CARRIBA 2010 & 2011

#16 - Climbing up for the clouds

2011-04-25T17:57:00.000-07:00

Today we had very clean conditions and the lower atmosphere was predominantly influenced by marine aerosol. After a short shower we took off sharp at 13:51 UTC under cloud-free conditions. At the beginning we flew a short horizontal leg near sea level to Charly 1, followed by a vertical profile up to 8.000 ft to Charly 2, as usual. The CCN concentration was very low and almost constant with increasing altitude. It ranged from 50 to 100 #/cm³ at 0.3 % supersaturation. Afterwards we decided to go for low level cumulus clouds above the sea. But in reality the helicopter had to climb up to about 10.000 ft for these clouds, because they were quit convective and developed so fast, as can be seen in the first figure. At about 14:25 UTC, ACTOS had the first cloud contact and by the means of PICT a mean droplet size of about 35 µm was measured. We had the chance to fly on top and at the edge of this cumulus congestus cloud three times. A shift in droplet sizes to larger values was found. Possible explanations for this effect are (a) growing droplets in a still towering cloud or (b) PICT measured droplets at different cloud heights. During the whole flight no cirrus pertubated the radiation measurements, only a very thin fast disappearing stratocumulus was located at our flight altitude. Then we went for other cumulus clouds, some of them contained clearly smaller droplets of about 25 µm and others also larger ones of about 35 µm in diameter, see second figure. Being quite northward of Barbados over the sea and becoming really tired because of the lack of oxygen at this high altitude, we decided to turn back to Charly 2 and to descend down to 3.000 ft, which was approximately the height of the cloud base. A horizontal leg at 3.000 ft to Charly 1 and also one at 1.500 ft was performed on the way back to the airport under cloud-free conditions. Considering the former leg, a maximum CCN concentration of 250 #/cm³ was determined by the mini-CCNc operating in the scanning mode, see third figure. At the higher supersaturation values we can assume that all the potential CCN are already been activated to cloud droplets.

Now we are done, that was our last scheduled measurement flight of CARRIBA 2011 with the helicopter CFNHG carrying ACTOS and SMART-Helios. Many thanks to all contributors and the people who gave me the opportunity to be a part of this project!

Porpoise dives around cloud base

2011-04-24T11:30:00.000-07:00

Today we performed (probably) our second last flight. After the low level leg at a height of 50 m (ACTOS height) above the sea, we started the profile up to 8000 ft (helicopter height). During this time almost all clouds in our measurement area disappeared. Only north of Ragged Point nice cumulus clouds were located above the sea with a cloud top at 6500 ft. So, we decided to chase these clouds. Afterwards, we flew back to our measurement area and investigated conditions around cloud base east of Ragged and Deebles Point. We started with a horizontal leg at a height of 3000 ft, followed by four porpoise flights between 1500 ft and 3000 ft and finished with a horizontal leg at 1500 ft (helicopter height). Before the last leg, the mini CCNC was switched to the scanning mode. We finished the flight with a low level leg above sea heading to the airport.

Flight #14

2011-04-23T12:44:00.000-07:00

For the flight today we took off at 13:26 UTC. After profiling the atmosphere up to 8000 ft we directly started with cloud chasing over the ocean on the eastside of Barbados. Due to the large vertical extension of the first cumulus cloud we choose, we had to ascend again until we reached 8500 ft. For this first cloud PICT was measuring cloud droplets with a mean diameters of 40 µm. Outside the cloud at 0.1 % supersaturation the minature-Cloud Nucleation Counter measured an almost constant value of the total CCN number concentration with 40 cm^-3. After circling this cumulus cloud for several minutes we decided to investigate a slightly higher dissapearing shallow alto cumulus cloud layer. The cloud droplets of this cloud layer were smaller with a mean value of about 20 µm detected by PICT.
Afterwards we began to analyze some smaller low level cumuli. In the following we performed some porpoise flights between 1500 ft and 2500 ft. After almost two hours flight time and without breakdown of any measurement instruments we landed at 15:22 UTC. As you can see in the graph, the total number cocentration of the measured CCN did not changed significantly at different altitudes. At 0.3 % supersaturation it was roughly stable at 100 CCN cm^-3.

Very clean clouds

2011-04-22T11:53:00.000-07:00

After the dust of the last few days we had some very clean clouds today. PICT measured mean droplet diameters of up to 40 μm (see exapmle on the right) and there were only few CCNs. First we started flying a profile in our measurement area, which was soon cancelled to catch the few clouds above the sea (north of Ragged Point) before they move over land. The cloud base was about 1600 ft high. Afterwards we went back to the measurement area and finished the profile from 8000 ft down to 1000 ft. Meanwhile a lot of nice cumuli were carried with the southeastern wind towards us, which we started chasing then. Moving towards Barbados they grew quite fast. During chasing we got too far north, so we went back to the measurement area, where we catched tinier cumuli. Unfortunately, there was cirrus above us almost all the time. Then cloud chasing was finished and we stayed at about 1600 ft below the clouds so the Mini-CCNC could perform the scan mode. Heading back to the airport we finished with a low level leg.

Growing and towering cumulus

2011-04-20T11:19:00.000-07:00

During the weather briefing, we recognized cumulus clouds above the sea. So we decided to catch clouds over the ocean in contrast to the flights of yesterday. After the profile from 180 ft (ACTOS height) to 8000 ft (helicopter height) in our measurement area, only very thin cumulus clouds were below us (see upper picture). Additionally, a slightly increased concentration of aerosols and CCNs was detected in 8000 ft. Thus, we decided to stay there for a 5 minutes long leg. Afterwards, we tried to catch the thin cumulus clouds and recognized growing ones over the island. In the middle of the island, the cumulus clouds towered and their tops were partly separated and drifted eastwards resulting in a compact altostratus layer. That is shown in the lower picture, which also shows a cumulus congestus at the west coast of Barbados including some showers. We catched the thicker cumulus clouds at the east coast of Barbados, while the developed altostratus covered the sky above us. Thus, the radiation measurements were handicapped. On our way back to the airport we found some cumulus clouds, which were not influenced by this layer - but there was cirrus above.

2011-04-20T06:03:00.001-07:00

To show you all what Birgit meant with "a full round-trip around the island" here is a screenshot of our GPS tracking of flight 10.

Biomass burning on Barbados

2011-04-19T16:06:00.000-07:00

After our contact to probably polluted clouds in the morning we had the chance to sample clouds at the same place in the afternoon.
Again we started with a vertical profile from 200 ft (ACTOS) to about 8000 ft (helicopter) in our measurement area. Since there were no clouds off the east coast we decided to fly to the west coast where a couple of mature cumuli stayed almost the complete day - the ones Birgit already observed in the morning.
On our way there we performed a horizontal leg at 6000 ft and recognized increased aerosol number concentration and CCN concentration probably due to biomass burning (see upper picture with one bigger fire in the north of the island).
Finally, we were able to catch the clouds near the west cost (but over land) and performed several cloud passages at different altitudes with ACTOS inside the cloud and at the very top. It was really amazing to watch these big cumuli growing and disappearing right next to each other. It is a pity that my camera ran out of power just as we reached the first clouds... The lower pictures shows one of my last pictures for today.

