Author: natalieratcliffe3

Cape Verde with a Chance of Dust Storms

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Natalie Ratcliffe – n.ratcliffe@pgr.reading.ac.uk

My PhD project was could have been done entirely from behind a computer screen, but I ended up in Cape Verde for 3 weeks in June 2022 on a field campaign.

Though the island of Sao Vicente is one of the Cape Verde (= green cape) islands, it wasn’t particularly green…

Working with Dr Franco Marenco from The Cyprus Institute (CyI) and my supervisor at Reading, Dr Claire Ryder, I managed to get some funding to spend 3 weeks in Cape Verde alongside an organised campaign. The ASKOS campaign was created to calibrate and validate aerosol, wind and cloud products from the Aeolus satellite, launched in 2018. They planned on using a combination of ground-based instruments and drones supplied by the Unmanned Systems Research Laboratory (USRL) with CyI to profile dust above Cape Verde to compare with the Aeolus aerosol products.

My PhD project is based around trying to understand how some large dust particles (diameter > 20 um) are travelling much further from the Sahara than expected based on their deposition velocity. One theory about how these particles are transported so far is that they are vertically mixed throughout the depth of the Saharan Air Layer (SAL, dry dusty air layer transported from the Sahara, typically up to ~6 km altitude) during convective mixing in the daytime. At night, with the removal of this convection, these large particles begin to settle through the SAL at a faster rate than other fine particles, before being mixed up again to the top of the SAL during the convective day. This is hypothesised to increase the time taken for the particles to reach the surface, encouraging long-range transport of these coarse particles. We proposed to fly drones with optical particle counters attached up through the SAL during the day and night to see if this theory has any standing.

Before I could go to Cape Verde came all the admin and preamble for going on a field campaign. Before booking flights and accommodation, the wonderfully long health and safety risk assessment form must be completed and approved. Reading through that form really makes it feel like you’re going to face every single threat known to humankind while you’re off campus; hurricanes, volcanoes, Covid-19, getting bitten by ticks (other animals/insects are available), sunburn (to be fair, a very real concern for me) and even getting hacked and bribed. I suppose being prepared for all these eventualities is meant to make it less scary

I had three virtual meetings with everyone involved in the campaign before we travelled, so I had a little bit of an idea what I was supposed to be doing when we were out there. Though to be honest, I still wasn’t entirely sure until a couple of weeks before we left! Claire and I had to introduce our work and what we wanted to achieve from this campaign. I was a little apprehensive as we were going to be requesting to collect data in the very early morning (3-6am ish) meaning we’d have to ask some of the other scientists to be up very early (or late depending on your opinion).

The Wall-e LiDAR. Wall-e was looking at the orientation of the dust particles. eVe was there too but she was basically just an all-white version of Wall-e (disappointing).

Now we get to the fun part where I actually go on the campaign (or on holiday as some people kept insisting. FYI, this was absolutely not the case). Most days would start with a few of us looking at the forecast to work out when we should aim to fly the drones. We would decide on a plan for the day, a suggested plan for the next day, briefly looking at data from the day before and then collating this all into a newsletter which was sent out to everyone on the campaign. These forecasts were useful for those collecting in-situ observations as well as those working on the ground-based remote sensing equipment. It also became very clear in these meetings that each scientist had a preferred forecasting model. We had so many options for forecasts (SKIRON, Met Office, CAMS, IAASARS, ECMWF etc), as well as varying satellite retrievals (EUMETSAT Dust RGB, MODIS NASA AOD, NOAA GOES-East visible images etc) and near-real-time observations from the ground instruments (PollyXT LIDAR, HALO Doppler wind lidar, CIMEL Sunphotometer etc) that there was occasionally some jostling to work out which forecast and measurements to trust and focus our planning based on! I was then able to go to the airport to help the flight team. I would refer to the most recent reading from the lidar and suggest which layers in the dust should be sampled with filters, as well as checking the wind lidar to make sure it wasn’t getting windier.

