Ilmatieteen laitoksen omat julkaisut - FMI publications

 

Recent Submissions

  • Hippi, Marjo (Ilmatieteen laitos - Finnish Meteorological Institute, 2022)
    Finnish Meteorological Institute Contributions 183
    Wintertime slip injuries are a very common problem in Finland as well as in other countries where winter conditions are frequent. According to surveys, on average every third person in Finland slips each winter and more than 50,000 persons are injured needing medical attention. Slipping causes human suffering as well as significant financial costs due to medical expenses and sick leaves. On some of the most slippery days, the number of slipping injuries can be so high that the hospital emergency departments are crowded with patients requiring surgery. The severity of slipping injuries typically increases with age. In addition, the number of slips and slip related injuries are more common among women than men. Finland has set a goal to increase the share of sustainable transport modes, such as walking and cycling, in the future. The aim is to reduce greenhouse gas emissions from transport and improve public health. Walking and cycling are to be the primary means of transport, especially for short distances in dense urban areas. In addition, the aim is to improve traffic safety and to develop walking and cycling infrastructure. This dissertation presents in which weather situations slips occur more than usual. In addition, the work presents a meteorological tool to help predicting weather conditions that cause pedestrian sidewalk slipperiness. Weather has a significant role in pedestrian’s wintertime slips and resulting injuries. In this dissertation, it has been investigated what are the weather situations that increase the risk of slipping and what is the spatio-temporal distribution of slips. Special attention has been given to situations with clearly more slips than usual, i.e. so called peak days of slipping injuries. The results show that snow and ice significantly increase the risk of slipping, and that most of the wintertime slips occur when the temperature is near zero degrees or slightly below it. This dissertation presents a numerical model predicting slipperiness from the pedestrian’s point of view. The model is developed at the Finnish Meteorological Institute. The thesis presents the physical principles of the model and how the slipperiness classification is implemented. The model is a tool for meteorologists to supports the decision making when issuing warnings about slippery sidewalk conditions. In addition, the model benefits winter road maintenance personnel and also public with better sidewalk condition and issued warnings. Climate change will have a major impact on future winters, especially in the northern latitudes. The winter season is shortened and near zero temperatures are becoming more frequent also during mid-winter, meaning more slippery conditions during that period. It is expected that the slip period will become shorter but at the same time more intense.
  • Nevanlinna, Heikki (Ilmatieteen laitos - Finnish Meteorological Institute, 2022)
    Raportteja - Rapporter - Reports 2022:4
    Tämä tutkimus käsittelee kansainvälisen polaarivuoden 1932–1933 aikana toimineen Petsamon magneettisen observatorion havaintotuloksia. Mukana on lyhyt katsaus polaarivuoden aikana ja sen jälkeen uudella suomalaisella meteorologisella radiosondilla tehdyistä kokeista 1930-luvun lopulla. Näitä kahta aihepiiriä yhdistää FM Mauri Tommila (1905–1971), joka toimi Petsamon observatorion johtajana ja joka sen jälkeen osallistui merkittävällä panoksella yhdessä Vilho Väisälän kanssa radiosondin kehittelyyn 1934–1939. Sondi valmistui operatiivisen sääpalvelun käyttöön vuonna 1936. Väisälän sondia testattiin vuosina 1937 ja 1939 Huippuvuorilla ja Atlantilla. Molemmissa retkikunnissa Tommila oli mukana. Petsamon observatorio oli yksi Suomen geofysikaalisen tiedeyhteisön kontribuutioista polaarivuoden tutkimus- ja havainto-ohjelmiin. Sen päätehtävä oli rekisteröidä maan magneettikentän vaihteluja jatkuvasti toimivilla laitteilla ajan havaintokäytäntöjen mukaisesti. Päävastuu observatorion toiminnoista oli Suomalaisella Tiedeakatemialla ja sen Sodankylän observatoriolla. Tarvittavat rekisteröintilaitteet oli hankittu Tanskan meteorologiselta laitokselta ja ne edustivat aikansa mittausteknologista huippua. Observatorio oli myös Ilmatieteen laitoksen tärkeä havainto- ja koeasema polaarivuoden ohjelmassa. Polaarivuoden havainto-ohjelman ja laiterakennuksien suunnittelun olivat tehneet Sodankylän magneettisen observatorion johtaja Eyvind Sucksdorff (1899–1955) ja Ilmatieteen laitoksen johtaja Jaakko Keränen (1883–1979). Keränen oli Sodankylän magneettisen observatorion ensimmäinen johtaja 1913–1917 (Nevanlinna, 2014). Petsamon observatorio sijaitsi lähellä Pohjoisen jäämeren rannikkoa Petsamojoen suistossa. Petsamo on nykyään Venäjän hallinnoimaa aluetta. Petsamon magneettinen observatorio oli toiminnassa 13 kuukautta 1.8.1932–31.8.1933 välisen ajan. Rekisteröintitulokset tieteelliseen käyttöön muodostuivat alan käytännön mukaisista magneettikentän eri komponenttien tuntikeskiarvoista. Mauri Tommila julkaisi tulokset taulukkojen muodossa yhdessä tarvittavien metadatatietojen kanssa kansainväliseen tutkimuskäyttöön (Tommila, 1937a). Tässä julkaisussa on yhteenveto tehdyistä magneettikentän mittauksista. Vertailu Sodankylässä tehtyihin samanaikaisiin rekisteröintituloksiin osoittavat, että Petsamon observatorion rekisteröintitulokset ovat olleet korkeatasoisia ja että julkaistu aineisto on tieteellisiin analyyseihin käyttökelpoista. Kaikki Suomen vanhat historialliset magneettiset rekisteröintiaineistot ovat nyt digitoitu Petsamon aineiston valmistuttua. Vanhin niistä on Helsingin magneettisen observatorion havainnot 1844–1910. Petsamon observatorioon rinnastuu Sodankylän magneettiseen ja meteorologiseen observatorioon polaarivuodelta 1882– 1883. Myös sen magneettiset ja meteorologiset havainnot uudelleen julkaisu ja digitoitu (Nevanlinna, 2017a).