Clouds over Bridgetown

2011-04-19T12:32:00.000-07:00

Today, we started earlier than usual: take off was already at 9:00 local time. We had almost blue sky above the ocean and only a few scattered clouds above the island. As on the days before, we flew at first a profile from approximately 60 m above sea surface to a height of 8000 ft helicopter height above the ocean. However there were still no clouds around us. We recognized a few small clouds above the northern part of Barbados and started flying there. It took some time to reach this region and the clouds were almost gone when we reached them. But PICT got a few droplets to measure to check if the new setup works better. From the north of the island we recognized that the area around Bridgetown was nearly covered with clouds and asked for permission to fly there.That was approved, thus we followed the west coast down to the area of Bridgetown. Finally we got some more cloud contacts above the city area and at least a chance to check the new settings of PICT. After spending a couple of minutes there the flight time was over and we flew back to the Concorde helipad. From the first quicklook it looks like the cloud was more polluted than those above the sea the last days and was probably influenced by the island (PICT was doing well!). During this flight we made a full round-trip around the island to catch our clouds in the end.

Flight #9

2011-04-18T10:51:00.000-07:00

Today we started our measurement flight at 9:45 local. Directly after departure we performed a horizontal leg with ACTOS at 200 ft above sea level heading to our measurement area near Ragged Point. After reaching this area we began to ascent for a vertical profile up to 8000 ft heading north. During the ascent we recognized a field of small cumuli slightly north of our measurement area and we decided to hunt for them.All systems seemed to work well and we were lucky to catch more cumuli on our way back into the intended measurement area. Arriving there, unfortunately, nearly all clouds disappeared so we stopped cloud hunting to focus on aerosols. Therefore, we performed horizontal legs at 3000 ft and 1600 ft (helicopter) and in between a couple of vertical profiles (like porpoise dives) to characterize conditions near cloud base. First quicklooks from the aerosol data point to weaker dust concentrations which can also be verified by the MPI lidar quicklook.

It never rains in April

2011-04-17T07:57:00.000-07:00

Again Dust and Clouds

2011-04-16T11:33:00.001-07:00

Today the dust layer was still obvious from the lidar plot, but the concentration decreased and it seems to be mixed also into the marine boundary layer. We choose a similar flight pattern as the last days: first a vertical profile up to 8000 ft (helicopter height) followed by a horizontal leg for approximately 20 min within the dust layer. Both were done over the sea without any cloud contact. In general, there were no low clouds above the ocean today, but there were nice cumuli over the island (see the picture below).

Thus we went there and dipped ACTOS into them. Some were really thick up to more than 8000 ft and contained a lot of liquid water. We continued cloud chasing for approximately 40 min in height between 5000 and 6000 ft. Before going back to Concorde helipad we went below cloud level for another short horizontal leg. This layer was obviously influenced by biomass burning, the particle concentrations were relatively high and we could also smell it.

After all, another interesting flight giving probably interesting results about the influence of transported dust on trade wind cumulus clouds.

Evidence of Saharan dust in the marine boundary layer

2011-04-15T16:40:00.000-07:00

A typical size distribution of marine aerosol was measured on April the 9^th at the ground-based measurement station at Ragged Point (red). The Aitken and accumulation mode, seperated by the so called Hoppel-minimum can be seen in the Figure. On April the 15^th a Saharan dust layer with a maximum total number concentration at 2-4 km height was situated above the measurement region. Through synoptic scale advection of these Saharan dust to the measurement region since 14/04/2011 and following downmixing of those particles into the boundary layer, the shape of the number size distribution has changed. Compared to the typical measured number concentration in this marine region (red), the entrainment of the Saharan dust causes an increased number concentration (black) and the typical shape of the Hoppel-minimum gets almost lost.

Flight #07 with a lot of cirrus

2011-04-15T11:08:00.000-07:00

Today we performed our 7th flight with all systems running well. A Saharian dust layer between 2 and 4 km was indicated by the MPI lidar, therefore we startet our flight pattern ( 13:42 - 15:25 UTC) with a profile and a subsequent level flight in 2.5 km off the East coast to get a scan with the CCNC.

An Aster satellite overpass was scheduled for 10:37 local - unfortunately there were only very tiny cumulus clouds over the water and we decided to chase a few clouds over land. We sampled a lot of droplets but for the whole day the sky was covered with cirrus clouds so a direct comparison of our measurements with the satellite data will be difficult.

Finally, we got a few clouds over the ocean before we came back to Concorde helipad. An example of our quicklook monitor inside the helicopter is shown in the picture. The lower time series shows the liquid water content of a shallow cumulus clouds, the upper one is the uncalibrated temperature value.

From (Saharan) dust till droplet

2011-04-14T15:49:00.000-07:00

Today we performed two quite successful measurement flights including a fully functioning PICT! Both flight pattern included a vertical profile up to 8000 ft off the coast near Ragged Point where the dust layer was located. Afterwards a horizontal flight leg was performed to get full aerosol number size distributions and CCN spectra.
Observed CCN concentration lay in the order of 700 per cubic centimeter and the dust was even visible to the naked eye (see picture).
After the leg in 8000 ft we descended and went for cloud chasing. Fortunately, PICT worked very well and recorded lots of drops - even some lucky ones around 55 microns. Thus, last night's work was definitely worth it.

Thanks to Tina - we both edited this post.

Getting a taste of some juicy cumulus clouds

2011-04-13T20:59:00.000-07:00

Today gave us the chance to get a first taste of some juicy cumulus clouds with the phase Doppler interferometer (PICT), recently arrived from Michigan Tech thanks to grad student and courier extraordinaire Matt Beals. The flight began at 09:45 local time and after a vertical profile to 6500 feet we dropped low enough to sample the tops of actively growing cumulus clouds at a flight level of approximately 3500 feet. As can be seen in the accompanying photograph, these clouds were covered by a solid cloud layer well above the flight level. Peak liquid water contents in the cumulus clouds were around 2 grams per cubic meter. Cloud tops were sampled for the next 50 minutes, and then we dropped to cloud base at a flight level of approximately 1800 feet to perform a last level flight before heading to the helipad.

Unfortunately the phase Doppler instrument was not functioning properly, so we could not obtain drop size distributions, beyond a general picture of drop diameters between 15 and 35 micrometers. Post-flight tests finally localized the instrument problem to a slight misalignment of the laser, which we were able to correct with the expert advice of our Artium Technologies colleagues, and a lot of patience and alignment help from Tina, Dieter, Holger, and Sylwester. When we finally got home at about 21:45, 12 hours after the flight began, we were all very happy to have reached the point where we can measure nice Doppler bursts and we have every indication that the instrument will work properly on the next flight.

First cloud contact

2011-04-10T12:55:00.000-07:00

Today the third measurement flight of this campaign took place. We had two levels of clouds in the morning, one at 1600 ft and one at 8000 ft. This higher layer covered nearly the whole sky, while there were only scattered cumulus clouds below, but significantly more than yesterday. Thus, the conditions for cloud formation were obviously different and we tried to analyze that in detail. Means, we flew a similar pattern as yesterday: starting with a transfer to the open sea followed by a vertical profile from 50 m to 2000 m. In the meantime we reached a nice field of Cumulus clouds below us. We went down to the clouds and passed several of them at a height around 1200 m.

To compare with yesterdays flight we went down below cloud level to 1100 ft. We flew a horizontal leg there for approximately 7 min followed by vertical profiles through the transition layer: between 1100 and 2500 ft. Since there was still flight time left, we flew through some more clouds and this time the second higher cloud layer was almost gone. After another horizontal leg within 2500 ft between clouds we flew back to the airport below cloud base.

