Author: michellecain

Impressions of the ZWAMPS trip to Zambia

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JANUARY – FEBRUARY 2019

A guest post from MOYA’s sister project, ZWAMPS. Photos and text by Trish and Tim Broderick

Trish and Tim Broderick flew Emirates to Lusaka from Harare on the evening of Sunday 27th January 2019.  They were met at the airport by Abby, a very friendly and pleasant man, from the car hire company.   We settled comfortably into the Cresta Golfview Hotel along the Great East Road, which was to be our home for the next couple of weeks.

The original intention had been to drive from Harare, with camping kit loaded.  However, the chaos over the economic situation and the resulting hours-long queues for fuel made it impractical, and we did not know if fuel would be available for the return journey.  As it turned out we would not have needed the camping kit.

28th Jan:  The following morning, having received the hire car, we set out for the Geological Survey.  We had a problem: Tim only had very old maps of Lusaka city, which has grown and changed over the years.  We did try to buy an up to date map, but were either told they had not been printed or were out of stock.  The exciting part of this, for Tim, was driving in Lusaka traffic using an automatic car for the very first time!  Trish kept a hand on his left leg and whenever his muscles tightened, as if to seek the clutch, she squeezed hard to remind him not to do that!!

It turned out to be a very long morning as we were ‘Lost in Lusaka’.  Tim believed that, as part of the Ministry of Mines, the Geological Survey was incorporated in the same building.  However, it seemed that both had moved from the original location as per his map!  Eventually, finding the Ministry at its new location in the Government Complex, parking and finding someone to talk to on the 14th floor, a kind staff member drew us a map and we set off again.  Closely following the instructions we went wrong again and ended up at the gates of the Zambian Air Force Headquarters!!  Finally a gate guard nearby insisted on getting into our vehicle to conduct us to the right place… and there it was.  Francis Chibesakunda, the Chief Hydrocarbon Officer said he’d been expecting us all morning and it was now past 2 o’clock.  Meanwhile our daughter in Harare had been following our adventures with some amusement and had offered to help find the way from her phone.  That would have been fine if we’d had a physical address!!  At last Tim was able to settle down to make arrangements with Francis, and we met the rest of the Hydrocarbon team, who were very interested and already well informed about the task ahead.  Young Musa Lambakasa, the new Environmental Officer, was assigned to us and we made arrangements for the next day.  That was to be, on Euan’s suggestion, a visit to the Chunga dumpsite north of the city!  During the day we’d found time to visit a local shopping mall where we bought gumboots, which proved very necessary on the trip.

29th: The next morning after an excellent breakfast at the hotel we set out to pick up Musa and made our way to the dump.  It is huge and phew, what a smell that invaded one’s nostrils and lasted after we left.  Tim had looked on Google Earth at images of the dump and could see the direction of a smoky plume carried by the prevailing wind, so, the plan was to take air samples more or less along the path of the plume and finally upwind for the control.  As Tim was training Musa in the art of air catching, a guard came along and insisted that we required permission from his superior, a lady, as it turned out.  We were quite surprised that there were guards, all in radio contact, but it seemed that they act as some kind of control of the dumping and scavenging for recyclables that takes place.  Aside from being delaying, and averting a need for a letter of authority from the Municipality, there was no problem as Musa displayed his diplomatic talents that we came to rely on all the days we were in Zambia.  Trish’s photos show the progress of the air samples through the dump until we reached a cemetery and finally burgeoning high-density settlement (Fig. 1-3).  Consulting his out of date map, Tim decided on a spot in a ‘mealie field’ where we could take a control sample.  Well, and of course, the place chosen was totally built up with small dwellings, vendors and crowds of people (Fig. 4).  Eventually a spot was found where the control sample could be taken.  That ended our work for day one!

Fig 1: Chunga Dump, Lusaka

Fig 1: Chunga Dump, Lusaka

Fig 2: Musa learns to catch air

Fig 2: Musa learns to catch air

Fig 3: Downwind plume from Chunga Dump

Fig 3: Downwind plume from Chunga Dump

Fig 4: Searching for a control point!

Fig 4: Searching for a control point!