  • Viljanen, Ari; Kauristie, Kirsti; Laitinen, Tiera; Osmane, Adnane; Palmroth, Minna; Rintamäki, Emilia; Savola, Mikko; Siirtola, Roope; Suni, Jonas; Turc, Lucile (Ilmatieteen laitos - Finnish Meteorological Institute, 2022)
    Raportteja - Rapporter - Reports 2022:2
    Tässä hankkeessa kerättiin tietoa äärimmäisen voimakkaiden avaruussää-myrskyjen vaikutuksista erilaisiin teknisiin järjestelmiin. Selvitykseen osallistuivat Ilmatieteen laitos, Helsingin yliopisto (HY, Avaruusfysiikan tutkimus) ja Change in Momentum -yritys. Raportissa esitellään laajasta kirjallisuustutkimuksesta kerättyä tietoa voimakkaista myrskyistä ja tietokonesimulaatioiden tuloksia. Raportin loppuosassa käsitellään avaruussäämyrskyihin liittyviä suoria ja välillisiä yhteiskunnallisia riskejä, kuvataan verrokkimaiden kansallisten riskiarvioiden tuloksia jaesitellään varautumisharjoituksiin soveltuva äärimmäisen avaruusmyrskyn skenaario. Kirjallisuustutkimuksessa kiinnitettiin erityistä huomiota avaruus-säämyrskyjen aiheuttamiin ongelmiin sähkönjakelujärjestelmissä niiden laajojen kerrannaisvaikutusten vuoksi. Nopeat vaihtelut Maan magneetti-kentässä synnyttävät jakelujärjestelmiin haitallisia geomagneettisesti indusoituneita (GI) virtoja. Äärimmäisten myrskyjen aikaan saattaa esiintyä jopa kolme kertaa suurempia magneettikentän aikaderivaattoja Euroopassa mitattuihin arvoihin verrattuna. Haittavaikutuksille altis alue ulottuu Keski- ja Etelä-Eurooppaan asti. Meidän tulee siis varautua myrskyjen aiheuttamiin välillisiin vaikutuksiin esim. kansainvälisten toimitusketjujen ongelmien seurauksena, vaikka Suomen sähkönjakelujärjestelmän GI-virtojen sietokyvyn tiedetään olevan hyvä. Koska geomagneettisia myrskyjä riittävän tarkasti kuvaavat aikasarjat ovat verrattain lyhyitä (<150 vuotta), tilastollisissa arvioissa esiintymistodennäköisyyksille esiintyy vielä paljon vaihtelua. Kirjallisuudessa annetut arviot yleisesti vertailukohteena käytetyn vuoden 1859 Carrington-myrskyn kaltaisen ääritapahtuman todennäköisyy-delle seuraavan 10 vuoden sisällä vaihtelevat välillä 0,5–20 %. Hankkeessa testattiin ensimmäistä kertaa Helsingin yliopiston Vlasiator-simulaatiota avaruussäämyrskyjen mallinnuksessa erityisesti satelliittien toimintaympäristöön liittyen. Suurteholaskentaa vaativa Vlasiator on maailman ainoa mallinnustyökalu, joka kattaa koko lähiavaruuden ja kuvaa tarkasti avaruusplasman ionien vaikutuksen myrskyjen kehittymiseen. Simulaatiot osoittivat, että äärimmäisten myrskyjen aikaan geostationaariset ja navigointi-satelliitit menettävät ajoittain magnetosfäärin antaman suojan Auringon hiukkaspurkauksia vastaan. Geostationaaristen satelliittien hiukkasmittausten perusteella HY:n tutkijat arvioivat myös, että korkeaenergiaisten elektronien vuot saattavat olla äärimmäisissä tilanteissa 1–3 kertaluokkaa suuremmat kuin aiempien myrskyjen aikana mitatut satelliittiteknologialle ongelmia aiheuttaneet vuot. Tässä hankkeessa vuosina 2021–2022 tehtyjä Vlasiatorajoja ja muuta tutkimustyötä tarkennetaan ja laajennetaan Suomen Akatemian rahoittamassa “Preparing for the most extreme space weather” -hankeessa vuosina 2020–2023.
  • Médus, Erika (Ilmatieteen laitos - Finnish Meteorological Institute, 2022)
    Finnish Meteorological Institute Contributions 182
    Regional and global climate models are important tools to study the past climate and estimate the impacts of future climate change. Climate models can also provide input for other models that simulate, for instance, hydrological cycle or road weather. Recently, running climate models with fine grid spacings (< 4 km) has become affordable at climatic scales (10 years or more) due to increased computational resources. With such grid resolutions, deep convection can be resolved explicitly leading to an improved representation of heavy precipitation. Heavy precipitation events can cause major environmental and socioeconomic hazards due to flooding, landslides, and erosion, and therefore, their accurate representation in climate models is crucial. It has been shown that extreme precipitation events have become globally more frequent over recent decades as a result of global warming, and they are expected to intensify further in the future due to climate change. Motivated by the expected better representation of heavy precipitation compared to previous methods, high-resolution regional climate model simulations covering 1998–2018 were performed for the first time over the Nordic region with a regional climate model, HARMONIE-Climate (HCLIM). In this thesis, the skill of HCLIM in representing the features of the present-day climate was evaluated by comparing the model simulations to several observations. Moreover, the applicability of the HCLIM data to drive a road weather model, RoadSurf, was investigated. Because running high-resolution climate models is computationally expensive, the added value provided by such models needs to be quantified. Therefore, this thesis assessed the benefits of a high-resolution HCLIM setup with explicitly resolved deep convection at 3 km grid spacing over a setup with 12 km grid spacing and deep convection parameterization. In addition, past trends in observed extreme precipitation between 1901 and 2020 were investigated in order to put the future trends in context. The results of this thesis indicate that precipitation extremes have intensified in the Nordic-Baltic region. Extreme events also occur later in the year compared to the beginning of the last century. Precipitation extremes and other present-day climate characteristics over the Nordic region were well captured by HCLIM. In addition, the HCLIM-driven RoadSurf model demonstrated a good skill in representing road weather in the region. The high-resolution HCLIM setup was shown to improve especially high-intensity sub-daily precipitation events in line with studies conducted over other regions. The results support the use of HCLIM and RoadSurf models to produce climate change impact projections for the Nordic region. Furthermore, the results of this thesis emphasize the need for high-resolution convection-permitting regional climate models to reliably simulate high-intensity precipitation events.
  • Verronen, P. T. (Ilmatieteen laitos - Finnish Meteorological Institute, 2022)
    Raportteja - Rapporter - Reports 2022:1
    The 11th International Workshop on Long-Term Changes and Trends in the Atmosphere will be held between 30 May and 3 June, 2022, at the Finnish Meteorological Institute in Helsinki, Finland. The workshop is organised by the Finnish Meteorological Institute. The workshop gathers together more than 50 scientists from the EU, USA, India, Canada, Argentina, Norway, China, Switzerland, and UK. This report is the official abstract book of the workshop. The scientific topics include: ● Stratospheric and mesospheric observations ● Simulations and predictions of the stratosphere and mesosphere ● Changes in the ionosphere and thermosphere ● Dynamic, physical, chemical and radiative mechanisms ● Role of the stratosphere and mesosphere for climate The workshop is sponsored by the International Association of Geomagnetism and Aeronomy (IAGA) and the International Association of Meteorology and Atmospheric Sciences (IAMAS).
