2nd part of SOA flights on the 1st, 3rd and 4th of July:

1^st of July:

On Sunday 1^st, the Zeppelin equipped with the CL5 – SOA layout, started the flight with a height profile in Ozzano. Afterwards it continued to Monte Cimone, a mountain with a measurement site in the Apennines. Since some of the instruments there are also characterizing aerosols, this flight permitted to get a better insight into aerosol properties at different heights for this mountain site. To reach the mountains, we first crossed Bologna and then followed a valley in the west of the city. In this way we could measure the transition of air masses coming from rural and urban sites. During the morning hours the wind was mostly coming from the Monte Cimone, which is one of the highest peaks in this part of the Apennines but later on the wind basically stopped. While following the valley, the Zeppelin mostly flew at low heights of about 500ft. At the same time, the measurement vehicle MOSQUITA followed the Zeppelin’s path on the ground. 

3^rd of July:

On this day a longer flight was chosen towards Bosco Fontana. This is a protected forest region north of Bologna, very close to Mantova. The forest consists of broad-leaved trees, which is the common local tree type for this region. This target was chosen to support measurements that are taking place there within the scope of the Èclaire project. This is an EU funded project that investigates climate change and pollution impacts for European ecosystems. 

 

Our objective was to start the flight at 6a.m with CL5-SOA layout, reach Bosco Fontana and circle around this area at different height levels. Although the transfer flight towards the forest turned out to be trickier due to strong head winds, we managed to do three profiles at three different heights just above the forest. On this specific day the overall outside temperature was of only 31°C, compared to the almost 40°C of the previous days, which allowed us to reach each time the maximum height of 2000ft without having to release any helium. On all three occasions we reached above the planetary boundary layer, which was clearly visible in the measured particle concentrations. While doing these circles, the MOSQUITA followed us on the ground.

On the way back to Ozzano airport we basically followed the Po River towards the south, passing several industries. Finally the Zeppelin landed at 11:35 a.m. 

4^th of July:

On this day the flight to Monte Cimone with CL5- SOA was repeated since there had been some problems at the ground site on the previous flight. At 6a.m. the Zeppelin was headed to Bologna, crossed the industrial zone and flew into the valley that starts west from the city. Again the MOSQUITA could follow the Zeppelin path very well through the valley. During this 5 hour flight, the Zeppelin went back and forth between industrial zone and mountain site to detect differences in air masses coming from the rural and urban sites.

Summary of the last weeks

First of all, apologies for not updating this blog sooner. The last weeks have been filled with almost non-stop flying. When the instruments did not need flight preparations, calibrations or other maintenance, the scientists used every available minute to prepare quick-look-data, so the next flights could be planned based on the days observations.
To give an overview of what has been done so far, the past days are summarized individually below.

14.06.2012

On Thursday the 14th of June, the weather finally allowed for a start of the transfer flights. On this day, the airship was moved to Wels (AT) from Friedrichshafen (DE). The cabin layout used for the 14th and all other transfer flight days is the photochemistry centered CL8.

15.06.2012

On Friday, the Zeppelin flew from Wels (AT) to Gorizia (IT/SI). To be able to make this big distance around the Alps, it was agreed upon that no scientific operator would be on board for this flight.
Of course, this situation worried the scientists a bit, but all instruments ran without problems throughout the flight.

 

16.06.2012

On Saturday, there was a technical problem with the Airship. It was thought that this would prevent any flight for that day, but the Zeppelin employees worked on the problem swiftly and had the broken part replaced by noon. The Zeppelin was then flying across the adriatic sea and arrived at the local airport in Ozzano (IT) at 6 pm. This airport is serving as the base of operations for all flights during the 2012 Po-Valley phase of the PEGASOS field campaign. The scientists were welcomed by the bolognese institute ISAC-CNR for a kick-off-meeting. In this meeting, the available ground-based measurement sites and the instrumentation available on the Zeppelin were presented to an interested scientific audience. Also, procedures and lines of communications for the coordination of the measurements were established.

 

17.06.2012

Sunday was reserved for maintenance on the instruments and on the airship.

 

18.06.2012

On Monday, still having the photochemistry package on board, we decided to do height profiles at St. Pietro Capofiume (SPC), where a supersite (english description here) of ISAC-CNR is located. To characterize the chemical composition of the atmosphere during breaking up of the nocturnal boundary layer, the flight started at 4:50 am and ended at 11:30 am. By ending the flight at this time, we also preserved the instruments from damage by the extreme temperatures of 36°C in the shade (reached in the early afternoon) and much higher in the light.
In the evening, the slightly cooler temperatures were used to change the cabin layout to the nucleation-centered CL9.