30th Jan: The Ngwerere River foray. The next day we collected Musa and set out on the airport road for an apparent reed bed identified on Google Earth.  Tim’s difficulty was to find any suitably open sites within reach of Lusaka, now a city with over 2.5 million inhabitants.  On the way Musa received a phone call instructing us that the FAAM BA146 had arrived with the party of scientists from Entebbe, from where the first phase of the operation had taken place across Uganda.  We were asked to meet them as the welcoming party as the plane was parked at the Civil Aviation Authority (CAA) hardstand (Fig. 5) where we were to find the presiding major.  This took some time as the crew had been bussed to the airport for immigration formalities.  Eventually scientists and crew came through the doors and we were able to make some brief introductions before they made their way to the hotel and we continued to the Ngwerere River.  This was only after an altercation over a suggested fine for parking in the VIP slot, to which we were directed, but which was skilfully negotiated to zero by Musa. Once we had crossed the river bridge and assessed the presence of an extensive reed bed (Fig. 6), Tim chose spots for sampling along the wooded and cultivated roadside.  Working backwards to the source target, we achieved a suitable sample suite, including the control point.  Musa was requested to return to the CAA office, whereupon we were invited to take a preview of the plane.  That was a privileged moment and Musa’s excitement, for one, could not be suppressed, especially given the barrage of instrumentation encountered.  Tim then dropped Trish back at the hotel before fighting the intensely congested traffic to take Musa back to a point where he could find transport home.  The evening was spent getting to know some of the scientists and crew, particularly Mo (Maureen Smith), who had done most of the pre-expedition organising.

Fig 5: Preview of FAAM G-Luxe

Fig 5: Preview of FAAM G-Luxe

Fig 6: The Ngwerere reed bed

Fig 6: The Ngwerere reed bed

31st Jan:  This was a day when Trish rested, recovering from flu, it was a welcome relief.  Tim and James France from Royal Holloway, went to the Geological Survey to order maps and reports and to the nearby Surveyor-General for topographic map coverage.  This took up most of the morning.   Dave Lowry arrived at mid-day and, as the airport shuttle had failed, Tim and James went to pick him up at the airport.  Then it was back to the Survey to introduce Dave to the counterparts and to pick up maps.

That day Dave Simpson in particular was running around trying to finalize the necessary military authorization for the intended flights.  The signature came the next morning, so the sorties could go to schedule.

There had been talk of our going to Lake Bangweulu, by road, but in discussion it was realised that this venture was too ambitious for the time available.  It is a ten-hour drive from Lusaka to any suitable place to stay and the area is so large that it would require at least six days there to do the job justice.  Later our experiences of distance and disaster made us realise that it is a trip that has to be very well thought out.  It would be better to go in more than one vehicle with a team that would add security in the event of any mishap.  We would also have to ensure that the tools in the car, especially the jack, are suitable for all conditions.  Mike Daly recommended that we acquire a satellite phone as one is often out of range of a cell phone signal.  We are thinking of July or August, probably during the Zimbabwe school holidays for that excursion, as it will mean that our photographer daughter might be available.

1st Feb:  The day’s sortie covered Lake Bangweulu and adjacent swampland, returning along the Luangwa and Muchinga rift escarpments in the hopes of picking up helium anomalies relating to hot springs.  James was on this flight filling Tedlar bags for all he was worth.  With Dave Lowry we collected air in the hotel grounds near the golf course, which we could not see, but impala graced the lawns.

2nd Feb:  This was an exciting day for Tim as he had missed the Bangweulu flight the day before.  This time they zig-zagged across the Kafue Flats, and the Lochinvar hot springs.  Trish again stayed back at the hotel and enjoyed watching the plane’s progress from the Ops Room, which had been set up in the hotel conference centre.  This was Musa’s first ever flight and he had the privilege of sitting with Stefan as his mentor.  It was a great experience for Tim and for Senior Geologist, Everisto Kasumba, to view the intimate detail of the flood plain, its dynamics and to follow the progress and view the data acquisition in real time.  A real Wow!

In the afternoon we shopped with Dave and Stephan, who needed gum boots, and we had to stock up with snacks and drink for the next day’s adventure.

