NAWDEX Campaign – Experiencing the Jet Stream

Email:  j.maddison@pgr.reading.ac.uk

NAWDEX (North Atlantic Wave and Downstream impact Experiment) was an International field campaign led by Ludwig-Maximilians-Universität (LMU) Munich and the Deutsches Zentrum für Luft- und Raumfahrt (DLR) Oberpfaffenhofen in cooperation with the Eidgenössische Technische Hochschule (ETH) Zurich and the Office of Naval Research in the USA, with many other international collaborators. Multiple aircraft were deployed from Iceland (the HALO aircraft and the DLR and Safire Falcons) and the UK (the FAAM aircraft) to take meteorological measurments with the aim of providing knowledge of mid-latitude dynamics and predictability. There was involvement from across the UK, including the University of Reading, the University of Manchester, and the Met Office as well as from the FAAM.

The NAWDEX operations centre was based in Keflavik, Iceland (number 27 in Figure 1), which I visited for a week to join the campaign as one of the representatives from the University of Reading, UK. I was tasked with being the ground-based observation coordinator.

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Figure 1: Radiosonde launch locations for the campaign.

A Europe-wide network of radiosonde launch locations (Figure 1) had been readied for additional launches during the NAWDEX period. Our role was to choose sites to launch sondes from that would complement measurements taken by the aircraft and/or support one of the NAWDEX objectives. Of particular interest was downstream high impact weather events over Europe. It was great to be given real responsibility and be able to actually contribute to the NAWDEX project.

Below is a typical daily schedule I would have in Iceland:

Daily schedule:

UK call: 8:30am Icelandic. Conference call between UK parties discussing plans for the coming days and any updates from Iceland or the UK.

General meeting: 12pm Icelandic. Go over brief weather summary, instrument status reports, flight plans for the coming days and reports of previous flights.

Weather meeting: 4pm Icelandic. Detailed look at the weather situation for the short and medium-ranges, highlighting key features that would be of interest to fly into, e.g. extratropical transitions of tropical cyclones (which we were fortunate to observe more than once). Radiosonde launch updates.

In between: assessing forecasts and flight plans for the coming days and meeting with scientists for their input to decide where we want to launch radiosondes from. Along with preparing slides to present to the group proposed launch locations and emailing various meteorological services to request the launches (the most time consuming).

My time in Iceland was a great learning experience. Working with some of the pre-eminent scientists in the fields of dynamics and predictability (and spending most of the day discussing the weather!) really helped improve my understanding of the development of mid-latitude weather systems and better understand their predictability.

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Figure 2: On-board the FAAM aircraft.

After returning from Iceland I got the opportunity to fly on the FAAM aircraft (Figure 2) whilst it was on a mission for another project. The flight aim was to perform a radiometer inter-comparison by taking coordinated measurements of deep-frontal cloud to the north of Scotland with the HALO and Safire aircraft. The flight was remarkably turbulent free (I‘d been hoping for more of a roller coaster ride), although we did perform a profile right through the cloud to an altitude of less than 50 ft, which was pretty fun! Whilst on the aircraft we were also able to plot measurements being taken in real time on an on-board computer.

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Figure 3: Flying at an altitude of 35 ft.

NAWDEX was a great opportunity to get first-hand experience of a major international field campaign (and see some of Iceland).

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The impact of Climate Variability on the GB power system.

Email: h.bloomfield@pgr.reading.ac.uk

Bloomfield et al., 2016. Quantifying the increasing sensitivity of power systems to climate variability. View published paper.

Within the power system of Great Britain (GB), there is a rapidly increasing amount of generation from renewables, such as wind and solar power which are weather-dependent. An increased proportion of weather-dependent generation will require increased understanding of the impact of climate variability on the power system.

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Figure 1: Predicted installed capacity from the National Grid Gone Green Scenario. Source: National Grid Future Energy Scenarios (2015).

Current research on the impact of climate variability on the GB power system is ongoing by climate scientists and power system modellers. The focus of the climate research is on the weather-driven components of the power system, such as the impact of climate variability on wind power generation. These studies tend to include limited knowledge of the whole system impacts of climate variability. The research by power system modellers focuses on the accurate representation of the GB power system. A limited amount of weather data may be used in this type of study (usually 1-10 years) due to the complexity of the power system models.