  • Laurila, Terhi K. (Ilmatieteen laitos - Finnish Meteorological Institute, 2022)
    Finnish Meteorological Institute Contributions 181
    Strong winds can cause large impacts and damage to society. Many sectors, such as wind energy, forestry and insurance, are highly affected by winds. Thus, preparedness and adaptation to winds and windstorms is essential in both weather (days) and climate (decades) time scales. The aim of this thesis is to better understand the near surface mean and extreme wind climate in northern Europe and Finland and the role of extratropical cyclones in contributing to the extreme winds. This thesis investigated the main characteristics of wind and windstorm climate in northern Europe and Finland over a 40-year period. The wind and windstorm climate was found to have large inter-annual and decadal variability and no significant linear trends. The well-known seasonal cycle was detected: winds in northern Europe are up to 30 % stronger in winter than in summer and while there are on average 5–6 windstorms per month in winter in northern Europe there are none in summer months. A more surprising result was that the number of all extratropical cyclones does not vary between seasons. Windstorms were found to be the most frequent over the Barents Sea whereas weaker extratropical cyclones occur over the land areas in northern Europe. The development and structure of strong winds in windstorms in northern Europe and Finland were examined. The results show that the strongest wind gusts associated with windstorms shift and extend from the warm sector to behind the cold front during the evolution. The cold-season (Oct–Mar) windstorms are overall stronger and spatially larger than warm-season (Apr–Sep) windstorms. For example, the central pressure is on average 9 hPa deeper and the maximum wind gust 2 ms-1 stronger in cold-season windstorms than in warm-season windstorms. Analysing a case study of storm Mauri, a damaging windstorm in Finland in September 1982, shows that an individual windstorm development can vary largely from the climate’s general concept. The case study also found that during storm Mauri the wind speeds over land areas in Finland are underestimated in the weather model by 2–13 ms-1 compared to observations, but the location of strong winds is correctly predicted. Lastly, this thesis investigated what meteorological factors affect the intensity of windstorms in northern Europe. This was studied by using an ensemble sensitivity method. The sensitivities of windstorm intensity to all studied meteorological factors were 20–75 % higher in the cold season than in the warm season. This implies that cold season windstorms are potentially better predictable than warm-season windstorms. The strongest impact to the intensity of northern Europe windstorms is from the low-level temperature gradient which is therefore an important variable to follow when forecasting windstorms. The results from this thesis highlight the importance of examining long-term inter-annual variations, instead of just linear trends, to get a broader understanding of the climate. Moreover, the results emphasize the need of both general conceptual models and individual case studies to better understand the large variety of windstorm development paths.
  • Hannula, Henna-Reetta (Ilmatieteen laitos - Finnish Meteorological Institute, 2022)
    Finnish Meteorological Institute Contributions 180
    Remote sensing of snow is a method to measure snow cover characteristics without direct physical contact with the target from airborne or space-borne platforms. Reliable estimates of snow cover extent and snow properties are vital for several applications including climate change research and weather and hydrological forecasting. Optical remote sensing methods detect the extent of snow cover based on its high reflectivity compared to other natural surfaces. A universal challenge for snow cover mapping is the high spatiotemporal variability of snow properties and heterogeneous landscapes such as the boreal forest biome. The optical satellite sensor’s footprint may extend from tens of meters to a kilometer; the signal measured by the sensor can simultaneously emerge from several target categories within individual satellite pixels. By use of spectral unmixing or inverse model-based methods, the fractional snow cover (FSC) within the satellite image pixel can be resolved from the recorded electromagnetic signal. However, these algorithms require knowledge of the spectral reflectance properties of the targets present within the satellite scene and the accuracy of snow cover maps is dependent on the feasibility of these spectral model parameters. On the other hand, abrupt changes in land cover types with large differences in their snow properties may be located within a single satellite image pixel and complicate the interpretation of the observations. Ground-based in-situ observations can be used to validate the snow parameters derived by indirect methods, but these data are affected by the chosen sampling. This doctoral thesis analyses laboratory-based spectral reflectance information on several boreal snow types for the purpose of the more accurate reflectance representation of snow in mapping method used for the detection of fractional snow cover. Multi-scale reflectance observations representing boreal spectral endmembers typically used in optical mapping of snow cover, are exploited in the thesis. In addition, to support the interpretation of remote sensing observations in boreal and tundra environments, extensive in-situ dataset of snow depth, snow water equivalent and snow density are exploited to characterize the snow variability and to assess the uncertainty and representativeness of these point-wise snow measurements applied for the validation of remote sensing observations. The overall goal is to advance knowledge about the spectral endmembers present in boreal landscape to improve the accuracy of the FSC estimates derived from the remote sensing observations and support better interpretation and validation of remote sensing observations over these heterogeneous landscapes. The main outcome from the work is that laboratory-controlled experiments that exclude disturbing factors present in field circumstances may provide more accurate representation of wet (melting) snow endmember reflectance for the FSC mapping method. The behavior of snow band reflectance is found to be insensitive to width and location differences between visible satellite sensor bands utilized in optical snow cover mapping which facilitates the use of various sensors for the construction of historical data records. The results also reveal the high deviation of snow reflectance due to heterogeneity in snow macro- and microstructural properties. The quantitative statistics of bulk snow properties show that areal averages derived from in-situ measurements and used to validate remote sensing observations are dependent on the measurement spacing and sample size especially over land covers with high absolute snow depth variability, such as barren lands in tundra. Applying similar sampling protocol (sample spacing and sample size) over boreal and tundra land cover types that represent very different snow characteristics will yield to non-equal representativeness of the areal mean values. The extensive datasets collected for this work demonstrate that observations measured at various scales can provide different view angle to the same challenge but at the same time any dataset individually cannot provide a full understanding of the target complexity. This work and the collected datasets directly facilitate further investigation of uncertainty in fractional snow cover maps retrieved by optical remote sensing and the interpretation of satellite observations in boreal and tundra landscapes.
