Saturday, October 31, 2009

Glaciers, Ice Ages and Climate Change

One weekend, we went to local library. While kids looked for novels, I was looking for some nonfiction books for them to read. I picked up several books, including "Frozen Earth: Explaining the Ice Age". Before they even touched the book, I started to read the book and was quickly absorbed into it!!

The book was very well written for readers of all levels. It explained first what glacier is, and then how scientists discovered that there were ice ages long time ago, most recent one 20,000 years ago. The focus of the book though was about how scientists in many generations tried to understand why ice ages come and go.

The history of the process of understanding ice ages was told in a fascinating way - like a detective story - evidence, theory, some evidence to support a theory, other evidence to disapprove it, new theories proposed and new evidence, and finally after 100 years, in 1976, finally two astronomical theories were confirmed as the main reasons behind the ice age, and thus the cycles of global climate change. The story showed the vigor of scientific discovery, and the difficult long journey to fully understand ice age. To me, an engineer, the process of understanding the ice age is a perfect example of root cause analysis - before we know the root cause, we only know partial truth.

So what are the main causes of ice age or global climate change?

Before giving the answer, we need some explanations of astronimical terms. Earth orbit around Sun changes gradually from circle to ellipse due to gravitational interactions between planets in solar system and it repeats itself in 100,000years. Earth axis of rotation is an imaginary line from south pole to north pole, it has an angle to the normal of orbit plane. This angle is called a tilt. The axial tilt angle is ~ 23.5 degrees. The axial tilt is not a constant, it changes from 22degrees to 25 degrees in 41,000 years. The axis is not fixed with respect to the normal either, it moves around it in a circle, or wobbles, this is called axial precession, the axial precession completes a circle in 22,000 years.

Simply said, the main causes to climate change are: 1) earth orbit eccentricity; 2) earth axial tilt, and 3) earth axial precession. of the three factors, eccentricity has the largest impact on climate. The cycle of eccentricity is 100,000 years, for axial tilt it is 41,000 years, and axial precession, 22,000 years. These are first order factors that influence climate on earth; volcano dust, carbon dioxide, Sun spots influence climate change, but in a small way, in math language, these are second order effect.

The facts that amazed me inlcude:

1. In 1860s, Scotsman James Croll used earth orbit and axial precession to explain ice ages - an astronomical theory. In 1890s, Yogoslavia mathematician Miluin Milkankovitch, added axial tilt change into the astronomical theory, but he neglected the orbit change. In 1976, the combined astronomical theory of Croll and Milkankovitch about ice age and global climate cycles were confirmed through oceanographic studies.

2. Earth has been warming up for the past several thousand years. Due to human activities, primarily green house effect from carbon dioxide production, earth will reach a super warm state in 100 years. The super warm state is predicted to last 1000 years or so.

3. The earth, however, will get into another ice age in 20,000 to 25,000 years.

So despite carbon dioxide being a second order factor in climate change, it will perturb the natural path of climate change significantly in 100 to 1000 years, negligible in astronomical time, but tremendous for human time. We need to reduce CO2 emission to minimize the global warming and thus prevent catastrophic climate to human.


R.V. Fodor, Frozen Earth: Explaining the Ice Ages, Enslow Publishers, 1981.

J. Imbrie, K. Imbrie, Ice Ages: Solving the Mystery, Enslow Publishers, 1979.

Saturday, October 24, 2009

Foliage in my Neighbourhood

The best known foliage viewing area in Texas is at Lost Maples State Natural Area, which is 370 miles away from Dallas, a 7 hour drive. The best foliage view time should be from mid October to early November depending on weather. Unfortunately school is still in session, and kids still have lots of activities during weekends. It is hard to find time to go there for families with school age children.

If you look around, then you will find that your neighbourhood, your community park are full of colors. Here is what I saw in my neighbourhood last year.

In 2008, trees in my neighborhood, started to color in mid October. I noticed that the foliage were getting more and more wide spread, brighter, week by week, during my routine weekend morning jogging. I decided to take my camera to record the foliage in my neighbourhood on November 9, 2008.

