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Meteorological forcing at the air-water interface is the main determinant of the heat balance of most lakes (Edinger et al., 1968; Sweers, 1976). Year-to-year changes in the weather therefore have a major effect on the thermal characteristics of lakes. However, lakes that differ with respect to their morphometry respond differently to these changes (Gorham, 1964), with deeper lakes integrating the effects of meteorological forcing over longer periods of time. Other important factors that can influence the thermal characteristics of lakes include hydraulic residence time, optical properties and landscape setting (e.g. Salonen et al., 1984; Fee et al., 1996; Livingstone et al., 1999). These factors modify the thermal responses of the lake to meteorological forcing (cf. Magnuson et al., 2004; Blenckner, 2005) and regulate the patterns of spatial coherence (Chapter 17) observed in the different regions (Livingstone, 1993; George et al., 2000; Livingstone and Dokulil, 2001; Jarvinen et al., 2002; Blenckner et al., 2004)

Meteorological forcing at the air-water interface is the main determinant of the heat balance of most lakes (Edinger et al., 1968; Sweers, 1976). Year-to-year changes in the weather therefore have a major effect on the thermal characteristics of lakes. However, lakes that differ with respect to their morphometry respond differently to these changes (Gorham, 1964), with deeper lakes integrating the effects of meteorological forcing over longer periods of time. Other important factors that can influence the thermal characteristics of lakes include hydraulic residence time, optical properties and landscape setting (e.g. Salonen et al., 1984; Fee et al., 1996; Livingstone et al., 1999). These factors modify the thermal responses of the lake to meteorological forcing (cf. Magnuson et al., 2004; Blenckner, 2005) and regulate the patterns of spatial coherence (Chapter 17) observed in the different regions (Livingstone, 1993; George et al., 2000; Livingstone and Dokulil, 2001; Jarvinen et al., 2002; Blenckner et al., 2004)

Molecular dynamics (MD) computer simulations are used routinely to compute atomistic trajectories of complex systems. Systems are simulated in various ensembles, depending on the experimental conditions one aims to mimic. While constant energy, temperature, volume, and pressure are rather straightforward to model, pH, which is an equally important parameter in experiments, is more difficult to account for in simulations. Although a constant pH algorithm based on the $\lambda$-dynamics approach by Brooks and co-workers was implemented in a fork of the GROMACS molecular dynamics program, uptake has been rather limited, presumably due to the poor scaling of that code with respect to the number of titratable sites. To overcome this limitation, we implemented an alternative scheme for interpolating the Hamiltonians of the protonation states that makes the constant pH molecular dynamics simulations almost as fast as a normal MD simulation with GROMACS. In addition, we implemented a simpler scheme, called multisite representation, for modeling side chains with multiple titratable sites, such as imidazole rings. This scheme, which is based on constraining the sum of the $\lambda$-coordinates, not only reduces the complexity associated with parameterizing the intra-molecular interactions between the sites, but is also easily extendable to other molecules with multiple titratable sites. With the combination of a more efficient interpolation scheme and multisite representation of titratable groups, we anticipate a rapid uptake of constant pH molecular dynamics simulations within the GROMACS user community.

Molecular dynamics (MD) computer simulations are used routinely to compute atomistic trajectories of complex systems. Systems are simulated in various ensembles, depending on the experimental conditions one aims to mimic. While constant energy, temperature, volume, and pressure are rather straightforward to model, pH, which is an equally important parameter in experiments, is more difficult to account for in simulations. Although a constant pH algorithm based on the $\lambda$-dynamics approach by Brooks and co-workers was implemented in a fork of the GROMACS molecular dynamics program, uptake has been rather limited, presumably due to the poor scaling of that code with respect to the number of titratable sites. To overcome this limitation, we implemented an alternative scheme for interpolating the Hamiltonians of the protonation states that makes the constant pH molecular dynamics simulations almost as fast as a normal MD simulation with GROMACS. In addition, we implemented a simpler scheme, called multisite representation, for modeling side chains with multiple titratable sites, such as imidazole rings. This scheme, which is based on constraining the sum of the $\lambda$-coordinates, not only reduces the complexity associated with parameterizing the intra-molecular interactions between the sites, but is also easily extendable to other molecules with multiple titratable sites. With the combination of a more efficient interpolation scheme and multisite representation of titratable groups, we anticipate a rapid uptake of constant pH molecular dynamics simulations within the GROMACS user community.