CNR supersite in St. Pietro Capofiume

19.06.2012

In the days before Tuesday, the researchers at the SPC supersite observed new particle formation events almost every day. So for the 19th, the Zeppelin flew to SPC with the freshly installed CL9 package to explore the vertical extent of nucleation. The results of this day are still under discussion, also at the ground site there was no very clear nucleation observed.
On this day, the Zeppelin was accompanied by the mobile laboratory MOSQUITA of the swiss PSI institute. The evening was again used for a cabin layout change to the secondary organic aerosol package CL5. 

MOSQUITA mobile laboratory

 

20.06.2012

On Wednesday, the CL5 package flew to SPC for height profiling. Interestingly, a clearly different evolution of aerosol composition in time has been observed for the different altitudes, until the differences disappeared at around 1 pm.

Nitrate concentration evolving over time, datapoints coloured by altitude.

 

21.06.2012

On Thursday, still operating CL5, the Zeppelin did transects between the northwest an the southeast, going as deep into the valleys of the Apennines as buoyancy and thermal activity allowed. For this day, the chemical weather forecast predicted a plume of polluted air being transported from the east of the Po-valley to the west, through relatively clean air brought in over the Apennines. Judging from quick-look data, this plume was existent and has been cut into with the Zeppelin several times.

 

22.06.2012

On Friday, the Zeppelin flew with the CL5 cabin layout towards the adriatic sea via SPC and back again. To our surprise, we did not see a big difference between land and sea with most instruments. The NOx instrument did see an increase in NO2 at the coastline, which can probably be attributed to the highways there. The Zeppelin started at 6 am and returned at 10:30 am. In the afternoon, there was a press conference to inform the local media about the project.

23.06.2012

After nine days of almost non-stop action, scientists and Zeppelin crew retreated to a well earned day off on saturday.

24.06.2012

On Sunday, the airship left Ozzano at 9 am, flying past SPC and to the adriatic sea once more. From there, a few transects to the east-nordeast were flown, exploring the variability of atmospheric compositon and aging of airmasses. The airship returned at around 3 pm, most instruments on the verge of shutting down due to too high temperatures. In the evening, the cabin layout was changed to the photochemistry package CL8.

 

25.06.2012

On Monday, the photchemistry package was used to investigate the atmospheric composition at Bologna and its downwind region on that day. The flights included going up in the valleys of the Apennines again.

 

26.06.2012

There were thunderstorms with rain predicted for Tuesday afternoon. Weather like this decreases the condensational sink, thereby increasing the likelihood for new particle formation events. With that in mind, the cabin layout was changed to the nucleation package CL9 in the morning.

27.06.2012

Today, the nucleation package left for the SPC supersite in the early morning. There, the Zeppelin flew circles in different heights. Ground based measurements at SPC seem to indicate a nucleation event, so we are all excited to find out about the results of the Zeppelin-based measurements at different altitudes.

Transfer to Italy - update

After two weeks in Friedrichshafen, the Zeppelin and the scientists are now eager to get moving to Po valley in Italy. There, we will have the longest part of our 2012 campaign.
Unfortunately, weather with heavy rain prohibits flights at the moment. As there is a high pressure area expected to be inbound, we are hoping for a start on wednesday afternoon/thursday morning from Friedrichshafen.

Depending on exact weather conditions, the flight will lead to Wels (AT), or Graz (AT) directly.
The goal is then to make it to Gorizia (IT/SI) or even Ozzano (IT) directly on Friday.

Make sure to check out the Zeppelin location on our tracker if you are planning to see the airship fly!

Science at Sunrise

Guest Writer: Glenn M. Wolfe, University of Wisconsin, Madison

Like a delicious cake, that atmosphere is comprised of many layers. The thickness of – and mixing between – layers is determined by a number of meteorological phenomena that vary across time and space. Most terrestrial life on the Earth dwells in the lowermost region, the planetary boundary layer (PBL). Because humans are creatures of the surface, the immediate impact of our emissions is strongly felt here. This brings to mind the intriguing question of how the atmosphere would respond to a future world with flying cars, but I diverge…

The height of the PBL is mainly controlled by the sun. Solar heating at the ground warms the air, which rises while mixing turbulently with surrounding air (for an example of turbulent mixing, watch the steam rise from your coffee). The vertical extent of this mixing can be as much as 1 or 2 km on a hot summer’s day. At night, the PBL collapses and the region of mixing at the surface is shallower (less than 100 m).

These boundary layer dynamics can impact air quality. For example, pretend that the PBL is a box. We emit gases into this box at a constant rate.  If the height of our PBL box decreases by a factor of 10, then the concentration of gases (the amount per unit volume) will increase by a similar factor. In other words, we’re putting the same amount of pollutants into a smaller box. On the other hand, many secondary pollutants – such as ozone and particulate matter, the key components of urban smog – are only produced through sunlight-driven processing of surface emissions.

