Saturday, March 29, 2014
BYU Merit Badge PowWow: Weather
The BYU merit badge PowWow for the Boy Scouts occurs twice a year. Scouts come to classes on two Saturdays to complete the requirements for different merit badges. I taught the weather class and helped about 150 scouts earn the weather merit badge. It was a lot of fun teaching and hope I can do it again next year. You can find my power-point slides and worksheet by clicking the picture of the weather merit badge in the top corner of this blog or going to http://nathangblaylock.com/wxMeritBadge.html.
After the PowWow my brother and I picked up a pizza and played some Frisbee golf at Provo's Bicentennial Park. The trees have blossomed, so it must be spring!
Thursday, March 20, 2014
Florida Panhandle Sea Breeze
Open-cell cumulus clouds form from rising thermals of warm air. These clouds form over land because solar heating causes pockets of warm air to rise. Since air cools when it rises, water vapor in the parcel of air condenses and forms a cloud. This rising motion is balanced by sinking motions around the thermal. Sinking air warms and evaporates the cloud.
The video below shows a satellite loop over the Florida panhandle on March 20, 2014. You can see the development of the open-cell cumulus over the land. Notice the lack of cloud development over the ocean and lakes. This is because water don't heat up as quickly as land. Thus, buoyant air parcels form over the land and not over water. Also notice that the cloud boundary retreats from the coast as the day progresses. This is caused by the sea breeze which blows cool, stable air from the ocean inland. The development of open-cell convective clouds is essentially cut off by this stable air.
2014-03-20
Over oceans it is common to see open-cell cumulus clouds appear in areas of cold air advection. Cold air advection is caused by winds blowing from colder temperature to warmer temperatures. Since the water surface is relatively warmer than the air above, parcels of warmer air at the ocean surface become buoyant and rise to and form clouds.
This image is an example of open-cell cumulus clouds over the ocean. Here, cold air advection is taking place as indicated by the wind barbs (yellow) crossing the isotherms (blue colored lines) from color temperatures to warmer temperatures. The image below is kind of low quality and shows the cold air advection is weak, but you can see the pockets of clouds over the ocean.
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| 2014-03-20 19:00 UTC |
Perhaps you can see the clouds better in this higher resolution image:
Spring is Here!
Today is the first day of spring! Looking out the window I can see the leaves on the trees begin to bud out. Soon we'll see the tulips and daffodils. Another sign of spring is my messy car when I park under a tree. Looks like those birds are coming back. I've since found a new parking spot that isn't under tree.
The University of Utah celebrated spring break last week, so my brother and I went to southern Utah to enjoy the spring weather where it was a little warmer. This was my first trip to Zion National Park. That place is probably my new favorite national park. I loved the red rock and green vegetation (you don't see much green stuff at Arches National Park).
The University of Utah celebrated spring break last week, so my brother and I went to southern Utah to enjoy the spring weather where it was a little warmer. This was my first trip to Zion National Park. That place is probably my new favorite national park. I loved the red rock and green vegetation (you don't see much green stuff at Arches National Park).
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| My brother and I safely made it to the top of Angel's Landing. If you've done this hike, you know what I mean by "safely." |
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| Looking up towards Angel's Landing. This climb is not for people afraid of heights! Photo: NGB |
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| Part of the Angel's Landing trail. Looking down I didn't realize how high we climbed. This part felt like climbing stairs! |
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| Some wild flowers on the trail. |
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| The Virgin River runs through the park. My brother and I spent a lot of time skipping rocks here. |
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We also made a trip to St. George, Utah, where the trees have already blossomed and flowers are already planted.
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| Blossoms on trees in front of the St. George Temple. Photo: NGB |
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In a park we enjoyed walking in our shorts and playing a game of Kubb. If you don't know what Kubb is then you better check it out here.
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| This is me playing Kubb. Look at how green the grass is, too! Another sign of spring! Photo: NGB |
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| I think my brother won more games than me. Photo: NGB |
So, what is so significant about Spring? Spring occurs on one of the two equinoxes in a year. An equinox is when the axis of the earth is tilted neither away nor towards the sun. At this time the sun is directly overhead the equator. If you lived on the equator, at noon the sun would be directly above your head.
Compare the above image of an equinox with the northern hemisphere winter and summer solstice below. The earth's axis is tilted away form the sun in winter and toward the sun in summer.
