Why is it so cold?

Posted on February 6, 2014 - 10:42:23

Why is it so cold? Simply put, cold is caused by the absence of heat. Sometimes conditions are such that there is much less heat in an area. For instance:

Snow cover reflects solar radiation. That means, that if the ground is covered in snow, even on a sunny day, the sun doesn't warm the earth because the sunlight is reflected back into space.

Shorter amount of daylight mean less time for the sun's warming rays. Plus, during the winter season, the sun strikes the earth at a sharp angle, meaning the sun's rays are spread out further (less concentrated), so they have less warming power. 

Lack of cloud cover at night allows heat to escape into space. While I love those beautiful winter nights when the sky is clear and the stars are bright, I know that the lack of cloud cover means that any heat that may have accumulated during the day will be lost to space. When there are clouds, the cloudcover helps to trap the heat in the troposphere (lower level of the atmosphere). 

The jet stream brings cold air down from the Arctic. The jet stream is a meandering band of air that circles the planet. (There are four jet streams circling the planet from west to east - two polar jet streams and two tropical jet streams) Here's a short animation (from NASA) of the jet stream. Sometimes, the polar jet stream dips further south, due in part to increased snow cover across large areas of land - which means... less heat.

“Bitter cold” is a term that’s getting a lot of use this winter – and with good reason. The word bitter – while typically used to describe something that has a disagreeable taste – means something that causes a harsh or stinging sensation, which is exactly what very cold weather will do.

With a high of -15º forecast for Monday (January 6th), and wind making it feel even colder, I think it’s safe to say that Monday’s cold will be bitter indeed. 

From a health standpoint, there are many reasons to be cautious when venturing outside in this weather:

 - Hypothermia : This is defined as the body temperature dropping from the normal 98.6º below 95º. Hypothermia can occur when outdoors in extremely cold weather for a long period of time, even if dressed warmly. It can also occur rather quickly when someone is outside for even s short period of time if they are not dressed for the cold. Symptoms of hypothermia include shivering, slurred speech, irrational behavior, shortness of breath and eventually, unconsciousness.

 - Frostbite : Freezing temperatures can cause exposed part of the body to lose feeling and color. Nose, ears, cheeks, chin, fingers and toes are the most likely to be affected. In extreme cases, frostbite will lead to amputation. Symptoms to look for include numbness, skin that feels unusually firm or waxy, and skin that appears white or grayish-yellow.

 - Heart attack: If you have a heart condition, high blood pressure, or a family history of heart disease, be careful not to over-exert yourself if shoveling snow. Sudden physical exertion in cold weather – which occurs when lifting and throwing a heavy shovel full of snow – has been linked to heart attacks. Take lots of breaks to rest and warm up.

 - Falling down: I’ve fallen down once this winter due to slipping on icy pavement. I wasn’t hurt, but I know several people who have broken wrists, hips, arms and ankles due to slipping on ice. A couple of tips to avoid slipping on ice:

1) Wear shoes with good traction. If you don’t have any, invest in slip on traction devices like Yak Trax – they work like chains on tires by providing metal cleats that bite into the ice to keep you from slipping.

2) Use a walking stick, preferably one with a pointed tip. This will improve balance while walking across a slick surface.

If you do find yourself falling, try to remember not to put your arms out to catch yourself – that is the cause of most wrist and arm fractures when falling. Instead, try to remember to tuck your arms in, relax your body and roll so that you land on your shoulder and then roll onto your back. The rolling motion helps dissipate the energy from striking the ground. Trust me, I’ve done this, and it does work. 

In general, there are commonsense steps you should take to stay safe in the bitter cold:

 - Wear a hat: Mom was right – wearing a hat in cold weather is one of the smartest things to do, as a lot of heat will escape through your head if you don’t.

 - Dress in layers: Layers trap air between the layers, and air is a great insulator.

 - Stay dry: If you get wet, change into dry clothes as soon as practical. Moisture will speed heat loss.

 - Eat food and drink water: Being outside in the extreme cold causes the body to burn more calories. Also, the air holds less moisture as the temperature drops, so it is important to make sure your body is well hydrated. But, avoid alcohol – it can cause your body to lose heat more quickly.

If driving in the cold, be sure to have your cell phone with you, as well as a set of jumper cables, a bag of sand or kitty litter for traction if needed, and an ice scraper.