We examined long-term relationships between Cladocera and limnogeological and climate variables in a late Holocene lake sediment sequence to assess cladoceran responses to climate change and reconstruct past climate variations in southern Finland, near the Baltic Sea coast. Elemental composition, organic matter, and inferred water quality variables were used to constrain paleoenvironmental (until 4500 cal BP) conditions and human impact. Fossil Cladocera assemblages, ephippia, and body size trends were utilized to estimate mean July air temperature (T Jul) variability, open-water season length, and water-temperature regimes. Results revealed stable cladoceran communities, dominated by Eubosmina, until 500 cal BP, followed by major assemblage changes including increases in Chydorus cf. sphaericus, Alonella spp., and Bosmina longirostris. Pb and Cu concentrations were associated temporally with increasing human impact and warming climate during the past few centuries, and were the most significant factors in explaining cladoceran community changes, based on redundancy analysis. A Cladocera-based T Jul reconstruction estimated elevated temperatures for the end of the Holocene Thermal Maximum, a cooler period during ~3000–2000 cal BP, slightly increased temperatures during 1200–800 cal BP corresponding to the Medieval Climate Anomaly (MCA), and lower temperatures during the Little Ice Age (LIA), 800–200 cal BP. The reconstruction also suggests that significant climate warming took place during the twentieth century. Cladocerans mostly associated with warm periods included B. longirostris and Pleuroxus uncinatus, whereas Alona affinis, A. quadrangularis, and C. cf. sphaericus were associated with colder climate. Compared to a reference Chironomidae-inferred T Jul reconstruction from the same region, discrepancies were apparent in amplitude of temperature change, as the temperature variability in the cladoceran-based record was muted until ~200 cal BP. During the LIA, increased ephippia and body size agreed with the temperature reconstruction, but suggested a severely shorter open-water season and reduced water temperatures compared to the preceding late Holocene episodes, even though the cladoceran T Jul showed quite similar temperatures for these periods. Our results suggest that fossil cladoceran assemblages, ephippia, and morphological attributes respond sensitively to long-term climate fluctuations and this record reflects well the major climate events of the late Holocene and provides realistic paleoclimatic estimates for maritime southern Finland.

We examined long-term relationships between Cladocera and limnogeological and climate variables in a late Holocene lake sediment sequence to assess cladoceran responses to climate change and reconstruct past climate variations in southern Finland, near the Baltic Sea coast. Elemental composition, organic matter, and inferred water quality variables were used to constrain paleoenvironmental (until 4500 cal BP) conditions and human impact. Fossil Cladocera assemblages, ephippia, and body size trends were utilized to estimate mean July air temperature (T Jul) variability, open-water season length, and water-temperature regimes. Results revealed stable cladoceran communities, dominated by Eubosmina, until 500 cal BP, followed by major assemblage changes including increases in Chydorus cf. sphaericus, Alonella spp., and Bosmina longirostris. Pb and Cu concentrations were associated temporally with increasing human impact and warming climate during the past few centuries, and were the most significant factors in explaining cladoceran community changes, based on redundancy analysis. A Cladocera-based T Jul reconstruction estimated elevated temperatures for the end of the Holocene Thermal Maximum, a cooler period during ~3000–2000 cal BP, slightly increased temperatures during 1200–800 cal BP corresponding to the Medieval Climate Anomaly (MCA), and lower temperatures during the Little Ice Age (LIA), 800–200 cal BP. The reconstruction also suggests that significant climate warming took place during the twentieth century. Cladocerans mostly associated with warm periods included B. longirostris and Pleuroxus uncinatus, whereas Alona affinis, A. quadrangularis, and C. cf. sphaericus were associated with colder climate. Compared to a reference Chironomidae-inferred T Jul reconstruction from the same region, discrepancies were apparent in amplitude of temperature change, as the temperature variability in the cladoceran-based record was muted until ~200 cal BP. During the LIA, increased ephippia and body size agreed with the temperature reconstruction, but suggested a severely shorter open-water season and reduced water temperatures compared to the preceding late Holocene episodes, even though the cladoceran T Jul showed quite similar temperatures for these periods. Our results suggest that fossil cladoceran assemblages, ephippia, and morphological attributes respond sensitively to long-term climate fluctuations and this record reflects well the major climate events of the late Holocene and provides realistic paleoclimatic estimates for maritime southern Finland.

