A swamp and a city

michellecain Leave a comment
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

michellecain Leave a comment
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!

The Botanical Gardens Redux

michellecain Leave a comment
Sampling cows at the botanical gardens

 

On Wednesday, we came back to the Botanical Garden in Entebbe to take some more air bags from termite mounds and cows methane emissions. Even though a thunderstorm was coming (and probably this is why all the meteorologists stayed in the hotel), we managed to get a great range of samples. Thanks to our guide, Peter, we even found some termites and got very close to the local cows.

The Garden is also a great place for bird spotting – part of our group turned into ornithologists. We have seen monkeys, which escaped from the zoo and local dogs too.

So far, the ground work is very successful and we hope, that we will get some great samples from the aircraft as well!

By Dominika Pasternak

Papyrus: a methane emitter and natural wind vane

michellecain Leave a comment
The papyrus swamp measurements team
Tue 22 January 2019
Part 1

Having planned out the next few days flights – to lakes/wetlands as well as fires – and with no point refining the plans based on the weather forecast because we don’t know exactly when we will be able to start flying, I’ve joined Rebecca again to do some air sampling. This time with intent, and with a full rucksack containing anything I might need (unlike yesterday).

We are currently in a taxi out to see a contact, Steve Forsyth, who works at Mission Aviation Fellowship – Uganda, and is based at an airfield by a papyrus swamp. MAF is an organisation that operates small aircraft to transport refugees from nearby countries like the Democratic Republic of Congo or Sudan. The swamp will be a source of methane and so will be a good opportunity to work out the carbon-13 fingerprint of such an ecosystem. The principal investigator of this project, Euan Nisbet, has sampled here before, so it will be good to find out whether the fraction of carbon-13 varies over time or is very consistent.

Getting out of the conference room is a good chance to stop obsessing over ever evolving weather forecasts and see some of Uganda. And I can make myself useful by taking photos of the sampling location at very least.

Part 2

We are on the way back from the airfield now. It was completely surrounded by papyrus swamp, which meant we could access it quite easily. We were escorted around the airfield by Ivan, who was essential in helping us not get our feet wet (we were not keen to lose a trainer in the swamp!) while getting as close to the swamp as possible.

The papyrus plants were extremely tall in places – close to 4m probably. Some areas were cut down to the stem, and they grow back in about a month according to Ivan. The stems themselves are very strong, and are excellent wind vanes of you ever are in need of one. Which I did, as I was taking wind measurements to accompany the air samples.

In all, we took 13 samples from locations close to the surface of the water up to about 2m high, all around the edge of the swamp, plus one background sample further away from it. This will allow us to find out the carbon-13 fingerprint of this papyrus swamp, where there were the highest methane concentrations. For example, the papyrus that was cut down to ground level may emit more or less methane than the fully grown area and maybe the measurements will give us an indication of that.

 

Serendipitous sampling

michellecain Leave a comment
Monday 21 January 2019
Termite mound

Taking an air sample beside a termite mound (Steve Andrews, Rebecca Fisher and our very understanding tour guide)

Today was another down day, with access to the aircraft for instrument scientists. We are fairly well prepared for the flights, as we originally wanted to start flying today, but hold-ups with permissions mean that we will be lucky to fly tomorrow. So we have got several flight plans fully prepared, and we are just keeping an eye on the weather forecasts and waiting for the all clear.

Instead of obsessing over the weather, some of us went to buy local SIM cards and have lunch. So far, so uneventful. We then decided to walk back to the hotel via the botanical gardens, and this is where the day turned up some unexpected excitement. Rebecca Fisher from Royal Holloway, a seasoned and clearly very dedicated field scientist, had come prepared with three air sampling bags and a pump. So when we saw termite mounds in the botanical gardens, Rebecca and I were grinning with glee, as termites are one of the more unusual sources of methane, and one which we hadn’t measured before! The down side of our enthusiasm was that the termites weren’t terribly pleased and one bit me. I admit that termites weren’t on the risk assessment as we had no idea we would see any.