Fewer CCNs since the Saharan dust vanished

2011-04-10T11:08:00.000-07:00

Yesterday, the helicopter together with ACTOS and SMART-Helios flew profiles and legs over the Atlantic ocean near by the east coast of Barbados in order to measure the dynamical, thermodynamical and microphysical properties of the transition layer (atmospheric layer between marine boundary layer and trade wind inversion) under cloud-free conditions. Also 5 dolphin flights were carried out between 1100 and 2500 ft to analyze the top of marine boundary layer. The miniature-Cloud Condensation Nucleus (CCN) counter on ACTOS as well as the ground-based CCN measurements on Ragged Point showed much less CCN numbers of about 50-100 than on 06.04.2011 (first test flight). During this flight there was a Saharan dust layer with a maximum height of about 3 km (measured by the MPI-lidar on Deebles point) and 200 CCNs were measured.

Good News: SMPS is working!

2011-04-08T09:36:00.000-07:00

After horrible hours of installing and deinstalling of any available version of LabView software, we made it to compile and run the SMPS software. Many, many thanks to Thomas!! First test measurements at ground do not show any problems and ACTOS seems to recover from its "spectrometer problem". The picture shows "USER1"-LED running which caused a lot of happiness :). Results from first measurements will follow....

Showers... - no flight today (2011-04-08)

2011-04-08T07:50:00.000-07:00

Overcast conditions and several showers made a safe take-off with ACTOS impossible. Afternoon, there will be a workshop at CIMH and an increased chance of showers is predicted, therefore we canceled all flights for today.

Eagle sees clouds

2011-04-07T09:39:00.000-07:00

This is an example of the Eagle data: A cloud "image" at 646 nm wavelength from Deebles Point, and the (uncalibrated) radiance spectra of a cloudy pixel inside the red box (top) and a clear-sky pixel (bottom). Eagle "images" are a bit tricky as their coordinates are not x and y but x and t.

ACTOS & HELIOS

2011-04-07T09:16:00.001-07:00

Our continuous all-sky camera at Deebles Point caught this image of the heli with ACTOS and HELIOS yesterday. The fence is that of the MPI station.

First ACTOS flight

2011-04-06T14:21:00.000-07:00

Today, we performed the first flight with ACTOS and SMART-Helios. The aim of this flight was to test the setup and to provide data for a comparison with MPI observations. Therefore, all flight activity was off the coast close to Deebles Point with a few low-level flights. Since PICT and the SMPS were both not running we decided to avoid cloud contact and measured profiles from 30 to 2000 m with a special focus on cloud base height. A few legs in 50 m above sea level completed the flight pattern. After a first look into the data, all devices were running without obvious problems.

The picture shows ACTOS passing by the MPI station at Deebles Point in a height of 60 m above sea level.

The Eagle has landed

2011-04-06T08:16:00.000-07:00

One of the new instruments in this second part of CARRIBA is the hyperspectral imager Eagle, which we have installed at the MPI research site at Deebles Point. We bought it only very recently, and it seems to operate fine and we'd like to thank MPI Hamburg for providing us with the spot and proper voltage supply. The Eagle will spectrally scan the clouds passing over Deebles Point whenever ACTOS and HELIOS are airborne.

CARRIBA 2.0 (beta)

2011-04-06T07:28:00.000-07:00

We are back!
Since April 1st the whole crew (old and new) is back in Barbados.
The instruments are being tested and a dummy flight was performed on April 4th.
Again, the HELIOS dummy was destroyed.
Most instruments seem to work fine, with the exception of the SMPS and Tina's PICT, but support is on the way.
Today we plan to perform the first science flight with ACTOS and HELIOS, we'll keep you posted.

CARRIBA 2011 - Back to Barbados!

2011-03-26T09:19:00.001-07:00

Hello,
pretty soon we will be back on Barbados for the second campaign of the CARRIBA project. Helicopter flights are scheduled for the period from April 4th to April 26th and flight reports will be posted again after each flight!

Bye bye Barbados

2010-12-06T07:58:00.000-08:00

The last measurement flight during our first Barbados campaign was done on Saturday (27.11.). As the picture shows two low cloud levels were present: one at ~600 m and a secon one at ~ 1900 m. After take-off we flew ~ 60 m above sea level to the south. There, we started a vertical profile up to 8000 ft to the east. Due to strong wind from the east, the ground speed was almost zero. During the profile, we passed both cloud layers and decided to perform measurements in both of them. We started with a horizontal leg in the upper cloud layer, followed by few vertical profiles through this layer.
After that, we went down and tried to catch some of the low-level cumuli without the second layer above. This was difficult to realize since there were only few of these clouds in the range we could reach within our flight time. But we got some and the quicklook showed obviously some particle bursts at cloud edges.
That was the last measurement flight for this year, but we are planning to come back next year!

Bye, bye barbados! We enjoyed the last month and our stay here and collected enough exciting data to spend the whole german winter with them...

Cloud hole hunting

2010-11-26T10:02:00.000-08:00

Today we took off delayed because we had to wait until a shower passed by. ACTOS became airborne at 14:00 UTC (10:00 local). At the beginning we performed a low level leg at 200 ft (ACTOS) heading to C1 near Ragged Point. Afterwards, we had to ascend to avoid a shower at the east coast and climbed up to 8500 ft above the cloud top. Cloud base was located at about 1500 ft. Unfortunately, the cloud situation was dominated by a heavy shower nearby so cloud chasing became a difficult task. Cloud top was highly variable (see picture) and we decided to descend and tried to catch the cumulus clouds at about 3000 ft. On our way back we had to ascend again to avoid another shower and climbed up to 10000 ft. Above this shower we found a stratiform layer covering nearly the whole island, which confronted the pilots with a new task: cloud hole hunting. Finally, we found one to descend below and performed a last horizontal leg at 2000 ft heading Grantley Adams.

Flight #15

2010-11-26T07:28:00.000-08:00

Our 15^th research flight took place yesterday, Thursday Nov. 25^th. As often before, we first headed out east to the sea and then flew north along the coastline, above the water, at a heights of about 200ft above ground (for ACTOS). When we were at our waypoint “C1” (east of Ragged Point), we started a profile, heading north, that carried us up to our maximum heights of 8000ft. The cloud base was at about 2000ft, and higher up there were again small cloud layers at about the cloud top heights (at about 6000ft - well, a few cumulus clouds extended above that height). After having finished the profile we tried to sample these thin layers for a while. However, they were not only thin but also not very stable, so we have to see in the data how much of them we really sampled. In general, there were more of these small cloud layers and also more and larger cumulus clouds above land than above the sea. We also chased cumulus clouds for a while (there were enough around). We were going round and round and round, so that we eventually were at the north-west-coast of Barbados. We went back to the eastern side of the island, and descended back south, above water, towards “C1”, at the heights of the clouds, from about 5500ft to 2000ft, without much contact to clouds (really only a few seconds). Having reached “C1”, we flew a last level leg below cloud base, at 1500ft, towards the airport.

Technical Info II

2010-11-25T13:30:00.000-08:00

The 1-micron wire did not survived and has been replaced by a 2.5-micron wire. The LiCor will run as an open-path system until the end of the campaign. The CCNC has been removed for calibration and will not join the flight(s) on Friday (Nov 26th).

The spare part for SMART-Helios has arrived and is currently integrated. Flight hours for two research flights are left and hopefully the flights will be performed with a fully running SMART.

Per steam engine from Grenada to Barbados?

2010-11-24T10:52:00.000-08:00

This morning we decided to fly again to Ragged Point. After a first low level leg at 300 ft (ACTOS) we climbed up to 8000 ft for a vertical profile. Unfortunately, all clouds near the east coast disappeared, so we decided to go to our measurement area south of the island. Arriving there we performed horizontal legs at 4000 ft and 3000 ft and prompt some nice cumuli showed up. At 3000 ft ACTOS sampled lots of clouds with various cloud top heights and cloud base around 2000 ft. It was amazing to follow the fast development of these clouds from small frazzles to mature ones. The liquid water content reached maximum values around 1 g m-3 and the FastCPC recorded high fluctuations in the particle number concentration (interstitial) at cloud edges. In between some looked like smoke clouds from steam engines (see picture). Finally, we made a horizontal leg below cloud base at about 1500 ft on our way back to the Concorde Center.