The aim of this study was to evaluate climate impacts of a typical Finnish wind farm. Three research questions were: 1) What is the typical Finnish wind farm’s carbon footprint? 2) what is the energy payback time of the typical Finnish wind farm? and 3) does the typical Finnish wind farm have a better net-negative impact on climate than the commercial forest area on which it was built? Data for the study were collected via academic literature, wind turbine life cycle assessment reports, geographic information system (GIS) analysis and through the Natural Resources Institute Finland’s Statistics database. The GIS analysis was conducted to retrieve the volume of roundwood on the wind farm’s site. The carbon footprint of the typical Finnish wind farm was found to be 7,18 g CO2e/kWh and the wind farm’s energy payback time 7,06 months. This study found that during 22 years (consisting of the wind farm’s construction and operation phases) the typical Finnish wind farm had a net-negative impact on climate change of at least 169 767,72 t CO2. In the absence of the typical Finnish wind farm, producing the equivalent amount of electricity by Finnish electricity mix was considered in calculating the net impact of the commercial forest area. This resulted in a net-positive impact on climate change of 192 393,42 t CO2. However, the typical Finnish wind farm did not represent a carbon sink. Climate impacts represent only a part of environmental impacts caused by wind power. The results of this study might have implications for the acceptability of wind power by general society as well as used for calculating climate impact assessment. Tutkimuksen tavoitteena oli arvioida tyypillisen suomalaisen tuulivoimapuiston ilmastovaikutuksia. Aihetta lähestyttiin kolmella tutkimuskysymyksellä selvittäen tuulivoimapuiston 1) hiilijalanjälki ja 2) energiantakaisinmaksuaika sekä 3) onko puistolla parempi nettonegatiivinen ilmastovaikutus kuin talousmetsällä, johon se on rakennettu. Tutkimuksen aineisto kerättiin akateemisen kirjallisuuden, elinkaariarviointi-raporttien, paikkatieto-analyysin (GIS) ja Luonnonvarakeskuksen tietokannan avulla. GIS-analyysillä selvitettiin runkopuun määrä tuulivoimapuistoalueella. Tyypillisen suomalaisen tuulivoimapuiston hiilijalanjälki on tulosten perusteella 7,18 g CO2e/kWh ja tuulivoimapuiston energiantakaisinmaksuaika 7,06 kuukautta. Tutkimuksessa havaittiin, että 22 vuoden aikana (puiston rakentaminen ja tuotantovaihe) tyypillisellä suomalaisella tuulivoimapuistolla on nettonegatiivinen ilmastovaikutus, joka on vähintään 169 767,72 t CO2. Skenaariossa, että tuulivoimapuistoa ei rakennettaisi, talousmetsän ilmastovaikutusten laskennassa on huomioitu vastaava sähkömäärän tuotto suomalaisella energialähteiden yhdistelmällä. Tässä tapauksessa netto-positiivinen vaikutus on tulosten perusteella 192 393,42 t CO2. Tuloksia ei voi kuitenkaan tulkita niin, että tuulivoimapuisto olisi hiilinielu. Ilmastovaikutukset ovat yksi osa tuulivoiman aiheuttamista ympäristövaikutuksista. Tämän tutkielman tuloksilla voidaan hyödyntää ilmastovaikutusten arvioinnin laskennassa ja niillä olla osaltaan vaikutuksia siihen, kuinka tuulivoima nähdään yhteiskunnassa. ei tietoa saavutettavuudesta unknown accessibility

