Since there was no flight planned for today and tomorrow, I took the opportunity to visit the Amazon Tall Tower Observatory (ATTO), a field site in the middle of the jungle 150 km NE of Manaus. This station is operated jointly by our Institute and the Brazilian National Amazon Research Institute (INPA), together with a large group of Brazilian and German partners. The centerpiece of the site is going to be a 325-m tall tower, from which measurements of trace gases, aerosols, and micrometeorology will be made. The project was initiated in 2008, but since planning and construction of the tall tower proceeded quite slowly, we decided early on to build a “Not-quite-so-tall Tower” (80 m high), and began measurements there in 2011. I wanted to see how the construction of the tall tower was progressing, and visit our resident science team.
The trip to the site takes about 5-6 hours, about 1-2 hours on paved roads, an hour on a dirt road, over an hour on a speed boat on the Rio Uatumã, and finally as much as an hour on a rough dirt road through the jungle, with some waiting times in between to make the connections. The dirt road is always a work in progress. In the rainy season, the lower part dissolves into a long lake of mud, and becomes unpassable even for jeeps. When we drove up from "Porto ATTO", our landing on the Rio Uatumã, to the observation station, we had to make serveral stops to get out of the way of road construction. All in all, I left Manaus at about 06:20 and made it to ATTO just for lunch.
The afternoon was spent looking at the construction site for the tall tower and looking at the three container labs that make up the present measurement site. At the moment, the “tall tower” is about 1 m tall, but all the foundations have been cast as well as the anchors where the cables will be attached that hold the tower. These anchors consist of concrete columns that go 6 m into the ground. All the steel for the construction is lying around the tower base in the forest, and we have been told that the actual tower construction will start this Thursday!
The container labs now are quite impressive. One lab houses the aerosol measurements. The air for these measurements is piped down from a dedicated 80-m mast that is placed directly next to the lab container, to avoid particle losses. A second container houses a variety of trace gas measurements, including ozone and nitrogen oxides. The third container is dedicated to high-precision measurements of CO2, CO, and CH4.
The day ended with a nice dinner (beans, rice, fish, meat, and salad) and discussions with the local science team over a few beers. Sleeping accommodations are in a jungle lodge, surrounded by mosquito netting, where everybody lies in comfortable hammocks.
Uli Pöschl from the Max Planck Institute for Chemistry, Mainz, who was an important member of our coordination group for the first half of the campaign, left this morning to return to Germany. Unfortunately, Danny Rosenfeld, another key member of the team was also called home today on a family emergency. So, this morning we had the last chance to take a picture of the steering group together.
(Today's blog comes to you courtesy of guest blogger Manfred Wendisch)
On Friday we had an exciting HALO flight with the objective to validate satellite measurements and collect data in and above the clouds. HALO was supposed to meet the high-flying satellite over the measurement area on its way southward, which requires an extremely exact timing by the pilots. Additionally, we wanted the meeting point to be at a certain altitude above nice convective clouds. It was almost unbelievable with which precision the pilots managed to fulfill this strange request! Actually, HALO was at exactly at the planned place above the clouds at the right time, amazing!
We took off 11:00 local time, shortly after the first cumuli started to pop up. It is always fun for me to watch these very regular visible signs of the beginning of convection each morning here in Manaus. You may almost set your wristwatch at 10 am because that time the clouds start to evolve each day. After take-off we flew northward and observed high cirrus clouds, which would make the comparison with the satellite measurements more complicated. We took it as a challenge and decided during the flight to try to reach the high cirrus and to even fly above it. Here the exceptional capabilities of HALO came into play; HALO can fly high and for a long time. Indeed we managed to reach a flight level of 45,000 ft; we even got over the cirrus top. This was an amazing experience, seeing the contrast between the dark-blue upper atmosphere and space and the bright cirrus.
After returning to lower levels, we chased convective clouds most of the rest of the flight. Air traffic control was very flexible and allowed the pilots to change levels and heading frequently to catch the most appropriate parts of the clouds. The pilots fly into the clouds only if their on-board radar indicates it is safe to penetrate. In this way we managed to sample almost 30 clouds on our 7-hour flight. Again, this was only possible because HALO offers such awesome possibilities of long endurance and high ceiling.