The aim of this project is to bridge the gap between these two groups of research, by understanding the impact of climate variability on the whole GB power system.In this project, multi-decadal records from the MERRA reanalysis* are combined with a simple representation of the GB power system, of which the weather-dependent components are electricity demand and wind power production. Multiple scenarios are analysed for GB power systems, including 0GW, 15GW, 30GW, and 45GW of installed wind power capacity in the system.

This study characterises the impact of inter-annual climate variability on multiple aspects of the GB power system (including coal, gas and nuclear generation) using a load duration curve framework. A load duration curve can be thought of as a cumulative frequency distribution of power system load. Load can be either power system demand (i.e. the NO-WIND scenario) or demand minus wind power (ie. the LOW, MED and HIGH scenarios).

The introduction of additional wind-power capacity greatly increases the year-year variability in operating opportunity for conventional generators, this is particularly evident for baseload plant (i.e. nuclear power plants). The impact of inter-annual climate variations across the power system due to present-day level of wind-farm installation has approximately doubled the exposure of the GB power sector to inter-annual climate variability. This is shown in Figure 2 as the spread between the red and blue curves (from the LOW scenario) is double that of the black curves (the NO-WIND scenario).

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Figure 2: Load duration curves for the NO-WIND and LOW scenario in black and grey respectively. The two most extreme years from the LOW scenario are 1990 and 2010, plotted in red and blue respectively. Vertical dashed lines show the percentage of time that baseload-plant (91%) and peaking plant (7%) are required to operate

This work has shown that as the amount of installed wind power capacity on the power system is increased, the total amount of energy required from other generators (coal, gas, nuclear) is reduced. Wind therefore contributes to decarbonising the power system, however the reduction is particularly pronounced for plants which are operating as baseload rather than peaking plant (i.e. oil fired generation) where an increase in required production is seen.

This study adds to the literature which suggests that the power system modelling community should begin to take a more robust approach to its treatment of weather and climate data by incorporating a wider range of climate variability.

For more information contact the author for a copy of the paper with details of this work: Quantifying the increasing sensitivity of power system to climate variability (submitted to ERL).

* A reanalysis data set is a scientific method for developing a record of how weather and climate are changing over time. In it, observations are combined with a numerical model to generate a synthesised estimate of the state of the climate system.

NERC Course on Polar Fieldwork Skills

Email: r.frew@pgr.reading.ac.uk

The aims of the NERC funded BAS run course, “A skills framework for delivering safe and effective fieldwork in the polar regions”, were to learn how to safely and effectively plan and carry out fieldwork at the poles. And in doing so, to give 16 early career polar scientists across a range of disciplines the opportunity to go to the Arctic and learn practical fieldwork skills that we don’t pick up from our day to day office work.

The first part took place at Madingley Hall in Cambridge where we were briefed as an entire cohort on planning, logistics, instrumentation, risk assessment, GPS mapping, health and safety, and were exceedingly well fed as part of the process….

The sunny early morning views that greeted us into Ny Ålesund.

Next we set off to put what we had learnt into practice in Ny Ålesund, on the Island of Spitzbergen (translates as ‘pointy mountains’) in Svalbard. Ny Ålesund is a small international village predominantly inhabited by scientists, with a peak population in summer of around 150, and a hardy winter population of 35 toughing out the minimal daylight hours and chilling temperatures, which reach minimums of around -20°C! Our journey began with three flights, and a stopover in Longyearbyen, also known as Santa Claus town, although it looks a lot more industrial than the name implies. We then had a 3.30am start which was aided by the 24 hour daylight to get the boat to Ny Ålesund. After 4 hours of queasiness we arrived at the NERC UK Arctic research station in Ny Ålesund.

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The group all kitted out in front of the NERC UK Arctic Research Station. Photos courtesy of Simon Morley.

The first task we had to do after arrival was the rifle training course. This felt like a dangerous activity to be doing at 2pm in the afternoon after a 3.30am start. However it is safe to say we were all sufficiently awake after the first gun shot… We never left the NERC Arctic base without a massive rucksack full of layers, food, water, flask etc and most importantly a rifle and flare gun in case of running into a polar bears. As we are essentially trespassing on the bears’ territory, it is up to us to avoid disturbing them and to use rifles for self-defence as a last resort.