Technical Info

2010-11-24T08:08:00.000-08:00

After the first flight (Nov 24th), the LiCor-System has been changed from a closed to an open-path system. A few spikes during cloud penetrations might occur due to scattering!The UFT is now running with an 1-micron wire; new settings: I = 0.1 mA, G = 100 (former settings: I = 0.2 mA and G = 200). Both changes are in order to increase resolution but with a slightly increased chance of malfunction.

Another nice cloud flight

2010-11-23T11:01:00.000-08:00

Today was another nice chance for chasing trade wind cumulus clouds. Take-off was around 9:30 local. We went to the open sea near Ragged Point and started a full profile from 80 m to 2400 m above sea level. Afterwards we stayed at this highest level and and flew a 10-min long horizontal leg. Many cumulus clouds were below us but many of them had higher cloud tops. Nice clouds were all around us, thus it was not difficult to spent the rest of the flight with cloud measurements. We passed various cumulus clouds in different heights which was really impressive, because all these cauliflower heads around were still growing. It was also interesting to see how fuzzy most of the cloud edges were and how quickly they were changed.

Flight #12

2010-11-22T11:11:00.000-08:00

Today we decided again to fly to the east coast. After takeoff we performed a low level leg along the coast line on our way to Ragged Point at 300 ft (ACTOS) above sea level. Afterwards, we ascended to get a vertical profile near the east coast. Reaching 8000 ft we recognized a very stratiform cloud which was located just a few hundred feet higher. So the pilots asked for permission to climb up which was immediately approved by ATC and we performed measurements inside a homogeneous cloud at 8500 ft for more than 10 minutes (see upper picture). A very nice optical phenomenon came along with us - within the shadow of the helicopter a glory appeared (lower picture). Thereafter, we descended to sample cumulus clouds at various altitudes from 4000 ft to 6000 ft for another 45 minutes. Cloud base was mostly located near 2000 ft and cloud top very variable. Finally, we flew again horizontal legs under cloud free conditions at 3000 ft and a low level leg near Ragged Point on our way back to Concorde Helipad.

Clouds, clouds and music

2010-11-21T14:37:00.000-08:00

The second flight of this day started at 18:28 UTC. During noon, small cumulus clouds developed and started to grow. Since the most clouds were located at the east coast, we decided to fly to Ragged Point. After a leg at a height of 240 feet (Actos height) above the ocean, we climbed up to 10000 feet. As we looked down, lots of nice clouds were below us. We ask the pilots to descent and to chase for clouds. During chasing, we could follow the development of tiny cumulus clouds to mature ones. The first picture shows the cloud situation during the profile and the second one only 20 minutes later at the height of the clouds. Afterwards, we flew back to the airport at a height of 3000 feet.
Finally, the pilots did a good job, caught a lot of clouds and provided a nice entertainment program. I really enjoyed my first research flight.

Clouds on vacation

2010-11-21T08:20:00.000-08:00

Today we performed again an early flight and took off at 9:30 local (13:30 UTC). The LIDAR quicklook from Deebles Point (picture on the right, thanks to MPI Hamburg!) looked very promising and indicated a lifted layer with enhanced depolarization ratio at ca. 2 km above sea level and another layer reaching from sea level to about 1 km. Since there were no clouds we decided to focus on these layers.
Close after takeoff the Helicopter turned towards our measurement area south of Grantley Adams International Airport (GAIA, picture below). On our way to the reserved area we performed a low level leg at about 800 ft above sea level, so ACTOS was at about 300 ft. Afterwards, we ascended to 10000 ft to make a full vertical profile and stayed there for at least ten minutes. Thereafter, we started our "aerosol layer chasing" and performed several horizontal legs at 6000 ft, 2000 ft, 1500 ft and again a low level leg. The data will tell us, if we caught the different layers.
Unfortunately, HELIOS is still forced to stay on ground but today there were lots of cirrus clouds... Finally, although there were no clouds within our duration my first research flight was a very interesting one.

PS: Clouds are back and ACTOS is again airborne at the moment...

ACTOS is back but without HELIOS

2010-11-20T12:00:00.000-08:00

The last three days we learned the meaning of bank holidays: our helicopter had to stay on ground until some money found its way from one bank in Leipzig to another one on Barbados which really still takes days. However, it arrived yesterday and we are allowed to fly again. Today in the morning, the weather conditions were not suitable to start a measurement flight: we had showers and high cumulus towers all around. Thus we were waiting for our chance and it came: Around noon the showers were gone and the clouds to the east looked nice and calm.
As usual, HELIOS started first, but in the last minute he realized that Christoph was not there to carry him. This must have been a real shock for HELIOS and disturbed immediately his power supply.
Bad-smelling smoke came out and the start was stopped. A second try was done without HELIOS and was more succesful. The measurements started with a full profile from 100 m above water to approximately 2400 m. During the profile we passed several cumulus clouds with variable height, thickness and cloud base. On top of these clouds was again a stratified cloud layer, today it was more homogeneous than last time. Our maximum height was above this layer and a view from there is shown on the upper picture. A first horizontal leg was flown with ACTOS in this cloud before we declined below (see picture on the left) and started the chasing of cumulus clouds. This was really nice and effective and PICT had again the chance to measure lots of droplets. Close to the end of the flight the small cumulus clouds dissappeared and larger ones were visible near the airport. Very soon after landing it started raining again. So we had at least one nice flight today and hope that HELIOS will recover and be back with us soon!

Wenn's mal wieder länger dauert...

2010-11-18T06:43:00.001-08:00

Da der Barbados-Alltag mal wieder von längeren Wartepausen geprägt ist, soll auch dieser Blogeintrag unter dem Motto "Warten" stehen. Das kleine Video zeigt einige Motive aus dem Ganztagstest der SMART-HELIOS Kamera vom 10.11., wo ACTOS und HELIOS am Boden bleiben mussten (wie jetzt auch) und stattdessen das Starten und Landen mit Wasserkanistern und Fahne geübt wurde... Enjoy!

PICTs erster Flug

2010-11-16T12:52:00.000-08:00

Für den heutigen Jungfernflug von PICT waren die Bedingungen optimal - es konnten viele Wolken "gejagt" und durchflogen werden. Somit konnte das Instrument ordentlich auf Herz und Nieren getestet werden. Die ersten Ergebnisse sind durchaus zufriedenstellend. Als Beispiel sind hier Zeitreihen von Tropfendurchmesser und Tropfengeschwindigkeit, sowie die dazugehörigen Histogramme gezeigt. Man kann gut die Lücke zwischen zwei Wolkenteilen erkennen und eine trimodale Struktur in den Tropfendurchmessern.

The day without power

2010-11-16T12:42:00.000-08:00

While preparing ACTOS for the start this morning we had a complete power failure at the container. This seems to be a serious problem and the power did not come back until now (17:00 local). However, we were able to improvise and prepared ACTOS for another flight. PICT was implemented and Tina was curious to see some real cloud data.
The helicopter started at 10:30 local and flew again to the area close to Ragged Point. There, a vertical profile up to 8000 ft was flown above the ocean. There were only few thin clouds over the ocean and more 'real' cumulus clouds over the island. Thus, cloud chasing looked more successful over the island and we did that. I realized that the battery power of ACTOS was lower than the days before and decreased more rapidly. After roughly half an hour of cloud chasing I decided to go back since the power was really low. A few minutes later ACTOS shut off and the measurements of course were over. Back on ground the batteries were fine and we could not really explain the power failure during the flight. However, it was a nice flight with many cloud contacts and suitable to check if the new PICT was working well.

