Canopy uptake dominates nighttime carbonyl sulfide fluxes in a boreal forest

Nighttime vegetative uptake of carbonyl sulfide (COS) can exist due to the incomplete closure of stomata and the light independence of the enzyme carbonic anhydrase, which complicates the use of COS as a tracer for gross primary productivity (GPP). In this study we derived nighttime COS fluxes in a boreal forest (the SMEAR II station in Hyytiälä, Finland; 61°51′ N, 24°17′ E; 181 m a.s.l.) from June to November 2015 using two different methods: eddy-covariance (EC) measurements (FCOS-EC) and the radon-tracer method (FCOS-Rn). The total nighttime COS fluxes averaged over the whole measurement period were −6.8 ± 2.2 and −7.9 ± 3.8 pmol m−2 s−1 for FCOS-Rn and FCOS-EC, respectively, which is 33–38 % of the average daytime fluxes and 21 % of the total daily COS uptake. The correlation of 222Rn (of which the source is the soil) with COS (average R2  =  0.58) was lower than with CO2 (0.70), suggesting that the main sink of COS is not located at the ground. These observations are supported by soil chamber measurements that show that soil contributes to only 34–40 % of the total nighttime COS uptake. We found a decrease in COS uptake with decreasing nighttime stomatal conductance and increasing vapor-pressure deficit and air temperature, driven by stomatal closure in response to a warm and dry period in August. We also discuss the effect that canopy layer mixing can have on the radon-tracer method and the sensitivity of (FCOS-EC) to atmospheric turbulence. Our results suggest that the nighttime uptake of COS is mainly driven by the tree foliage and is significant in a boreal forest, such that it needs to be taken into account when using COS as a tracer for GPP

Evaluating two soil carbon models within the global land surface model JSBACH using surface and spaceborne observations of atmospheric CO₂

The trajectories of soil carbon (C) in the changing climate are of utmost importance, as soil carbon is a substantial carbon storage with a large potential to impact the atmospheric carbon dioxide (CO2) burden. Atmospheric CO2 observations integrate all processes affecting C exchange between the surface and the atmosphere. Therefore they provide a benchmark for carbon cycle models. We evaluated two distinct soil carbon models (CBALANCE and YASSO) that were implemented to a global land surface model (JSBACH) against atmospheric CO2 observations. We transported the biospheric carbon fluxes obtained by JSBACH using the atmospheric transport model TM5 to obtain atmospheric CO2. We then compared these results with surface observations from Global Atmosphere Watch (GAW) stations as well as with column XCO2 retrievals from the GOSAT satellite. The seasonal cycles of atmospheric CO2 estimated by the two different soil models differed. The estimates from the CBALANCE soil model were more in line with the surface observations at low latitudes (0 N–45 N) with only 1 % bias in the seasonal cycle amplitude (SCA), whereas YASSO was underestimating the SCA in this region by 32 %. YASSO gave more realistic seasonal cycle amplitudes of CO2 at northern boreal sites (north of 45 N) with underestimation of 15 % compared to 30 % overestimation by CBALANCE. Generally, the estimates from CBALANCE were more successful in capturing the seasonal patterns and seasonal cycle amplitudes of atmospheric CO2 even though it overestimated soil carbon stocks by 225 % (compared to underestimation of 36 % by YASSO) and its predictions of the global distribution of soil carbon stocks was unrealistic. The reasons for these differences in the results are related to the different environmental drivers and their functional dependencies of these two soil carbon models. In the tropical region the YASSO model showed earlier increase in season of the heterotophic respiration since it is driven by precipitation instead of soil moisture as CBALANCE. In the temperate and boreal region the role of temperature is more dominant. There the heterotophic respiration from the YASSO model had larger annual variability, driven by air temperature, compared to the CBALANCE which is driven by soil temperature. The results underline the importance of using sub-yearly data in the development of soil carbon models when they are used in shorter than annual time scales