As a scientific platform, the Zeppelin affords the unique opportunity to characterize the transition from nighttime to daytime boundary layers – to unravel the complex confluence of chemistry and meteorology at sunrise. That is, if you don’t mind working by moonlight.

At 2:15 AM, a dozen drowsy scientists rallied in the hangar to begin flight preparations. An early start was needed to build two instruments into the cabin for the gas-phase photochemistry package (strong winds precluded doing this on the previous day). In defiance of sleep deprivation, spirits were high and we were all excited for this ambitious flight plan. The Zeppelin ground crew and pilots also worked efficiently to ensure an on-time take-off, and at 4:30 AM the airship departed for the Cabauw tower.

After conducting several height profiles around sunrise (6:00 AM), the airship returned to Rotterdam to refuel and then sped back to Cabauw. Based on computer models and previous tower measurements, our Dutch collaborators predicted that the daytime boundary layer would begin to develop around 8:00 AM. To capture this growth and its influence on atmospheric composition, the Zeppelin flew continuous height profiles near the tower.

After five such profiles, the airship returned to Rotterdam and docked at 11:00 AM. The scientists followed their normal routine of post-flight calibrations and celebrated a successful conclusion to our journey in The Netherlands.

We slept well that night.

Preliminary data shows that the Zeppelin did indeed dip in and out of the nascent PBL. Equally remarkable is the fact that all instruments worked properly throughout the flight – a rare occurrence on any field campaign. This truly unique dataset will provide new insights on the coupling between human activities and natural processes.

Google Earth overlay of the Zeppelin flight path (in yellow). The inset shows the altitude in meters as a function of time in blue.

Zeppelin tracker now live

For the last flights in the Netherlands we exchanged the cabin layout back to the photochemistry package. You can now locate the Zeppelin online at:

http://zeppelin.icg.fz-juelich.de/zeppelinlocation/

So have a fun weekend and let us know if you saw the Zeppelin fly by.

Flights over the Netherlands

The last few days have been very busy for the scientists, with flight planning based on chemical forecasts, instrument calibrations, layout changes, quick look data preparation there was little time for anything else. As we can work on this blog only when time allows, we would like to apologize for the lack of updates and summarize the recent events.

Saturday, May 19

On Saturday, we had a flight with the photochemistry-centred cabin layout. The Zeppelin was accompanied by the small research aircraft Sky Arrow of the University Wageningen.

At 11 am local time, the airship lifted off, heading towards Cabauw, where KNMI meteorological tower is located.

There, the Zeppelin flew in circles on several altitudes to get height profiles of atmospheric composition as measured with every instrument.

Coordinated with our Zeppelin flights, a NO₂ sonde was released, to extend these measurements to higher altitudes.

At approximately 4 pm, the Zeppelin had to return, because bad weather was forecasted to come in. Due to this forecast, the Zeppelin had to be made lighter to be able to lift off its rear section while connected to the mast truck. In essence this means we had to take out some of our instruments and store them in the hangar in the meantime. This is greatly improving the safety of the airship at the ground at higher windspeeds.

Sunday, May 20

On Sunday, an inbound weather system grounded the Zeppelin. The scientists made the best of the situation and worked on detailed planning for the flights to come, their instruments and their data.

Monday, May 21

The secondary organic aerosol cabin layout was installed early Monday morning.

At 10 am local time, the airship took off, flight direction towards Gelderland in the east of the Netherlands.

After arriving there, a few circles were flown in different heights over a forest. After that, the Zeppelin flew to a measurement station south of Wageningen, where another height profile was measured. As soon as that was done, the flight continued west towards Cabauw, where KNMI scientists awaited the Zeppelin to release another NO₂ sonde.

After circling on three height levels, the Zeppelin returned to Rotterdam the Hague Airport, where it arrived shortly after 4 pm. The data from this flight are thus for the first time providing us with height dependent information on the aerosol composition in the boundary layer.

As the weather prediction promised rain for the night, we had to uninstall two instruments again to counter the water weighing heavily on the Zeppelin hull.

Tuesday, May 22

According to the forecast for the visibility, which is a limiting factor for Zeppelin flights, the flight for Tuesday was scheduled for noon. Some work was done to replace a broken converter in the power supply rack in the Zeppelin. The occasion was used to also install some ventilation in that rack. Unfortunately, some problems were discovered that forced some of us to climb up the Zeppelin out on the airfield.

Unexpectedly, there was an inspection of the airship and all racks by the Human Environment and Transport Inspectorate of the Dutch Ministry of Infrastructure and the Environment. The inspection revealed no major problems, so we were allowed to continue our missions over the Netherlands.