3rd Feb:  This was the day we drove to the Blue Lagoon along the Mumbwa Road while the plane flew its ‘Union Jack’ survey over the Lukanga Swamp.  Dave Lowry has written this section up for the blog along with our eventful trip to Mazabuka on 5th.  Meanwhile the plane landed safely on return from Lukanga, but then a problem arose with the wing flaps meaning that the flight, planned to obtain profile samples over Lusaka before refuelling for their onward return to Entebbe, had to be cancelled.  This was a disappointment for some of the Geological Survey people who had been invited on the flight, but especially for the flight engineers.  In order to make repairs to what was thought to be a software problem, parts had to be flown out from the UK.  It all worked out and the plane was able to return to Entebbe

4th Feb:  Not knowing how long the delay would be most of the scientific contingent, including Mo, departed on commercial flights via Entebbe and then onward to the UK.  With pilots exchanged ex Entebbe and the problem solved, the plane was flown to Entebbe for final logistical arrangements before returning to England.

Meanwhile, Tim discovered that a puncture had developed on the hire car during the night and the right rear wheel had to be changed.  This was repaired at a nearby roadside facility, and the vehicle was badly in need of a wash.  Then with brake fluid leaking everywhere, the car hire people had to be called in, and it took the remainder of the day to obtain a replacement vehicle.   All was well that ended well.  It was fortuitous that this all happened whilst in Lusaka.

5th Feb:  Mazabuka and the blow-out.  Due to the lost day in Lusaka there was no time for Dave, James, Musa and the Broderick’s to venture forth, overnight in Monze and join Mike Daly to witness his sampling of the Bwanda and Gwisho hot springs in Lochinvar National Park, the site of a geothermal energy investigation south of the Kafue.  Mike was there to sample the emitted gasses in flasks for their helium content.  He measured temperatures in the order of 90oC in the eyes of these springs.

Dave Lowry has penned an account of our adventures to Mazabuka and thence to the Nenga pump station close to the Kafue and beyond the sugar plantations where we were able to take a suite of air samples.

6th / 7th Feb:  Dave and James departed for the UK on 6th whilst the FAAM crew with their BA146 reached Entebbe.  Musa, Trish and Tim then drove the replacement Pajero to Kabwe and booked in at the Broken Hill Lodge for the night.  We were aiming for the Lukanga swamp and by dint of trial and error, local questioning, GPS and our map managed to find the right road, which we tried out that afternoon.   In the wake of the previous night’s rain, this proved to be a very rutted, ponded and muddy road made feasible by its laterite base.   We got about half way to Chilumba School, but had developed the confidence that we could make the remaining distance to Waya Fishing Village, despite the gruelling 4 x 4 driving required in the face of a stream of charcoal-bearing bicycles, ox carts, motor cycles and the occasional vehicle (Fig. 7).  Fortunately it did not rain in the night and we set out early the following morning.  The road was appalling and it took hours to navigate, but eventually we arrived at the fishing village where the locals displayed the expected curiosity at our visit.  Musa explained what we wanted to do and we confirmed that they had seen the plane traversing the swamp two days before.  Welcomed, we set off in the company of the village head and several other friendly fishermen along an elevated dike adjacent to the dredged channel leading into their dugout canoe harbour (Fig. 8).   Reaching the swamp margin (Fig. 9), into which we waded to collect our first tedlar samples, the local watched with interest.  Eventually as we worked our way back sampling the seasonally inundated wetland and then the termitaria-studded dry zone (Fig. 10), the village head insisted on holding the fishing rod so as to be part of the exercise and of course he had to be in Trish’s photographs!  Cattle from the village were grazing in the drier zones along the swamp margin and we took our control sample in the tall mixed brachystegia woodlands back east along the access route.  We had to plan the drive back so as to reach Lusaka before dark, which we almost did.  From the main road we could see that high rain storm clouds had gathered in the direction of Lukanga Swamp west of Landless Corner and we were very grateful to think that we had not been caught in the wet on that tiresome road.  It had been an exhausting time for Tim as he navigated every yard of the road, choosing which way to go and following the most recent tracks of other vehicles.