13CO(J=1−−0)^{13}CO(J = 1 -- 0) Depression in Luminous Starburst Mergers

It is known that the class of luminous starburst galaxies tends to have higher $R =^{12}CO(J=1--0)/^{13}CO(J=1--0)$ integrated line intensity ratios ($R>20$) than normal spiral galaxies ($R \sim 10$). Since most previous studies investigated only $R$, it remains uncertain whether the luminous starburst galaxies are overabundant in $^{12}$CO or underabundant in $^{13}$CO. Here we propose a new observational test to examine this problem. Our new test is to compare far-infrared luminosities [$L$(FIR)] with those of $^{12}$CO and $^{13}CO [L(^{12}CO)$ and $L(^{13}CO)$, respectively]. It is shown that there is a very tight correlation between $L(^{12}CO)$ and L(FIR), as found in many previous studies. However, we find that the $^{13}$CO luminosities of the high-R galaxies are lower by a factor of three on the average than those expected from the correlation for the remaining galaxies with ordinary $R$ values. Therefore, we conclude that the observed high $R$ values for the luminous starburst galaxies are attributed to their lower $^{13}$CO line intensities.Comment: 9 pages (aaspp4.sty), 3 postscript figures (embedded). Accepted for publication in Astrophysical Journal Letter

High Density Molecular Gas in the IR-bright Galaxy System VV114

New high resolution CO(3-2) interferometric map of the IR-bright interacting galaxy system VV114 observed with the Submillimeter Array (SMA) reveal a substantial amount of warm and dense gas in the IR-bright but optically obscured galaxy, VV114E, and the overlap region connecting the two nuclei. A 1.8 x 1.4 kpc concentration of CO(3-2) emitting gas with a total mass of 4 x 10^9 Msun coincides with the peaks of NIR, MIR, and radio continuum emission found previously by others, identifying the dense fuel for the AGN and/or the starburst activity there. Extensive CO(2-1) emission is also detected, revealing detailed distribution and kinematics that are consistent with the earlier CO(1-0) results. The widely distributed molecular gas traced in CO(2-1) and the distributed discrete peaks of CO(3-2) emission suggest that a spatially extended intense starbursts may contribute significantly to its large IR luminosity. These new observations further support the notion that VV114 is approaching its final stage of merger, when violent central inflow of gas triggers intense starburst activity possibly boosting the IR luminosity above the ultraluminous threshold.Comment: 11 pages, 2 figures, accepted for publication in ApJ

The thermal state of molecular clouds in the Galactic Center: evidence for non-photon-driven heating

We used the Atacama Pathfinder Experiment (APEX) 12 m telescope to observe the J_KaKc=3_03-2_02, 3_22-2_21, and 3_21-2_20 transitions of para-H_2CO at 218 GHz simultaneously to determine kinetic temperatures of the dense gas in the central molecular zone (CMZ) of our Galaxy. The map extends over approximately 40 arcmin x 8 arcmin (~100x20 pc^2) along the Galactic plane with a linear resolution of 1.2 pc. The strongest of the three lines, the H_2CO (3_03-2_02) transition, is found to be widespread, and its emission shows a spatial distribution similar to ammonia. The relative abundance of para-H_2CO is 0.5-1.2 10^{-9}, which is consistent with results from lower frequency H_2CO absorption lines. Derived gas kinetic temperatures for individual molecular clouds range from 50 K to values in excess of 100 K. While a systematic trend toward (decreasing) kinetic temperature versus (increasing) angular distance from the Galactic center (GC) is not found, the clouds with highest temperature (T_kin > 100 K) are all located near the nucleus. For the molecular gas outside the dense clouds, the average kinetic temperature is 65+/-10 K. The high temperatures of molecular clouds on large scales in the GC region may be driven by turbulent energy dissipation and/or cosmic-rays instead of photons. Such a non-photon-driven thermal state of the molecular gas provides an excellent template for the more distant vigorous starbursts found in ultraluminous infrared galaxies (ULIRGs).Comment: 23 pages, 11 figures, A&A in pres