  • Naakka, Tuomas (Ilmatieteen laitos - Finnish Meteorological Institute, 2022)
    Finnish Meteorological Institute Contributions 179
    Water vapour is an effective greenhouse gas, but clouds, which are formed when water vapour condenses into water droplets or ice crystals, may have an even greater effect on radiative energy transfer through the atmosphere. In addition, absorption or release of the latent heat of vaporization and transport of water vapour are part of the heat transport from the Tropics towards the Poles. Thus, atmospheric water vapour greatly affects the energy balance of the atmosphere and is also an important component of the water cycle. This thesis addresses the subject of atmospheric moisture and the processes affecting it in the Arctic and Antarctic. The studies comprising the thesis are mostly based on atmospheric reanalyses. In the polar regions, meteorological observation networks are sparse, due to their remoteness and the harsh environment, and therefore traditional observations have not provided a comprehensive picture of atmospheric conditions in the polar regions. In recent years, atmospheric reanalyses have also become more accurate in remote areas, which has enabled detailed studies of atmospheric moisture in the polar regions. In the polar regions, the mostly negative radiation budget of Earth’s atmosphere-surface system shapes the distribution of water vapour in the atmosphere, especially the vertical structure of specific humidity. The polar regions are sinks for atmospheric water vapour, due to their typically small local evaporation, and even condensation of moisture on the surface. Therefore, moisture transport from the lower latitudes balances the moisture budget in the polar regions. This type of moisture budget favours the formation of specific humidity inversions. Our results show that specific humidity inversions are common in the polar regions, and their occurrence near Earth’s surface is linked with surface conditions: radiative surface cooling, occurrence of temperature inversions in winter and cold sea surfaces or melting of sea ice in summer. Advection of warm, moist air masses over a cold surface in summer is vital for formation of specific humidity inversions. Below the approximately 800-hPa level, interactions between the atmosphere and Earth’s surface clearly affect both the atmospheric moisture content and moisture transport. Our results show that the northward moisture transport near the surface is mostly balanced by southward transport. Moisture transport clearly shapes the spatial distribution of the atmospheric moisture content. Regional trends in atmospheric moisture content in the Arctic are also mostly the results of long-term variations in atmospheric circulation. The negative net radiation budget, weak evaporation and extensive contribution of moisture transport to atmospheric moisture content also characterize moisture conditions in the Antarctic. The results show that, due to geographical conditions, specific humidity inversions in Antarctica are even more persistent than those in the Arctic. This is associated with stronger isolation of air masses in inner Antarctica from advection of warm, moist air masses than in the Arctic. The results also show that when a cold, dry air mass flows from the continent towards the ocean, it undergoes adiabatic warming, which together with downward sensible heat fluxes enables evaporation on Antarctic slopes. Overall, this thesis contributes to our understanding of how the spatial distribution of atmospheric moisture content interacts with moisture transport and with physical processes such as evaporation and condensation in polar regions.
  • Saarnio, Karri; Vestenius, Mika; Kyllönen, Katriina (Ilmatieteen laitos - Finnish Meteorological Institute, 2021)
    Raportteja - Rapporter - Reports 2021:2
    Kansallinen ilmanlaadun vertailulaboratorio varmistaa Suomessa tehtävien ilmanlaatumittausten korkean laadun tekemällä ilmanlaatumittausten auditointeja ja vertailumittauksia. Tässä hankkeessa arvioitiin hiukkasmittausten vaatimuksenmukaisuutta keskittyen erityisesti keskimääräisen altistumisindikaattorin (AEI) määrittämiseen käytettävään mittaukseen. Tutkimuksessa arvioitiin Helsingin Kalliossa mitatun PM2,5-altistumisindikaattorin mittauksen tulosten soveltuvuutta ja edustavuutta Suomessa. Havaittiin, että Kallion mittaus edustaa hyvin keskimääräistä pienhiukkasaltistusta sekä pienhiukkaspitoisuuden vuositrendiä Suomessa. Lisäksi vuodesta 2015 eteenpäin Suomen kaupunkitausta-asemilla tehtyjen PM2,5-mittausten keskiarvot niin asemakohtaisesti kuin asemien yhteisenä keskiarvona alittavat kokonaisuudessaan vuoden 2020 keskimääräisen altistumisindikaattorin enimmäisarvon 8,5 µg/m3, jota käytetään altistumisen vähennystavoitteen arvioinnissa. AEI-mittaukseen käytetyn TEOM 1405 -hiukkasmonitorin mittaustuloksia vertailtiin Kalliossa menetelmästandardin SFS-EN 12341:2014 mukaisella vertailumenetelmällä saatuihin tuloksiin. Havaittiin, että AEI-laskentaan käytettävä Kallion TEOM 1405 -laite täyttää niukasti standardissa määritetyn 25 %:n epävarmuusvaatimuksen ja sillä tehtävän mittauksen laatu riittää altistumisindikaattorin määrittämiseen, vaikka vertailtavat pitoisuudet olivat yleisesti ottaen pieniä eikä menetelmästandardin SFS-EN 16450:2017 mukaisen vertailumittauksen pitoisuusvaatimus täyttynyt vertailujaksolla korkeiden pitoisuuksien puuttuessa. Tässä raportissa esitellään myös tulokset jatkuvatoimisille hiukkasmittalaitteille järjestetyistä vertailumittauksista Virolahdella ja Helsingissä sekä PM10- että PM2,5-hiukkaskokojakeelle sekä näiden lisäksi Kuopiossa ja Lahdessa PM2,5-hiukkaskokojakeelle. Vertailumittauksista saatujen tulosten perusteella määritettiin ensimmäistä kertaa korjauskertoimet FIDAS 200 -hiukkasmittalaitteen PM10- ja PM2,5-mittaukselle Suomessa. Tulosten perusteella FIDAS 200 -hiukkasmonitori soveltuu ulkoilman PM10- ja PM2,5-hiukkaskokojakeiden mittaukseen Suomessa käyttäen tässä raportissa esitettyjä korjauskertoimia, vaikkakin on huomioitava, että kertoimet eivät täytä ekvivalenttisuuden osoittamiselle asetettuja vaatimuksia. Kyseisiä kertoimia on kuitenkin suositeltavaa käyttää siihen asti, kunnes ekvivalenttisuus on osoitettu seuraavassa ekvivalenttisuuden osoittamiskampanjassa. Kahta muuta jatkuvatoimista laitetta (SHARP 5030 ja TEOM 1405) verrattiin referenssikeräimeen Virolahdella ja Helsingissä. Havaittiin, että Kuopion vertailumittauksessa 2014–2015 eri laitteille määritetyt korjauskertoimet eivät aina sovellu eri paikoissa ja eri vuodenaikoina PM10- ja PM2,5-hiukkaspitoisuuksien mittauksiin, koska mittauspaikat ja niiden olosuhteet vaihtelevat. Tämän takia vertailulaboratorio esittää ekvivalenttisuuden osoitusta viiden vuoden välein sekä jatkuvaa ohjelmaa käytettävien kertoimien soveltuvuuden osoittamiseksi paikallisilla vertailumittauksilla, joissa jatkuvatoimisten hiukkasmonitorien mittaustuloksia verrataan vertailumenetelmää vastaan eri paikoissa ja vaihtelevissa olosuhteissa jatkuvana kampanjana pitempiaikaisesti, puolesta vuodesta vuoteen kestävillä paikallisilla vertailuilla. Näillä ns. ongoing-mittauksilla voidaan osaltaan varmentaa Suomessa mitattavien PM10- ja PM2,5-hiukkasmittausten laatu ja vertailukelpoisuus myös varsinaisten ekvivalenttisuuden osoittamiseen soveltuvien vertailumittauskampanjoiden välillä.