Fig 7: Charcoal on the road to Lukanga

Fig 7: Charcoal on the road to Lukanga

Fig 8: Trish the ‘bag lady’, Lukanga

Fig 8: Trish the ‘bag lady’, Lukanga

Fig 9: The Lukanga Swamp, Waya

Fig 9: The Lukanga Swamp, Waya

Fig 10: Drier grass & termitaria zone, Waya

Fig 10: Drier grass & termitaria zone, Waya

8th Feb:  This was our last day and the first requirement was to get the car washed before we delivered our air bags, aside from those that had gone on the plane, to the Geological Survey to be sent to Euan and Rebecca in Egham by DHL, and also to say our goodbyes to the Director, Francis, Musa and the Survey team.  We really hope that Musa will be with us on the trip to Lake Bangweulu, possibly along with James and/or Dave.   Following a modicum of shopping, we returned the car in good shape, apart from the fact that we could never release the 4-wheel drive lever.  Mike Daly had warned us that he’d never hired a car in Zambia that had not had some mechanical problem.  This is why we need to plan the Bangweulu trip so carefully.

Lukanga Swamp Map

Lukanga Swamp Map

 

 

 

The Kafue Flats Experience

michellecain

By Dave Lowry, Tim and Trish Broderick, Musa Lambakasa, James France, Stéphane Baugitte
Photos by Tim and Trish Broderick and Dave Lowry

The first ZWAMPS campaign consisted of both aircraft and ground surveys, these being linked most closely in the Kafue Flats region over the period Feb 2 to 5. The Kafue Flats are a floodplain wetland, extending from Itezhi-Tezhi Dam in the west, some 240 km east to Kafue town and never more than 50 km wide (https://en.wikipedia.org/wiki/Kafue_Flats). The river has changed course many times across its plain leaving scattered oxbow lakes and isolated snake-like sections of meanders to stagnate outside of flood season (Fig. 1).

Fig. 1 River Kafue lakes and meanders.

Fig. 1 River Kafue lakes and meanders.

The surveys and sampling commenced on Saturday with an intensive 4-hour zigzag flight over the region, designed by Keith Bower (Fig. 2), with elevated methane noted toward the eastern end near the start of the flight, before vertical mixing reduced these signals. The flight was very much enjoyed by Tim and our Zambian Ministry of Mines group, including Musa. Separating out the wetland source from the flight measurements and isotope data will be quite difficult because there were also numerous rural cattle herds and very extensive burning plumes producing methane (Fig. 3).

Fig. 2 End of the zig-zag flight

Fig. 2 End of the zig-zag flight

Fig. 3 Biomass burning plumes close to river

Fig. 3 Biomass burning plumes close to river

On Sunday we attempted to find our way by road to the northern margin of the Kafue Flats through the Blue Lagoon national park. After a 3-hour drive from Lusaka we reached a faded sign saying Nakeenda Lodge 9 km.  The national park sign was even more rusted. Soon we realised that this part of the park had not been visited for a long time as the track became more an overgrown and very muddy path, so we decided to sample air from a dambo in the pristine savanna (Fig. 4). The site was full of butterflies of numerous species, and even a praying mantis was catapulted into the car as we brushed past the luxuriant vegetation (Fig. 5).

Fig. 4 Stéphane directing air sampling

Fig. 4 Stéphane directing air sampling

Fig. 5 Mantis on water bottle

Fig. 5 Mantis on water bottle

Undeterred we decided to approach the park from the NW corner and reached a barrier. Here the head park ranger directed us to the managed game area and wetland.  After a few kilometres we turned off along a narrow track not on maps or GPS. Then followed 20 km over 90 minutes down a narrow and churned up track. As we passed across the invisible park boundary we came to a fishing camp on a rise above the floodplain and its associated biting insects. We were greeted by excited children and an ox cart (Fig. 6). Turns out that we were still some kilometres from the river, the resident lechwe antelope or the Game Ranger patrol camp. At this point we realised we had to get back to Lusaka before dark.

The return was no quicker, especially being interspersed with air sample collection in the pristine national park grassland (Fig. 7), as we carefully traced our way back along interweaving tracks using the GPS. We approached the outskirts of Lusaka as night fell, and on a road without lighting, carefully negotiated many minibuses without lighting and pedestrians bustling across the road to lively markets. Alarm bells had been ringing back at base when we failed to arrive back for the evening briefing and our Blue Lagoon destination was all that was known. As the city approached and phone reception returned we were able to let all know we had not broken down in the bush.