Was lange währt...

2010-11-15T15:07:00.000-08:00

Es ist da! Unser letztes Instrument, um vollständige Passatwindwolken-Charakteristiken zu erstellen ist nun endlich eingetroffen: das PICT. Mittels Phase Doppler Interferometry können nun nicht nur Informationen bezüglich der Tropfengeschwindigkeit (dazu haben wir ja schon das LDA), sondern auch über die Tropfengröße erhalten werden. Nach ersten Test wurde es heute an ACTOS angebracht und wird morgen seinen ersten Flug machen. Wir sind schon alle gespannt auf die Daten, die es liefern wird!

New cloud layer discovered

2010-11-15T11:19:00.000-08:00

Today we performed one flight in the morning with similar weather conditions as the last days. We started at 10:00 local and flew again directly to the area near Ragged Point. The flight pattern started with a vertical profile up to 8000 ft followed by a horizontal leg in that height. Beeing up there we realized a thin cloud layer in the cloud top height of cumulus clouds. This layer has not been there the days before. We dropped ACTOS into this layer and followed the cloud for a while. The liquid water content (LWC) was between 0.1 and 0.3 g/cm^3. After few minutes this layer disappeared and we started chasing cumulus clouds again. They were highly variable and still growing, the maximum LWC exceeded 1 g/m^3 several times. The flight pattern probably looks very chaotic but obviously the pilots enjoyed the cloud chasing. We did it for a while until our flight time was almost over. Before flying back we made another horizontal leg below cloud base for comparison with ground measurements. On the way back to the airport we passed Ragged Point and Deebles Point again, best wishes to all the colleagues measuring there!

Chaotic clouds

2010-11-14T12:24:00.000-08:00

After some trouble-shooting in the morning we finally could take off at 1:20pm local. We tried again to heading off the East coast around Ragged Point but the flight startet with 8 minutes of hovering in 50 m with ACTOS stil on the field until we got finally flight permission from ATC.

We defined a 10 km long leg in the North of Ragged Point to avoid any conflict with commercial traffic and were nearly free to do what we want. After a profile up to 7500 ft we tried to sample clouds and we got a lot of them in different heights - sometimes at cloud top, sometimes at the cloud edge.

Again, cloud tops were very inhomogeneous. Most clouds were still actively growing which was quite a challenge for the pilots. A lot of clouds produced precipiation - even a few very shallow ones which resulted in many rainbows below us. Sometimes virgae could be observed between the clouds (see photo above). After a final horizontal leg in 1000 ft above sea level ACTOS and the helicopter got washed in a slight shower.

This was definitively the flight with the most cloud contacts - we're getting better!

CCN measurements on ACTOS

2010-11-13T15:36:00.001-08:00

On board of ACTOS we have a miniaturized CCNc, contributed by Greg Roberts, who is here in Barbados with us. The instrument has been measuring very reliably during all of the 5 flights we had so far, and once ACTOS is back in place, the data can be viewed almost immediately (within minutes, really). This is a very nice feature, as it can give us some clues about what was sampled during the flights, and this then can tell us which heights might be interesting for the second flight of the day.

The way the mini-CCNc was set up so far, it measured CCN at a super-saturation of 0.3%. The plots show the CCN number concentration measured during the initial profiles of 4 of the 5 different flights (the morning flight of yesterday, Nov. 12^th, is not shown). Both, yesterday and today, the data collected during the morning and the afternoon flight were not much different, while the day to day variability and the variations with heights are stronger than we had expected.

Let’s see which additional surprises might be hidden in the now constantly increasing amount of data.

Flight #5 to Ragged Point

2010-11-13T12:20:00.000-08:00

Again, we made a second flight this afternoon starting around 13:40 local time. We went into 'our' area south east of the air port and flew a full profile up to 2600 m. From the lidar data we had seen that above 2000 m the aerosol concentration decreased, thus we wanted to measure there. To get also size resolved particle concentrations and CCNs we stayed there for a few scans. Afterwards we went down to cloud level (~1200 m) and tried to find any cloud. But there was not a single one in our area while around us there were beautiful trade wind cumulus cloud like on all these pictures... (see above)
Therefore, the pilots asked for permission to leave our area and the tower allowed us to fly north. So we followed the coastline and found several nice big cumulus clouds. We passed those clouds several times very close to Ragged Point and Deebles Point. This was the chance to make nice pictures of both sites from above.
One the left picture one can see the lighthouse of Ragged Point as well as the measurement tower.
After all another succesful flight, lets have a look into the data!

Saturday, Nov 13th - the morning f(l)ight (#4)

2010-11-13T07:23:00.000-08:00

Today everything was well prepared, the helicopter was refueled and we could take off from the Concorde helipad at 09:15 local. A few cumulus clouds were in our operational area but we started with a profile up to 2200 m. The cloud situation was extremely inhomogeneous and it looked like every cloud had its own cloud base and to define cloud top was even more difficult. The cloud edges were very fuzzy and sometimes clouds nearly dissipated before we could penetrate them a second time. Finally, I let the pilots decide which cloud was best to sample since they have the better view from the cockpit. At the end we made two horizontal legs in 500 and 420 m above the ocean which was close to the lowest cloud base.

The picture shows the cloud situation from ACTOS' point of view - very small cumuli with diameters of maximal 200 m.

Flight #3

2010-11-12T16:24:00.000-08:00

This afternoon flight #3 took place. After a first look in the data it seems that this was also a successful 90-minutes measurement flight. Our observations started with an ascent up to a height of about 6.500 feet followed by a horizontal leg there. Subsequently, we went down to cloud-level (3.000 feet) and flew another horizontal leg. Unfortunately, no clouds were there to chase… so we decided to go below cloud base, which was at approximately 1.500 feet (helicopter height). At this altitude we could be sure that ACTOS was performing measurements in the marine boundary layer. After that we back to cloud level, but still no clouds were within our operational area. When it was time to fly back to the Concord Centre we were really lucky, because finally clouds crossed our way. It was an amazing view seeing ACTOS to disappear in the clouds and SMART-Helios doing a solo-flight above the clouds!

The second flight - first cloud...

2010-11-12T16:18:00.000-08:00

After the test flight yesterday, we performed the first real measurement flight today. The scheduled take-off was delayed due to re-fueling the helicopter - the fuel had to be paid cash and it took 30 minutes to get change - welcome to Barbados! Finally, take off was 10:20 local but from now we can pay with credit card...The cloud situation was difficult and the first part was under clear-sky conditions starting with a profile up to 6000 ft followed by two level flights in 1000 and 2000 ft. Nearly all systems were running only the navigation unit of ACTOS produced no data - my fault and during the next flights hopefully all systems will run. The last 15 minutes we sampled some nice cumulus clouds before we had to finish the flight. Although these clouds were very small and thin, the liquid water content was up to 0.5 g/m^3 - welcome to the Tropics! The picture shows ACTOS first contact with trade wind cumuli, above SMART-Helios keeps the overview.

The cooperation with air traffic control was nearly perfect and two commercial airliners had to wait for us until we safely arrived at Concorde helipad - thanks to ATC!

ACTOS in Aktion

2010-11-12T07:22:00.000-08:00

Der zweite Messflug läuft derzeit. Hier ein Eindruck von den Vorbereitungen kurz vor Start. Bei über 30°C war das kein Vergnügen.