  • Jokinen, Pauli; Pirinen, Pentti; Kaukoranta, Juho-Pekka; Kangas, Antti; Alenius, Pekka; Eriksson, Patrick; Johansson, Milla; Wilkman, Sofia (Ilmatieteen laitos - Finnish Meteorological Institute, 2021)
    Raportteja - Rapporter - Reports 2021:8
    Tässä raportissa on ilmanpaineen, lämpötilan, suhteellisen kosteuden, sademäärän, lumensyvyyden, tuulen, auringonpaisteen ja kokonaissäteilyn ilmastotilastoja vertailukaudelta 1991–2020. Lisäksi on ensimmäistä kertaa tuotettu vertailukaudelle meritilastoja vedenkorkeudesta, veden pintalämpötilasta ja merijäästä. Havaintoasemien ja hila-aineiston perusteella on uuden 1991–2020 vertailukauden Suomen keskilämpötila noin 0,6 astetta edellistä 1981–2010 vertailukautta lämpimämpi. Verrattuna jaksoon 1961–1990 on uusi vertailukausi noin 1,3 astetta lämpimämpi. Ilmastollisia ja merellisiä tilastoja voidaan hyödyntää esimerkiksi ajankohtaisen sää- ja meriolosuhteiden laittamisessa historialliseen viitekehykseen. Lisäksi tilastoista on apua muun muassa kuukausien päähän ulottuvien sääriippuvaisten päätösten tekemisessä sekä ilmastonmuutoksen etenemisen seurannassa. Vertailukauden tilastot ovat tuotettu Maailman ilmatieteen järjestön (WMO) ohjeiden mukaisesti. Edellisten vertailukausien tapaan on esimerkiksi puuttuvien havaintojen määrässä käytetty kansallisesti tiukempia rajoja kuin WMO:n ohjeissa on kehotettu. Jakso 1991–2020 on sekä kansainvälisesti että Suomessa virallinen vertailukausi ennen kuin seuraava vertailukausi eli 2001–2030 otetaan käyttöön.
  • Hämäläinen, Karoliina (Ilmatieteen laitos - Finnish Meteorological Institute, 2021)
    Finnish Meteorological Institute Contributions 177
    The renewable energy sources play a big role in mitigating the effects of power production on climate change. However, many renewable energy sources are weather dependent, and accurate weather forecasts are needed to support energy production estimates. This dissertation work aims to develop meteorological solutions to support wind energy production, and to answer the following questions: How accurate are the wind forecasts at the wind turbine hub height? What is the annual distribution of the wind speed? How much energy can be harvested from the wind? How does the atmospheric icing affect wind energy production and how do we forecast these events? The first part of this dissertation work concentrates on resource mapping. Wind and Icing Atlases bring valuable information when planning wind parks and where to locate new ones. The Atlases provide climatological information on mean wind speed, potential to generate wind power and atmospheric icing conditions in Finland. Based on mean wind speed and direction, altogether 72 representative months were simulated to represent the wind climatology of the past 30 years. A similar detailed selection could not be made with respect to icing process due to lack of icing observations. However, sensitivity tests were performed with respect to temperature and relative humidity, which have an influence on icing formation. According to these sensitivity tests the selected period was found to represent the icing climatology as well. The results are presented in gridded form with 2.5 km horizontal resolution and for 50 m, 100 m and 200 m heights above the ground, representing typical hub heights of a wind turbine. Daily probabilistic wind forecasts can bring additional value to decision making to support wind energy production. Probabilistic weather forecasts not only provide wind forecasts but also give estimations related to forecast uncertainty. However, probabilistic wind forecasts are often underdispersive. In this thesis the statistical calibration methods combined with a new type of wind observations were utilized. The aim was to study if Lidar and Radar wind observations at 100 m’s height can be used for ensemble calibration. The results strongly indicate that the calibration enhances the forecast skill by enlarging the ensemble spread and by decreasing RMSE. The most significant improvements are identified with shorter lead times and with weak or moderate wind speeds. For the strongest winds no improvements are seen, as a result of small amount of strong wind speed cases during the calibration training period. In addition to wind speed, wind power generation is mostly affected by atmospheric icing at Northern latitudes. However, measuring of icing is difficult due to many reasons and, furthermore, not many observations are available. Therefore, in this thesis the suitability of a new type of ceilometer-based icing profiles for atmospheric icing model validation have been tested. The results support the usage of this new type of ceilometer icing profiles for model verification. Furthermore, this new extensive observation network provides opportunities for deeper investigation of icing cloud properties and structure.
  • Nordling, Kalle (Ilmatieteen laitos - Finnish Meteorological Institute, 2021)
    Finnish Meteorological Institute Contributions 176
    Anthropogenic aerosols alter the climate by scattering and absorbing the incoming solar radiation and by modifying clouds’ optical properties, causing a global cooling or warming effect. Anthropogenic aerosols are partly co-emitted with anthropogenic greenhouse gases, and future climate mitigation actions lead to the decline of anthropogenic aerosols’ cooling effect. However, the exact cooling effect is still uncertain. Part of this uncertainty is related to the structural differences of current climate models. This work evaluates the present-day anthropogenic aerosol temperature and precipitation effect and factors affecting the model difference. The key objectives of this thesis were: 1) What are the climate effects of present-day anthropogenic aerosols?, 2) What mechanisms drive the model-to-model differences?, and 3) How do future reductions affect local and global climates? The global models ECHAM6 and NorESM1 were used to evaluate the present-day climate effects with theidentical anthropogenic aerosol scheme MACv2-SP. Results reveal that an identical anthropogenic aerosol description does not reduce the uncertainty related to anthropogenic aerosol climate effects, and the difference in the estimated difference is due to model dynamics and oceans. The key mechanism driving the difference in the models was evaluated using data from the Precipitation Driven Model Intercomparison Project (PRMIP). Similar mechanisms drive the model-to-model difference for greenhouse gases and aerosols, where the key drivers are the differences in water vapor, the vertical temperature structure of the atmosphere, and sea ice and snow cover changes. However, on a regional scale, the key drivers differ. Future anthropogenic aerosol effects were evaluated using new CMIP6 data. This work shows the importance of anthropogenic aerosols for current and future climate change. For amore accurate assessment of climate impacts of anthropogenic aerosols, one needs to also consider remote effects of the local aerosols. The Arctic regions are particularly sensitive to midlatitude aerosols, such as Asian aerosols, which are expected to decline in the next decades. To gain a more accurate estimation of anthropogenic aerosols, it is not sufficient to only focus on composition and geographical distribution of aerosols, as the dynamic response of climate is also important. On global temperature results did not indicate clear aerosols signal, however future temperature development over the Asian regions is modulated by the future Asian aerosol emissions.