It was a crispy, beautiful Autumn morning. The tree in my front yard, was colorful, part of leaves turned gold brown, part were still green. The roses beneath the tree was blooming. Looking across the street, a bright yellow was in sight.

The fall color, chimney and blue sky formed a unique combination at one place; as a matter of fact any color looked great under this bright blue sky. There were more bright color trees at the community park, red, yellow, and further more, a family of ducks were in the pond and a heron stood by the water.

Looking around, it was so colorful, so lively, so beautiful, my usual 45 minute early morning jogging prolonged to about 2 hours, just to enjoy the foliage in my neighbourhood and to take in the crisp autumn air.

We don't have to go far to enjoy the beauty of nature.

Saturday, October 17, 2009

Mendenhall Glaicer Flightseeing and Walk-about Tour - by Justin

On August 4th, 2009, my father and I woke up very early. It was not even 6AM, and yet my father and I had already started dressing in heavy jackets and thick pants, just as one would expect of two mountaineers. In essence, we were, as this land excursion would take us onto a river of ice in the middle of a mountain range- Mendenhall Glacier.

After we disembarked the cruise, the short bus ride to the Juneau International Airport was uneventful, with several bald eagle sightings at the nearby Douglass Island. At the airport, there was a special building for this excursion. We watched a short safety video there, then we were required to fasten ice boots over our normal shoes and walked over and climbed into the helicopters. With me and my dad being lighter than the other travelers, we got the privilege to sit up front next to the pilot. We were given headsets to dampen the sound of the helicopter blades and so the pilot could communicate with us. Our safety instructor gave a thumbs up, which our pilot returned, and with a lurch, we gained altitude. We rose higher and higher until the landing pad was only a speck in the distance, and the mountains were looming before us. Fortunately for us, the Yukon wildfire smoke had cleared up, giving us a good view of the ice field.
When we reached an altitude slightly higher than that of the mountain peak, we made our way up the mountain ridge, till we got a panorama view of the entire area around the glacier. The glacier itself was a river of ice, white mottled blue, with flecks and streaks of gray and black, like someone had taken a paintbrush and dabbed and brushed on ugly streaks of dark color on a bright and awe capturing scene. The melted glacier water ran off the end into a lake. The lake, like all glacial waters, was a silt-like gray-green color, complete with several chunks of ice floating in it. The mountains around the glacier were gray and brown around the glacier, but as they rose up, the green trees and shrubs appeared, every once in a while layered over with a blanket of snow. It was a beautiful sight, green mountains, white ice, and blue sky. We climbed over and around the mountains, and we saw more of the glacier. In actuality, the glacier is a half mile wide by seventy six miles long. As we landed, I could see that there was more blue ice than the eye can perceive from looking from a bird’s point of view. The area of our immediate landing was a clear blue patch of ice. The wind whipped my hair, and now instead of a range of green mountains looming in front, a sheet white and blue ice stretched from where my feet touched, all the way through the mountains, twisting and turning.

As we walked along the ice, we observed many interesting natural phenomenon. The ice remains at a constant temperature of thirty one degrees Fahrenheit, just below freezing, yet there are several streams of rain water and snow melt that flow on top of the glacier, which remain liquid year-round, and have the duty of carving and shaping the ice, much like a river shapes a canyon. The natural blue ice also intrigued many people within out group. Every year, there is a heavy perennial snow, which means it doesn’t melt, and the snow compacts upon itself, forming a very tight crystalline ice structure that has little air. When sunlight hits the ice, it absorbs all the colors, except for blue, which has the shortest wave length. When more air is let into the ice, like the top layers, it will absorb all the colors, leaving white for the eyes to perceive. Before it was time to go, we got the privilege to drink crystal clear, ice cold, mineral rich water from one of the small streams on the ice face. Before we knew it, we were all piled into the helicopter again, as it gave a small lurch during the vertical takeoff.

Experiencing a glacier by walking up on it was thrilling. I wish one day to go back there and go hiking up and around the glacier.

