[ Music/Rainstorm ]
>>High Ice Water Contents are conditions found in large convective storms.
[ Thunder ]
>>It could even be hurricanes, tropical storms, as we're flying in here in this location.
HIWC conditions have high concentrations of ice crystals. The process by which these large
volumes of ice crystals are formed is that you develop an updraft in a warm, moist region. This air
rises, and as it rises to higher altitudes, it expands, because the density and pressure
become smaller. This causes the temperatures to become below freezing. So then the vapor
condenses out, it forms into ice crystals. The top parts of these large convective complex
can expand over hundreds of square miles. And so they're something that's not easily
avoided and aircraft daily fly through these type of scenarios. What we don't know is what
is the concentration of ice crystals that may occur in these clouds. They're not easily
detected by radar because of their small size. This leads to aircraft sometime flying into
these ice crystals because they don't sense that there is a threat from using their radar.
These high density, or volume, of ice crystals then can result in the engines losing power.
And also they can result in certain sensors on the airplane not functioning properly.
One of the things that we want to do is to utilize radars, existing radars that are onboard
the aircraft, and develop algorithms which will be able to detect these high levels of
ice crystals that might be dangerous and allow us to navigate through thunderstorm anvils
or cloud masses that are produced from the large convective systems.
[ Radio Chatter ]
[ Airplane taking off ]
[ Wind ]
[ Music ]
>>PRCO radio, NASA 817...
>>NASA 817, go ahead...
>>Yes ma'am, just to keep you appraised of what we're planning to do, we're gonna be working
what's left of Hurricane Danny between 18 North 57 West and 15 North 57 West probably
within about 20, 30 miles laterally back and forth for about 2 hours.
>>Ok, thank you.
[ Music ]
>>Mission, you getting readings?
>>They're asking for HIWC readings.
>>I see the IKP is registering a higher value, we are in High Ice Water Content now
>>Pilots are commenting it's pretty heavy.
>>Lyle, what did we get for a peak there?
>>Just at around 2 grams.
[ Music ]
>>What we are doing here with our in-situ measurements is trying to relate the Ice Water Content
levels to what the radar signatures are being recorded by Steve's systems.
>>Here we are, collecting weather radar data and in situ probes, and correlating the two
along our flight path. The radar that we're using today is a commercial weather radar.
In front of me you can see four different displays- various different tilts of the radar
antenna. One that's significantly above our flight level, one at our flight level, one
below our flight level, and then one significantly below our flight level. With that volume of
space that we're covering, we're hoping to be able to detect signatures, things that
are like a thumbprint or a fingerprint of this atmospheric condition.
>>We have four instruments. We have an isokinetic evaporator probe. What it does is the ice
crystals are going inside the isokinetic probe, where all of that ice crystal is evaporated.
We're measuring the water vapor evaporating through those particles to get the total condensate
water vapor. We have three other probes on the wingtips, they measure the ice particle
sizes. This screen over here is one of the particle probes that we have onboard the airplane.
We're getting a representation of the particles that we're flying through. What we see right
here in this particular display is the satellite IR depiction, with the flight track. What
we're trying to do is find regions of High Ice Water Content, which is typically found
in the cold cloud top area, which is depicted by the white and purple areas. We are working
with the information from the ground, from the satellite information, to pick out waypoints.
We pass that information to the mission manager, who provides it to the navigator, who provides
it to the pilots.
>>PRCO, NASA 817 we have one other point I'd like to work, it's 1-5-0-0 North, 5-5-0-0
West.
>>We're monitoring and making sure that we are getting into the kinds of conditions that
we are wanting to get into.
You can see we're currently flying in the weather and looking for the icing. And
you can't see anything out the front, so we're primarily relying on our instruments to know
where we're going and make sure we're going where we need to go and collecting the data
that we need.
[ Ice hitting window ]
>>Ice water went to near zero, and is now trending back up.
>>So Steve, in that last run, when we reached about two, radar, was it still green?
>>Yeah, no, I think it was even black.
>>This is a pretty interesting section here. Just like Steve predicted.
>>Tim, I think you've got a pitot disagree.
>>We have a pitot issue right now.
>>We lost both airspeeds.
>>This HIWC mission is a little bit different than most of our science missions. You know,
our concern that we're flying our four engines into engine icing conditions. We are also
concerned about our pitot static and our total air temperature probes, that they could ice
up during the mission. With both pitots failed, we can continue for about ten more minutes
in the failed, anomalous situation. But we're looking for a way to get out of the icing
condition. Typically, it's just flying out of the clouds and things will clear up, the
other way is to actually descend.
They're coming back. Looks like they're back. Science, our pitots are back.
>>Steve, will you be good for East-West runs?
>>I should be.
>>Maybe we can get a recommendation from the ground on what those might be.
[ Music ]
>>It looks like we're starting to get the decline in ice water. We're down about six tenths
now, half a gram, six tenths.
>>Ok. Nice profile though, eh? Gee.
>>It's good data.
[ Music ]
[ Airplane Landing ]
>>This has been different. We had our anomalies with some of like, the air data computers,
which loses the airspeed indication for the pilots. We had those happen because of all
the icing and stuff that was getting on the pitot probes. Kind of got everybody on edge,
and everybody's just kind of making sure that we're staying within our correct airspeed
and we're not, something else is not being effected at the same time.
>>We're flying in the soup, as pilots would call it, because there's clouds all around.
The aircraft itself is getting exposed to a lot of moisture and cold air, when you start
coming out of it to return to base, it thaws out.
[ Music/Background Noise ]
>>We have to check the radome occasionally,
especially after flying for awhile in there, because those small particles can start eroding
away the coating. And the moisture inside the radome will make the radar ineffective.
>>What we were able to accomplish during this 3 week campaign, we had ten flights, and we
were able to gather the radar data and the in situ measurements for high ice water content
data. It was a complete success, we went way beyond my expectations. So, thank you DC-8.
[ Music ]