The collaboration with the pilots (Steffen, Michael) and the aircraft technician (Tommy) was just awesome, the whole crew including the PhD students operating the instruments in the back of the plane (Mareike, Frank, Thomas, Daniel) had a lot of fun and enjoyed the whole flight. We learned a lot and marveled what incredible clouds Mother Nature presents us here in Brazil. Look at the amazing pictures attached!
Don't worry, just a short entry: Believe it or not, the containers with our equipment, which had been held up in customs here since early August, were finally released TODAY!!! Thanks go to Bruno and Roberta for working hard to get this to happen. I won't bore you with the gory details of the story, which contains customs agents that fell ill, lost documents, and a couple of week of "The containers will be surely released tomorrow...".
Our Brazilian colleagues recommended that we should begin the exportation procedure TODAY. Good advice, I think!
The day started out sunny, with just a little bit of cirrus in the sky. By about 0830L, the vultures near the airport were testing the first slight thermals, but even they could not make it very high above the ground. By 0930, they had better success, and the first very small cumulus clouds showed up in the sky. After the usual hectic pre-flight period, HALO took to the sky at 1029 local time, or 1429Z.
Today, we wanted to investigate the behavior of clouds growing in clean air, and the models and satellite images had predicted that we would find good conditions for this purpose around Boa Vista, some 600 km north of Manaus. We performed a slow climb to 39,000’ through a moderately hazy boundary layer with about 600 CN/cc. At this time, cloud bases were about 3600’ and cloud tops reached 6000’. At 1456Z we arrived at FL390, stayed there for some 5 minutes and began our descent again into the BL. Some large cumulonimbus clouds to the NW looked like they reached above 40,-000'. The Cb in the image to the right could actually be seen on the Aqua MODIS satellite image, and we ended up sampling its outflow later in the flight (after 1831Z).
The highest tops were now at ~18,000’ and average tops at ~15,000’. In the BL, we found CN counts of 600-800 /cc. After turning south again near Boa Vista, we sampled the growing cu’s from cloud base at 3500’ up to 36,000’, and the headed southeast to sample the Cb outflow mentioned before. After about an hour of this, at 1912Z, we left this outflow, to fly to another large outflow from a beautiful, big Cb closer to Manaus (picture below). Here we were greeted by the noise of static discharge, a smoggy smell in the air (ozone? NO2?), and high particle counts (~4000/cc). A bit spooky, but very exciting to us! After 1954z we left this outflow, descended, entered the mixed layer at 14,000’ with CN ~550/cc.
On the final approach to Manaus airport, we flew along a huge and threatening looking thundershower. Good thing we were able to land before this came over the airport! Landing was at 2020Z.
The science crew today was Meinrat Andreae (Mission PI), Micael Cecchini, Florian Ewald, Mira Krüger, and Sergej Molleker.
Since ACRIDICON-CHUVA is a joint experiment with the IARA flight campaign using the US-DOE G1 aircraft, it is essential to compare the measurements taken on the two aircraft. And what better way to do this comparison than to have the two aircraft actually flying formation side-by-side in the air! So the flightplan for today had both aircraft taking off more or less at the same time, fly in formation over the ground sampling site near Manacapuru, study clouds over the same area, and then have them go their separate ways doing additional tasks.
Takeoff was just after 1100L, followed by formation flight at 1500’ below a cloud base of about 2500’. Rachel Albrecht was the flight scientist on HALO, and Luiz Augusto Machado was with Jason Tomlinson of the G1. Cloud sampling on HALO began at 1220L at about 4000’ and continued up to 14,000’, where the convection topped out at the time (1416L). The aircraft then went to 43,000’ for some radiation measurements, and descended again to lower levels to sample some more clouds and cloud outflow. Landing was at 1619L.
(Thanks to Stephan Mertes, Luiz Machado, and Rachel Albrecht for the pictures!)
