PASCAL meets ACLOUD

Wednesday afternoon the PASCAL crew visited us at the airport. After we explained our instruments to them, we took one large group pictures of the PASCAL and the ACLOUD team together.

Visit time

Yesterday Polarstern arrived in Longyearbyen. So many of us visited Polarstern in the morning and in the afternoon the Polarstern people visited our airplanes.
After meeting Polarstern many times from above, we were really happy to set foot on the ship. We had a look at the working conditions and all the instruments on board.
Also the Polarstern group was really interested in our aircraft and the installed instruments.
In the evening we all had together a nice dinner and party.

The ACLOUD campaign has still one week to go, whereas the PASCAL campaign ended yesterday.

9th encounter

But this time, they met Polarstern for real :)

Rush hour at LYR

Unexpected long queue at the airport check-in at 1 AM in the middle of the "night". That's because some commercial flights to Oslo leave at 2:30 AM. Four hours later, Polar 5 / 6 took of for another combined Polarstern - A-Train mission. This morning CloudSat and the other satellites of the A-Train constellation twice pass Polarstern in close distance, once at 8:00 and after one orbit a second time at about 9:30 local time. This chance will be used to combine all three types of remote sensing, ground-based, airborne (Polar 5), and space-borne with in situ measurements by Polar 6. Just don't look into one of the lidar laser beams

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No flight = time for waffles.

Today again the weather did not allow a flight. A occlusion does pass Svalbard... It is cloudy, quite dark and it rains... At the same time, these clouds are also in the area of Polarstern, where measurements would have been quite complicated. So we decided not to fly today and use the day for preparing the next days.














This free time also can be spent to make some waffles. In the hotel of our meeting room every afternoon a waffle iron is setup with all incredients needed for a good afternoon snack. Some of us like it sweet with jam, some heartly with norwegian cheese.

Leipziger high-quality work

Polar 5 and Polar 6 are airborne again. Finally, the weather improved, no fog today,... and we again meet Polarstern at roughly 82° N. Today, boundary layer profiles will be sampled at different latitudes between Polarstern and the northern tip of Svalbard. 

Therefore, both aircraft fly legs of roughly 8 min in different altitudes. Pictures from the take off preparation are posted here:

https://twitter.com/MarioMech1/status/874968830128336897

Meanwhile some of us are still left on ground and spend the time in the Spitzbergen Hotel, formerly  known as Funken-Hotel. This is one of the older buildings in town. Walls are labelled with old construction drawings of the mining sites. Many of them were obviously build by german ingeneurs. The lorry trail, actually, by a company from Leipzig... 

Fog - Forecast vs. Reality

After two days when we were grounded because fog was forcasted but not present directly over the airport, today forecasts look better and no fog was predicted by the latest TAF from yesterday.

As Murphy's law predicts, of course today the fog was acutally present and again allowed ny flight activities with Polar 5/6. We used the time to drive above the fog and take some sunny pictured on top of the Advendsdalen.

Other impressions of today's fog:
https://twitter.com/TDonth/status/874201426993479680
https://twitter.com/TDonth/status/874170905454407680

Later we followed the landing approach of a commercial aircraft on FlightRadar24. Even this aircraft equiped with automatic landing systems which allow to fly in non-visual conditions did need about three approaches until it finally landed safely.

As time goes by...

...while the snow melts down.

Since the two aircrafts are grounded due to fog unfavourable for takeoff and landing at LYR airport one can take a look back in time for the last weeks. While already very valuable data could be collected on the research flights also the landscape in Longyearbyen changed quite significantly. Especially when adding two pictures from before the campaign in March and April.

Currently the snow suffers from the warm and moist air transported to the area! Arctic amplification on even shorter time scales...?...no, it's just spring! :-)
With the wind direction turning more to the north flying conditions are supposed to improve over the course of the week. Keep fingers crossed!

Grounded due to fog

Webcam at Zeppelin Mointain

Unfortunally, we are grounded scince two days. This time the problem is the local weather. A warm and moist air mass was transportet into Svalbard producing low clouds up to the position of Polarstern. Low clouds and especially fog as predicted in the aviation weather forecast are not favorable for starting and landing an airplane under visual flight conditions. That's why had to cancel flights yesterday and to postpone this morning.

The strange situation is, that locally, no clouds or fog are present in Isfjorden while in Ny Alesund, the Kongsfjorden is completely overcasted as shown by the webcam at Zeppelin Mointain. This is certainly due to local effects of the mountains and fjords. Obviously these local conditions can not be precisely forecasted by the weather models... One reason why we are here and aim to characterize such clouds in detail. Only that these clouds now stop us from measuring. Let's hope for other winds and no clouds at the airport.