An equinox also means that every location on earth has 12 hours of day and 12 hours of night. The chart below illustrates how much sunlight a location will have on a clear day based on latitude and the time of year. Circled in red is the Spring Equinox where it is shown that all latitudes have 12 hours of sunlight. Another equinox exists near day 270, which is the Fall Equinox.
Friday, March 7, 2014
MODIS
MODIS is a special remote sensing instrument used to monitor the earth. The name is an acronym which stands for Moderate-Resolution Imaging Spectroradiometer.
Currently it is installed on two satellites--Terra and Aqua--and is used in airborne earth research like on NASA's DC-8 Flying Laboratory. The images this instrument creates are used to monitor cloud cover, monitor the progression of wildfires and smoke transport, estimate snow cover, and has many other uses.
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| MODIS instrument on NASA's DC-8 Flying Laboratory, June 2013 (c) Brian Blaylock |
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| Aqua Satellite. Image from NASA Eyes |
Terra and Aqua are polar orbiting satellites. As the earth rotates, the satellites sensors scan the earth taking a continuous picture. Below shows the location of the Aqua satellite and the orbit path.
Aqua and Terra, together, image the entire earth in about a day. The data they collect is transmitted back to earth, processes, and stitched together to form a complete picture. Below is an composite image for March 6, 2014. Because the earth is a sphere, data over some parts of the earth cannot be collected, and the missing data can be seen below.
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| Image from NASA Eyes |
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| Image from NASA Eyes |
The latest MODIS images can be found here:
Tuesday, March 4, 2014
A lesson of units
While working on my homework I was reminded how important expressing numbers with correct units really is. A number is not very useful until it's given a unit it represents. For example, the number five doesn't mean very much, but 5 gallons does. Also, 5 gallons means something completely different than 5 miles.
Several years ago a teacher in high school told my class a story about a Mars orbiter that crashed because one engineering team was working on the project in English units while another team working on the same project was using Metric units. Kilometers and miles are not the same thing. So the lesson here is that for whatever problem you are woking on, remember to communicate the units so people know exactly what your talking about.
Below is an article about the crash from the CNN:
September 30, 1999
By: Robin Lloyd
(CNN) -- NASA lost a $125 million Mars orbiter because a Lockheed Martin engineering team used English units of measurement while the agency's team used the more conventional metric system for a key spacecraft operation, according to a review finding released Thursday.
The units mismatch prevented navigation information from transferring between the Mars Climate Orbiter spacecraft team in at Lockheed Martin in Denver and the flight team at NASA's Jet Propulsion Laboratory in Pasadena, California. Lockheed Martin helped build, develop and operate the spacecraft for NASA. Its engineers provided navigation commands for Climate Orbiter's thrusters in English units although NASA has been using the metric system predominantly since at least 1990. No one is pointing fingers at Lockheed Martin, said Tom Gavin, the JPL administrator to whom all project managers report. "This is an end-to-end process problem," he said. "A single error like this should not have caused the loss of Climate Orbiter. Something went wrong in our system processes in checks and balances that we have that should have caught this and fixed it." The finding came from an internal review panel at JPL that reported the cause to Gavin on Wednesday. The group included about 10 navigation specialists, many of whom recently retired from JPL. "They have been looking at this since Friday morning following the loss," Gavin said. The navigation mishap killed the mission on a day when engineers had expected to celebrate the craft's entry into Mars' orbit. After a 286-day journey, the probe fired its engine on September 23 to push itself into orbit. The engine fired but the spacecraft came within 60 km (36 miles) of the planet -- about 100 km closer than planned and about 25 km (15 miles) beneath the level at which the it could function properly, mission members said. The latest findings show that the spacecraft's propulsion system overheated and was disabled as Climate Orbiter dipped deeply into the atmosphere, JPL spokesman Frank O'Donnell said. That probably stopped the engine from completing its burn, so Climate Orbiter likely plowed through the atmosphere, continued out beyond Mars and now could be orbiting the sun, he said. Climate Orbiter was to relay data from an upcoming partner mission called Mars Polar Lander, scheduled to set down on Mars in December. Now mission planners are working out how to relay its data via its own radio and another orbiter now circling the red planet. Climate Orbiter and Polar Lander were designed to help scientists understand Mars' water history and the potential for life in the planet's past. There is strong evidence that Mars was once awash with water, but scientists have no clear answers to where the water went and what drove it away. NASA has convened two panels to look into what led to the loss of the orbiter, including the internal peer review panel that released the Thursday finding. NASA also plans to form a third board -- an independent review panel -- to look into the accident.