The aim of this study was to evaluate climate impacts of a typical Finnish wind farm. Three research questions were: 1) What is the typical Finnish wind farm’s carbon footprint? 2) what is the energy payback time of the typical Finnish wind farm? and 3) does the typical Finnish wind farm have a better net-negative impact on climate than the commercial forest area on which it was built? Data for the study were collected via academic literature, wind turbine life cycle assessment reports, geographic information system (GIS) analysis and through the Natural Resources Institute Finland’s Statistics database. The GIS analysis was conducted to retrieve the volume of roundwood on the wind farm’s site. The carbon footprint of the typical Finnish wind farm was found to be 7,18 g CO2e/kWh and the wind farm’s energy payback time 7,06 months. This study found that during 22 years (consisting of the wind farm’s construction and operation phases) the typical Finnish wind farm had a net-negative impact on climate change of at least 169 767,72 t CO2. In the absence of the typical Finnish wind farm, producing the equivalent amount of electricity by Finnish electricity mix was considered in calculating the net impact of the commercial forest area. This resulted in a net-positive impact on climate change of 192 393,42 t CO2. However, the typical Finnish wind farm did not represent a carbon sink. Climate impacts represent only a part of environmental impacts caused by wind power. The results of this study might have implications for the acceptability of wind power by general society as well as used for calculating climate impact assessment. Tutkimuksen tavoitteena oli arvioida tyypillisen suomalaisen tuulivoimapuiston ilmastovaikutuksia. Aihetta lähestyttiin kolmella tutkimuskysymyksellä selvittäen tuulivoimapuiston 1) hiilijalanjälki ja 2) energiantakaisinmaksuaika sekä 3) onko puistolla parempi nettonegatiivinen ilmastovaikutus kuin talousmetsällä, johon se on rakennettu. Tutkimuksen aineisto kerättiin akateemisen kirjallisuuden, elinkaariarviointi-raporttien, paikkatieto-analyysin (GIS) ja Luonnonvarakeskuksen tietokannan avulla. GIS-analyysillä selvitettiin runkopuun määrä tuulivoimapuistoalueella. Tyypillisen suomalaisen tuulivoimapuiston hiilijalanjälki on tulosten perusteella 7,18 g CO2e/kWh ja tuulivoimapuiston energiantakaisinmaksuaika 7,06 kuukautta. Tutkimuksessa havaittiin, että 22 vuoden aikana (puiston rakentaminen ja tuotantovaihe) tyypillisellä suomalaisella tuulivoimapuistolla on nettonegatiivinen ilmastovaikutus, joka on vähintään 169 767,72 t CO2. Skenaariossa, että tuulivoimapuistoa ei rakennettaisi, talousmetsän ilmastovaikutusten laskennassa on huomioitu vastaava sähkömäärän tuotto suomalaisella energialähteiden yhdistelmällä. Tässä tapauksessa netto-positiivinen vaikutus on tulosten perusteella 192 393,42 t CO2. Tuloksia ei voi kuitenkaan tulkita niin, että tuulivoimapuisto olisi hiilinielu. Ilmastovaikutukset ovat yksi osa tuulivoiman aiheuttamista ympäristövaikutuksista. Tämän tutkielman tuloksilla voidaan hyödyntää ilmastovaikutusten arvioinnin laskennassa ja niillä olla osaltaan vaikutuksia siihen, kuinka tuulivoima nähdään yhteiskunnassa. ei tietoa saavutettavuudesta unknown accessibility