Another joint flight toward Polarstern

After a two day break, today Polar 5 & 6 are again up in the skies. Destination: Ny Alesund -- A-Train -- Polarstern -- Ny Alesund -- and back.

As it happens, Polar 6 always takes off first, then Polar 5 follows. After 13 flights, this already became kind of a ACLOUD ritual. As Bill, our Polar 6 pilot in command, said: "P6 always goes first!".

This picture was taken during one of the last starts. So why is the Polar 5 schadow not in place? Or is it just another Polar Shark?

Take care when next time passing the glacier!

We could start playing some good music via the headphones having 5 hours P5/6 missions.

Second week over and spring arrived

The second week of ACLOUD flight activities ended with some spectacular clouds in the Isfjorden and spring like temperatures in Longyearbyen.
Polar 5&6 did fly for a fourth time to RV Polarstern. Yesterday it was the third time in a row we could sample the "same" clouds. At least clouds in the same air mass, which was warm air transported from south-west and sliding over the cold sea ice. The measurements worked well and we were quite surprised, that these clouds still produced a lot of ice crystals.

Also in the Isfjord a special cloud was present all the day close to the mountians. Streched like a snake along the slope of the mountaind, it reminds to the Maloja Snake in the Alps.


Here in town and sourrounding, the snow melts very quick. Also some first tiny flowers were discovered.

Fascinating Clouds in False Color

During ACLOUD we often look at satellite images to determine the coordinated of the flight pattern and have a most recent look on the weather or to analyze in which area and clouds regime the last flights have been finally flown. One instrument we like is MODIS for which a lot of images and products are available online. Looking into the detailled images you can discover a multitude of different cloud structures and phenomena. Especially when using false color images such like these:






Clouds pressing into the fjords...

Vortex like clouds at the southern tip of Svalbard...

Inhomogeneous convective clouds?

Strato cumulus in different scales...

Non-Flight Day Activities

Yesterday no flight was scheduled because the local weather was expected to show low clouds and limit the flight conditions. As it may happen, the day finally was almost completely sunny. Some of the ALCOUD Team used the time to participate in the Spitsbergen Marathon. A 10km run, the Spitsbergenmila, was the goal, In total, about 300 runner were on the track in the 10K, full and half marathon and guarded by a polar bear watch outside the town. All of the ACLOUD Team finished having a lot of fun on the scenic track down to the airport which we usually only go by car.

Polly without XT

On Polarstern the TROPOS is operating a lidar system PollyXT to measure cloud and aerosol profiles with a strong laser beam (polly.tropos.de). Here in Longyearbyen we also could find some Polly although it will not last until the end of ACLOUD. 

Half an hour ago Polar 5 and 6 departed from Longyearbyen to visit the PollyXT at Polarstern. On board Polar 5 we operate a similar instrument, the AMALi (Airborne Mobile Aerosol Lidar). Let's hope for good measurements. 

Strange holes

Any idea about these holes?

Meeting Polarstern

On Tuesday Polar 6 had the first meeting with Polarstern. One goal was measuring aerosol next to Polarstern. On Polarstern aerosol measurements are carried out as well, so comparisons are possible.
Yesterday, for further comparisons and also for detecting clouds even in low level flights, the pointing direction of the LIDAR was changed to look upward, like it is doing on Polarstern.

Terminus of the glacier close to Longyearbyen

At the beginning of the yesterday flight, a glacier on the way to Ny-Aalesund was overflown in low altitude to measure the albedo and the reflectivity. At the AWIPEV observatory in Ny-Aalesund all remote sensing instruments were running and are providing a good opportunity for comparisons.
The meeting with Polarstern and Polar 5 & 6 went really well and the measurements provided good results.


Also yesterday the pilot crew of Polar 5 changed as scheduled and a new pilot and a new copilot had control of the plane. In the next days also the new pilots of Polar 6 will arrive.

Polarstern breaking ice

Not an albedo flight

Yesterday we aimed the second time for a meeting with Polarstern. Initially planned as a clear sky flight to measure the surface albedo of sea ice in different areas and close to Polarstern, this plan did not work out in detail. Exactly in the observation area we encountered again a large field of thin low level clouds. The forecast models did predict that these clouds will disolve in the evening but they did not that fast showing that weather models still have serious ploblems in predicting clouds over sea ice.

Due to the flexibility of Polar 5 & 6 we quickly could change our plans during the flight and switched into cloud mode flying below, in, and above clouds. The meeting with Polarstern also had to be adjusted. When Polarstern hit the sea ice, the cruising speed drastically decreased and the predicted position was far from the location of Polarstern during the flight. Communication with the tower of Polarstern worked well and we finally found the ship. Again we sampled the clouds in different altitutes and added legs for remote sensing and the aerosol and trace gas profile.
Obviously people on board Polarstern were aware of our overflights and took some pictures.