Finally, when it is cold, don’t leave your pets outside for very long, unless there is a sheltered, warm spot that they can go into. Pets can get hypothermia and frostbite just like people!

 - Lisa Haderlein , Executive Director, The Land Conservancy of McHenry County

People, animals and plants acclimate to winter weather

Posted on January 17, 2014 - 09:51:51

Most years, I dread January – cold, sleet, ice, and heavy grey skies. But not this year. 

Because winter started in earnest last November, I am already acclimated to the cold. I’ve slipped on the ice (once) and shoveled snow – multiple times. Instead of being tired of winter, I was actually quite comfortable with the winter routine when we hit January.

In fact, I still haven’t worn my winter coat – that’s right. I’m wearing my fall canvas field coat with a fleece vest on top. Unprecedented! (For the record, I did not leave my house on the two coldest days of the year. But that's part of acclimating to winter, as you will learn below).

Acclimatization is a natural process where plants and animals adjust to seasonal (or other temporary) changes in their environment. For instance, as average temperatures slowly decrease from fall to winter, one’s system will adjust to the changing temperature. (Note: acclimatization is different than adaptation. Adaptation is what happens when species evolve over generations to have different characteristics than their parents.)

Plants that are meant to grow in a northern climate have genes that cause them to go dormant for a period of time when there is less light and the temperatures are cold. The reason that plants from more southern climates often die during northern winters is because they do not have the ability to adjust to the seasonal change in temperature.

Humans are warm-blooded (endotherms) like all other mammals and need to take steps to reduce heat-loss during the cold weather.

Like many birds and mammals, people add layers of insulation to stay warm during the cold. In our case, the insulation is in the form of clothing – for our feathered and furry friends, it may be more feathers, a thicker coat, or additional layers of fat.

Some animals (and people) stay warm in winter by moving south. Others choose to hibernate for long-periods, conserving energy by dropping their metabolism to just 1-5% of what it is during active periods. Some birds and small mammals, like chickadees and shrews, enter a lower-energy state called torpor at night, dropping their body temperature as a way to reduce heat-loss while sleeping.

Another way to stay warm on a cold winter day is to be active. Cross-country skiing, snow-shoeing or taking a hike will all cause the body to generate heat. For birds and mammals, the most common daily activity is finding food. Maybe we humans would put on less weight during the winter if we had to work a little harder at feeding ourselves!

TLC’s winter oak rescues are a great way to warm-up. Cutting and stacking brush gets one’s blood flowing, and a brush fire keeps everyone toasty. Harvard area events will be held on the following dates: 

January 20th, Maguire Woods, 5507 Irish Lane, 10am – 1pm. From the intersection of Route 14 and McGuire Road in Harvard, take McGuire 3.6 miles to Irish Lane and head north 0.3 miles to the work site.

January 25th, Gateway Park, Heritage Lane and Route 23, Harvard, 9am-noon.

February 17th, Van Maren’s Woods, 20202 Lembcke Road, 10am – 1pm. Take Route 14 south from Harvard to Lembcke, turn right, and proceed 1.2 miles to the work site.

TLC is offering a free Winter Tree Identification class, January 18th, 10am-2pm at Hennen Conservation Area, 4622 Dean Street, Woodstock. Join TLC’s Ecologist, Melissa Hormann, to learn how to identify trees using the twigs and bark. The first hour will be inside looking at twig samples, and the next three hours will be spent walking the hiking trails and using your new skills. Wear clothes appropriate for an outdoor winter hike.

TLC’s Annual Celebration Brunch will take place January 26 from 11-2pm at D’Andrea’s Banquets in Crystal Lake. Join old friends and new as the organization marks another successful year of land preservation. This year, TLC is excited to welcome special guest Mark Hirsch, a photojournalist who gained international acclaim for his daily photos of “That Tree,” a lonely bur oak on the edge of a farm field near his home in Platteville, Wisconsin. Tickets are $50 for non-members ($40 for members) and are available at www.conservemc.org or by calling 815-337-9502 by 5pm Wednesday, January 22nd.

Be cautious venturing outside in the bitter cold

Posted on January 6, 2014 - 14:10:52

Why is it so cold? Simply put, cold is caused by the absence of heat. Sometimes conditions are such that there is much less heat in an area. For instance:

Snow cover reflects solar radiation. That means, that if the ground is covered in snow, even on a sunny day, the sun doesn't warm the earth because the sunlight is reflected back into space.