Tampereen Kaleva opiskelijoiden asuinympäristönä:case Vanha Domus

Tiivistelmä. Tampereen opiskelija-asuntosäätiö TOAS järjesti joulukuussa 2019 yhdessä Suomen Arkkitehtiliitto SAFAn kanssa kaikille avoimen yleisen arkkitehtuurikilpailun Vanha Domus -nimisen korttelin arkkitehtisuunnittelusta. Kilpailulla haettiin vaihtoehtoisia ideoita alueen kehittämiseksi. Ehdotuksen tuli tukea TOASin pääperiaatetta kohtuuhintaisten opiskelija-asuntojen tarjoajana, sopia arkkitehtuuriltaan alueen kaupunkiympäristöön ja liittyä luontevaksi osaksi ympäröivää kaupunkirakennetta. Vanha Domus opiskelija-asuinrakennus sijaitsee Tampereen Kalevan kaupunginosassa noin kahden kilometrin päässä ydinkeskustasta. Kohtuuhintaisten opiskelija-asuntojen kysyntä Tampereella on voimakkaasti kasvanut. Vanhan Domuksen korttelilla on keskeisellä sijainnilla, julkisen liikenteen palveluiden läheisyydessä edellytykset myös jatkossa vastata tähän tarpeeseen. Sammonkadulle tuleva raitiotie vahvistaa alueen liikenneyhteyksiä entisestään. Tontilla sijaitseva Vanha Domus rakennuskokonaisuus on tullut teknisen käyttöikänsä päähän ja tarvitsee mittavat korjaustoimenpiteet tilojen nykyaikaistamiseksi. Kilpailutyötä tehdessä yksi pääkohdista ja keskeisistä suunnitteluhaasteista oli tarkastella tontilla olemassa olevan rakennuksen vaihtoehtoisia kehittämistoimenpiteitä sekä pohtia, millä tavoin kortteliin saadaan luotua viihtyisää asuinympäristöä ja kilpailuohjelmassa annetut tavoitteet täyttävä ympäristöön sovittautuva arkkitehtoninen kokonaisratkaisu. Suunnitelma pyrkii uudisrakentamisen keinoin luomaan ympäristöön kaupunkikuvallisesti ja arkkitehtonisesti sovittautuvan sekä vanhaa rakennuskantaa täydentävän ratkaisun. Ehdotus on arkkitehtuuriltaan muodostunut kollaasimaisesti alueen rakennetun ympäristön viittauksista, millä uudisrakennuskokonaisuudelle luodaan omanlaista identiteettiä ja sitoutetaan osaksi ympäristöään. Asuinkorttelikokonaisuudesta muodostuu ympäristöön sointuva, toiminnallisesti selkeä ja kaupunkitilaa elävöittävä kokonaisuus, mikä jäsentyy luontevaksi osaksi ympäröivää vanhan rakennuskannan muodostavaa kaupunkiympäristöä. Diplomityöni koostuu viidestä osasta, missä ensimmäinen osa käsittelee lyhyesti työhön liittyviä taustatietoja kuten Tampereen korkeakouluopiskelijoiden asumisen tilastoja. Toisessa osassa käydään läpi suunnitteluun vaikuttavia lähtötietoja ja kolmannessa osassa olemassa olevan rakennuksen nykytilaa. Neljäs osa käsittää määrätylle suunnittelualueelle itsenäisesti luodun ja kilpailuun hyväksytyn suunnitelman havainnekuvineen, piirroksineen ja selostuksineen. Viimeinen viides osa sisältää yhteenvedon diplomityöstä sekä kiitokset. Liitteenä on lisäksi esitetty suunnitelmasta laaditut piirustusplanssit pienennettyinä.Kaleva of Tampere as residential environment for students : case the Old Domus. Abstract. In December 2019, the Tampere Student Housing Foundation (TOAS), together with the Finnish Association of Architects (SAFA), organized a general and open architectural competition for the architectural design of a block called Old Domus. The competition sought alternative ideas for developing the area. The proposal was to support the main principle of TOAS as a provider of affordable student housing, to agree on architecture in the urban environment of the area and to become a natural part of the surrounding urban structure. The Old Domus student-residential building is located in the Kaleva district of Tampere, about 2 kilometres from the city centre. The demand for affordable student housing in Tampere has grown strongly. The old Domus block is centrally located, in the vicinity of public transport services, and the prerequisites will continue to meet this need. The tramway to Sammonkatu will further strengthen the area’s transport connections. The old Domus building complex on the plot has come to the end of its technical service life and needs extensive repairs to modernize the premises. In the course of the competitive work, one of the main points and key design challenges was to examine alternative development measures for an existing building on the site and to consider how to create a comfortable living environment in the block and an overall architectural solution that meets the objectives set out in the competition programme. Through new construction, the plan aims to create a solution that is suitable for the environment in a city-like and architectural way in complements the old building stock. In terms of architecture, the proposal has consisted of references to the built environment of the area, creating a unique identity for the new building complex and to reconsile it as part of its environment. The residential block consists of an environmentally adaptable, functionally clear and enlivening urban space which is structured as a natural part of the urban environment that makes up the surrounding old building stock. My master’s thesis consists of five parts, where the first part briefly deals with background information related to the work such as statistics on university student housing in Tampere. The second part examines the starting data affecting the design and the third part examines the current state of the existing building. The fourth part comprises independently created a plan in a specific design area with illustrations, drawings and narrations which has approved for the competition. The last fifth part contains a summary of the master’s thesis and thanks. In addition the drawing plans drawn up with a reduction are also attached

