day by saving money!

 

March 20 – Spring Forward

Today’s factismal: Today is the first day of Spring, the twentieth day of Spring, and the forty-ninth day of Spring.

Right now, you are probably scratching your head, wondering if I’ve lost my mind. How can one season start three different times? The answer lies, as it so often does, in the ineluctable propensity of mankind to name things. Back in the days of the early Roman kings (about 2,700 years ago), the calendar ran from late spring to early winter and then went silent for a couple of months. The Romans held various fertility and harvest festivals to celebrate the seasons, but the actual date when those were held slipped around a bit thanks to those missing two months. It wasn’t until Julius Caesar fixed the calendar that we started seeing folks who could say with any authority (a legion of armed men is authority, right?) that Spring was officially over and Summer had begun.

Visitors to the National Cherry Blossom Festival (My camera)

We no longer use the blooming of trees to determine the seasons – or do we? (My camera)

The interesting thing is that, while the various Roman provinces didn’t like the Romans very much (after all, what had Rome done for them other than the aqueducts, sanitation, roads, education, and the wine?), they loved the calendar because it made it easier for them to observe their religious rites and mark their seasons. And one of the most influential (at least in Europe) set of seasons was the one that modern pagans call “the Wheel of the Year”, which divided the year into four seasons (Spring, Summer, Winter, and Fall) and arranged them so that the middle of each season happened on an astronomically significant date. The middle of Winter would show up on December 21 (the Winter Solstice), the middle of Spring would occur on March 20 (the Vernal Equinox), the middle of Summer would be on June 21 (the Summer Solstice), and the middle of Fall would roll in on September 21 (the Autumnal Equinox). This method of timing the seasons lasted for more than 1,900 years; you can see its influence in things such as Shakespeare’s “Midsummer’s Night’s Dream” which takes place on the Summer solstice.

But as we moved into the 20th century, we decided that those dates didn’t work well for us (mainly because there is nothing special to mark February first as the start of Spring). So we came up with a new system. Actually, we came up with two new systems. Around 1950, the meteorologists decided that the seasons would start on the first day of a specific month, so that each season was roughly the same length of time. Spring ran March, April, and May, Summer took up June, July, and August, Fall was September, October, and November, and Winter was December, January, and February. (These seasons are generally referred to as “meteorological spring” etc.)

M42 (Orion Nebula) Over Virginia (My camera)

The stars don’t set our calendar either – or do they?  (My camera)

At about the same time, the astronomers decided that they weren’t going to let no stinking pagans decide when the seasons started based on obsolete astrological superstitions; instead, they’d start the seasons based on the stars. So the astronomers decreed that Spring would begin on the Vernal Equinox, Summer would come in on the Summer Solstice, Fall would commence on the Autumnal Equinox, and Winter would hold sway beginning on the Winter Solstice. That this effectively shifted the seasons by half a wavelength was irrelevant; it just made more sense to the astronomers.(These seasons are generally referred to as “astronomical spring” etc.)

The three seasonal calendars in use today

The three seasonal calendars in use today

So, as a result, we now have three different dates to start each season. Of course, Mama Nature is famous for not reading calendars (as anyone who has been caught in a May snowstorm can attest); she starts her seasons when she wants and marks it by changes in the plants and animals. And it turns out that there are a lot of scientists who are more interested in reading her calendar than man’s. If you would like to help them do so by recording when the leaves change color or the butterflies leave or the buds blossom in your area, then why not write a few pages in Nature’s Notebook?
https://www.usanpn.org/natures_notebook

August 25 – Storm of The Century

Today’s factismal: Ten years ago, Hurricane Katrina made landfall.

There’s no doubt about it; 2005 was a record year for hurricanes. In the Pacific basin, there were 39 named storms, 20 hurricanes, 5 five major hurricanes. (Yes, they call them “typhoons”, but they are the same phenomenon.) In the Atlantic basin, there were 28 named storms, 15 hurricanes, and 7 major hurricanes. And one of those seven major hurricanes in the Atlantic basin was Katrina. Katrina would be the costliest natural disaster in the history of the United States, with a price tag of $108 billion and a death toll of 1,245. Though most of that damage centered on New Orleans, Katrina’s trail of devastation stretched from the Bahamas to Ohio. But New Orleans was the worst casualty. Plagued by run-down infrastructure and stripped of the delta by decades of channel dredging, the city was wrecked after the storm.

A building collapsed by Katrina (My camera)

A building collapsed by Katrina
(My camera)

At that, New Orleans got lucky with Katrina. Had the storm remained a 5, instead of dropping in intensity as it reached land, then the wind and debris damage would have been much worse. Had Katrina approached on the east side of new orleans, instead of the west, then the levees would have failed earlier and more conclusively. And had Katrina come on New Orleans during a Spring tide (an unusually high tide) instead of during low tide, even the French Quarter would have been inundated. But lucky or not, Katrina did more damage in less time than any other storm in US history.