  • Vestenius, Mika (Ilmatieteen laitos - Finnish Meteorological Institute, 2021)
    Finnish Meteorological Institute Contributions 178
    Air pollution is an important environmental risk to human health and ecosystems around the world. Particulate matter (PM), especially fine particulate matter, is an important part of this air pollution problem. Particle composition varies greatly and depends on the emission source. In addition to inorganic components, organic particulate fraction can contain several hundred organic compounds from anthropogenic and natural sources. The health risk of particulate is related to the particle size and the compounds inside or on the surface of the aerosol particles. The overall aim of this thesis was to study the selected chemical substances of atmospheric aerosol from both anthropogenic and natural sources. Concentrations of polycyclic aromatic hydrocarbons (PAH) and biogenic organic acids in aerosol were measured, and their effect on the local air quality was estimated. The sources of PAHs, trace elements, biogenic volatile organic compounds (BVOCs), and persistent organic compounds (POPs) in air were studied using positive matrix factorization (PMF), which was used as the main source apportionment tool in three of five papers and for the unpublished data in this thesis. Particles from burning emissions, e.g., diesel particles and particles from biomass burning, are the most toxic in our daily environment. Because of intensive wood use for heating and in sauna stoves, residential biomass burning is the major PAH air pollution source in Finland. Sources of atmospheric PAH pollution and its influence on local air quality were estimated at Virolahti background air quality station and in the Helsinki Metropolitan Area (HMA). The main source of PAHs at Virolahti were found to be combustion- and traffic-related source from the direction of St. Petersburg. Instead, local traffic appeared to have a very small influence on PAH levels in HMA, as local residential wood burning was found to be the main b(a)p source in Helsinki Metropolitan Area. Biogenic VOCs like monoterpenes and sesquiterpenes are highly reactive and oxidize rapidly in the atmosphere, producing secondary organic aerosol (SOA). We showed that positive matrix factorization (PMF) is a useful tool in estimating separate sources in a quasistationary dynamic system like ambient VOC concentrations in the boreal forest. Selected biogenic organic acids were measured from fine particles in the boreal forest in order to estimate their influence on aerosol production. Results indicated that sesquiterpene emissions from boreal forest are probably underestimated and their oxidation products probably have more important role in the SOA production that previously estimated. The Kola Peninsula area was found to be the major source of heavy metal pollution at Pallas. However, as Norilsk Nickel has now partly shut down its metallurgical operations, the trace element and SO2 emissions from the Kola Peninsula should be declining in the future. The ambient concentrations of POP compounds are globally declining but, in the Arctic, for some compounds this is not the case. In the source apportionment study for Pallas 1996–2018 POPs data, relatively big portion of measured POPs at Pallas came within the marine source from clean areas from the north. These long-lived compounds, which have migrated into the Arctic from the southern areas along the air and sea currents for many decades, are now released back into the atmosphere from the melting Arctic ice cover due to global warming. For these compounds, the Arctic has turned from the sink to the source.
  • Ruosteenoja, Kimmo (Ilmatieteen laitos - Finnish Meteorological Institute, 2021)
    Raportteja - Rapporter - Reports 2021:7
    In this report, we have evaluated the performance of nearly 40 global climate models (GCMs) participating in Phase 6 of the Coupled Model Intercomparison Project (CMIP6). The focus is on the northern European area, but the ability to simulate southern European and global climate is discussed as well. Model evaluation was started with a technical control; completely unrealistic values in the GCM output files were identified by seeking the absolute minimum and maximum values. In this stage, one GCM was rejected totally, and furthermore individual output files from two other GCMs. In evaluating the remaining GCMs, the primary tool was the Model Climate Performance Index (MCPI) that combines RMS errors calculated for the different climate variables into one index. The index takes into account both the seasonal and spatial variations in climatological means. Here, MCPI was calculated for the period 1981—2010 by comparing GCM output with the ERA-Interim reanalyses. Climate variables explored in the evaluation were the surface air temperature, precipitation, sea level air pressure and incoming solar radiation at the surface. Besides MCPI, we studied RMS errors in the seasonal course of the spatial means by examining each climate variable separately. Furthermore, the evaluation procedure considered model performance in simulating past trends in the global-mean temperature, the compatibility of future responses to different greenhouse-gas scenarios and the number of available scenario runs. Daily minimum and maximum temperatures were likewise explored in a qualitative sense, but owing to the non-existence of data from multiple GCMs, these variables were not incorporated in the quantitative validation. Four of the 37 GCMs that had passed the initial technical check were regarded as wholly unusable for scenario calculations: in two GCMs the responses to the different greenhouse gas scenarios were contradictory and in two other GCMs data were missing from one of the four key climate variables. Moreover, to reduce inter-GCM dependencies, no more than two variants of any individual GCM were included; this led to an abandonment of one GCM. The remaining 32 GCMs were divided into three quality classes according to the assessed performance. The users of model data can utilize this grading to select a subset of GCMs to be used in elaborating climate projections for Finland or adjacent areas. Annual-mean temperature and precipitation projections for Finland proved to be nearly identical regardless of whether they were derived from the entire ensemble or by ignoring models that had obtained the lowest scores. Solar radiation projections were somewhat more sensitive.
  • Bohlmann, Stephanie (Ilmatieteen laitos - Finnish Meteorological Institute, 2021)
    Finnish Meteorological Institute Contributions 175
    Atmospheric pollen is a well-known health threat causing allergy-related diseases. As a biogenic aerosol, pollen also affects the climate by directly absorbing and scattering solar radiation and by acting as cloud condensation or ice nuclei. A good understanding of pollen distribution and transport mechanisms is needed to evaluate the environmental and health impacts of pollen. However, pollen observations are usually performed close to ground and vertical information, which could be used to evaluate and improve pollen transport models, is widely missing. In this thesis, the applicability of lidar measurements to detect pollen in the atmosphere is investigated. For this purpose, measurements of the multiwavelength Raman polarization lidar PollyXT at the rural forest site in Vehmasmäki (Kuopio), Eastern Finland have been utilized. The depolarization ratio was identified to be the most valuable optical property for the detection of atmospheric pollen, as nonspherical pollen like pine and spruce pollen causes high depolarization ratios. However, detected depolarization ratios coincide with typical values for dusty mixtures and additional information such as backward trajectories need to be considered to ensure the absence of other depolarizing aerosols like dust. To separate pollen from background aerosol, a method to estimate the optical properties of pure pollen using lidar measurements was developed. Under the assumption that the Ångström exponent of pure pollen is zero, the depolarization ratio of pure pollen can be estimated. Depolarization ratios for birch and pine pollen at 355 and 532 nm were determined and suggested a wavelength dependence of the depolarization ratio. To further investigate this wavelength dependence, the possibility to use depolarization measurements of Halo Doppler lidars (1565 nm) was explored. In the lower troposphere, Halo Doppler lidars can provide reasonable depolarization values with comparable quality to PollyXT measurements. Finally, measurements of PollyXT and a Halo StreamLine Doppler lidar were used to determine the depolarization ratio at three wavelengths. A wavelength dependence of the particle depolarization ratio with maximum depolarization at 532 nm was found. This could be a characteristic feature of non-spherical pollen and the key to distinguish pollen from other depolarizing aerosol types.