If you enter Brazil on a researcher visa, you must register with the Federal Police within 30 days. That sounds easier than it is – but since we have to do this quite a lot in conjunction with our permanent station near Manaus, one of our colleagues has written a 5-page manual to explain the procedure. Well, over the previous days we had acquired the necessary bank receipts, notarized passport copies, appointment receipts, and so on, and so at 0700 we headed in two carloads to the Policia Federal. We got there at 0730, waited for them to open, signed in, and – waited. My turn came about 1100. I was looked over, photographed, and fingerprinted. That also sounds easier than it is. Fingerprinting was with some electronic scanner, which obviously didn’t like my fingers. For each finger, it took about 10 to 50 attempts, with the friendly young lady grabbing my finger and rolling it around on the glass plate, with varying amounts of pressure. Alternatingly, I was asked to rub my finger across my forehead to provide more grease, and then had my finger wiped with a Kleenex to remove excess grease and sweat. Well, after some 20 minutes the procedure was over, leaving both parties somewhat exhausted. At 1130, after only four hours, I was able to leave with a new piece of stamped and signed paper that made me a legal scientific visitor to Manus!
Since this amount of waiting really didn’t impress anyone all that much, we were looking for more pain and ventured to get our airport badges from Infraero (I was told some call it Infernaero). We left the hotel again at 1320, drove to the airport, got the badge that allowed us into the office where we were supposed to get the badge, and – waited. After about half an hour, an employee came out and declared that the airport computer network was down, and they weren’t sure if and when it was going to come up again. After debating at length whether it was better to wait and take a chance or to come back tomorrow - and take a chance – we decided to stick it out for a while. Well, at about 1530 the network came alive again, and at 1550 at least those of us had a badge, who were expected at the 1600 planning meeting. We spent the rest of the day planning for an intercomparison flight tomorrow and listening to presentations.
Today, finally, came the day we all had been waiting for! At 0915L I drove to the airport with the flight crew and met the other scientists who had been at work since 0700 to get the instruments prepared. The science team consisted of myself, our Brazilian scientist Rachel Albrecht, Florian Ewald, Daniel Fütterer, and Emma Järvinen.
The aircraft was already parked on the apron, since in spite of the fact that we had contracted (and paid) for a hangar, that hangar was still filled with an old ATR52 that was being repaired and painted. But actually, it was quite comfortably cool inside HALO, thanks to an efficient air conditioner. In the hectic hours before takeoff, the cabin is so crowded with all the scientists getting their instruments ready that it is almost impossible to move around, and I sat down in the hangar instead.
I was a bit anxious at this time: Was the aircraft really going to work? Would the instruments perform? Would we be able to convince ATC to let us do the “crazy” flight patterns that our work required? Would I be able to navigate the aircraft through the complex manoeuvers that cloud profiling required? Would the pilots consider the cloud passages safe enough to make these runs time after time? Would too much ice accumulate on the aircraft to keep working?
Looking at the sky I could see that the cirrus in Manaus region was quite dense, which might be a problem for some of our radiation measurements and might suppress cumulus convection. But, to my relief, cumulus had been building since about 1030L (1430Z) and the sky beckoned us to start cloud sampling.
Takeoff was at 1606Z and we climbed out into a quite hazy sky. The haze topped out at about FL130 and we saw abundant cu’s all around us. After climbing to FL300 through some cumulus outflows we held this altitude for about 5 min, and then descended again into the boundary layer (BL). We reentered the haze at 11,000’, passed cloud base at 4000’, and at 1652Z crossed the Rio Tapajos, a major tributary of the Amazon, at about 2000’ above ground. The hazy air contained about 2000 particles per cc. There was a small fire with a smoke plume along the river and the vegetation alternated between forest and regions of savanna vegetation, which is called cerrado in Brazil.
At 1703Z we began our climb again, passed cloud base at 4100’, and did another up and down profile to FL300. At 1704Z we turned west in the BL at Alta Floresta (ATF) and flew over large deforested areas to our cloud profiling region about 30 nm west of ATF. Cloud bases here were at 5800’ indicating that we were in a slightly different airmass from before. We began cloud profiling at 1750Z with a 5000’ run below cloud base at SAT 19°C and CN ~2000/cc. For the actual profiling, we made 23 passages through clouds at 16 different levels. Some of these passages were only slightly bumpy, but other shook us around quite a bit. At the lowest levels we encountered only water cloud drops, then a zone with water and ice between FL220 and FL300, and only ice particles above this level. In the higher ice clouds, we had some encounter with static electricity, which made us a little nervous, and we made sure to stay away from the bigger cumulonimbus clouds to avoid any chance of lightning. Then, according to our plan, we had wanted to sample the ice cloud region at the temperature around -40°C, but we did not see any young cloud elements at this level, which seemed safe to enter, and so we decided to head north towards Manaus. Massive cloud anvils to the west above us looked threatening enough to hasten our departure.