After learning some more about indigenous and non-indigenous plants in the gardens, and spotting various birds (kingfisher, ibis, cormorant, egret and a few more unidentified ones) and a troop of monkeys, we found some cows hanging out with some egrets. And of course, took another sample, cows being a favourite methane source to measure.

Cows and egrets in the Botanical Garden, Entebbe

Cows and egrets in the Botanical Garden, Entebbe

One final sample on the beachfront later, and we were done with the sampling. Rebecca will analyse the air back in the UK to see how much carbon-12 and carbon-13 there is in the methane. Sampling close to a source (e.g. a termite mound) is a way to identify that source’s signature amount of carbon-13 relative to carbon-12. The better we know this from a range of different sources, the better we can work out the origin of a methane measurement far away from the source, by matching up this so-called isotopic fingerprint.

For more about this kind of isotopic fingerprinting, see this blog from our previous campaign about methane in the Arctic.

sampling a cow

A cow shows Shona Wilde and Rebecca Fisher what she thinks of their air sampling!

There is no science without coffee

michellecain Leave a comment
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.

Large methane emissions from Amazonian floodplain trees

aoife.grant Leave a comment

Blog Author: Emanuel Gloor, University of Leeds

A recent study led by Sunitha Pangala presented the discovery and showed the importance of a previously unknown conduit of methane from floodplains to the atmosphere in the Amazon. The conduit are trees. To demonstrate the importance of this conduit two approaches have been pursued. On the one hand methane flux from tree stems has been measured in floodplain trees of many river stems of the Amazon and for a large number of trees. This data was up-scaled using area estimates of seasonally flooded floodplains.

Sampling set-up for methane from tree stems. Photo Credit: Sunitha Panagala

Setting up of methane tree sampling equipment. Photo credit: Sunitha Pangala

Aircraft were used to regularly (bi-weekly) take vertical profile samples of the lower troposphere methane concentration field. These data together with a back-trajectory based atmospheric inverse transport model were used to estimate the total Amazon basin methane balance. This tropospheric methane sampling program is being led by Luciana Gatti at INPE in Sao Jose dos Campos, Brazil.

While there is disagreement between upscaling of previously known methane flux processes and the aircraft based methane balance, inclusion of the discovered additional flux path leads to good agreement between the two approaches. The discovery of the tree conduit is important because the Amazon contributes a substantial fraction of methane emissions from wetlands globally. This contribution is approximately 8-10% of all contemporary methane emissions to the atmosphere.

Besides Sunitha Pangala and Luciana Gatti, scientists from several other institutions were involved in the study including from the Open University, NOAA, ESRL and University of Leeds.

The full article is available here:

Large emissions from floodplain trees close the Amazon methane budget, Sunitha R. Pangala, Alex Enrich-Prast, Luana S. Basso, Roberta Bittencourt Peixoto, David Bastviken, Edward Hornibrook, Luciana V. Gatti, Humberto Marotta Ribeiro, Wanderley Rodrigues Bastos, Olaf Malm, Emanuel Gloor, John Miller, Vincent Gauci (2017) Nature, 552, 230–234, doi:10.

Moorland fires – BBC film of MOYA flight

aoife.grant Leave a comment
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.”

Methane session Open for Abstracts – AGU Washington

aoife.grant Leave a comment

The MOYA projects PI Euan Nisbet will be convening a session on methane in the AGU Fall Meeting. This years AGU will be held in Washington, D.C. from  the 10th-14th of December. Abstract submission closes on the 1st of August 2018 so get writing!