First flight with ACTOS and SMART-Helios over Barbados

2010-11-11T16:24:00.000-08:00

Good afternnon! After a long time of waiting for different types of permissions and several days of delay due to the hurricane we finally got it and this afternoon our Canadian helicopter took off for the first short test flight. After 45 minutes our pilots landed the helicopter and ACTOS/SMART-Helios safely at the Concorde Museum. During the flight, all systems seem to operate well but the first steps of data processing will continue over the night and I hope tomorrow we should know if everything was running well. The flight itself was mainly a profile under clear sky conditions up to about 7000 ft and then we had to go back since it was close to sunset. For usual measurement flights we expect an endurance of about 1.5 hours. For tomorrow a flight is scheduled in the morning after a briefing at 08:15 local.
Cheers, Holger

Der Hubschrauber ist da!

2010-11-11T05:50:00.000-08:00

Es geht voran! Gestern nachmittag gegen 16 Uhr Ortszeit ist der Hubschrauber bei uns am Concorde-Center eingetroffen. Es ist ein Bell Long Ranger Typ 1 (wie auch in Cabauw, daher uns gut bekannt). Das ist schon ein wichtiger Schritt, leider fehlt aber noch die letzte Genehmigung, dass er hier mit ACTOS fliegen darf. Wir hoffen, dass sie heute kommt.

Immerhin durften wir gestern schon einmal Start und Landung mit einem Netz voller Wasserkanister mit ca. 250 kg Gewicht testen. Der Hubi hat es geschafft und eine kleine Platzrunde damit gedreht, weiter durften wir nicht.
Jetzt heißt es wieder warten.. Aber noch hoffen wir dass es heute vielleicht den ersten Messflug geben kann.

Clear Sky Rainbow

2010-11-11T04:23:00.000-08:00

Heute Morgen fotografiert. Der Regenbogen entstand aus einer kleinen Wolke. Nachdem diese vollständig ausgeregnet war, blieb der Regenbogen noch mehrere Minuten bestehen. Sogar der Sekundärbogen war zeitweise zu sehen.

Nicht nur uns macht die Hitze zu schaffen...

2010-11-09T08:42:00.000-08:00

... sondern auch der ganzen Messtechnik. Die Temperaturen sind in den letzten beiden Tagen nochmal gestiegen; dazu kommen weniger Wolken, schwächerer Wind und mehr Sonnenschein. Bodentests von ACTOS und SMART-HELIOS am Boden haben gezeigt, dass die äusseren Bedingungen ohne abkühlenden Wind extrem warm werden können. Die Temperatursensoren auf ACTOS stiegen in der Sonne bis auf 47°C. Bei SMART-HELIOS schaltete sich die CPU mehrmals bei über 110°C ab. Die Lösung war schnell gefunden. Ein Lüfter muss her. (Wer verkauft eigentlich solche lüfterlose Rechner, die nichtmal bei Raumtemperatur standhalten?)
Mittlerweile sind wir mit den Umbauten zur Verbesserung der Kühlung bei SMART-HELIOS fertig und der erste 2-stündige Test wurde bestanden. Die CPU Temperatur blieb diesmal unter 60°C. Also glatt 50K weniger. Bevor es nun mit den Messungen richtig losgehen kann, muss der Pot dann noch austariert werden. Dazu wird HELIOS wie im Bild zu sehen im Container aufgehängt. Ohne Front-Kappe zeigt die Schnauze natürlich grad weit nach oben. Mit kleinen Zusatzgewichten ist es aber kein Problem HELIOS in der Waage zu halten. Wenn das geschafft ist, sind wir, so denken wir zumindest, für's erste startklar. Fehlt noch der Hubi, der aber jeden Moment eintreffen kann.

Aerosolmessungen auf ACTOS

2010-11-08T06:58:00.000-08:00

Das Warten auf den Hubschrauber gibt uns viel Zeit für intensive Tests der Geräte. So haben wir alle Aerosolgeräte in den letzten Tagen laufen lassen und miteinander verglichen, soweit möglich. Besonders interessant ist das natürlich für den neuen FastCPC im Vergleich mit den gut charakterisierten TSI-CPCs. Generell ist die Hintergrundbelastung hier sehr niedrig, allerdings stehen wir direkt neben dem Rollfeld des Flughafens, wo es durchaus effektive Partikelquellen gibt. So sind die Variationen sehr beachtlich und gehen schnell mal über 2 Größenordnungen. Das sieht man auch in diesem Plot, der einen Vergleich der beiden CPCs über 30 min zeigt. Der FastCPC wurde hier über 1 s gemittelt um beide besser vergleichen zu können. Grundsätzlich laufen beide schön parallel, bei sehr niedrigen Konzentrationen ist der FastCPC etwas niedriger, bei sehr hohen etwas höher. Konzentrationen über 10000 cm^-3 kann der TSI 3762 nicht mehr korrekt auflösen, da ist der FastCPC offensichtlich besser. Bei den kommenden Messflügen werden auch beide als Totalzähler mitlaufen, so dass wir immer noch eine Referenz haben.
OPC und SMPS haben auch gemessen und wurden von Florian ausgewertet und invertiert. Hier ist ein Plot zu sehen, der ein Mittel über mehrere Messungen zeigt während unserer Standort hier offensichtlich stark von Turbinen- und Fahrzeugabgasen beeinflusst wurde. Hintergrundverteilungen sehen sicher anders aus, die gibts dann nach dem ersten Flug.

Inzwischen gibt es gute news, der Hubschrauber ist gestern in der Dominikanischen Republik gelandet und sollte bis morgen früh hier sein.

Erste Ergebnisse von "Ragged Point"

2010-11-07T14:05:00.000-08:00

Hier kommen die ersten Ergebnisse der Messungen an Ragged Point. Beispielhaft ist hier eine Größenverteilungsmessung dargestellt. Man beachte die „extrem hohen“ Partikelanzahlkonzentrationen, die wir hier zu verzeichnen haben. Das ist messtechnisch eine echte Herausforderung. Bloß kein winziges Loch in der Aerosolleitung, schon sind die Ergebnisse falsch. Da war natürlich erst mal Lecksuche angesagt. Aber, alle Lecks gefunden und schon wurde am 5.11.10 fleißig los gemessen. Die ersten kappa Werte gibt es auch schon, nur so viel: kappa ist hier nicht 0.3 und vor allem abhängig von der Größe des Partikeldurchmessers. Heißt so viel wie, anderer Durchmesser, andere Chemie. So das war´s von der Bodenmessungsseite fürs erste. LG an alle fleißigen Leser, Katrin.

Erweiterte Bodenmessungen

2010-11-07T12:08:00.000-08:00

Seit zwei Tagen werden die Wolken über dem Flughafen von Barbados auch durchgängig vom Ceilometer vermessen. Tiefe Cumulus Wolken mit einer Wolkenunterkante ab 350m werden meisten während der Nacht gemessen. Am Tag beobachten wir über dem Flughafen vermehrt Cirren. Heute waren erste schöne Cumulus Wolken über dem Atlantik zu sehen.

Die Bodenmessungen wurden durch Vaisala Sensoren für Druck, Temperatur und Feuchte erweitert. Auf Grund der Signalübertragung wurde dieser nicht am Masten sondern in der Nähe des Containers (am Pfahl einer Straßenlaterne) montiert.