Production, growth and properties of ultrafine atmospheric aerosol particles in an urban environment

Number concentrations of atmospheric aerosol particles were measured by a flow-switching type differential mobility particle sizer in an electrical mobility diameter range of 6–1000 nm in 30 channels near central Budapest with a time resolution of 10 min continuously from 3 November 2008 to 2 November 2009. Daily median number concentrations of particles varied from 3.8 × 10<sup>3</sup> to 29 ×10<sup>3</sup> cm<sup>−3</sup> with a yearly median of 11.8 × 10<sup>3</sup> cm<sup>−3</sup>. Contribution of ultrafine particles to the total particle number ranged from 58 to 92% with a mean ratio and standard deviation of (79 ± 6)%. Typical diurnal variation of the particle number concentration was related to the major emission patterns in cities, new particle formation, sinks of particles and meteorology. Shapes of the monthly mean number size distributions were similar to each other. Overall mean for the number median mobility diameter of the Aitken and accumulation modes were 26 and 93 nm, respectively, which are substantially smaller than for rural or background environments. The Aitken and accumulation modes contributed similarly to the total particle number concentrations at the actual measurement location. New particle formation and growth unambiguously occurred on 83 days, which represent 27% of all relevant days. Hence, new particle formation and growth are not rare phenomena in Budapest. Their frequency showed an apparent seasonal variation with a minimum of 7.3% in winter and a maximum of 44% in spring. New particle formation events were linked to increased gas-phase H<sub>2</sub>SO<sub>4</sub> concentrations. In the studied area, new particle formation is mainly affected by condensation sink and solar radiation. The formation process seems to be not sensitive to SO<sub>2</sub>, which was present in a yearly median concentration of 6.7 μg m<sup>−3</sup>. This suggests that the precursor gas was always available in excess. Formation rate of particles with a diameter of 6 nm varied between 1.65 and 12.5 cm<sup>−3</sup> s<sup>−1</sup> with a mean and standard deviation of (4.2 ± 2.5) cm<sup>−3</sup> s<sup>−1</sup>. Seasonal dependency for the formation rate could not be identified. Growth curves of nucleated particles were usually superimposed on the characteristic diurnal pattern of road traffic direct emissions. The growth rate of the nucleation mode with a median diameter of 6 nm varied from 2.0 to 13.3 nm h<sup>−1</sup> with a mean and standard deviation of (7.7 ± 2.4) nm h<sup>−1</sup>. There was an indicative tendency for larger growth rates in summer and for smaller values in winter. New particle formation events increased the total number concentration by a mean factor and standard deviation of 2.3 ± 1.1 relative to the concentration that occurred immediately before the event. Several indirect evidences suggest that the new particle formation events occurred at least over the whole city, and were of regional type. The results and conclusions presented are the first information of this kind for the region over one-year long time period

