July 12, 2010
Today's data, at first glance, seems a bit insane. However, before anything else, it should be stated that the day was exceptionally cloudy. It was so cloudy that haviland could not take any Microtops data because she never saw the sun. Today also had a high pollen count, with pollen supposedly in the "dangerous for asthmatics" values. Also, there was a yellow air quality alert. Worse than green, but not as bad as orange. But dark grey clouds took up 75-85% of the sky almost all day. There was a thunderstorm last night, so Haviland was interested in seeing if that showed up in teh temperature graph. However, what showed up more than anything on the graphs were the high returns at high altitudes.
The data run today began at 1:02pm GMT and lasted until 4:08pm GMT, when it started raining. It was not raining hard, but Haviland closed the hatch just to make sure. It sprinkled outside, on and off, for the next five hours, so Haviland did not start EARL up again after the initial rain.
All of that having been said... look at those clouds!
Up at 7 kilometers, 8 kilometers, and 10 kilometers, there were clouds almost at the exact same time lasting from 1:50pm GMT until 2:30pm GMT. Then there was another cloud that was about a kilometer thick that lasted from 2:30pm GMT until 3:00pm GMT. These cirrus clouds only lasted for a short period of time, but the backscatter returns were very high. Two more clouds appeared simultaneously at about 8 and 10 kilometers for about thirty minutes at 3:00pm GMT. And all of that is only what was happening in the upper atmosphere!
In the lower atmosphere, there was a dense cloud at about 4.5 kilometers that lasted from 1:02pm GMT until 1:40pm GMT. Then, at about 3:00, there started being lower-range clouds that eventually led to a rain shower. The clouds stayed mostly at 1 kilometer, but a few got all the way up to 2 kilometers. At 4:00pm GMT, there were several layers of clouds: clouds at 1 kilometer, clouds at 2 kilometers, and possibly more above that point. When it started raining, there were three very distinct cloud layers with a few meters of each other, which seems to be the signalling point for "it's about to rain!"
The data run today began at 1:02pm GMT and lasted until 4:08pm GMT, when it started raining. It was not raining hard, but Haviland closed the hatch just to make sure. It sprinkled outside, on and off, for the next five hours, so Haviland did not start EARL up again after the initial rain.
All of that having been said... look at those clouds!
Up at 7 kilometers, 8 kilometers, and 10 kilometers, there were clouds almost at the exact same time lasting from 1:50pm GMT until 2:30pm GMT. Then there was another cloud that was about a kilometer thick that lasted from 2:30pm GMT until 3:00pm GMT. These cirrus clouds only lasted for a short period of time, but the backscatter returns were very high. Two more clouds appeared simultaneously at about 8 and 10 kilometers for about thirty minutes at 3:00pm GMT. And all of that is only what was happening in the upper atmosphere!
In the lower atmosphere, there was a dense cloud at about 4.5 kilometers that lasted from 1:02pm GMT until 1:40pm GMT. Then, at about 3:00, there started being lower-range clouds that eventually led to a rain shower. The clouds stayed mostly at 1 kilometer, but a few got all the way up to 2 kilometers. At 4:00pm GMT, there were several layers of clouds: clouds at 1 kilometer, clouds at 2 kilometers, and possibly more above that point. When it started raining, there were three very distinct cloud layers with a few meters of each other, which seems to be the signalling point for "it's about to rain!"
The depolarization returns from today are really quite interesting. All of the cloud layers perceived on higher altitudes of the Range Corrected Backscatter graph show up on the Depolarization Ratio graph, indicating that the clouds had high ice concentrations. The clouds at 8 and 10 kilometers were likely cirrus clouds, considering the high backscattered depolarized light counts. However, it is very interesting to note that the cloud at 8 kilometers that lasted from about 3:00pm GMT until 4:00pm GMT had just as strong of a backscattered depolarization signal as the boundary layer and lower atmosphere in general. What does this indicate? A cloud at that height should have ice within it due to ice freezing at altitudes above 7 kilometers, but if there is ice in the cloud, then that ice showed no stronger returns than the lower atmosphere. This could mean several things, the most important two of which are: A) the seemingly-strong signal coming from the Range Corrected Backscatter graph was not actually
that strong and so the returns on the Depolarization Ratio graph should be expected to be that
low, which can't be the case;
B) the weak return from the Depolarization Ratio graph should actually be considered a strong
return since the sections around it are just noise, which is possible; or
C) the strong returns on the Range Corrected Backscatter graph versus the weaker returns on
the Depolarization Ratio graph indicate that the cloud at 8 kilometers was composed of
more water than ice, which is less likely since clouds at that height should be almost all ice
and since it was not a significantly warm enough day to heat up the atmosphere at that altitude.
Another important question revolves around what was occuring at about 4.5 kilometers from 1:02pm GMT until 1:40pm GMT. There seems to have been a very thin cloud at that altitude, however, the cloud almost seems to blend into the atmosphere below it all except for the top part of the cloud, which produces significantly stronger returns. Is that an actual cloud? Is it a plane contrails? Planes probably do not fly that low in the atmosphere, but it is so thin that it does not seem to be a cloud. Clouds at that altitude are usually at least somewhat thick, but this one seems severely thin. What is happening?
that strong and so the returns on the Depolarization Ratio graph should be expected to be that
low, which can't be the case;
B) the weak return from the Depolarization Ratio graph should actually be considered a strong
return since the sections around it are just noise, which is possible; or
C) the strong returns on the Range Corrected Backscatter graph versus the weaker returns on
the Depolarization Ratio graph indicate that the cloud at 8 kilometers was composed of
more water than ice, which is less likely since clouds at that height should be almost all ice
and since it was not a significantly warm enough day to heat up the atmosphere at that altitude.
Another important question revolves around what was occuring at about 4.5 kilometers from 1:02pm GMT until 1:40pm GMT. There seems to have been a very thin cloud at that altitude, however, the cloud almost seems to blend into the atmosphere below it all except for the top part of the cloud, which produces significantly stronger returns. Is that an actual cloud? Is it a plane contrails? Planes probably do not fly that low in the atmosphere, but it is so thin that it does not seem to be a cloud. Clouds at that altitude are usually at least somewhat thick, but this one seems severely thin. What is happening?
Also, look at the first clouds that show up at about 7 kilometers to 8 kilometers at 1:50pm GMT. On the Range Corrected Backscatter graph, the backscattered light is most intense at the bottom section of both clouds, down at the right end. In the Depolarization Ratio graph, the backscattered depolarized light is more intense on the underside of the clouds on the left. Does this signify anything? We should keep an eye out for similar signals in the future, but for now, it is probably just food for thought.