Sonne - Wolken - Regenschauer

2010-11-06T08:11:00.000-07:00

Hier ein kurzer Eindruck zur aktuellen Wolkensituation über Barbados. Schließlich sind diese ja das Ziel der ganzen Aktion. Leider konnte sich bis jetzt noch keine ungestörten Passatwinde mit durchsetzten. Ex-Hurricane Tomas hat anscheinend immernoch großen Einfluss auf die gesamte Karibik. Somit haben wir die letzten Tage mit abwechselnder Bewölkung leben müssen. Mehrere teils kräftige Regenschauer inbegriffen. Es quillt jeden Tag ganz ordentlich, wobei auch schon die kleinste Wolke Regen bringen kann. Wie auf den Bild zu sehen. Man beachte: Der Regenbogen ist vor! dem Cumulus congestus.

Mit der Wolkenkamera zeichnen wir das Ganze seit zwei Tagen auch auf. Der erste Zeitraffer lässt wunderbar erkennen, dass von Zirrus, über Altostratus bis hin zu niedrigen Culumluswolken alles dabei ist. Nicht wundern. Die Kamera besitzt noch keinen Regenschutz. Deshalb ist zeitweise eine Folientüte zu sehen.

Bleibt abzuwarten, wie sich die Bewölkung in den nächsten Tagen entwickelt. Da im Moment noch nicht geflogen wird, sehen wir das noch ganz entspannt.

Bodenmessungen an "Ragged Point"

2010-11-05T21:11:00.001-07:00

Jetzt muss hier endlich auch mal darüber berichtet werden, dass es außer den Messungen mit ACTOS auch noch Bodenmessungen gibt, die wir hier auf Barbados durchführen. Die finden an „Ragged Point“ statt, nah an der östlichsten Spitze von Barbados, direkt über den Klippen.

Wir durften unsere Messgeräte dort im Container der „University of Miami“ aufbauen (DMPS und CCNc - jetzt ist der Container ziemlich voll) und auch deren Aerosoleinlass benutzen, der sich auf einem 17m hohen Turm befindet, direkt über den Klippen (ganz schön windig, da oben). Die Schäden, die Hurrikane „Tomas“ dort hinterlassen hat, hielten sich glücklicherweise in Grenzen, und Miguel (der die Station von Miami aus betreibt und der uns diese Woche über hilft) hat mittlerweile alles wichtige wieder repariert. Katrin und ich, wir beschäftigten uns während dieser Woche hauptsächlich mit dem Aufbau an „Ragged Point“. Und dank der Mithilfe von Thomas und Miguel können gerade im Moment erste Daten gemessen werden. Eines ist schon jetzt klar: die Luft hier ist momentan sehr, sehr sauber. Eine Folge von "Tomas" und den noch immer auftretenden (und für die Jahreszeit zu häufigen) Regenschauern.

Es geht voran

2010-11-04T15:40:00.000-07:00

So, da ich als einzige aufgrund der Ermangelung eines PICT zum Warten verdammt bin, möchte ich Euch zumindest die Fortschritte der anderen Teammitglieder präsentieren:

Zum einen hat heute der FastCPC in seiner neuesten Version zum ersten mal seinen Platz im Inneren von ACTOS gefunden. Erste Bodenmessungen sahen vielversprechend aus. Nun sind wir alle gespannt auf die "airborne" Messungen.

Zum zweiten wurde das Ceilometer in Betrieb genommen und nun können wir sagen: Die Wolkenuntergrenze der Cumuli lag heute im Mittel bei 450 m.

Auch das Strahlungsteam hat allen Grund zu strahlen, da das gestern aufgebaute CORAS heute durchgängig Daten geliefert hat. Und SMART-HELIOS ist auf dem besten Wege, demnächst unter dem Hubschrauber seine ersten Caribik-Messungen zu machen.

Zwischendurch wurden wir immer mal wieder von teilweise recht heftigen Schauern zu Zwangspausen verurteilt. Aber als Wissenschaftler weiß man sich ja zu helfen, indem man kleine Wolkenstudien betreibt...

Was bleibt zu sagen? Alles wartet auf den Hubschrauber, seine 2 Piloten und.... genau: Das PICT! ;-)

Nachtrag "Tomas"

2010-11-04T15:29:00.000-07:00

Hallo Leser,

nachdem Holger bereits von unserem "Überleben" des Hurrikanes berichtet hat, ein kleiner Nachtrag von mir in Form eines Bildes. Die Aufnahme entstand während unserer verzweifelten Suche nach Nahrung und diverser Genussmittel. Da uns nicht ganz klar war, wie hoch die Straße überflutet war, ließen wir ein paar Pkws passieren und probierten es danach selbst. "Türen und Fenster geschlossen halten"... Augen zu und durch!

PS: Auch das haben wir trockenen Fußes überlebt.

Und die Sonne strahlt...

2010-11-03T16:08:00.000-07:00

Staatstrauer in Barbados! Der heutige Tag wurde überschattet vom Staatsbegräbnis des erst letzte Woche verstorbenen Premierministers David John Howard. Unser Beileid!
Trotzdem konnten heute weitere Fortschritte verzeichnet werden. Unter der glühenden Sonne von Barbados haben André und ich heute das Bodenmessgerät CORAS aufgebaut, inklusive Spezialvorrichtung für die verwendete Spiegelreflexkamera. Damit sind nun simultan Allsky-Wolkenbilder möglich (und Bilder unseres Camps). Erste Messungen am Nachmittag aus dem sichtbaren Spektrum lassen die stark variable Wolkensituation erahnen.
Auch bei SMART-HELIOS gibt es erste Fortschritte zu vermelden.
Nachdem gestern der Irradianzkopf und der Lagesensor integriert wurden, haben wir heute die neue Verkabelung zwischen Spektrometern und Datenaufzeichnung angebracht und einen erstern Testlauf gestartet. Wenn labview artig ist, sollte morgen auch da die Datenaufzeichnung prinzipiell funktionieren.
Zum Feierabend konnten wir nach Hähnen, Affen, Fröschen, Colibris und Schildkröten eine weitere Spezies im Glenville Gardens entdecken: Glühwürmchen...

Sturm vorbei - jetzt geht's los!

2010-10-31T20:46:00.000-07:00

Nachdem der Sturm abgezogen ist und sich das Leben auf der Insel recht schnell normalisiert hat, haben wir heute endlich angefangen unser Lager am Concorde Museum am Flugplatz aufzubauen. Der Himmel war noch bedeckt und es nieselte nur vereinzelt so dass wir ohne allzu große Sonnenbrandgefahr das Zelt über unserem Container aufbauen konnten. Leider haben wir erst heute bemerkt dass beim Transport zwei große Löcher in das Containerdach gerissen wurden und bei dem Hurrikan doch einiges an Wasser den Weg in den Container gefunden hat. Größere Schäden haben wir aber dadurch nicht zu beklagen.

Nachdem wir unser Zelt aufgebaut hatten sind wir dann nach "Deebles Point" gefahren um nach dem "MPI-Observatorium" zu schauen. Es gab seit dem Hurrikan keine Information über evtl Schäden an den Geräten. Der Kontakt zu der Station war in der Nacht des Orkans abgebrochen. Von aussen gesehen scheint die Station den Sturm gut überstanden zu haben, ob Wasser eingebrochen ist konnten wir natürlich nicht erkunden. Nur der Strom ist in dem ganzen Gebiet unterbrochen und an den Überlandleitungen sind Schäden sichtbar. Hoffentlich können diese schnell behoben werden und die Station kann ihren Messbetrieb wieder aufnehmen.

Morgen kommen dann weitere Kollegen aus Leipzig und Frankfurt und die "Mannschaft" ist bis auf unseren Piloten fast komplett! Die ersten Flüge sind für Anfang nächster Woche geplant.