The marks on this building show that it was searched and no bodies were found (My camera)

The marks on this building show that it was searched and no bodies were found
(My camera)

Much of the damage was inevitable. But much of it could have been avoided with better forecasts. What the meteorologists needed was more observations in order to give better predictions. What they needed was people like the members of the Citizen Weather Observer Program who send in reports about severe weather (and the other kind, too) that is then used to make better predictions. If you think that you’ve got what it takes to be a CWOP member, head over to:
http://wxqa.com/

November 7 – Snowbody’s Business

Today’s factismal: Meteorologists have more terms for snow than Eskimos do.

One fact that everyone knows is that Eskimos have lots of words for snow. It only makes sense that they would; after all, every year the Arctic is covered with the stuff for the better part of six months. But what many people don’t know is that meteorologists have even more terms for snow than the Eskimos do!

"Snow on water" (My camera)

“Snow on water”
(My camera)

Of course, that does depend a little on how you define “words related to snow” and “Eskimo” (we’re pretty sure on what folks mean by “meteorologist”). There isn’t one group of Eskimo any more than there is one group of people in Europe. There are at least twenty-six distinct languages spoken by “Eskimos” (that is, indigenous people living in the Arctic Circle); though the languages all share a common ancestor (much as English and German and Afrikaans do), they differ in how many words they have for any given topic including snow.

And then there is the problem of defining words related to snow. Is “snowing” different from “snow”? Is “snowstorm” different from “blizzard”? Fortunately for us, linguists have been arguing over questions like this for the better part of a century. Based on one influential dictionary for the Yup’ik people, many people say that the Eskimos (or at least the Yup’ik) have fifteen distinct words for snow. They include snowflake (qanuk), frost (kaneq), fine snow/rain particles (kanevvluk), drifting snow (natquik), clinging snow (nevluk ‘clinging debris’, nevlugte- ‘have clinging debris’), fallen snow on the ground (aniu), soft, deep fallen snow on the ground (muruaneq), the crust on fallen snow (qetrar), freshly fallen snow on the ground (nutaryuk), snow floating on water (qanisqineq), snow bank (qengaruk), a block of snow (utvak), a snow cornice (navcaq), a blizzard or snowstorm (pirta), and a severe blizzard (cellallir).

The Hubbard glacier (My camera)

The Hubbard glacier
(My camera)

What about meteorologists? They worry about all types of weather, snow included, and have developed a very exacting terminology for snow and ice. Their lexicon includes snow ablation (snow removal by erosion), avalanche (snow rushing downslope in a mass), blizzard (a winter storm with sustained winds in excess of 35 mph that causes drifting and blowing snow and limited visibility), blowing snow (snow that is being blown by the wind and limits visibility), depth hoar (large crystals that form in snowbanks due to strong temperature gradients), diamond dust (tiny snowflakes too small to branch), drifting snow (snow moved around by the wind that doesn’t limit visibility), flurries (light snowfalls for short time periods), freshet (the increase in river flow caused by melting snow and ice), frost (small ice crystals formed on the surface of cold objects), frozen dew (what it sounds like), glacier (a packed mass of snow and ice), graupel (snowflakes that are coated with ice), heavy snow (more than four inches of snow accumulation in twelve hours), ice pellets (just what they sound like), ice storm (precipitation that falls as rain but freezes on contact with the ground), lake effect snow (the enhanced snowfall that happens on the down wind side of a lake), polycrystalline snow (several snowflakes fused together), quality of snow (the percent by weight of a snow sample that is ice), sleet (snow that melts and refreezes on the way down), snow (duh), snow depth (how deep the frozen precipitation is on the ground), snow flurries (light snow showers), snow grains (very small, white, opaque grains of ice), snow pellets (large white, opaque grains of ice), snow shower (snow falling for brief periods), snow squalls (intense but short periods of moderate to heavy snowfall and strong, gusty winds), snowburst (a very intense shower of snow), snowfall (how much snow has fallen), snowflake (duh), water equivalent (how much water you’d get if you melted the snow), whiteout (blowing snow that reduces the visibility to zero), and winter storm (a heavy snowfall event). If you were keeping score, that’s thirty-three terms or more than twice the number that the Eskimos use!

Hoar on leaves and plants in Oklahoma (My camera)

Hoar on leaves and plants in Oklahoma
(My camera)

Of course, all of that terminology is useless without some data to back it up. And that’s where you come in! All you have to do is go outside when it snows, measure the depth of the snow, and tweet it to the University of Waterloo’s Snowtweets Project. For more details, drift on over to:
http://snowcore.uwaterloo.ca/snowtweets/