Shorter amount of daylight mean less time for the sun's warming rays. Plus, during the winter season, the sun strikes the earth at a sharp angle, meaning the sun's rays are spread out further (less concentrated), so they have less warming power.

Lack of cloud cover at night allows heat to escape into space. While I love those beautiful winter nights when the sky is clear and the stars are bright, I know that the lack of cloud cover means that any heat that may have accumulated during the day will be lost to space. When there are clouds, the cloudcover helps to trap the heat in the troposphere (lower level of the atmosphere).

The jet stream brings cold air down from the Arctic. The jet stream is a meandering band of air that circles the planet. (There are four jet streams circling the planet from west to east - two polar jet streams and two tropical jet streams) Click here http://www.youtube.com/watch?v=C_HiBj0teRY  to see a short animation (from NASA) of the jet stream. Sometimes, the polar jet stream dips further south, due in part to increased snow cover across large areas of land - which means... less heat.

“Bitter cold” is a term that’s getting a lot of use this winter – and with good reason. The word bitter – while typically used to describe something that has a disagreeable taste – means something that causes a harsh or stinging sensation, which is exactly what very cold weather will do.

With a high of -15º forecast for Monday (January 6th), and wind making it feel even colder, I think it’s safe to say that Monday’s cold will be bitter indeed.

From a health standpoint, there are many reasons to be cautious when venturing outside in this weather:

- Hypothermia . This is defined as the body temperature dropping from the normal 98.6º below 95º. Hypothermia can occur when outdoors in extremely cold weather for a long period of time, even if dressed warmly. It can also occur rather quickly when someone is outside for even s short period of time if they are not dressed for the cold. Symptoms of hypothermia include shivering, slurred speech, irrational behavior, shortness of breath and eventually, unconsciousness.

- Frostbite . Freezing temperatures can cause exposed part of the body to lose feeling and color. Nose, ears, cheeks, chin, fingers and toes are the most likely to be affected. In extreme cases, frostbite will lead to amputation. Symptoms to look for include numbness, skin that feels unusually firm or waxy, and skin that appears white or grayish-yellow.

- Heart attack . If you have a heart condition, high blood pressure, or a family history of heart disease, be careful not to over-exert yourself if shoveling snow. Sudden physical exertion in cold weather – which occurs when lifting and throwing a heavy shovel full of snow – has been linked to heart attacks. Take lots of breaks to rest and warm up.

- Falling down . I’ve fallen down once this winter due to slipping on icy pavement. I wasn’t hurt, but I know several people who have broken wrists, hips, arms and ankles due to slipping on ice. A couple of tips to avoid slipping on ice:

1) wear shoes with good traction. If you don’t have any, invest in slip on traction devices like Yak Trax – they work like chains on tires by providing metal cleats that bite into the ice to keep you from slipping.

2) Use a walking stick, preferably one with a pointed tip. This will improve balance while walking across a slick surface.

If you do find yourself falling, try to remember not to put your arms out to catch yourself – that is the cause of most wrist and arm fractures when falling. Instead, try to remember to tuck your arms in, relax your body and roll so that you land on your shoulder and then roll onto your back. The rolling motion helps dissipate the energy from striking the ground. Trust me, I’ve done this, and it does work.

In general, there are commonsense steps you should take to stay safe in the bitter cold:

Wear a hat. Mom was right – wearing a hat in cold weather is one of the smartest things to do, as a lot of heat will escape through your head if you don’t.

Dress in layers – layers trap air between the layers, and air is a great insulator.

Stay dry. If you get wet, change into dry clothes as soon as practical. Moisture will speed heat loss.

Eat food and drink water. Being outside in the extreme cold causes the body to burn more calories. Also, the air holds less moisture as the temperature drops, so it is important to make sure your body is well hydrated. But, avoid alcohol – it can cause your body to lose heat more quickly. 

If driving in the cold, be sure to have your cell phone with you, as well as a set of jumper cables, a bag of sand or kitty litter for traction if needed, and an ice scraper.

Finally, when it is cold, don’t leave your pets outside for very long, unless there is a sheltered, warm spot that they can go into. Pets can get hypothermia and frostbite just like people!

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