Terrestrial wildlife around Ny Ålesund. The greatest wildlife threat we faced was the cheeky Arctic fox stealing our sandwiches!

In Ny Ålesund you are very far removed from civilisation, even via digital means as there is no wifi (due to a large experiment detecting quasars) or phone signal. Therefore life in Ny Ålesund feels timeless, as outside events that rampage on social media feel far removed and irrelevant. However signatures of global warming are evident, with the extent of glaciers noticeably retreating each year, and sea ice becoming a rarer and rarer occurrence in the fjord within the living memory of residents of Ny Ålesund.

From left to right: View of Ny Ålesund, the closest we came to a polar bear in the doorway of the mess building, old hut from the mining industry.

The past mining infrastructure is evident everywhere, and classified as ‘heritage’, meaning that despite thinking of them as eyesores, in the otherwise immaculate views the run down infrastructure is actually protected as part of Ny Ålesund’s history. The NERC UK Arctic base was very cosy, we definitely weren’t roughing it like all those early polar explorers! The base is run by station manager Nick Cox, who was full of stories about everything and anything. Most evenings ended with everyone staying at the base gathering together for storytime with Nick in the living room of the UK Arctic base. Everyone in Ny Ålesund went to the mess building (best view I’ve ever had whilst eating breakfast!) in the centre of Ny Ålesund for meals, and on Saturdays everyone makes more of an effort to change out of work clothes and enjoy good food and wine together before heading to the small pub which opens on Saturday nights for people to gather to drink, chatter and dance.

Every time we left the UK station we had to take an enormous rucksack filled with food (packed lunch and lots of snacks, Mars bars disappeared like gold dust), waterproofs, spare layers, emergency blanket, first aid kit, temporary shelters, spare batteries for any equipment needed, flare gun, rifle, bullets, a satellite phone (one between the group), radio (at least one for each separate group). Keeping in contact via radio is very important, even if our group was going to be just 15 mins late we had to radio in and let the people at the station now so they can amend the signing out book. There was also a radio line for all of the stations in Ny Ålesund, so everybody would know if somebody was in trouble or extra help was needed. All the extra layers were essential. In just the five days we were there, we saw sun, rain, snow, sometimes all in one day! Preparing for all eventualities and all of the `what ifs’ is essential for polar fieldwork.

We had two main projects that required fieldwork planning and execution. The first was a two day marine biology project (led by Simon Morley from BAS) which was undertaken in two boats followed up by lab work. We took sediment grabs, plankton nets, CTD profiles (measurements of salinity, temperature and density), put down traps overnight. The aim was to investigate the difference between near rivers and near glaciers, and build up a picture of the food web there. Understanding the small marine creatures at the base of the food web and their temperature tolerance has important implications for larger marine and terrestrial creatures higher up the chain.

Left to right, getting our hands dirty sieving the sediment samples on the boat, putting on the immersion suits before getting onto the smaller boat in case of falling in! Photos courtesy of Simon Morley and Ed King.

The second two day task (led by Ed king from BAS) was to investigate the retreat of a glacier about 4-5km from Ny Ålesund called Midtre Lovénbreen. We carried out was to do a ground penetrating radar survey along and across the nearest glacier to Ny Ålesund to measure the ice thickness. Also, we mapped out the snout of the glacier and took photos to compare the glacier to previous years. A 15-20m retreat of the snout of the glacier relative to last year was measured!

Clockwise from left: Setting up the geophysics kit for a transect on the glacier, Midtre Lovénbreen in 1999, Midtre Lovénbreen September 2016. Glacier photos courtesy of Ed King.

The five or so days we had in Ny Ålesund flew by and before we knew it, it was time for us all to take the (very choppy) boat journey back to Longyearbyen before heading back to the UK. I really, really enjoyed the course, and I would highly recommend to any PhDs or Postdocs who study the poles to consider applying for the course in 2017!

Thanks to everyone at BAS involved in organising the course, in particular Alistair Crane, Blair Fyffe, Simon Morley, Ed King, Nick cox, and of course Ali Teague for organising all of the logistics and ensuring we all got there and back as smoothly as possible!