The USRL team getting ready for launch. The drones were thrown rather than taking off from the ground. The pilot is in the middle; he has a controller and a headset which he can use to pilot the drone.
The drone path, windspeed, ground speed and altitude can be watched from the ground.

Looking back, we should have focused our forecasting on the wind and cloud more than the dust concentration. Initially, we were planning to measure when there was an interesting or high concentration dust event over the island. However, we eventually realised that the wind and cloud cover were the most limiting factors for measuring in terms of the in-situ and ground-based measurements, respectively. This unfortunately meant that, on a few occasions, the flight team were stuck at the airport waiting for the winds to drop before they could launch the drones. Or that the remote sensing teams couldn’t take results at the same time as the drones because there was too much cloud. It was a learning experience for everyone involved!

I’ve taken away four things from this campaign that it seems will probably happen on any field campaign, so take note if you ever get the opportunity!

  • You’ll get to meet some really cool people
  • Probably get food poisoning
  • Your equipment will break at some point
  • And many things will go wrong… It’s an inevitability

Some of the issues we faced were: instruments taking longer to calibrate and setup than expected, helium arriving two weeks late, missing weather balloons, two got covid, five got food poisoning, one drone crash-landed, too windy to fly the drones, not dusty enough, too cloudy for the lidars… It was definitely an exercise in contingency planning. I did say that this was a fun experience and I do mean it! Though there were many tense moments where things went completely opposite to the plan, I got to meet a lot of cool scientists, learn about new instruments, go to Africa for the first time and get hands on with some dust at last!

Feel free to check out this blog post which I wrote for ESA’s Campaign Earth blog page: (https://blogs.esa.int/campaignearth/2022/08/03/delving-deep-into-dusty-skies-on-the-askos-aeolus-field-campaign/).

This blog article is part of the DAZSAL project that is supported by the European Commission under the Horizon 2020 – Research and Innovation Framework Programme, H2020-INFRAIA-2020-1, Grant Agreement number: 101008004, Transnational Access by ATMO-ACCESS.

Panto 2021: Hybrid edition – Semi-Lagrangian Rhapsody! 

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Charlie Suitters – c.c.suitters@pgr.reading.ac.uk
Hannah Croad – h.croad@pgr.reading.ac.uk
Isabel Smith – i.h.smith@pgr.reading.ac.uk
Natalie Ratcliffe – n.ratcliffe@pgr.reading.ac.uk

The pantomime has been one of the highlights of the year for the last 3 decades in the Met department. This is put on by the PhD students, and usually performed in person at the end of the Autumn term. Despite the ongoing COVID-19 pandemic, the panto is going from strength to strength, with a virtual instalment in 2020, and adapting to the hybrid format this year. It’s amazing to see the department tradition continue.  

This year the four of us (Charlie Suitters, Hannah Croad, Isabel Smith and Natalie Ratcliffe) agreed to organise the panto. It was clear that the panto this year would need to cater for both people joining in person and virtually, and with the lingering uncertainty of the covid situation in the UK, we came to a group decision to pre-record the performance in advance. This would provide the best viewing experience for everyone, and provided a contingency if the covid situation worsened. In hindsight, this was a good decision. 

This year’s panto was called Semi-Lagrangian Rhapsody, an idea based on the story of the band Queen. On Thursday 9th December 2021 we screened our pre-recorded pantomime in a hybrid format, with people watching both in the Madejski lecture theatre on campus and at home via Teams (probably in their pyjamas). Our story begins with our research group, Helen Dacre, Keith Shine, and Hilary Weller, on the lookout for a fourth member. In an episode of Mets Factor, the group sit through terrible auditions from Katrina and the Rossby Waves, Wet Wet Wet, the Weather Girls and Jedward (comprised of John Methven and Ed Hawkins), before finally stumbling upon Thorwald Stein (aka Eddy Mercury). The research group QUEEN (Quasi-Useful atmosphEric Electricity Nowcasting) is formed. Inspired by an impromptu radiosonde launch on the MSc field trip and skew-Ts (Chris knows!), QUEEN develop a Semi-Lagrangian convection scheme for lightning. Our narrator, SCENARIO administrator Wendy Neale, tells the story of the ups and downs of QUEENs journey, culminating in a presentation of their Semi-Lagrangian Rhapsody to the world at the AMS conference.  