Tomas

2010-10-30T14:18:00.000-07:00

Hallo Leute!
Wir haben wohl das Schlimmste Überstanden - zumindest der Wind hat nicht mehr Orkanstärke und der Hurrikane Tomas zieht langsam ab aber er bringt noch ordentlich Wasser. Die Straßen sind nur mit äußerster Vorsicht zu befahren und zum Teil steht das Wasser bis zu 30 cm auf der Straße – für normale PKWs die absolute Grenze. Den ACTOS-Container haben wir nicht erreichen können da der ganze Flughafenbereich wie ausgestorben da liegt und wir damit vor verschlossenem Tor zur Umkehr gezwungen wurden. Die Schäden auf der Insel sind wohl nicht so dramatisch aber die Restaurantbesitzer am Wasser haben viel Arbeit vor sich – die Freisitze und Bars am Wasser sind meist beschädigt oder zerstört. Es war beeindruckend zu sehen wie im Hafen von Bridgetown große Boote schaukelten bzw. Segelyachten „sehr schief“ vertäut an der Mole lagen.

Funkstille...

2010-10-30T12:21:00.000-07:00

Dank Tomas gibts momentan keine aktuellen news aus der Karibik, deshalb gebe ich mal weiter, was ich so gehört und gelesen habe. Besagter Tomas hat sich vom tropischen Sturm zum Hurrikan intensiviert und dabei Barbados überquert. Auf der Insel hat es kräftig geregnet und gestürmt, der Wind hat jetzt wohl schon deutlich abgenommen. Das öffentliche Leben ist praktisch zum Erliegen gekommen: Geschäfte und Restaurants sind geschlossen und man wagt sich besser nicht vor die Tür. So etwas kommt auf Barbados wohl nicht so häufig vor, sagt man dort. Zumindest in Glennville Garden gibts kein Internet, zumindest bisher nicht. Details gibts dann von dort.
Der Meeresbezwinger Tomas...

Zollfreigabe

2010-10-29T10:52:00.000-07:00

Der ACTOS-Container hat soeben seine Zollfreigabe erhalten - lief alles problemlos ab. Die lokale Zoll-Brookerin hatte alles perfekt vorbereitet. Fast noch wichtiger, der Container sieht noch genauso aus wie wir ihn in Leipzig verabschiedet haben. ACTOS und das weitere Equippment haben den Transport gut überstanden. Die Luftfracht wird vorraussichtlich am Montag freigegeben.

Wetter....

2010-10-29T08:11:00.000-07:00

Liebe Kollegen, das Warten auf den Zoll gerät zur Nebensache wenn man die Entwicklung dieser tropischen Störung zu einer Zyklone beobachten kann. NOAA will heute nachmittag ein Flugzeug schicken welches die aktuelle Entwicklung und Stärke untersuchen soll. Der Kern zieht wohl zwischen Trinidad und Barbados hindurch - aber da ist leider nicht viel Platz. Ich habe Barbados rot markiert und die berechnete Zugbahn eingemalt.

Tropische Zyklone in der Karibik?

2010-10-28T17:35:00.000-07:00

Die Wettervorhersagen des Hurrikanzentrums in Miami (http://www.nhc.noaa.gov/gtwo_atl.shtml) prognostizieren für die kommenden Tage etwas ungemütliches Wetter auch für Barbados (gehört zu den "windward Islands"). Zur Zeit (9pm local) ist es recht schwül bei 28 Grad C und 85% Luffeuchte und die Zirren und Schauer deuten schon auf die ersten Ausläufer dieser tropischen Störung hin:

A VIGOROUS TROPICAL WAVE LOCATED OVER THE TROPICAL ATLANTIC ABOUT 725 MILES EAST-SOUTHEAST OF THE WINDWARD ISLANDS IS PRODUCING A LARGE AREA OF SHOWERS AND THUNDERSTORMS. THIS SYSTEM CONTINUES TO SHOW SIGNS OF ORGANIZATION...AND ENVIRONMENTAL CONDITIONS APPEAR TO BE FAVORABLE FOR GRADUAL DEVELOPMENT OF THIS DISTURBANCE DURING THE NEXT COUPLE OF DAYS. THERE IS A MEDIUM CHANCE...50 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES WESTWARD OR WEST-NORTHWESTWARD AT 15 TO 20 MPH. REGARDLESS OF DEVELOPMENT...THIS SYSTEM IS EXPECTED TO BRING LOCALLY HEAVY RAINFALL AND STRONG GUSTY WINDS TO THE WINDWARD ISLANDS...VENEZUELA...AND NORTHERN PORTIONS OF GUYANA DURING THE NEXT COUPLE OF DAYS.

Glenville Gardens

2010-10-28T03:17:00.000-07:00

Guten Morgen, da es noch nichts wissenschaftliches zu berichten gibt und über Nacht weder Fragen zum Thema Zoll, Behörden noch Logistik beantwortet werden konnten werde ich kurz aus Glenville Gardens berichten - unserer schönen ruhigen Unterkunft mit Holzhütten und Blechdächern. Diese Dächer wären nicht erwähnenswert, wenn sie nicht extrem laut wären wenn eine ganze Herde dieser netten Affen/Meerkatzen hinüberrennt und dort Fangen spielt - morgens um 6 Uhr... Leider mögen diese Tiere die gleichen Früchte die ich hier auch mag - nur können sie etwas besser klettern...

Mit ein wenig Glück findet heute ein Treffen mit den Luffahrtbehörden statt und wir können unser Einsatzgebiet und die Flugbedingungen weiter spezifizieren. Noch ist man etwas misstrauisch bzgl der Stabilität unseres ACTOS-Systems aber wir werden sie schon überzeugen.

Gestern abend sind dann noch etwa 350 kg Luftfracht am Flughafen angekommen, so langsam ist die Ausrüstung komplett; das letzte System wird wohl am 1. November direkt aus Miami inkl Techniker bei uns eintreffen.

Typische Wolkensituation über Barbados

2010-10-27T16:53:00.000-07:00

Um einen Eindruck von den typischen Wolken der Passatregion zu bekommen habe ich heute nachmittag ein paar Fotos am Flugplatz gemacht. Bemerkenswert ist die fast konstante Wolkenbasis der flachen Kumuluswolken um etwa 500 m. Leider war tagsüber noch ein Zirrus aufgezogen der auf den Fotos nicht so deutlich zu erkennen ist.

Die niedrige Wolkenbasis und die relativ geringe vertikale Erstreckung bieten ideale Vorraussetzungen für Flüge mit ACTOS; dennoch sollte man auf Schauer aus diesen Wolken jederzeit gefasst sein.

Es geht los!

2010-10-27T13:58:00.000-07:00

Liebe Kollegen und Freunde der Passatwindwolken!

Wir möchten Euch einladen ein wenig an unserer ACTOS-Kampagne auf Barbados teilzuhaben und werden daher regelmäßig von unseren Aktivitäten auf diesem Blog berichten. Vor allem sollen unsere Messflüge an dieser Stelle kurz dargestellt werden und somit wird jeder "Mitfliegende" zeitnah ein wenig von seinem Flug erzählen. Die Flugberichte werden dann auf englisch verfasst werden.

Ich bin nun schon seit fast zwei Tagen auf der Insel und heute ist dann auch endlich unser Container an seinem Bestimmungsort, dem Concorde Center am Fughafen angekommen(siehe Bild) - leider noch bis Freitag unter Zollverschluss. Am Samstag werden wir dann mit dem Aufbau des Zeltes beginnen und uns so langsam auf die ersten Tests hier vorbereiten.