Fig. 6 Ox cart and children in the camp

Fig. 6 Ox cart and children in the camp

Fig. 7 Musa and Dave fishing for air

Fig. 7 Musa and Dave fishing for air

On Monday we had planned to sample on the south side of the floodplain, overnight in the Relax Hotel in Monze and then meet up with Mike Daly at the Lochinvar hot springs on Tuesday, but after breakfast Tim noticed that the Ford had a rear puncture from our toils the previous day, which fortunately hadn’t materialised on the evening drive back. Tim headed off hoping for a quick fix, but a brake fluid leak was also discovered from a distorted and corroded seal. Many discussions and calls later a replacement vehicle was delivered at 6 in the evening.

Plans quickly changed and the proposed rendezvous with Mike was scrapped due to the long distance, and the focus for Tuesday was to get into the sugar cane plantations and wetlands near Mazabuka. All was fine until about 2 hours into the drive when, on probably the steepest hill climb on the Kafue-Livingstone main road, there was a load bang from the rear of the vehicle. This time a major blow out and a 3 cm long rip in the tyre. Tim and Musa got to work on the jack while we jammed the other wheels with some lovely roadside calc-silicate boulders. Convoys of lorries heading for Botswana and South Africa laden with copper and other goods struggled past us. It soon became apparent that the supplied jack was not high enough for our Landcruiser, but we managed to flag down a local farmer and get the change done.

That’s when we noticed a 1cm diameter, perfectly round hole through the alloy wheel below the rip in the tyre, with a very clear entry and exit direction from a high velocity impact (Figs. 8 and 9). None of us had seen anything like that before and we still don’t know the cause, so we will leave this to your imagination.

Fig. 8 Hole in the alloy wheel – inside view

Fig. 8 Hole in the alloy wheel – inside view

Fig. 9 Hole in the alloy wheel – outside view

Fig. 9 Hole in the alloy wheel – outside view

At Mazabuka we found a tyre repairperson and then followed a wild goose chase to find a welder, then through sugar cane plantations to a market for electrodes, which then didn’t work because the alloy was wrong and required a DC current. After 2 more lost hours, we had a reality check, dumped the wheel and tyre into the back and decided to risk it on the spare and take the 30 km of dirt tracks NE toward the wetlands and river. With co-ordination of aerial images and GPS we headed down a narrow track and finally came to lush vegetation, reed beds (bulrushes) and clusters of water lilies, before the track stopped abruptly in a small clearing populated by a group of fisher folk. We proceeded to collect air samples from different heights in the reed beds. In the midst of this the reeds seemed to part and a small canoe cruised into the bank laden with good-sized Kafue bream (Figs. 10 and 11).

Fig. 10 Boatmen in the reed beds

Fig. 10 Boatmen in the reed beds

Fig. 11 Cargo of Kafue bream

Fig. 11 Cargo of Kafue bream

The drive back was far less eventful. The next morning the car hire people inspected the wheel and seemed overly keen to give us our deposit back and get us on our way. We can certainly look back on a couple of eventful and somewhat surreal days that we won’t forget in a hurry and hope that the few highly prized air samples were well worth our efforts to collect them.

The Lusaka Leg

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Operations base in Lusaka, Zambia

Flight planning at the operations base in Lusaka, Zambia

The final swamp survey of the campaign has just landed, so I thought this would be a good time for an update on our work here in Zambia. Since arriving on Wednesday we’ve conducted three flights over three different wetland areas, with each of them providing a rich, complex dataset for us all to get our teeth into when we get home. The Kafue river floodplain and the Bangweulu and Lukanga swamps all exhibited the telltale signs of strong methane emitters, with large concentrations enhancements observed during each flight. This large signal should make Rebecca’s life easier when determining source isotopic signatures (see “Meanwhile, back in the lab”), and we have started putting our heads together to determine the best ways of calculating how much methane each source area emits. While we won’t get into the nitty-gritty of the data analysis until we return, sitting together in the bar after a flight provides a great opportunity to foment some ideas.

The Bangweulu sortie was particularly special for me, as it was my first flight up in the jump seat as mission scientist 1. At first it seems like a daunting task, choosing where and at what height to fly in order to get the most out of the time available. However, with sage advice from veteran mission scientists beforehand, patience from the pilots, and help and encouragement from the rest of the team down the back, all went smoothly. Having surveyed the swamp, we flew back along a rift valley, hugging as close to the side wall as we could, looking for any sign of geological emissions. The data from this will need picking over in more detail before conclusions can be drawn, but from a scenery perspective this has to take top spot among flights I have ever been on. Looking up at the Muchinga Mountains from 1500 ft above the valley floor was a breathtaking sight for which I feel very privileged.

