Flight number six: Stratocumulus cumologenitus



After a cold front passage during the night from Friday to Saturday cumili humili clouds were present over Graciosa during the late morning. As forecasted Stratocumulus cumologenitus clouds showed up during noon and slowly became denser. As planned ACTOS and Smart-Helios were ready for take-off at 2.30pm. Soon the Helicopter started to lift the two measurement systems up towards the clouds. Besides HaloHolo all instruments were running and recording. Smart-Helios take-off did not happen as smoothly and unfortunately data recording failed after half an hour of flight.
First the helicopter flew north to towards the open ocean while climbing up to 2000m altitude. At 200m thick stratocumulus cloud was encountered in 500m below 5K per 100m strong inversion. The cloud had a liquid water of 5g/m^3 maximum. Though, another weaker inversion was located 500m above the other one.
The lonely mountain (by Birgit)
Two aerosol legs still in North-South direction were then flown in 2000m and 1300m, respectively. In the cloud tops one could see clearly the influence of Graciosa as clouds over the island were deeper and had more a cumulus character. In the distance far south the lonely Mount Pico overlooked the clouds and some cumulus mediocris were at its side.
Realizing that more denser stratocumulus were located west of the helicopter track it was decided to fly legs through the clouds in East-West direction. A couple of legs within in the clouds were then flown. Liquid water contents inside the clouds still had maximum of 5g/m^3 at cloud top. Due to an approaching plane, the cloud-flights had to be stopped for a while but afterwards three porpoise dives were flown all the way through the inversion and the clouds. Before it had to go back to the airport, a last leg was flown 200m below the cloud base in order to catch some information of CCN.
As the northerly ground wind was rather gusty ACTOS landing was quite rough, but besides a broken skid on ACTOS, nothing was damaged, luckily.

posted by Kai


Kommentare

Kommentar veröffentlichen

Beliebte Posts aus diesem Blog

Final flight or one more?

Bild
Below the helicopter Eye-to-eye with a cloud The helicopter returned from Pico with everyone smiling. As ACTOS and SMART-HELIOS were ready for take-off, the smile of the pilots got a bit smaller due to their reduced lunch break. But nevertheless, we started at 12:55. As the Stratocumulus was too far to the north, we decided to make some Aerosol-legs. In total we did four of them on 7000 ft, 4000 ft, 2000 ft and 1000 ft, so one above the inversion and 3 below. We saw some slashes of wales. But every time we got closer, they disappeared again. During our flights we overflew and circumnavigated some single cumulus clouds. In the end, the only stratocumulus like cloud was in the lee of the island. On our way back, we sampled this cloud flying upstream to the island. Then we safely returned to the airport after almost two hours. SMART-HELIOS worked again the whole time with a reduced sensor package, while the inertial moment unit of ACTOS failed. Thus, it will be hard to corre
Mehr anzeigen

Short bye to Pico - My visit at Graciosa and the Helicopter-flight on Monday, 17th of July

Bild
Clouds over Graciosa - the only clouds that were close enough that day Last week Silvia asked me if I am interested in visiting the scientist-group at Graciosa and if I want to see how research and daily work is going on at Graciosa-airport. After shortly thinking about it (and some slight worries, that in the meantime when I am at Graciosa there could be another shut-down at the ICO-Station on Pico mountain) Birgit organized the flights. The trip to Graciosa took a whole day, because there were no direct flights from Pico to Graciosa and so I started around 9 am. First I had to take the ferry from Madalena to Horta and had my first flight from Faial to Terceira. After waiting a few hours at Terceira-airport I took of at 16:10pm and 30 minutes later I arrived at Graciosa. View from the helicopter It was nice to see how the group worked together and after a nice welcome, they introduced me a little in how everything works at the airport. The next day
Mehr anzeigen

It’s hard work to get good data

Bild
At some days, it is particularly hard work to get good data. Today was such a day. As the weather was still promising after the morning flight, we decided to have a second flight in the afternoon. Some stratocumulus cloud fields were present, so we cloud people wanted to go for catching some of them. The plan was to start directly after lunch break, but while sweating in the helicopter, we had to wait for the controller to finish lunchtime as well. Then, after starting the engines, a beep and a red light indicated a problem with one of the two power generators. The heli can fly with only one generator and a battery as backup, but the ACTOS data monitoring had switched to battery mode. Finally, after the usual start procedure “HELIOS airborne – continue climbing – ACTOS airborne” the ground crew noticed, that ACTOS wasn’t pointing into the direction of flight, so we decided to return to the airfield. The ground crew couldn’t find any suspicious failures and ACTOS was flying in
Mehr anzeigen