Metric system used by NASA for many years A NASA document came out several years ago, when the Cassini mission to Saturn was under development, establishing the metric system for all units of measurement, Gavin said. The metric system is used for the Polar Lander mission, as well as upcoming missions to Mars, he said. That review panel's findings now are being studied by a second group -- a special review board headed up by John Casani, which will search for the processes that failed to find the metric to English mismatch. Casani retired from JPL two months ago from the position of chief engineer for the Lab. "We're going to look at how was the data transferred," Gavin said. "How did it originally get into system in English units? How was it transferred? When we were doing navigation and Doppler (distance and speed) checks, how come we didn't find it?" "People make errors," Gavin said. "The problem here was not the error. It was the failure of us to look at it end-to-end and find it. It's unfair to rely on any one person."
It also has helped with the Polar Lander mission, set to land on Mars on December 3 and conduct a 90-day mission studying martian weather. It also is designed to extend a robotic arm that will dig into the nearby martian soil and search for signs of water.Lockheed Martin, which failed to immediately return a telephone call for comment, is building orbiters and landers for future Mars missions, including one set to launch in 2001 and a mission that will return some Mars rocks to Earth a few years down the line. NASA managers have said the Polar Lander mission will go on as planned and return answers to the same scientific questions originally planned -- even though the lander will have to relay its data to Earth without help from Climate Orbiter. Error points to nation's conversion lag Lorelle Young, president of the U.S. Metric Association, said the loss of Climate Orbiter brings up the "untenable" position of the United States in relation to most other countries, which rely on the metric system for measurement. She was not surprised at the error that arose. "In this day and age when the metric system is the measurement language of all sophisticated science, two measurements systems should not be used," Young said. "Only the metric system should be used because that is the system science uses," she said. She put blame at the feet of Congress that she said has squeezed NASA's budget to the point that it has no funds to completely convert its operations to metric. "This should be a loud wake-up call to Congress that being first in technology requires funding," she said, "and it's a very important area for the country."
Several years ago a teacher in high school told my class a story about a Mars orbiter that crashed because one engineering team was working on the project in English units while another team working on the same project was using Metric units. Kilometers and miles are not the same thing. So the lesson here is that for whatever problem you are woking on, remember to communicate the units so people know exactly what your talking about.
Below is an article about the crash from the CNN:
September 30, 1999
By: Robin Lloyd
(CNN) -- NASA lost a $125 million Mars orbiter because a Lockheed Martin engineering team used English units of measurement while the agency's team used the more conventional metric system for a key spacecraft operation, according to a review finding released Thursday.
The units mismatch prevented navigation information from transferring between the Mars Climate Orbiter spacecraft team in at Lockheed Martin in Denver and the flight team at NASA's Jet Propulsion Laboratory in Pasadena, California. Lockheed Martin helped build, develop and operate the spacecraft for NASA. Its engineers provided navigation commands for Climate Orbiter's thrusters in English units although NASA has been using the metric system predominantly since at least 1990. No one is pointing fingers at Lockheed Martin, said Tom Gavin, the JPL administrator to whom all project managers report. "This is an end-to-end process problem," he said. "A single error like this should not have caused the loss of Climate Orbiter. Something went wrong in our system processes in checks and balances that we have that should have caught this and fixed it." The finding came from an internal review panel at JPL that reported the cause to Gavin on Wednesday. The group included about 10 navigation specialists, many of whom recently retired from JPL. "They have been looking at this since Friday morning following the loss," Gavin said. The navigation mishap killed the mission on a day when engineers had expected to celebrate the craft's entry into Mars' orbit. After a 286-day journey, the probe fired its engine on September 23 to push itself into orbit. The engine fired but the spacecraft came within 60 km (36 miles) of the planet -- about 100 km closer than planned and about 25 km (15 miles) beneath the level at which the it could function properly, mission members said. The latest findings show that the spacecraft's propulsion system overheated and was disabled as Climate Orbiter dipped deeply into the atmosphere, JPL spokesman Frank O'Donnell said. That probably stopped the engine from completing its burn, so Climate Orbiter likely plowed through the atmosphere, continued out beyond Mars and now could be orbiting the sun, he said. Climate Orbiter was to relay data from an upcoming partner mission called Mars Polar Lander, scheduled to set down on Mars in December. Now mission planners are working out how to relay its data via its own radio and another orbiter now circling the red planet. Climate Orbiter and Polar Lander were designed to help scientists understand Mars' water history and the potential for life in the planet's past. There is strong evidence that Mars was once awash with water, but scientists have no clear answers to where the water went and what drove it away. NASA has convened two panels to look into what led to the loss of the orbiter, including the internal peer review panel that released the Thursday finding. NASA also plans to form a third board -- an independent review panel -- to look into the accident.