That leads me on to a topic that’s been covered many times in these blogs before, but now we’ve reached the end of the campaign I feel it bears repeating. These detachments are hard work, but the early starts and the weeks spent away from home don’t seem a hardship when you’re part of such a close team. As I write this we’re sitting out on the terrace with a Mosi in hand (other Zambia lagers are presumably available…) with impala wandering by, and I can reflect on friendships made and renewed. I’d completely echo Michelle’s earlier post – the rambling late night discussions, debates and arguments have been second to none, and I’ll certainly miss them when we leave. I’m looking forward to being home, but I’m looking forward to the next one too…

Farewell, and thanks for all the methane - Zwamps team

Farewell, and thanks for all the methane – Zwamps team

Bagsy the Air Samples: Life on the aircraft for the isotope bag sampling

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James France and his sack of bags

James France and his sack of bags

Unlike quite a lot of the science on board the FAAM aircraft, the high precision carbon isotopes in methane have to be done back at the lab at Royal Holloway. To make this happen, we have to collect bags of air mid-flight as we pass over areas of interest, trying to capture the range of sources in the flight plan. However, it does mean that our role can look at little bit budget compared to the needs of a complex and expensive instrument rack measuring species in real-time during the flights.

The life of the isotope sampling team depends on your point of view… The instrument scientist who has to turn up 4 hours before take-off sees the isotope sampler swanning onto the aircraft at the last minute, switching on a pump and a laptop and writing some sticky labels. The logistics team who despair after each flight as we hand over a massive sack containing around 20 bags of air and ask them to find somewhere to store them and then ship them back home. The crew who just hear calls on the radio from the less technically named “bags”. Suggested nicknames which have fortunately not gained traction include “Team Bags”, “Dr Bag” and “Bag Man”…

I prefer to think us more of an Ngolo Kante or Anders Herrera (Ed – can we have a football reference in a science blog?). It’s not altogether obvious what we contribute until all the data is looked at, well after the campaign is done.

Collecting the air

It really is a simple as it sounds. The FAAM aircraft is fitted a large air inlet line which directs air from outside the aircraft to the various instruments, and the bag sampler has a pump which allows air from the outside to be directed in to the bags. The bags are made by SKC, and have been demonstrated in the laboratory to hold the methane without any leaks for months at a time, which gives us plenty of time to do the analysis. To show the full complexity of it, I agreed to do a special with plenty of detail for an upcoming edition of the Barometer podcast run by the University of Manchester.

In order for us to get useful data to identify the source we need to collect a suite of samples at as large a range of concentrations of methane as possible, fortunately the aircraft is well equipped and can measure atmospheric methane concentration in real-time. We use this information to try to sample the air into the bags at the most scientifically useful points.

Why are we interested?

As I’m sure you’ve read on many other posts on this blog and others, methane is rising globally and we’re not entirely sure why… One of the possible reasons is an increase in emissions from tropical wetlands, so we’re on this campaign to try and gather information needed such as the isotopic source signature and the flux of methane being emitted from tropical methane sources. There’s a lovely new paper (shameless plug) which has just been accepted which looks at the impact of methane globally “Very strong atmospheric methane growth in the four years 2014 – 2017: Implications for the Paris Agreement” which will be available in the journal Global Biogeochemical Cycles soon…

We’ll keep the blog updated with something later in the year, once the laboratory analysis has started to take shape.

by James France

On the aircraft, “Team Bags” is James France, Rebecca Fisher and Dave Lowry of Royal Holloway University Earth Science Department.

On the ground, a separate but co-ordinated with the aircraft, sampling campaign is ongoing with Tim Broderick, Trish Broderick and Dave Lowry.

Meanwhile, back in the lab

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Wednesday 30th January

While FAAM and the ZWAMPS team head on to Zambia, I have returned home from a busy week of air sampling in Uganda. This week I’m back in the greenhouse gas lab at Royal Holloway. Soon we will have a lab full of Ugandan and Zambian air in Flexfoil bags and WAS cases, so we need to make some space.

