{"id":3719,"date":"2018-06-12T10:57:29","date_gmt":"2018-06-12T08:57:29","guid":{"rendered":"https:\/\/nilu.gnist.dev\/?p=3719"},"modified":"2020-05-07T12:46:09","modified_gmt":"2020-05-07T10:46:09","slug":"how-to-measure-air-quality-at-the-ends-of-the-world","status":"publish","type":"post","link":"https:\/\/nilu.gnist.dev\/en\/2018\/06\/how-to-measure-air-quality-at-the-ends-of-the-world\/","title":{"rendered":"How to measure air quality at the ends of the World"},"content":{"rendered":"

\u2013 The reason why it is so important to measure air quality in the Arctic and Antarctica is that those are the most vulnerable areas. We see changes there first, senior scientist Chris Lunder from NILU\u2019s Department of Monitoring and Instrumentation Technology explains.<\/p>\n

\u201cPre-industrial\u201d air<\/h2>\n

The Zeppelin Observatory near Ny-\u00c5lesund on Svalbard, and the \u00adTrollhaugen Observatory in Queen Maud Land, is where the air is purest in the northern and southern hemisphere, respectively. This means that NILU\u2019s scientists can measure air at what they refer to as the \u201cbackground level\u201d. The background level means the lowest level of different particles and gases present in the atmosphere, and it is only measurable in places where human activity does not contribute to local contamination. You find the cleanest air on earth in Antarctica, and from air samples taken there, scientists have the best information to say something about how the formation of particles in the air was before the industrial revolution.<\/p>\n

\u2013 Knowing the \u201cbackground level\u201d, we can use the air samples to figure out where pollutants come from, and the amounts of pollutants released.<\/p>\n

Showing trends over time<\/h2>\n

Greenhouse gases are mixed into the atmosphere, so there is always a certain \u201cbackground level\u201d of eg. CO2 in the air. How much higher levels can get varies from station to station, relative to local emissions and how the emissions are transported through the atmosphere.<\/p>\n

\u2013 The advantage of remote stations like Zeppelin is that it\u2019s easier to see trends over time there, because the variation from month to month is smaller, explains senior scientist Ove Hermansen. \u2013 You do not get such extensive fluctuations as monitoring stations in more populated areas may display, such as Mace Head in Ireland and the Jungfraujoch Observatory in Switzerland.<\/p>\n

These two European observatories are located so that they capture air coming in from the Atlantic Ocean. Air masses from this region are often affected by air from highly populated areas in the United States.<\/p>\n

If you want to measure the correct background levels, you need really remote observatories like Mauna Loa in the Pacific, Cape Grim in Tasmania and Ragged Point on Barbados. And the Zeppelin observatory, of course \u2013 the best background station in the northern hemisphere.<\/p>\n

\"Trollhaugenobservatoriet
Trollhaugen observatory in Antarctica Photo: Chris Lunder, NILU<\/figcaption><\/figure>\n

Control and calibration<\/h2>\n

For NILU to be able to perform high quality air measurements, it is important that those working at, and near the observatory, do not pollute the measurements. Thus, it is crucial to have control of everything in the immediate vicinity, from material selection at the station to where different sources of pollution, such as cars, are situated. The scientists must be absolutely sure that what they measure are real air samples from the Arctic and Antarctica.<\/p>\n

To be able to measure accurately, we need our equipment to be in top shape, Hermansen explains.<\/p>\n

\u2013 The equipment must be calibrated regularly, and correctly.<\/p>\n

How and when such calibration takes place depends on the measurement method and type of instrument. Most instruments are tested using a known air sample, a so-called \u201cstandard\u201d. In addition, NILU participates in \u201cring tests\u201d. During these, a gas bottle of air is sent from monitoring station to monitoring station across Europe. Each station measures air from the same bottle, and should get exactly the same result.<\/p>\n

\u2013 This calibration takes place within large networks, explains Hermansen. \u2013 NILU is involved in many different networks, each with its own comparative programmes for instruments and equipment for air sampling. This is not only about measuring accurately, as all measurement stations in a network should measure against the same reference so that the results are comparable.<\/p>\n

For particle instruments, there are no similar \u201cstandards\u201d. Thus, at a few years\u2019 intervals, representatives from up to twenty of the measurement stations meet at a calibration center in Europe to compare and check that these instruments measure the same.<\/p>\n

Strict routines<\/h2>\n

To ensure that they measure on the same scale as the other monitoring stations around the world, Lunder, Hermansen and senior engineer Are B\u00e4cklund spend a lot of time calibrating the instruments. There are strict procedures to follow.<\/p>\n

\u2013 Each station also has its own procedures, says B\u00e4cklund, \u2013 where we go through a variety of different validation protocols for the instruments. In order to meet the quality requirements we must show that we perform the validation properly and on a regular basis.<\/p>\n