Association of changes in work due to COVID-19 pandemic with psychosocial work environment and employee health: a cohort study of 24 299 Finnish public sector employees

OBJECTIVES: To examine the associations of COVID-19-related changes in work with perceptions of psychosocial work environment and employee health. METHODS: In a cohort of 24 299 Finnish public sector employees, psychosocial work environment and employee well-being were assessed twice before (2016 and 2018=reference period) and once during (2020) the COVID-19 pandemic. Those who reported a change (='Exposed') in work due to the pandemic (working from home, new tasks or team reorganisation) were compared with those who did not report such change (='Non-exposed'). RESULTS: After adjusting for sex, age, socioeconomic status and lifestyle risk score, working from home (44%) was associated with greater increase in worktime control (standardised mean difference (SMD)Exposed=0.078, 95% CI 0.066 to 0.090; SMDNon-exposed=0.025, 95% CI 0.014 to 0.036), procedural justice (SMDExposed=0.101, 95% CI 0.084 to 0.118; SMDNon-exposed=0.053, 95% CI 0.038 to 0.068), workplace social capital (SMDExposed=0.094, 95% CI 0.077 to 0.110; SMDNon-exposed=0.034, 95% CI 0.019 to 0.048), less decline in self-rated health (SMDExposed=-0.038, 95% CI -0.054 to -0.022; SMDNon-exposed=-0.081, 95% CI -0.095 to -0.067), perceived work ability (SMDExposed=-0.091, 95% CI -0.108 to -0.074; SMDNon-exposed=-0.151, 95% CI -0.167 to -0.136) and less increase in psychological distress (risk ratio (RR)Exposed=1.06, 95% CI 1.02 to 1.09; RRNon-exposed=1.16, 95% CI 1.13 to 1.20). New tasks (6%) were associated with greater increase in psychological distress (RRExposed=1.28, 95% CI 1.19 to 1.39; RRNon-exposed=1.10, 95% CI 1.07 to 1.12) and team reorganisation (5%) with slightly steeper decline in perceived work ability (SMDExposed=-0.151 95% CI -0.203 to -0.098; SMDNon-exposed=-0.124, 95% CI -0.136 to -0.112). CONCLUSION: Employees who worked from home during the pandemic had more favourable psychosocial work environment and health, whereas those who were exposed to work task changes and team reorganisations experienced more adverse changes

Non-volatile residuals of newly formed atmospheric particles in the boreal forest

The volatility of sub-micrometer atmospheric aerosol particles was studied in a rural background environment in Finland using a combination of a heating tube and a scanning mobility particle sizer. The analysis focused on nanoparticles formed through nucleation which were subsequently observed during their growth in the diameter range between 5 and 60 nm. During the 6 days of new particle formation shown in detail, the concentrations of newly formed particles increased up to 10 000 cm−3. The number of nucleation mode particles measured after volatilization in the heating tube at 280°C was up to 90% of the total number under ambient conditions. Taking into account the absolute accuracy of the size distribution measurements, all ambient particles found in the rural atmosphere could have a non-volatile core after volatilization at 280°C. As the regional new particle formation events developed over time as a result of further vapor condensation, the newly formed particles grew at an average growth rate of 2.4±0.3 nm h−1. Importantly, the non-volatile cores of nucleation mode particles were also observed to grow over time, however, at a lower average growth rate of 0.6±0.3 nm h−1. One implication of the volatility analysis is that the newly formed particles, which have reached ambient diameters of 15 nm, are unlikely to consist of sulfuric acid, ammonium sulfate, and water alone. A relatively constant ratio between the growth rate of the ambient particles as well as their non-volatile cores indicates that non-volatile matter is formed only gradually in the growing particles. The non-volatile fraction of the particles showed some correlation with the ambient temperature. The composition and formation mechanism of this non-volatile material in nucleation mode particles are, to date, not known