Once the air samples return to Royal Holloway we will first measure methane and carbon dioxide mole fraction in each sample using a Picarro cavity ringdown spectrometer, and we will check the measurements against those made by the onboard FGGA. Then it’s over to the mass spectrometer for methane isotopic analysis. We use continuous flow isotope ratio mass spectrometry to measure δ13C in methane in permil (‰). Each sample takes around an hour to analyse, and with more than 500 air samples expected from the MOYA and ZWAMPS campaigns that will mean a lot of time spent in the lab over the coming weeks.

Analysing methane δ13C in bags of air by isotope ratio mass spectrometry at Royal Holloway

Analysing methane δ13C in bags of air by isotope ratio mass spectrometry at Royal Holloway

Methane in background ambient air has an isotopic composition of around -47 ‰. Methane from biogenic sources such as wetlands is more depleted in 13C, making the isotopic composition more negative. Methane from fires is relatively enriched in 13C, making the isotopic composition less negative. This paper by Rebecca Brownlow provides some of the isotopic signatures we have measured from tropical methane sources in previous ground campaigns: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GB005689

Isotopic analysis of the samples collected onboard the aircraft will help distinguish the proportion of methane from fires and from wetlands in methane elevations seen over wide areas of tropical Africa.

By Rebecca Fisher

The MOYA podcast has landed

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MOYA has teamed up with the Barometer podcast to produce some special podcasts from the field.

In this introductory episode, Joe Pitt (instrument scientist and mission scientist on MOYA) has a chat with Grant Allen, the Manchester lead on MOYA. They talk about the scope of the project, including some of the challenges we face in doing such ambitious field work in a country that FAAM has not previously worked in.

Listen to this first episode here: https://thebarometer.podbean.com/e/moya-project-introduction-with-joe-pitt-and-grant-allen/

Into the fires

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Tuesday 29 January
Fire map from NASA https://firms.modaps.eosdis.nasa.gov/

Fire map from NASA on 29 January 2019 https://firms.modaps.eosdis.nasa.gov/

Today’s morning fires survey team are just on their way back from the airport. Yesterday’s flight was great (apart from the fiery temperatures in the cockpit and a very bumpy ride with the strong daytime turbulence/thermals). We sampled a mix of mile-wide flaming and smouldering fire lines in the north of Uganda with varying CH4/CO2/CO ratios and some interesting fire tracers reported from other instruments, sampled by flying along-wind and across-wind at heights between 1000 ft and 6000 ft above ground. We were joined by a couple of flocks of black and white birds at 3000 ft that passed the window rather fast… Much like the Senegal surveys, there was a thick regional haze from the fires and a faint smell of smoke for the whole flight.

Flight track from the north Uganda fire survey

Flight track from the north Uganda fire survey

We collected bag samples on each pass through the plumes for isotopic analysis and much of the material burning was low-level scrub and papyrus. The land was very dry (much drier than this time last year) and there were many tens of small and large fires in view from the horizon at 3000 ft, most of which appeared to be managed land clearance. The data collected on these flights will improve the knowledge of the isotopic signatures of biomass burning from these plant types in this region, which will better refine models that use isotope measurements as constraints on emission source regions and source types.

By Grant Allen

 

And I was just getting into the swing of things…

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Saturday 26 January
Flight C129 - Lake Wamala survey and sampling the plume downwind of Kampala

Flight C129 – Lake Wamala survey and sampling the plume downwind of Kampala

This morning, the aircraft did a repeat of yesterday’s flight plan over Lake Wamala and downwind of Kampala. This gives us another chance to examine the methane emissions from the lake and surrounding swamps (which I think are papyrus swamps like the ones we saw at the nearby airfield the other day), which also might have been polluted by some small fires dotted about the place, and to look at a more complex mix of pollutants coming from the capital city. The FAAM aircraft has done flights like this downwind of cities like London and Lagos, so it will be interesting to see what we find here. Everyone I spoke to seemed very happy with how the flight went, as collecting good data is what we are all here for!