Note: The day before, in Haines/Skagway, smoke from a forest fire in the Yukon Territory of Canada drifted over the sky, we had a less clear view of the glacier we saw that day than today.

Saturday, October 10, 2009

Denali Wilderness and Wild Life We saw

At the end of our 7 day Alaska cruise, we transferred to a coach and went to Denali National Park via an 8 hour scenic drive. Denali means the high one - it is also known as Mt. McKinley, it is the tallest mountain in North America. On the scenic drive, we stopped at Denali State Park, which is supposed to be one of the best areas for viewing Mt. McKinley. But we were not lucky to see it due to clouds.

My first impression of Denali national park was the cloud covered mountains and ever changing landscapes - green pine trees, red fire weeds, grey glacier rivers in wide valleys. Above ~ 2500 feet, there is no trees due to cold temperature and moisture-snapping winds.

The first evening at Denali, Justin and I walked to the glacier river bank after dinner : the glacier river was rushing forward, two pigeons rested on a rock in the river, pink wild weeds swinging in the wind and sun started to set.

The next day we would have a Tundra Wilderness Tour in the afternoon, we had the whole morning for ourselves, so we went to Park visitor center to check out what we could do. We chose horse shore lake trail, which is about 2.4 miles round trip. Horseshoe lake is a place where Moose wander around. When we got there, all we saw was other hikers. We walked into the bush to check a beaver dam, just then I felt a big piece of white stuff coming my way, looking again, a trumpeter swan was flying to us, it landed in front of us about 20- 30 yards away in the lake. Lily was quick and she caught the landing on her camcorder. The swan gracefully swam around, occasionally dipped its head into the water to eat plants at the bottom of the water. Then it did something we had never seen before, it flapped its wings. After watching the swan for a while, we started walking back and then I noticed a beaver swimming, apparently swimming back to its home - beaver dam.

In the afternoon, we went on for our Denali Tundra Wilderness Tour on a school bus like park shuttle. Denali Wilderness Tundra is a restricted area, no commercial vehicle can get in, very limited amount of private vehicles can get in by a lottery every year. It took about 40 minutes or so to get to the restricted area. All the passengers on board, looked outside hoping to see wild life. Driving forward, the bus was ascending, the road got narrower, trees became scarce. Now the bus was on the mountain range, and left hand side was a valley with a shallow glacier river running in the middle. I spotted something moving by the valley and told our driver/guide - "Caribou in the valley" and sure enough there were two caribous there, all of us got excited and everyone moved to the left hand side of the bus, took out camera to take pictures - the caribous were very far away, it was kind of hazy in the valley - due to smoke from Yukon forest fire, so it was not easy to take good pictures of them. The bus moved on. After a turn on the mountain road, I noticed another animal close to the road ahead of our bus, the bus pulled close, and it was a Caribou again, but it was so much closer and we could see it very clearly - its dark brownish skin, white bottom, huge antelopes and its bright eyes!

Later on someone else spotted Dall sheep in the woods at right hand side of the road. We got excited again. It was a surprise since Dall sheep typically stay at the top of mountains to avoid predators. Shortly afterwards we did see Dall sheep at their usual habitat, the rocky area at the top of mountains - they were just like pieces snows on the rocky mountain slop.

Just when we got use to see caribous, Dall sheep, I spotted something white-brownish moving on a mountain trow. Using his powerful tel camcorder, our guide told us what I spotted were a mother bear and her two cubs !! The mother bear was light brownish. They were so far away from us, we could see them clearly only by binoculars. I took a few blurred pictures of the bears. Could you see the light brown mother bear at the center right location of the picture? The two cubs were in the "northwest" direction of the mother bear. Click on the picture, you could see them better in the full size photo.

On the way back, something even more exciting happened. Somebody spotted a "dead" animal on a grass land not too far away from the road (we were in the valley now), which turned out to be a sleeping wolf! Two caribous came into sights. Then Justin spotted bears in the mountain. Our guide got very excited, he told us that he saw wolf once a week this season, and he had never saw Caribou, Bear and Wolf in the same general area before. We were very lucky!! Just then the wolf woke up, stretched its legs, yawn, and walked slowly in the direction of bears, ?! We were hoping to see the wolf chasing the Caribou. (Note: Our guide told us wolf always travel in pack, there must be other wolfs around and wolf was more likely to attack bears for the cubs then attacking the bigger caribou.)