  • Komppula, Birgitta; Karppinen, Tomi; Virta, Henrik; Sundström, Anu-Maija; Ialongo, Iolanda; Korpi, Kaisa; Anttila, Pia; Salmi, Jatta; Tamminen, Johanna; Lovén, Katja (Ilmatieteen laitos - Finnish Meteorological Institute, 2021)
    Raportteja - Rapporter - Reports 2021:6
    Ilmanlaatuselvityksessä on arvioitu Suomen ilmanlaadun nykytilaa ilmanlaadun mittausten sekä satelliitti-havaintojen avulla. Pitoisuuksien arvioinnissa olivat mukana seuraavat ilman epäpuhtaudet: typpidioksidi, typen oksidit, hengitettävät hiukkaset, pienhiukkaset, rikkidioksidi, hiilimonoksidi, otsoni, bentso(a)pyreeni, bentseeni, lyijy, arseeni, kadmium ja nikkeli. Näille ilman epäpuhtauksille on annettu ilmanlaadun arviointi-kynnykset ilmanlaatulainsäädännössä (79/2017, 113/2017). Ilmanlaatua on arvioitu ilmanlaadun seuranta-alueittain. Arvioinnissa käytettiin aineistona Suomen ilmanlaatumittausten pitoisuustuloksia vuosilta 2015–2019. Satelliittihavaintoja hyödynnettiin objektiivisen arvioinnin työkaluna typpidioksidi- ja hiilimonoksidipitoisuuksien alueellista vaihtelun arvioinnissa. Ilmanlaadun mittausten mukaan ilmanlaatu on monin osin parantanut Suomessa. Ilmanlaadun seurantatarve jatkuvin ilmanlaadun mittauksin on vähentynyt erityisesti NO2 ja PM10 osalta. Bentso(a)pyreenin mittauksia tulisi lisätä kaupunkialueilla seurantatarpeen tarkennuttua. Otsonipitoisuuksien alentamispyrkimyksissä tarvitaan kansainvälisen yhteisön toimia. Rikkidioksidin, hiilimonoksidin, bentseenin ja raskasmetallien matalia pitoisuustasoja voidaan monin paikoin teollisuusalueiden ulkopuolella arvioida muilla menetelmillä kuin jatkuvin mittauksin ja jatkuvatoimisia mittauksia onkin jo vähennetty. Satelliittihavaintojen avulla typpidioksidin (NO2) ja hiilimonoksidin (CO) pitoisuuksia ja alueellista jakaumaa on Suomessa analysoitu käyttäen pääasiassa TROPOspheric Monitoring Instrument (TROPOMI) satelliitti-instrumentin havaintoja. Hiilimonoksidin osalta satelliittihavaintoihin pohjautuva analyysi tehtiin ensimmäistä kertaa Suomeen. Tuloksista nähdään, että CO:n pitoisuus on Suomessa vuositasolla yleisesti matala ja alueelliset erot ovat pieniä. Myös typpidioksidipitoisuus on Suomessa yleisesti verrattain matala, mutta alueelliset erot ovat hieman selvemmin nähtävissä. Korkeimmat NO2-arvot havaitaan suurimmissa kaupungeissa. Käyttäen maanpintamittausten ja satelliittihavaintojen välistä riippuvuutta, satelliittihavaintojen koko ilmapilarin pitoisuuksista arvioitiin NO2:n ja CO:n maanpintapitoisuudet seuranta-alueille. Satelliittimittauksista arvioitu NO2:n vuosikeskiarvo pääkaupunkiseudulle on 28 μg/m3 ja muualla pääasiassa 10‒15μg/m3. Vastaavasti, CO:n vuosikeskiarvot Suomessa vaihtelevat pääasiassa välillä 160‒164μg/m3 eli olivat noin 0,16 mg/m3.
  • Manninen, Terhikki; Stenberg, Pauline (Ilmatieteen laitos - Finnish Meteorological Institute, 2021)
    Raportteja - Rapporter - Reports 2021:5
    Recently a simple analytic canopy bidirectional reflectance factor (BRF) model based on the spectral invariants theory was presented. The model takes into account that the recollision probability in the forest canopy is different for the first scattering than the later ones. Here this model is extended to include the forest floor contribution to the total forest BRF. The effect of the understory vegetation on the total forest BRF as well as on the simple ratio (SR) and the normalized difference (NDVI) vegetation indices is demonstrated for typical cases of boreal forest. The relative contribution of the forest floor to the total BRF was up to 69 % in the red wavelength range and up to 54 % in the NIR wavelength range. Values of SR and NDVI for the forest and the canopy differed within 10 % and 30 % in red and within 1 % and 10 % in the NIR wavelength range. The relative variation of the BRF with the azimuth and view zenith angles was not very sensitive to the forest floor vegetation. Hence, linear correlation of the modelled total BRF and the Ross-thick kernel was strong for dense forests (R2 > 0.9). The agreement between modelled BRF and satellite-based reflectance values was good when measured LAI, clumping index and leaf single scattering albedo values for a boreal forest were used as input to the model.
  • Erkamo, Sanna; Pilli-Sihvola, Karoliina; Harjanne, Atte; Tuomenvirta, Heikki (Ilmatieteen laitos - Finnish Meteorological Institute, 2021)
    Raportteja - Rapporter - Reports 2021:4
    This report describes the effects of climate change for Finland from the view of comprehensive security. The report examines both direct and indirect climate security risks as well as transition risks related to climate change mitigation. The report is based on previous research and expert interviews. Direct security risks refer to the immediate risks caused by the changing nature of natural hazards. These include the risks to critical infrastructure and energy systems, the logistics system, health and food security. Indirect security risks relate to the potential economic, political and geopolitical impacts of climate change. Climate change can affect global migration, increase conflict risk, and cause social tensions and inequality. Transition risks are related to economic and technological changes in energy transition, as well as political and geopolitical tensions and social problems caused by climate change mitigation policies. Reducing the use of fossil fuels can result in domestic and foreign policy tensions and economic pressure especially in locations dependent on fossil fuels. Political tension can also increase the risks associated with hybrid and information warfare. The security effects of climate change affect all sectors of society and the Finnish comprehensive security model should be utilized in preparing for them. In the short run, the most substantial arising climate change related security risks in Finland are likely to occur through indirect or transition risks. Finland, similar to other wealthy countries, has better technological, economic and institutional conditions to deal with the problems and risks posed by climate change than many other countries. However, this requires political will and focus on risk reduction and management.