Metric system used by NASA for many years A NASA document came out several years ago, when the Cassini mission to Saturn was under development, establishing the metric system for all units of measurement, Gavin said. The metric system is used for the Polar Lander mission, as well as upcoming missions to Mars, he said. That review panel's findings now are being studied by a second group -- a special review board headed up by John Casani, which will search for the processes that failed to find the metric to English mismatch. Casani retired from JPL two months ago from the position of chief engineer for the Lab. "We're going to look at how was the data transferred," Gavin said. "How did it originally get into system in English units? How was it transferred? When we were doing navigation and Doppler (distance and speed) checks, how come we didn't find it?" "People make errors," Gavin said. "The problem here was not the error. It was the failure of us to look at it end-to-end and find it. It's unfair to rely on any one person."
It also has helped with the Polar Lander mission, set to land on Mars on December 3 and conduct a 90-day mission studying martian weather. It also is designed to extend a robotic arm that will dig into the nearby martian soil and search for signs of water.Lockheed Martin, which failed to immediately return a telephone call for comment, is building orbiters and landers for future Mars missions, including one set to launch in 2001 and a mission that will return some Mars rocks to Earth a few years down the line. NASA managers have said the Polar Lander mission will go on as planned and return answers to the same scientific questions originally planned -- even though the lander will have to relay its data to Earth without help from Climate Orbiter. Error points to nation's conversion lag Lorelle Young, president of the U.S. Metric Association, said the loss of Climate Orbiter brings up the "untenable" position of the United States in relation to most other countries, which rely on the metric system for measurement. She was not surprised at the error that arose. "In this day and age when the metric system is the measurement language of all sophisticated science, two measurements systems should not be used," Young said. "Only the metric system should be used because that is the system science uses," she said. She put blame at the feet of Congress that she said has squeezed NASA's budget to the point that it has no funds to completely convert its operations to metric. "This should be a loud wake-up call to Congress that being first in technology requires funding," she said, "and it's a very important area for the country."
Sunday, March 2, 2014
Ski Day :)
Yesterday I spent a day skiing with my brother and cousin at the Canyon's ski resort in Park City, Utah. If I were a rich man I would ski more often. Still, I manage to go every year and have a great time.
The resort got some new snow on Friday, but it was heavy and wet, especially on the north side of the resort. It was also pretty windy on the north side, so we skied on an unpleasant wind crust for the first few runs. From the Mesoanalysis, a type of weather model that describes the past weather, we can see the strong western winds we were experiencing on the mountain in the morning. This map shows an analysis for the 700 mb level, which is about the height of the mountain peaks. Wind speed and direction are indicated by the orange wind flags. Each full flag represents about 5 mph, so the winds across Utah are between 15 and 20 mph. The time of this analysis is 15z, or 8:00 am MST, two hours before we started skiing.
The weather station at the Canyons also shows that it was windy, mostly blowing from the west. It also warmed up pretty nice by mid-day. The red box shows the approximate time we were are the resort.
The later half of the day we found much better snow on the south side of the resort. The south side is shaded from the sun and the thicker tree cover shielded the runs from strong winds.
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The resort got some new snow on Friday, but it was heavy and wet, especially on the north side of the resort. It was also pretty windy on the north side, so we skied on an unpleasant wind crust for the first few runs. From the Mesoanalysis, a type of weather model that describes the past weather, we can see the strong western winds we were experiencing on the mountain in the morning. This map shows an analysis for the 700 mb level, which is about the height of the mountain peaks. Wind speed and direction are indicated by the orange wind flags. Each full flag represents about 5 mph, so the winds across Utah are between 15 and 20 mph. The time of this analysis is 15z, or 8:00 am MST, two hours before we started skiing.
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| Mesoanalysis |
The weather station at the Canyons also shows that it was windy, mostly blowing from the west. It also warmed up pretty nice by mid-day. The red box shows the approximate time we were are the resort.
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| MesoWest.utah.edu |
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| kbkb (c) 2014 |
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