Six weeks have gone by since I arrived in Cape Verde but it feels like six months! It has been hard graft since Day 1: a steep learning curve, a test of patience and perseverance, and many sleepless nights. Was it worth it? Yes of course. The NCAS mobile radar operated successfully and continuously for 4 weeks and as a result we now have a very unique and exciting dataset. We finished preparing the radar for shipping yesterday and it is now sat at the port waiting for boat to arrive. It should leave Cape Verde around 6th September, arriving Portugal two weeks later, then onwards to the manufacturer in Germany for some maintenance before finally arriving back in Leeds mid-October. In the meantime I will be taking a well-earned holiday and regaining some energy in order to start planning the next deployment!
Each morning we have a weather briefing at 0830 where the PIs (Principal Investigators) and Mission Scientists look at the forecast for the current day and tomorrow. Today they had to make a call which of two flight plans to go with – ICE-D cloud flight or SAVEX flight (Sunphotometer Airborne Validation Experiment in Dust). The photo below shows the group examining the different model outputs, and I’m glad to say Clouds won the vote. However, as I write this, once again the only decent clouds are out at 200km range. Fingers crossed more develop closer to us.
Today is the 6th operational day on the trot. The aircraft has broken its record for number of flights on the run – 7 as of today. Unfortunately for the last two days all the clouds have been at a long range from the radar. Our scanning pattern starts with a surveillance scan at 1° elevation out to 300km range and then 12 scans from 2° up to 15°. For the surveillance scan at this maximum range the beam is 5.2km wide so it’s providing information from a large volume of atmosphere and is only useful for identifying cloud locations but tells us nothing about the vertical structure. Additionally, due to the curvature of the earth, the centre of the beam is at an altitude of about 10km! So, we decided to change the scanning pattern to include another two surveillance scans, a lower one at 0.5° and one at 1.5°, to try to get a little bit more information at long range to help inform the aircraft. The image below shows an example of what this gives us. It is vertical cross-section through clouds – think of taking a slice through a cake and being able to see the layers. It is still limited information, but better than the information from a single beam.
The first flight took place on 6th August. The main purpose was to test out instruments and coordination between the aircraft and radar, but there were also a lot of precipitating clouds around which provided an opportunity for science. Some moderately intense rainfall had been observed overnight and in the early hours, located 100km southwest of Praia and moving west. FAAM took off at 12L and initially targeted an area southeast of Praia for aerosol observations, before moving further west in the afternoon to penetrate some clouds. The radar observed an interesting change in the mode of cloud activity with the deeper convection moving west but only shallow clouds developing upstream.
It’s 2 weeks and 1 day since I arrived in Praia, Cape Verde, and what a whirlwind it has been. We’ve been incredibly busy setting up the X-band radar and have achieved an incredible amount in a short space of time, even if I do say so myself! We’ve had a great team of people without whom this wouldn’t have been possible – James Groves and Dan Walker (NCAS IT and all round superstars), John Bradford (Radar Engineer from Chilbolton) and Ryan Neely (NCAS/ICAS Lecturer & Instrument Guru).
We spent the first 5 days putting the radar back together – not too much of a jigsaw but it had to be done slowly and carefully. Then came the momentous day of craning the radar onto the platform. If I was a cat, I think I would have lost a few lives, after being put through the horror of this procedure! I certainly think a few more grey hairs have come through. Let’s just say that things are done “a little differently” in this part of the world and we had to supervise every single part very closely or else we’d be sat crying with a rather broken radar right now. Thankfully after several hours of deliberation and much shouting, we had completed our task and went back to the hotel for a well earned rest.
The following week we got stuck into the IT, setting up the office container for operating the radar and collecting the data. Having not yet had the radar operating continuously in one location for any period of time, we’re doing a lot of things for the first time and therefore we’re discovering a lot of bugs. This whole experience has been a big learning curve for myself and the team. I think it puts us in a good position for our future projects though. It was sad to say goodbye to James and Dan last Thursday, and of course everything started to go wrong during their last afternoon! But thankfully after we got a super duper new internet link installed on Friday we could skype them perfectly this week and make progress on our to-do list.
The FAAM aircraft arrived today; it was fun to see it land and taxi past the radar. Should be plenty more photo/video opportunities over the coming weeks. As I write this I am killing time until I go to the airport to pick up Alan Blyth and Zhiqiang Cui, who are part of a group of 20 people arriving tonight to join the project, including Jim McQuaid and Hannah Price from ICAS. The first potential flying day is Thursday, I hope we’ll be ready!
The mobile X-band radar arrived in Praia last Friday after a two week voyage from Portugal, in preparation for the Ice in Clouds Experiment – Dust (ICE-D), which is due to start at the beginning of August. Lindsay Bennett and Ryan Neely will be heading out to meet it 3 weeks today and get it up and running before the FAAM aircraft arrives. Rather a relief to see it in one piece…..well in fact it’s in two pieces, the antenna and waveguides were dismantled and boxed separately to protect them for the journey. There’s been a huge amount of preparation and organisation to get to this point, so we’re keeping our fingers and toes crossed that everything else goes to plan too.
Deployment of instrumentation on the Swedish Icebreaker Oden took place in Helsingborg at the end May. We have instrumentation deployed over seven decks not to mention on a 10m mast at the bow – going up on the scissor lift when out at sea is going to be an interesting experience!
One of the big innovations for this project is using active motion correction tables for the LiDAR and the Radiometer. Seeing your kit dangling in mid air is quite a worrying experience but the crew were brilliant and the installation was hassle free.
The Oden will head up to Tromso at the end of June and the cruise leaves 6th July. The first leg goes from Tromso to Barrow (Alaska) arriving there around 17th August. While in Barrow there will be a complete crew change and then the second leg back to Tromso sets out 22nd August (getting back in around 4th Oct). The tracks for each leg is slightly different but both will be up through the ice but towards the Russian side of the Arctic.
Spent the last couple of days in meetings with the KNUST project partners.
The Ghana supersite for DACCIWA is going to be based on the KNUST campus in Kumasi. The campus is enormous and very spread out but as the IOP is going to take place in June/July only the masters and Ph.D students are going to be around. The site we will be working at is part of the School of Agriculture but the School of Physics, who run the meteorology program, have a measurement compound there. Power and network are available in the classrooms adjacent to the compound (20 m away) so things aren’t looking to bad. They do suffer power outages that can last an around 30 minutes and we did have an hour long one during our first set of meetings so UPSs are the order of the day.
At the moment the temperatures are peaking around 35C at about 1pm and the humidity is around 65% with only marginal drop in temperature over night. I’m told this is the hottest time of the year and it should be distinctly cooler come June and July – hope this is true or some of the instruments are going to need a cooling system!!
Seen Kites, Vultures, Geckos, and Lizards and grasshoppers like this specimen. No snakes but evidence of scorpions.
Two days in now on this reconnaissance trip to Ghana for the DACCIWA project and have just got in to Kumasi. We’re based on the KNUST University campus and this is where we will deploying the kit. Tomorrow I get to have a look at the compound and start to work out what can actually be done and what is really going to have to be shipped from the UK.