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• 1. [Article] Century-Long Variability and Trends in Daily Precipitation Characteristics at Three Finnish Stations

  Long-term variations and trends in a wide range of statistics for daily precipitation characteristics in terms of intensity, frequency and duration in Finland were analysed using precipitation records ...

  Citation × Citation Citation Abstract Copy Title: Century-Long Variability and Trends in Daily Precipitation Characteristics at Three Finnish Stations Author: Irannezhad, Masoud, Marttila, Hannu, De-liang, Chen, Kløve, Bjørn Year: 2016 Long-term variations and trends in a wide range of statistics for daily precipitation characteristics in terms of intensity, frequency and duration in Finland were analysed using precipitation records during 1908－2008 from 3 meteorological stations in the south (Kaisaniemi), center (Kajaani) and north (Sodankylä). Although precipitation days in northern part were more frequent than in central and southern parts, daily precipitation intensity in the south was generally higher than those in the centre and north of the country. Annual sum of very light precipitation (0 mm < daily precipitation ≤ long-term 50th percentile of daily precipitation more than 0 mm) significantly (p Title: Century-Long Variability and Trends in Daily Precipitation Characteristics at Three Finnish Stations Author: Irannezhad, Masoud, Marttila, Hannu, De-liang, Chen, Kløve, Bjørn Year: 2016 Long-term variations and trends in a wide range of statistics for daily precipitation characteristics in terms of intensity, frequency and duration in Finland were analysed using precipitation records during 1908－2008 from 3 meteorological stations in the south (Kaisaniemi), center (Kajaani) and north (Sodankylä). Although precipitation days in northern part were more frequent than in central and southern parts, daily precipitation intensity in the south was generally higher than those in the centre and north of the country. Annual sum of very light precipitation (0 mm < daily precipitation ≤ long-term 50th percentile of daily precipitation more than 0 mm) significantly (p Close

• 2. [Article] The Role of Atmospheric Circulation Patterns in Agroclimate Variability in Finland, 1961-2011

  This study evaluates interannual variations and trends in growing season daily temperature sum and daily precipitation sum in Finland during 1961–2011, and their connections to well known atmospheric circulation ...

  Citation × Citation Citation Abstract Copy Title: The Role of Atmospheric Circulation Patterns in Agroclimate Variability in Finland, 1961-2011 Author: Irannezhad, Masoud, Chen, Deliang, Kløve, Bjørn Year: 2016 This study evaluates interannual variations and trends in growing season daily temperature sum and daily precipitation sum in Finland during 1961–2011, and their connections to well known atmospheric circulation patterns. Changes in summer (June–August) climate partially explain changes in growing season daily temperature sum and daily precipitation sum over Finland, which naturally decreased from south to north. On a national scale, growing season warmed and became wetter during 1961–2011, as growing season daily temperature sum and daily precipitation sum significantly (p < 0.05) increased by 5.01 ± 3.17°C year–1 and 1.39 ± 0.91 mm year–1, respectively. The East Atlantic pattern was the most influential atmospheric circulation pattern for variations in growing season daily temperature sum (rho = 0.40) across Finland and the East Atlantic/West Russia pattern was most influential for growing season daily precipitation sum variability (rho = –0.54). There were significant (p < 0.05) increasing trends in growing season daily temperature sum and daily precipitation sum throughout Finland during 1961–2011. Increased growing season daily temperature sum was mainly observed in northern, central, western, eastern and coastal areas of south-western Finland. This warming was positively associated with the East Atlantic pattern in the north, centre and south, but negatively associated with the East Atlantic/West Russia pattern in eastern Finland. Increased GSP mostly occurred in southern, eastern, western, central, northern and north-western Finland. These wetting trends were positively correlated with the East Atlantic pattern in the north and negatively correlated with the Polar pattern in the south and the East Atlantic/West Russia pattern in the east, west, centre and north-east of Finland. The overall agroclimatic year-to-year variability in Finland between 1961 and 2011 was mostly linked to variations in the East Atlantic and East Atlantic/West Russia patterns. Title: The Role of Atmospheric Circulation Patterns in Agroclimate Variability in Finland, 1961-2011 Author: Irannezhad, Masoud, Chen, Deliang, Kløve, Bjørn Year: 2016 This study evaluates interannual variations and trends in growing season daily temperature sum and daily precipitation sum in Finland during 1961–2011, and their connections to well known atmospheric circulation patterns. Changes in summer (June–August) climate partially explain changes in growing season daily temperature sum and daily precipitation sum over Finland, which naturally decreased from south to north. On a national scale, growing season warmed and became wetter during 1961–2011, as growing season daily temperature sum and daily precipitation sum significantly (p < 0.05) increased by 5.01 ± 3.17°C year–1 and 1.39 ± 0.91 mm year–1, respectively. The East Atlantic pattern was the most influential atmospheric circulation pattern for variations in growing season daily temperature sum (rho = 0.40) across Finland and the East Atlantic/West Russia pattern was most influential for growing season daily precipitation sum variability (rho = –0.54). There were significant (p < 0.05) increasing trends in growing season daily temperature sum and daily precipitation sum throughout Finland during 1961–2011. Increased growing season daily temperature sum was mainly observed in northern, central, western, eastern and coastal areas of south-western Finland. This warming was positively associated with the East Atlantic pattern in the north, centre and south, but negatively associated with the East Atlantic/West Russia pattern in eastern Finland. Increased GSP mostly occurred in southern, eastern, western, central, northern and north-western Finland. These wetting trends were positively correlated with the East Atlantic pattern in the north and negatively correlated with the Polar pattern in the south and the East Atlantic/West Russia pattern in the east, west, centre and north-east of Finland. The overall agroclimatic year-to-year variability in Finland between 1961 and 2011 was mostly linked to variations in the East Atlantic and East Atlantic/West Russia patterns. Close