  • Aalto, Juha; Venäläinen, Ari (Ilmatieteen laitos - Finnish Meteorological Institute, 2021)
    Raportteja - Rapporter - Reports 2021:3
    Forest and wildland fires are a natural part of ecosystems worldwide, but large fires in particular can cause societal, economic and ecological disruption. Fires are an important source of greenhouse gases and black carbon that can further amplify and accelerate climate change. In recent years, large forest fires in Sweden demonstrate that the issue should also be considered in other parts of Fennoscandia. This final report of the project “Forest fires in Fennoscandia under changing climate and forest cover (IBA ForestFires)” funded by the Ministry for Foreign Affairs of Finland, synthesises current knowledge of the occurrence, monitoring, modelling and suppression of forest fires in Fennoscandia. The report also focuses on elaborating the role of forest fires as a source of black carbon (BC) emissions over the Arctic and discussing the importance of international collaboration in tackling forest fires. The report explains the factors regulating fire ignition, spread and intensity in Fennoscandian conditions. It highlights that the climate in Fennoscandia is characterised by large inter-annual variability, which is reflected in forest fire risk. Here, the majority of forest fires are caused by human activities such as careless handling of fire and ignitions related to forest harvesting. In addition to weather and climate, fuel characteristics in forests influence fire ignition, intensity and spread. In the report, long-term fire statistics are presented for Finland, Sweden and the Republic of Karelia. The statistics indicate that the amount of annually burnt forest has decreased in Fennoscandia. However, with the exception of recent large fires in Sweden, during the past 25 years the annually burnt area and number of fires have been fairly stable, which is mainly due to effective fire mitigation. Land surface models were used to investigate how climate change and forest management can influence forest fires in the future. The simulations were conducted using different regional climate models and greenhouse gas emission scenarios. Simulations, extending to 2100, indicate that forest fire risk is likely to increase over the coming decades. The report also highlights that globally, forest fires are a significant source of BC in the Arctic, having adverse health effects and further amplifying climate warming. However, simulations made using an atmospheric dispersion model indicate that the impact of forest fires in Fennoscandia on the environment and air quality is relatively minor and highly seasonal. Efficient forest fire mitigation requires the development of forest fire detection tools including satellites and drones, high spatial resolution modelling of fire risk and fire spreading that account for detailed terrain and weather information. Moreover, increasing the general preparedness and operational efficiency of firefighting is highly important. Forest fires are a large challenge requiring multidisciplinary research and close cooperation between the various administrative operators, e.g. rescue services, weather services, forest organisations and forest owners is required at both the national and international level.
  • Venäläinen, Ari; Luhtala, Sanna; Laapas, Mikko; Hyvärinen, Otto; Gregow, Hilppa; Strahlendorff, Mikko; Peltoniemi, Mikko; Suvanto, Susanna; Nevalainen, Seppo; Peltola, Heli; Leskinen, Leena A.; Ala-Honkola, Hannu; Niskanen, Yrjö; Poikela, Asko; Maidell, Marjo; Horne, Paula; Ruuskanen, Olli-Pekka (Ilmatieteen laitos, 2021)
    Raportteja-Rapporter-Reports 2021:1
    Ilmastonmuutoksen seurauksena metsiin kohdistuvat sään aiheuttamat riskit kasvavat, ja siksi tarvitaan tehokkaita sopeutumistoimia. Maa- ja metsätalousministeriön rahoittamassa metsätalouden sopeutumista tukevassa Säätyö-hankkeessa olemme tehneet yhteenvedon sopeutumista auttavista tietoaineistoista, kehittäneet metsätaloutta hyödyttäviä sää- ja ilmastopalveluita sekä kartoittaneet metsätalouden sää- ja ilmastopalveluiden tarvetta. Lisäksi olemme kirjanneet keskeisiä sopeutumista edistäviä jatkokehitystoimia. Säätyö-hankkeessa kehitettiin maan pintakerroksen kosteutta ja kantavuutta kuvaava palvelutuote, jossa esitetään säätietojen avulla laskettu analyysi vallitsevasta tilanteesta sekä 10 vuorokauden ennuste. Hankkeessa myös testattiin pitkien kolmen kuukauden päähän ylettyvien ennusteiden käyttökelpoisuutta. Säätyön ennustepalvelua sivuaa, hyödyntää ja täydentää toinen Ilmatieteen laitoksen ja Metsätehon yhteistyöhanke nimeltään HarvesterSeasons (https://harvesterseasons.com/) HarvesterSeasons-palvelu hyödyntää maaston kantavuusolosuhteiden arvioinnissa pitkiä, noin kuuden kuukauden päähän ulottuvia ennusteita. Itä-Suomen yliopiston Metsätieteiden osastolla kehitettiin Ilmatieteen laitoksen kanssa yhteistyössä tuulituhoriskityökalun testiversio, minkä avulla voidaan laskea puuston tuulituhoon (puiden kaatuminen) tarvittavia tuulennopeuksia. Työkalu soveltuu tällä hetkellä vain tutkijakäyttöön. Säätyö-hankkeessa testattiin myös mahdollisuutta paikantaa pahimmat tuulituhoalueet välittömästi tapahtuneen myrskyn jälkeen. Menetelmänä käytettiin sääasemilla tehtävien tuulihavaintojen alueellista interpolointia. Menetelmän avulla analysoitiin kesällä ja syksyllä 2020 metsätuhoja aiheuttaneita myrskyjä. Myrskyn jälkeisen tilannekuvan laatijat pitivät tehtyjä kartta-analyysejä havainnollisina ja hyödyllisinä. Lumen kertymää puiden oksille, voidaan mallintaa säätietojen, kuten sademäärän, lämpötilan, ilman kosteuden ja tuulen nopeuden, avulla. Säätyö-hankkeessa lumituhoriskin arviointimallia kehitetiin edelleen siten, että kertyneen lumikuorman lisäksi selittäjäksi otetiin myös puuston ominaisuudet sekä maaston korkeusvaihtelut. Tehdyn verifioinnin mukaan abioottisten tekijöiden merkitys kasvoi äärimmäisissä lumikuormaolosuhteissa (talvi 2017–2018). Tavallisina talvina puolestaan korostui bioottisten tekijöiden merkitys. Vertailun mukaan toteutuneet lumituhot pystyttiin selittämään testatulla mallilla hyvin. Hankkeessa kartoitettiin haastatteluissa ja työpajassa tietotuotteiden käyttökohteita, hyötyjä, käyttöönoton edellytyksiä ja kehitysmahdollisuuksia. Tulosten mukaan tietotuotteille ja -palveluille nähtiin monipuolisia käyttömahdollisuuksia ja käytön myötä saatavia hyötyjä. Tietotuotteiden avulla olisi mahdollista kehittää ennakoivaa metsänhoitoa, joka pienentäisi tuhoista aiheutuvia taloudellisia vahinkoja. Tietotuotteiden mahdollistama entistä ajantasaisempi käsitys korjuuolosuhteista tehostaisi hakkuu- ja korjuuoperaatioiden toteutusta ja puuvarastojen hallintaa sekä vähentäisi maasto- ja runko- ja juuristovaurioita. Selvityksen mukaan tiedon käyttöönottoon vaikuttavat etenkin ajantasaisuus ja saatavuus. Vaikka hankkeessa kehitetyistä tietotuotteista ei oltu tällä hetkellä valmiita maksamaan niin haastatteluissa tuotiin esiin kuitenkin useita tietotuotteiden kehitysehdotuksia, joiden myötä niiden kaupallistamista pidettiin mahdollisena.

View more