The Lusaka Leg

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

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

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:

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

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:

Into the fires

Tuesday 29 January
Fire map from NASA

Fire map from NASA on 29 January 2019

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…

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

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

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!

There is no science without coffee

Ethiopian Coffee

Without coffee, there is no science

I write this at 8am on a Sunday in a bustling airport in Addis Ababa, with a few hours to spare before my connecting flight. I had intended to prepare a background post outlining the plan for the field work and the wider project, but doing  anything non-essential in the run-up to the trip proved a little over-ambitious.

A colleague and I are flying out to Entebbe, which is on Lake Victoria in Uganda, about 30km away from Kampala, to join the rest of the detachment team to work on the FAAM research aircraft. We took a red-eye flight from London and as a result I really needed the excellent Ethiopian coffee I just finished. We were supposed to start the research flights tomorrow, but the final sign off has not yet been obtained from the local officials – not for want of trying! So instead, today is a “hard down day”, meaning no access to the research aircraft at all, because without the sign off, we can’t get airborne.

So Monday will be used to get all the instruments up and ready while the aircraft remains on the ground and hopefully Tuesday we will get airborne. We really have a packed schedule, as we are only doing MOYA flights Tuesday to Friday and then one more on Tuesday next week (another project called HyVic is flying over Lake Victoria on the intervening days). The shorter detachment saves on costs, but means we are at the mercy of the weather. To make sure we can fly every day we have several different flight options to choose from: Lake Victoria, Lake Kyoga, Lake Wamala and wildfires in northern Uganda. We will pick one of these based on which location has the best weather conditions, and fingers crossed we have time to do 2 of each. We also hope to circuit Kampala to sample the city’s emissions as part of one of the flights.

Why are we going to all this effort? Mainly to figure out how much methane is coming out from the lakes, wetlands and wildfires. This will help us to piece together the global methane trends – a key factor in how much the planet will warm in the coming years. To do this, we sample the methane in the atmosphere while airborne, as well as ethane and other pollutants. Some of these measurements come in real time, others are taken back to the UK to analyse for carbon isotopes, which gives us a clue as to the emissions source. You will find blogs from our 2017 airborne field work, based in Senegal, where wildfires were sampled. I have to say, based on the turbulence we felt on the commercial flight here, I am not too keen on flying near wildfires (which cause turbulence from their heat) or storms (which are quite common even though this is the dry season for Uganda).

I think the boost from the coffee is wearing off now, so I will sign off from my first post. There will be more content over the coming week, when I hope to have more than a few hours doze before sitting down to write.

Moorland fires – BBC film of MOYA flight

This July we had an exciting unplanned measurement flight.
MOYA flight hours were used for James Lee, University of York, and Grant Allen, Manchester University, and their teams to sample over the moorland fires burning in northern England.

Moorland fires over Northern England. Photo Credit: North Yorkshire Fire Services

The air samples are going to give a useful comparison with the Senegal fires the MOYA flights studied last year, and the measurements from next year’s Ugandan campaign.

Sampling over a forest fire in Senegal from the FAAM aircraft, March 2017. Photo Credit: Axel Wellpott


Find the full BBC video here. 
BBC report:
“Scientists are flying a lab-on-an-aeroplane through the smoke of wildfires in the north of England, testing the air as they go.Fires like the one on Saddleworth Moor are predicted to be more common than usual across the UK and Europe this summer, raising concerns about pollution.BBC Science Correspondent Victoria Gill joined researchers on a converted passenger plane run by the Natural Environment Research Council.”