• 3. [Article] Atmospheric Circulation Patterns Explaining Climatological Drought Dynamics in the Boreal Environment of Finland, 1962-2011

  Understanding the atmospheric circulation patterns (ACPs) influencing drought development is important in management of this spatially extensive and recurrently prolonged natural hazard. Using the Standardized ...

  Citation × Citation Citation Abstract Copy Title: Atmospheric Circulation Patterns Explaining Climatological Drought Dynamics in the Boreal Environment of Finland, 1962-2011 Author: Irannezhad, Masoud, Ahmadi, Behzad, Kløve, Bjørn, Moradkhani, Hamid Year: 2017 Understanding the atmospheric circulation patterns (ACPs) influencing drought development is important in management of this spatially extensive and recurrently prolonged natural hazard. Using the Standardized Precipitation Evapotranspiration Index (SPEI), this study evaluates the spatio-temporal variability in climatological drought dynamics (in terms of intensity, frequency, duration, and extension) in Finland in 1962–2011. The SPEI values are calculated in 12-, 3-, and 1-month time steps (SPEI-12, -3, and -1, respectively) and the analyses are based on annual (SPEI-12Ann), seasonal (e.g. SPEI-3Win for winter), and monthly (e.g. SPEI-1Dec for December) time scales. The relationships between SPEI values and well-known ACPs of climate variability over Finland are also investigated. Our analysis shows that on national scale, the longest observed drought is 12 months (October 2002–September 2003) observed in SPEI-12 values. Droughts intensify in April, August, and September, and largely occur over the south, centre, east, and west of Finland. December has the highest frequency of droughts, but with significant wetting trends. Analysis of annual SPEI-12 indicates an increase in the probability of drought extent over time. In warm months (April–September), influential ACPs for temperature variability and drought conditions are mainly the Arctic Oscillation (AO) and the Scandinavia pattern. For the cold months (October–March), the AO, the North Atlantic Oscillation, the East Atlantic, and the Polar patterns influence precipitation deficit and SPEI. Although Finland has experienced wetting trends during the period 1962–2011, this study provides a detailed spatial assessment of climatological drought variability and the plausible atmospheric circulation drivers for the boreal environment of Finland in recent decades. Title: Atmospheric Circulation Patterns Explaining Climatological Drought Dynamics in the Boreal Environment of Finland, 1962-2011 Author: Irannezhad, Masoud, Ahmadi, Behzad, Kløve, Bjørn, Moradkhani, Hamid Year: 2017 Understanding the atmospheric circulation patterns (ACPs) influencing drought development is important in management of this spatially extensive and recurrently prolonged natural hazard. Using the Standardized Precipitation Evapotranspiration Index (SPEI), this study evaluates the spatio-temporal variability in climatological drought dynamics (in terms of intensity, frequency, duration, and extension) in Finland in 1962–2011. The SPEI values are calculated in 12-, 3-, and 1-month time steps (SPEI-12, -3, and -1, respectively) and the analyses are based on annual (SPEI-12Ann), seasonal (e.g. SPEI-3Win for winter), and monthly (e.g. SPEI-1Dec for December) time scales. The relationships between SPEI values and well-known ACPs of climate variability over Finland are also investigated. Our analysis shows that on national scale, the longest observed drought is 12 months (October 2002–September 2003) observed in SPEI-12 values. Droughts intensify in April, August, and September, and largely occur over the south, centre, east, and west of Finland. December has the highest frequency of droughts, but with significant wetting trends. Analysis of annual SPEI-12 indicates an increase in the probability of drought extent over time. In warm months (April–September), influential ACPs for temperature variability and drought conditions are mainly the Arctic Oscillation (AO) and the Scandinavia pattern. For the cold months (October–March), the AO, the North Atlantic Oscillation, the East Atlantic, and the Polar patterns influence precipitation deficit and SPEI. Although Finland has experienced wetting trends during the period 1962–2011, this study provides a detailed spatial assessment of climatological drought variability and the plausible atmospheric circulation drivers for the boreal environment of Finland in recent decades. Close