Happy that it was still possible to fly that day, we watched the Zeppelin taking off at around 5 pm.

As our forecast model predicted a set of emission plumes along the wind direction from northeast, we had decided to do as many cross-sections between Cabauw in the east and the North Sea in the west as the predicted incoming weather would allow. Quick-look data from the instruments verified the existence of strong gradients in the measurements.

After flying to Cabauw  and from there back to the coast and about 30 km out on the sea, the flight ended at around 7 pm. Two instruments had to be removed again for the night to ensure safety for the Zeppelin.

Wednesday, May 23

Unfortunately the weather has a too high risk for thunderstorms, so the Zeppelin is not flying today. Safety goes first! And we probably can use some of the time for producing quick look plots of our data and compare observations with forecasts.

Transfer flight, Mainz-Finthen to Rotterdam

In the morning the weather looked very overcast so that we were not sure if it would clear up for the flight to Rotterdam.

Suddenly the clouds vanished so the Zeppelin could start the second transfer flight at 10:36. As we had good weather conditions the pilots could fly an additional round over the airport so quality assurance measurements could be taken and journalists took nice shots of the Zeppelin. Then we left to heading to Bonn-Hangelar for the tankstop.

On the way from Bonn to Rotterdam we passed Cologne, lignite opencast mining areas and the Forschungszentrum Jülich. Crossing the Netherlands east to west, we passed over different source areas.

Meanwhile the scientists from Germany, Finland, Switzerland and the Netherlands held a first airport meeting to plan in more detail for the next flights and coordinate with our partners performing measurements at Cabauw tower and on board the Skyarrow, a small aircraft equipped to measure meteorological parameters and CO2 and water vapor concentrations and fluxes.

At 18:00 the Zeppelin landed at Rotterdam the Hague airport, where we eagerly awaited it. The operators of the individual instruments got ready to enter the Zeppelin for data downloads, instrument service and calibrations. For the few meters from the hangar to the Zeppelin we have to wear reflective vests to be clearly visible. At 21:30 finally all work was finished for the day and we are looking forward to our saturday flight, where we want to explore the vertical distribution of trace gases and pollutants close to the Cabauw tower.

Some coverage of the Zeppelin landing at Rotterdam and our project can be found at:

nos.nl - video

nos.nl - audio

radio1.nl

First transfer flight, Friedrichshafen to Mainz Finthen

After a delay of 3 days due to rainy weather conditions the Zeppelin equipped with the photochemistry package (CL-8) left the Friedrichshafen airport at 9:30. We had beautiful flying conditions, all the instruments worked without any trouble so far.. The weather was very sunny and cloudless. The outside temperature was about 5 °C so that the Zeppelin could reach heights of about 1500 ft above ground. The cold temperatures led also to good conditions in the gondola so that the scientist and the crew did not sweat a drop. 

On the ground meanwhile the equipment was packed by  the Ground crew and they made their way to Malmsheim the airport for the tank stop and than further to Mainz-Finthen.

The Zeppelin travelled past the svabian alp passing smaller cities as Sigmaringen, Tübingen and the castle Hohenzollern… flying mostly over rural regions covered with forest and some smaller villages heading towards Stuttgart. The measured concentrations of  the Nitrogen oxide, a pollutand mainly from traffic , showed the expected variations and to our surprise even showed the plume from Stuttgart at the forecasted location  but a bit more extended.

 At 11:15 the Zeppelin reached Malmsheim, which is close to Stuttgart, to make a quick refueling stop. Having spent 30 min on the ground we continued our way to Mainz-Finthen, flying over the highway A8 towards Karlsruhe passing Pforzheim.

Karlsruhe was reached at 12:30. The Rhine harbor, a region with a lot of industries especially refineries, was an excellent opportunity to observe the effects of these emissions on air quality. The Zeppelin cycled therefore at two heights over this region. The model forecast predicted low ozone in this aerea, the observation based on the quick look data confirmed. To see this kind of agreement of forecast and reality in realtime is really great.

Having spent 20 min cycling over Karlsruhe the Zeppelin continued its way towards Mannheim passing an agricultural region and the Rhine valley, different chemical conditions to be analzed.

Due to perfect weather conditions the Zeppelin reached Mainz-Finthen at 14:00, way before schedule. So additional measurements were possible above Mainz and the downstream Rhine valley.

At 16:45 the ground crew had prepared the mast, though they had  some delay by traffic, so that the Zeppelin could land.  We were welcomed very warmly in Mainz Finthen by a lot of people waiting to see the Zeppelin NT and our experiments.

As we could see in our quick look data, all instruments had worked well. So we secured our data, performed calibrations in the field, which is very different to the Zeppelin hangar and switched off our instruments for the night.