Of the five major animals at Denali, we saw Caribou, Dall Sheep, Grizzly Bear and Wolf. We did not see moose on the Tundra Wilderness Tour. When we got back to Denali town center that night, we were told Moose came to town! We missed it. But we were compensated at Anchorage, we saw moose on the coastline biking trail.

The next day, we left Denali in a morning drizzle. As our coach descended from our mountain hotel, the sun came out. A rainbow formed between mountains.

The excitement of discovery, the thrill of unexpected, made this an unforgettable exploration.

Saturday, October 3, 2009

Watching the Moon

There will be a full moon on October 3 this year, and it is a special full moon day in Chinese Lunar calendar - it is mid autumn festival. In Chinese culture, it is a time for the full house of the family being together, it is time for those far away from hometown to connect spiritually with their kins. Happy Mid Autumn Festival!

Some nights we see the moon, other nights we don't see it; some other times we see the moon in day time. But I really did not know much about moon phases. 2007 I was specially interested in the moon as Nicholas had a home work on recording moon phases during December and we learned a lot about the moon with him, as we read many books about moon together - new moon, waxing, first quarter, full moon, third quarter, waning ... We were trying to take pictures of the moon - unfortunately in that month the moon rose very early in the morning and set early in the afternoon - we did not have a good time to take a picture. One a Wednesday (per time stamp on the photo), I don't remember why, Nicholas and I were at home in the morning - we went out of the door, and a waning moon was there right above our our front yard, and we took this picture.

Occasionally I saw the moon in other color and scenery.

One night in Spring of 2008, we and other 3 families went to Lewisville lake camping. The camping site was on a peninsula. When it's getting dark, the 8 boys (2 from each family) started running around and playing hide and seek. The parents were sitting around and chatting. By chance I looked at east and saw this huge orange ball in the east above the lake, shinning its light on the lake's ripples. "Moon rise!" The boys stopped running and stared at the moon, parents stopped chatting and were amazed by this rare orange moon.

On December 1, 2008, When I went to day care to pick up Nicholas shortly after 6pm, I saw a happy face in the sky - formed by a crescent moon and two stars. I pointed this out to Nicholas to his astonishment. Checking on Dallas Morning News weather section, I found out that the two stars were actually two planets, Jupiter and Venus. The next day NBC news reported this interesting celestial phenomenon in the 5:30pm evening news! It turned out that it was quite a event in the circle of amateur astronomers. I took a picture of this smiley face - but I could not find it now, shown on the right was copied from Internet, it was taken actually from southern hemisphere.

When we travel, we usually do not pay attention to the moon at all. But once we notice it, we always feel something special. This summer we had our first ever cruise. The first night on board, after a formal 4 course 2 hour dinner, we walked on the deck a bit to burn some calorie. When we walked to the bow, a waxing moon was right there in front of us.

In summer 2006, when we had river rafting in Helena Canyon on Rio Grande, the guide told us a story about that people went to canyon during full moon. I could only imagine the white soft light from the moon shining into the canyon where there was no artificial light, reflection from the running water, the dark wall of the canyon in the back light, the sound of the river, singing of insects and beating of the hearts of young couples ..... a tranquility under the spell of the moon. I guess that is when people are moon struck.

A mesmerizing moon appeared right at home one day. A road in front our subdivision, running straight for several miles from east to west, is the road I take every day to go to work. There are trees and homes along the road, no tall buildings. One early morning, when I drove on this road, I drove up a slope, looking ahead, I saw this huge slightly yellowish white moon at the end of the road, right at my eye level!! I was moon struck momentarily .

Moon has its phases, economy has its cycles and life has its ups and downs. All we can do is to enjoy what we have.

References: 1) moon phase for any time of the year . 2) moon rise and set time