Natalie suggested the idea for the panto, and we all agreed that it was a great idea – especially with the potential for lots of Queen songs! Once we had our storyline, next came the script writing. This was a daunting task, but working as a team we managed to produce a decent first draft in one intensive script-writing week, full of amazing terrible meteorology puns. Whilst writing the script we decided on the best Queen songs for the plot (and for reasons that we cannot explain/remember, a Rebecca Black song too). Now it was time to alter the lyrics, which was a lot of fun! Only once we had written the songs did we actually consider the complexity of Freddie Mercury’s voice and how we, a bunch of non-musically talented PhD students, were going to attempt to do these songs any justice. It was too late to go back though, and we had to break the news to the band. Thankfully they were up to the challenge! 

From week 6 onwards, we were able to start recording scenes; we were lucky that we were able to film in-person in and around the Met Department. We were still able to include students who weren’t in Reading at the time by writing in virtual parts into the panto. This worked perfectly well given the very hybrid nature of life currently anyway. 

Like last year, we wanted to start earlier as we knew that we needed to be finished at least a week – preferably more – before the big night to give time to edit everything in time (there were still a couple of late nights just before the big night). The final late night session did lead to the incredible slow-mo shot of Nicki Robinson (Charlie) turning around in Bohemian Rhapsody, so there is something that can be said about late-night-induced-insanity!  

Come week 10, we had nearly finished all of our filming and only had the songs left to record. We arrived at the London Road music rooms not yet having heard any of the band’s rehearsals. They sounded amazing. Many thanks to James and Gabriel who had been organising the band throughout the term. Then we started singing and immediately reduced the quality! But with a bit of practice around the piano, we started to improve, though the beginning of Bohemian Rhapsody was still a little questionable… With lots of pizza, we managed to record all of the songs in two nights! The band did an amazing job to put up with our musical incompetence (we are so very sorry). 

Over the next week, our three video editors worked hard to put the whole panto together and I hope you agree that they did a good job. This all led up to the big night where we were able to offer a small pre-panto reception in the Met coffee room before the panto started (somewhat attempting to mirror the normal pre-panto buffet). Apart from one slip up in scene 4 (my apologies hehe – Natalie), the screening went nearly perfectly with very few hybrid IT complications. Additionally, we had the return of an in-person performance of Mr Mets by our own Jon Shonk, and a heartwarming singing performance from the staff, organised by Chris Holloway and Keith Shine. Not only were we gifted this, but we were able to enjoy an in-person after-party in the coffee room with DJ Shonk. Of course there were a few Queen songs scattered in the mix, though we realised we struggled to remember the original lyrics and were only able to sing the panto versions! Following the story of Queen may have been a good idea, but have we forever ruined their songs for ourselves forever now? Quite possibly… 

And on that bombshell, we’d like to thank everyone who was involved in this panto, whether that be those who we convinced to act, sing, play in the band, help organise the event or even just come along to the screening. The whole process of creating this panto was exhausting, but so incredibly fun. I (Natalie) am so glad I did it and had a great time, but I now understand the ‘I’ve done my time’ sentiment of the previous organisers. (Hannah) Organising the panto was a lot of work, but so much fun (see bloopers). This has been a really rewarding experience, to see it all come together on the night, and to contribute to a fantastic department tradition. 

This year we sold tickets for the in-person showing and asked for donations to the David Grimes Trust from those viewing from home. Thank you to everyone who has already donated. Your generosity is greatly appreciated. We have managed to raise £170 for the David Grimes Trust. If you would like to donate still, please find our email with details on how to do so from Hannah Croad. 

Thank you to everyone who watched Semi-Lagrangian Rhapsody on Thursday, we hope you had a fun evening whether you watched at home or in-person!