I wasn’t on board, as I’m going back to the UK tonight after nearly a week here. It’s a shame I only got to do one flight, but this is not that surprising given how uncertain it is doing field work in a country that we have never worked in before. You need to build in a lot of contingency for these things, and me having only one flight is not even close to being a factor in our plans. I came along to help with the heavy workload of planning and flying during an intense campaign, so hopefully the others who are staying for another week or more will have been able to pace themselves a bit more than they would otherwise. You can’t really have scientists working long days every day for weeks on end – it’s not healthy even if it’s just for a short time in the field. It also helps to have extra people on hand in case of illness. We have been putting 3 mission scientists on the crew list but flying just 2 of them. This means that if one of us feels even a little ill, they can stay on the ground without any problem with having the right passes sorted out for the airport in advance. This is working really well, as it’s fairly common to get a tummy ache on campaign in tropical regions, and nobody wants to be on an aircraft when that happens!

The operations centre for the field campaign

Just resting our eyes in the operations centre for the field campaign

I’ll miss the excitement of the field campaign when I go back to the UK, as you don’t get the same insight into every aspect of the work from afar – like discussing options for upcoming flights based on how the weather forecast is developing over breakfast, finding out the latest instrument issues or breakthroughs at lunch, or mapping out that future Nature paper over a Nile Special lager and curry in the evening. There is so much value to be gained from going on a campaign that I am extremely grateful I was able to take part. I will continue to send in forecast maps that I have set up with the Met Office for the campaign to help with the flight planning, and keep tabs on what’s going on, but I will really miss the random chats I won’t have with all the great people working on this project. The campaign hasn’t even finished, and I can’t wait until the next project meeting comes along!

 

A swamp and a city

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Friday 25 January

Part 1

On board the FAAM aircraft for flight C128

On board the FAAM aircraft for flight C128

I am on the bus to Entebbe Airport for my first and only MOYA flight. We have planned a flight over the nearby Lake Wamala, which is a lot smaller than Lake Victoria (which is like a sea really) or Lake Kyoga,  where they flew to yesterday. I am “mission scientist 1” for this flight, and James Lee from University of York, who will be mission 2, led the flight planning. This means that I sit in the cockpit with the pilots, and James sits at the back of the aircraft with more access to the live data as it comes in from the instrumentation. You get a fantastic view from the cockpit, with the flip side that it’s quite uncomfortable. Definitely worth it though!

We aim to see methane emissions from the lake, and mission 2 is critical in feeding information about the measurements to mission 1, who spends more time liaising with the pilots.

After Lake Wamala, we want to fly downwind of Kampala to measure the emissions from the city. Hopefully we can take off on time and get back before dark, otherwise we may have to modify our flight plan to avoid birds that come out at dusk. And judging by the dense clouds of flies I’ve seen over the lake after dark, maybe they are an issue too!

Part 2

Happy instrument scientists Dominika and Pat

Happy instrument scientists Dominika and Pat

What a great flight! After all the planning and working on the instruments on the aircraft, it feels like the campaign has got off to a great start. Firstly, it appears that ALL the key instruments worked. This might sound rather basic, but the aircraft is a very hostile environment for instrumentation. Lasers are easily misaligned, overheating can be a problem, changes to air pressure are a constant issue for some instruments. Congratulations to all the instrument scientists who have been working in the heat on the ground to get everything working so well.

We got some great measurements of methane downwind of Lake Wamala, Kampala and of some small fires again. I think we are all very happy that everything went to plan, the wind was as forecast, and the layers of methane in the atmosphere was as expected as well. It’s very rewarding and even euphoric when things work well, and it makes the 34C+ cockpit with a burning hot laptop on your lap well worth it!

And we’re off

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Thursday 24th January

Today saw the first science flight of MOYA get off the ground. It was so exciting that I completely forgot, and was in the middle of recording a podcast with Pat Barker from Manchester when it happened. I am sure there was a little cheer from everyone paying attention!

The aircraft went up to Lake Kyoga in the middle of the country, where the aim was to sample wetland emissions of methane. They also saw several plumes of smoke coming from fires, and much of the area was not actually wetland but relatively built up.

It was great to get things started and get some samples over this area. It may be more of a challenge to disentangle the signals from the lake and the fires, but that’s what happens in the real world – things are messy!

There will be a flight tomorrow (Friday 25th) if all goes to plan and then we will really get into the swing of things. Forecasts are looking good for a flight over another Lake and to sample the city of Kampala so I am really looking forward to that one – it’s got a bit of everything!