Sampling methane emissions from cows in Zimbabwe

The global burden of atmospheric methane has exhibited periods of both rapid growth and stagnation over the past two decades, with unexplained rapid growth since 2014. This growth has been accompanied by a negative isotopic shift (δ13C–CH4), reversing the trend of the past two centuries. Methane does not have a single dominant source, but rather a wide spectrum of anthropogenic and natural sources. This diversity of uncertain sources has led to a number of recent explanations for recent growth including: tropical wetlands, livestock, fossil fuels (coupled with declining biomass burning), and changes in the methane sink (via reaction with OH). The warming impact of methane’s unexpected growth is now the largest deviation from the Paris Agreement. This session invites work that investigates processes controlling the methane budget using in situ measurements, satellite observations, and modeling, as well as the ways in which emissions can be reduced.

Banned industrial solvent sheds new light on methane mystery

moya Leave a comment

This news post is about exciting findings by Matt Rigby and co-authors, which may hold the key to the sudden and unexpected global rise in atmospheric methane following almost a decade in which concentrations had stayed relatively constant. Below is press release published by the University of Bristol on this recent paper: ‘The role of atmospheric oxidation in recent methane growth’ by M. Rigby et al in Proceedings of the National Academy of Sciences

Model simulation of the hydroxyl radical concentration in the atmosphere.

Since 2007, scientists have been searching to find the cause of a sudden and unexpected global rise in atmospheric methane, a potent greenhouse gas, following almost a decade in which concentrations had stayed relatively constant.

Recent studies have explored a range of possible causes. Suggestions have included a rise in oil and natural gas extraction, increased emissions from tropical wetlands or increases in emissions from growing East Asian economies.

However, a new paper by an international team of scientists in the Proceedings of the National Academy of Sciences (PNAS) investigates an alternative possibility: a rise and fall in the concentration of the substance that destroys methane in the atmosphere, the hydroxyl radical.

Lead author, Dr Matt Rigby from the University of Bristol’s School of Chemistry and Cabot Institute, said: “A change in the hydroxyl radical concentration would be a neat explanation for the changes in methane that we’ve seen.

“It would mean that emissions may not have increased suddenly in 2007, but rather, risen more gradually over the last couple of decades.”

Since the global concentration of the hydroxyl radical cannot be measured directly, the team’s findings were made by studying the rate at which the solvent methyl chloroform, which is also destroyed by hydroxyl, was removed from the atmosphere.

Professor Ron Prinn from the Massachusetts Institute of Technology, who co-authored the paper and leads the Advanced Global Atmospheric Gases Experiment (AGAGE), an international project that measures greenhouse gas concentrations, said: “We have been monitoring trends in the methyl chloroform for nearly 40 years because of its role in depleting stratospheric ozone.

“Because methyl chloroform is now banned under the Montreal Protocol for the Protection of the Stratospheric Ozone Layer, we’ve see its concentration drop very rapidly.

“We can examine how this rate of decline changes from one year to the next to infer the hydroxyl radical concentration.”

Dr Steve Montzka from the National Oceanic and Atmospheric Administration (NOAA), who also co-authored the paper, and operates an independent measurement network for methylchloroform, added: “This paper re-examines some of the assumptions that had previously been made in studies of hydroxyl radical and methyl chloroform and shows how they influence our understanding of methane’s atmospheric sink.

“To me, one of the main findings is that our objective analyses of two sets of observations tells essentially the same story, even as it becomes more and more difficult to measure methyl chloroform given that its concentration is approaching zero.”

Dr Rigby added that there was still uncertainty remaining. He explained: “Whilst there are strong hints in our study that hydroxyl radical changes could be playing a significant role in the fluctuations in methane growth, our uncertainties are very large.

“In future, we need to think about new ways to reduce this uncertainty, if we are to truly understand changes in atmospheric methane.”

The study also lead to a more certain, but unexpected finding: that emissions of methyl chloroform had not dropped to zero.

Dr Rigby said: “Because its production is now banned globally, we were expecting to see no emissions of this substance at all. However, we have very strong evidence that emissions are continuing.”

The team are preparing a follow-up study that would determine where these emissions are originating. Meanwhile, they are continuing to monitor methane in the atmosphere, and are waiting to see whether its current rate of increase will continue.