On the way west and north, we passed through large areas of cloud outflow at FL330 to FL430, which contained lots of ice particles, but also very high concentrations (~5000/cc) of small aerosol particles that we think are produced in these cumulus towers. They appear to consist mostly of organic matter. As we went further north, the bigger ice particles from the clouds appeared to mix with particles from the cirrus clouds that had been prevailing in the region.
The long transect through outflow – in the cockpit we called it “grey soup” – ended when we entered a large clear area about halfway to Manaus, where we observed a beautiful sunset. Another large outflow just south of Manaus, then a turn over MNS, and north towards Boa Vista. We descended to reach ARVUM, our northernmost point, at 8000’ where particle concentrations were only ~500/cc. Since it was quite dark at this time, we felt that it was not safe to descend any further and headed back to SBEG, where we landed at 2329Z.
We were greeted by the rest of the science team and excitedly told our stories from the flight. All in all, we had an extremely successful flight that put to rest all of the worries that I had before we took off. The instruments worked (well, most of them) and the flight management between science and flight crews functioned very smoothly. ATC turned out to be very cooperative and the only hiccups were due to the occasional loss of communication because of the limited range of radio contact. Our Brazilian scientist, Rachel Albrecht, and Tenente Fialho managed to iron out some linguistic communication problems and succeeded in obtaining the magic word “Autorizado!” We wrapped up the day talking over well-deserved beers in the meeting room. “Thank you” to the team that had made it all possible, especially to our Brazilian partners!
(Photo credits to Meinrat Andreae, Steffen Gemsa, Florian Ewald, Emma Järvinen, and Daniel Fütterer)
All expeditions seem to begin with a period of seemingly endless waiting for supplies, permits, and the like. ACRIDICON, of course, is no different. We are still waiting for our container with scientific and aircraft equipment to be released from customs, and we have spent many “fun-filled” hours waiting to get badges to enter the airport. Getting your passport stamped by the Federal Police to validate your visa requires lengthy online filling of forms, visits to banks and notaries, and finally a visit to the offices of the Police, all in all a day of your life.
Most of the rest of the time is filled with meetings to discuss logistical issues, flight planning, coordination with Air Traffic Control, and so on. The good side of all this is that it gives the instrument scientists a chance to fix the many small and large problems that come up when one takes an aircraft full of high-tech equipment through lots of atmospheric turbulence, shaking and bouncing into the hot and steamy atmosphere of the Amazon.
Wednesday, 3 September, the day after arrival, the aircraft was promptly released from customs and the scientists could begin to download their data from the transit flights and work on their instruments. A nice benefit from all this hanging around was that I got to try out the pilots seat of HALO on the ground :-))! We also found out that Friday and Sunday would be national holidays, and airport access would be limited. Nevertheless, we made plans for a research flight on Friday, always the optimists. A very interesting part of the day was a series of short presentations by the scientist to introduce their instruments and objectives to the entire team.
On Thursday we first met with the representatives of the Brazilian Air Traffic Control, two Air Force lieutenants and a Sergeant. We were also introduced to the two young Air Force lieutenants, who were going to be the observers on our research flights. We then made the detailed plans for Friday’s flight, which was going to be a 700 mile transect from the smoke-polluted area around Alta Floresta to the clean atmosphere around Boa Vista in the north.
In the afternoon, we were to go to the airport to work on our instruments. I was supposed to get trained to operate a couple of instruments in flight, in addition to my job of flight scientist. This consists of coordinating the science and flight crews in flight and making decisions about what maneuvers to execute to get the aircraft to the right place and altitude for our measurements. For the training, we obviously needed aircraft access, which required badges. To get these, we first had to wait for the handling agent at Terminal 2, where we were told to go to Terminal 1, where we would be issued temporary badges. We all packed into our cars and drove over to the other terminal, waited again for our handling agent, and then were led to the airport offices for processing. There, we got badges that allowed us to get to another waiting room, where lots of people were already waiting. After only three hours and filing out more forms, we had our temporary badges, which allowed us to work on the aircraft for another two hours or so, while we had power at the aircraft. After all this, the day took a frustrating end, when the handling agent announced that tomorrow, Friday, there could be definitely NO flight because of the national holiday.
