Relationships between long-term trends of air temperature, precipitation, nitrogen nutrition and growth of coniferous stands in Central Europe and Finland

Abstract Background The implementation of emission mitigation policies in Europe over the last two decades has generally improved the air quality, which resulted in lower aerosol particle mass, particle number, and black carbon mass concentration. However, little is known whether the decreasing particle concentrations at a lower-altitude level can be observed in the free troposphere (FT), an important layer of the atmosphere, where aerosol particles have a longer lifetime and may affect climate dynamics. In this study, we used data from two high-Alpine observatories, Zugspitze-Schneefernerhaus (ZSF) and Jungfraujoch (JFJ), to assess the long-term trends on size-resolved particle number concentrations (PNCs) and equivalent black carbon (eBC) mass concentration separated for undisturbed lower FT conditions and under the influence of air from the planetary boundary layer (PBL) from 2009 to 2018. Results The FT and PBL-influenced conditions were segregated for both sites. We found that the FT conditions in cold months were more prevalent than in warm months, while the measured aerosol parameters showed different seasonal patterns for the FT and PBL-influenced conditions. The pollutants in the PBL-influenced condition have a higher chance to be transported to high-altitudes due to the mountainous topography, leading to a higher concentration and more distinct seasonal variation, and vice versa. The long-term trends of the measured aerosol parameters were evaluated and the decreased aerosol concentrations were observed for both FT and PBL-influenced conditions. The observed decreasing trends in eBC concentration in the PBL-influenced condition are well consistent with the reported trends in total BC emission in Germany and Switzerland. The decreased concentrations in the FT condition suggest that the background aerosol concentration in the lower FT over Central Europe has correspondingly decreased. The change of back trajectories in the FT condition at ZSF and JFJ was further evaluated to investigate the other possible drivers for the decreasing trends. Conclusions The background aerosol concentration in the lower FT over Central Europe has significantly decreased during 2009–2018. The implementation of emission mitigation policies is the most decisive factor and the decrease of the regional airmass occurrence over Central Europe also has contributed to the decreasing trends.

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Is the Last Years Abrupt Warming in the National Observatory of Athens Records a Climate Change Manifestation?

Global NEST Journal ◽

10.30955/gnj.000436 ◽

2013 ◽

Vol 9 (2) ◽

pp. 107-116

Keyword(s):

Time Series ◽

Air Temperature ◽

Eastern Mediterranean ◽

National Observatory ◽

Urban Effect ◽

Long Term Trends ◽

Temperature Records ◽

The 19Th Century ◽

Temperature Time

Instrumental data time series show an average global warming of approximately 0.90C over the last century. Eastern Mediterranean air temperature follows the northern hemisphere (NH) secular trend till 1970s, while the NH warming of the last 30 years is not noticeable in the eastern Mediterranean till 1990s. National Observatory of Athens (NOA) meteorological time series start from the last decades of the 19th Century, therefore are at first suitable for detection of long term trends in the region. In this study we investigate whether the abrupt increase of the NOA air temperature time series, which appears during the last few years, is the finger-print of the broader scale climatic change or it is a discontinuity in the record of urban effect or of station’s problems origin. It is shown that NOA air temperature records display a statistically significant discontinuity attributable to change of the station thermometers on 1995 and therefore NOA records must be treated with caution for long term air temperature trends detection.

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Classification and Long-term Trends of Seasons in Tokyo Determined from Air Temperature

JOURNAL OF JAPAN SOCIETY OF HYDROLOGY AND WATER RESOURCES ◽

10.3178/jjshwr.32.182 ◽

2019 ◽

Vol 32 (4) ◽

pp. 182-188

Author(s):

Hideyuki IWAMOTO ◽

Taikan OKI

Keyword(s):

Air Temperature ◽

Long Term Trends

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Opposite trends of sea-breeze speeds and gusts in Eastern Iberian Peninsula, 1961-2019

10.5194/egusphere-egu21-3411 ◽

2021 ◽

Author(s):

Shalenys Bedoya-Valestt ◽

Cesar Azorin-Molina ◽

José A. Guijarro ◽

Victor J. Sanchez-Morcillo

Keyword(s):