In addition to validating the instruments, the NILU crew must have full control over pressure, temperature and airflow through the air inlet the instruments are connected to. All measurements must be checked and logged, data transferred to NILU and disseminated to the different monitoring networks NILU is part of.<\/p>\n

Besides all this, NILU occasionally gets visits from representatives of the various networks, for example the Global Atmospheric Watch. They use their own instruments to perform control measurements on the instruments at Zeppelin.<\/p>\n

\"Zeppelinobservatoriet\"
Zeppelin observatory at Ny-\u00c5lesund, Svalbard Photo: Are B\u00e4cklund, NILU<\/figcaption><\/figure>\n

Valuable networks<\/h2>\n

Once a week, Hermansen goes through all the raw data and checks if they are correct. Only after this control, the measurements will be recorded as approved in the database. He also participates in monthly meetings with scientists from other European monitoring stations, where they go through all data plots, recorded calibrations and deviations. The deviations are carefully investigated to reveal the cause and find solutions.<\/p>\n

In addition, there are annual \u00adEuropean meetings, where scientists meet and present plots from their measurement stations. If there are any discrepancies, these are pointed out and discussed, and if the deviations are not explained, the data from this particular measurement station may be discarded.<\/p>\n

\u2013 This is how we ensure that all our data are of good quality, explains Hermansen, \u2013 and we learn a lot from each other during these discussions. Especially about instrument problems, which can be anything from a small leak to a worn-out pump or a missing gasket.<\/p>\n

All three can tell stories about cases where solving an instrument problem has taken days, weeks, even months \u2013 and it is in such contexts these networks demonstrate their worth. It gives the scientists the opportunity to learn from others\u2019 experiences, and find solutions faster than if they had worked alone.<\/p>\n

\"Det
The electric vehicle \u00abVesla\u00bb is used when the scietists visit Trollhaugen Photo: Jan Henrik Wasseng, NILU<\/figcaption><\/figure>\n

Alle de tre kan fortelle om tilfeller der det har tatt b\u00e5de dager, uker og m\u00e5neder f\u00f8r de har funnet ut hva feilen er. Og nettopp i den sammenhengen er slike nettverk gode \u00e5 ha. Der kan de h\u00f8ste av andres erfaringer for \u00e5 finne l\u00f8sninger raskere enn om de hadde jobbet alene.<\/p>\n

Norge og NILU i polare omr\u00e5der<\/h2>\n

Alle data NILU produserer ut fra m\u00e5lingene ved observatoriene er \u00e5pent tilgjengelig s\u00e5 snart de er kvalitetssikret og overlevert til oppdragsgiver. Data fra b\u00e5de Zeppelin og Trollhaugen blir mye brukt b\u00e5de av norske og internasjonale forskere, kan Lunder fortelle.<\/p>\n

\u2013 Zeppelin er mye mer tilgjengelig enn Trollhaugen p\u00e5 mange m\u00e5ter, sier B\u00e4cklund. \u2013 Det er mye enklere \u00e5 drifte en del av utstyret v\u00e5rt der enn p\u00e5 Trollhaugen, av rent logistiske \u00e5rsaker. Mannskap fra m\u00e5le- og instrumentavdelingen bes\u00f8ker i snitt Zeppelinobservatoriet annenhver m\u00e5ned. P\u00e5 Trollhaugen derimot, er de en gang i \u00e5ret. Observatoriet er tilgjengelig kun i den sydlige sommersesongen, da fly til Troll kun g\u00e5r i perioden november til februar. Ergo sier det seg selv at det er mer utfordrende \u00e5 holde alle typer instrumenter i kontinuerlig drift der.<\/p>\n

NILU har overv\u00e5ket luftkvaliteten ved Zeppelin-observatoriet siden 1989 (NILUs aller f\u00f8rste luftm\u00e5linger p\u00e5 Svalbard ble gjort i Ny-\u00c5lesund i 1974), og i Antarktis siden 2007. Hvordan ble det til at nettopp NILU m\u00e5ler luft fra pol til pol?<\/p>\n

\u2013 Norge er jo en polarnasjon, og NILU er i en enest\u00e5ende posisjon i forhold til \u00e5 forvalte ansvaret som ligger i \u00e5 overv\u00e5ke lufta og atmosf\u00e6ren i de polare regionene, sier Ove Hermansen.<\/p>\n

\u2013 NILU har bygget opp kompetanse og erfaring over tid, og har gjort seg fortjent til renomm\u00e9et som gir tilgang til de n\u00f8dvendige nettverkene. Vi har vist at NILU kan levere p\u00e5 kvalitet og kvalitetssikring, og det vil vi fortsette med, avslutter han.<\/p>\n

\"Chris
From the left: Chris Lunder, Are B\u00e4cklund og Ove Hermansen Foto: Finn Bj\u00f8rklid, NILU<\/figcaption><\/figure>\n

Read NILU annual report 2017:<\/h2>\n

Annual report 2017 (pdf)<\/a><\/p>\n

Read NILU annual report on the web (www.issuu.com):
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