Instead, Friday (5 Sep) was spent doing more instrument maintenance and refining our plans for a flight on Saturday. I also discussed with Danny Rosenfeld the details of the procedure for “cloud profiling”, which consists of making many passes through growing cumulus clouds from cloud base up to the ice plume that leaves the top of the clouds.
Two itineraries today - one that of HALO, which flew from the Cape Verde Islands to Manaus, the other my own on a commercial flight from Rio de Janeiro to Manaus.
HALO left Sal Airport in the cape Verde Islands at about 1500Z and first did two short sampling legs in the Sahara dust layer at 6000 and 11000 feet. Climbing up to flight altitude after these legs showed that the highest dust concentrations today were at levels above 11000', a bit higher than the day before. Then came the long crossing over the tropical Atlantic, which took HALO through the inter-tropical convergence zone (ITCZ) with some big convective systems, which show up as white blobs over the Atlantic on the satellite image below. Elevated aerosol concentrations were observed above some of these large convective clouds and cirrus outflow anvils. An example is on the picture to the right.
HALO reached the Brazilian coast at Fortaleza and then turned west to head for Manaus. Unfortunately, for legal reasons, we had to turn off our instruments an hour before reaching the continent, and could not get data during this part of the flight. Nevertheless, there are some beautiful pictures from this part of the flight. The images below show convective clouds growing out of a sometimes quite clean (first picture), sometimes smoke-polluted boundary layer over equatorial Brazil. Above Brazil HALO climbed up to test its ceiling altitude with its heave load of instruments, and reached an impressive 47,000 feet.
The picture below wins today's "Blogger's Choice Award"! It shows an long outflow from a cumulonimbus cloud, seen from an altitude of about 20,000' when approaching Manaus. Picture credits go to Steffen Gemsa for this one and to Johannes Schneider for the pictures above. At 2200Z (1800 local) HALO landed at the Manaus International Airport.
As promised, there is a second itinerary for this day! Since I was not on HALO, I took the commercial flight on Lufthansa to Rio de Janeiro (11:40 hours long), and then got to spend almost eight hours in beautiful Rio airport waiting for my connection for the 4:15 hour flight to Manaus. I was lucky enough to get a window seat on this flight, and could get a first survey of aerosol and cloud conditions along a stretch from about 23 S to 3 S. I'll show some pictures from this flight below, but keep in mind that pictures of aerosol hazes are, well, a bit hazy!
Starting from Rio, the aerosol burden increased going north, and my first image shows a typical sky at about 19 S. What it also shows is one of the big problems Brazil is facing at this time: the huge reservoir at Tres Marias in Minas Gerais State, like many other reservoirs in Brazil, is almost empty because of a severe drought that has been going on for a long time now. That makes our ACRIDICON-CHUVA research, which addresses the connections between aerosols, clouds, and rain, particularly relevant to this region.
From about 12°S on the air go so hazy that it became difficult to see the ground, and the densest haze was reached at around 10°S.
The cumulus convection was more active here as well than in the south, and many clouds were rising to our flight altitude of 36,000’ and even well above us.
On some of them, I could observe the typical wispy plumes of ice particles detraining from the cloud.
At about 6°S, the air became noticeably cleaner, and one could see small muddy rivers flowing through the rain forest.
Near Manaus, I had the first view of the Amazon River, which was below quite dense haze, apparently produced by some burning along the shores of the river further downstream to the east. North of the river was a line of cumulus convection.
Then came one of the main touristic features of Manaus, the Meeting of the Waters, where the muddy Solimões River to the South and the coffee-brown Rio Negro flow for a while side by side in the same channel, before they merge to form the actual Amazon River. This being the dry season, the view was a lot less clear than what one can see in the rainy season.
Finally, after a sweep by the city of Manaus, our home away from home for the next month or so, the Hotel Tropical and the Park Suites Hotel tower, located along the Rio Negro came into view just before landing at Manaus airport.