Wind Speed ◽

Iberian Peninsula ◽

Atmospheric Circulation ◽

Air Temperature ◽

Large Scale ◽

Sea Breeze ◽

Sea Breezes ◽

Long Term Trends ◽

Large Scale Atmospheric Circulation

<p>Long-term trends of local winds such as sea breezes have been less addressed in climate research, despite their impacts on broad environmental and socioeconomic spheres, such as weather and climate, agriculture and hydrology, wind-power industry, air quality or even human health, among many others. In a warming climate, sea breezes could be affected by changes on air temperature, as these onshore winds are thermally-driven by gradients between the sea-land air, but also by ocean-atmosphere oscillations or changes in large-scale atmospheric circulation. In the last few decades, advances in wind trends studies evidenced a recovery in global wind stilling during the last 10 years, and differences in the sign-magnitude of wind speed trends were found at seasonal-scale, suggesting the hypothetic effect of the reinforcement of local wind circulations in the warm seasons.</p><p>In this study, we analyze for the first time the long-term trends, multidecadal variability and possible drivers of the sea-breeze speeds and gusts in Eastern Iberian Peninsula during the last 58 years (1961-2019), using homogenized wind speed and gusts data from 16 meteorological stations. To identify potential sea breeze episodes, we developed a robust automated method based on alternative criteria. Our results suggest a decoupling between the declining sea-breeze speeds and the strengthening of the maximum gusts for much of the 1961-2019 period at annual, seasonal and monthly scales, but differences based on locations were also found. Because sea breeze changes can be driven by multiple complex factors (i.e. land use changes, land-sea air temperature gradient, complex orography, etc.), the attribution of causes is challenging. To better understand the causes behind the opposite trends between sea-breeze speeds and gusts, we investigate the effect of e.g. the changes in large-scale atmospheric circulation or physical-local factors.</p>

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Long-term trends in fog occurrence in the Czech Republic, Central Europe

The Science of The Total Environment ◽

10.1016/j.scitotenv.2019.135018 ◽

2020 ◽

Vol 711 ◽

pp. 135018 ◽

Cited By ~ 3

Author(s):

Iva Hůnová ◽

Marek Brabec ◽

Marek Malý ◽

Anna Valeriánová

Keyword(s):

Czech Republic ◽

Central Europe ◽

The Czech Republic ◽

Long Term Trends

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Construction of a surface air temperature series for Qingdao in China for the period 1899 to 2014

Earth System Science Data ◽

10.5194/essd-10-643-2018 ◽

2018 ◽

Vol 10 (1) ◽

pp. 643-652

Author(s):

Yan Li ◽

Birger Tinz ◽

Hans von Storch ◽

Qingyuan Wang ◽

Qingliang Zhou ◽

...

Keyword(s):

Time Series ◽

Air Temperature ◽

Surface Air Temperature ◽

Warming Trend ◽

Observation Data ◽

China Meteorological Administration ◽

Ascii Format ◽

Long Term Trends ◽

The City

Abstract. We present a homogenized surface air temperature (SAT) time series at 2 m height for the city of Qingdao in China from 1899 to 2014. This series is derived from three data sources: newly digitized and homogenized observations of the German National Meteorological Service from 1899 to 1913, homogenized observation data of the China Meteorological Administration (CMA) from 1961 to 2014 and a gridded dataset of Willmott and Matsuura (2012) in Delaware to fill the gap from 1914 to 1960. Based on this new series, long-term trends are described. The SAT in Qingdao has a significant warming trend of 0.11 ± 0.03 ∘C decade−1 during 1899–2014. The coldest period occurred during 1909–1918 and the warmest period occurred during 1999–2008. For the seasonal mean SAT, the most significant warming can be found in spring, followed by winter. The homogenized time series of Qingdao is provided and archived by the Deutscher Wetterdienst (DWD) web page under overseas stations of the Deutsche Seewarte (http://www.dwd.de/EN/ourservices/overseas_stations/ueberseedoku/doi_qingdao.html) in ASCII format. Users can also freely obtain a short description of the data at https://doi.org/https://dx.doi.org/10.5676/DWD/Qing_v1. And the data can be downloaded at http://dwd.de/EN/ourservices/overseas_stations/ueberseedoku/data_qingdao.txt.

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