scholarly journals Nitrogen Deposition on Danish Nature

Atmosphere ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 447 ◽  
Author(s):  
Thomas Ellermann ◽  
Jesper Nygaard ◽  
Jesper Christensen ◽  
Per Løfstrøm ◽  
Camilla Geels ◽  
...  
Keyword(s):  
Nitrogen Deposition ◽  
Critical Loads ◽  
Temporal Trends ◽  
Monitoring Program ◽  
Terrestrial Ecosystems ◽  
Marine Waters ◽  
Model Calculations ◽  
Nitrogen Loads ◽  
Long Term Trends

Eutrophication events are frequent in Inner Danish waters and critical loads are exceeded for much of the Danish sensitive terrestrial ecosystems. The Danish air quality monitoring program combines measurements and model calculations to benefit from the complementarities in data from these two sources. Measurements describe actual status, seasonal variation, and temporal trends. Model calculations extrapolate the results to the entire country and determine depositions to specific ecosystems. Measurements in 2016 show annual depositions between 7.5 and 11 kg N/ha to terrestrial ecosystems, and a load to marine waters of 5.3 kg N/ha. The deposition on Danish marine waters in 2016 was calculated to be 73,000 tons N with an average deposition of 6.9 kg N/ha. For terrestrial areas, the deposition was calculated to be 57,000 tons N with an average deposition of 13 kg N/ha. This is above critical loads for sensitive ecosystems. Long-term trends show a 35% decrease since 1990 in measured annual nitrogen deposition. At two out of four stations in nature areas, measured ammonia levels exceeded critical levels for lichens and mosses. Conclusions: Nitrogen loads and levels to Danish nature is decreasing, but critical loads and levels are still exceeded for sensitive ecosystems. Combining measurements and model calculations is a strong tool in monitoring.

scholarly journals Long-Term Trends in PBDEs in Sparrowhawk (Accipiter nisus) Eggs Indicate Sustained Contamination of UK Terrestrial Ecosystems

2012 ◽  
Vol 46 (24) ◽  
pp. 13504-13511 ◽  
Author(s):  
John D. Crosse ◽  
Richard F. Shore ◽  
Richard A. Wadsworth ◽  
Kevin C. Jones ◽  
M. Glória Pereira
Keyword(s):  
Terrestrial Ecosystems ◽  
Accipiter Nisus ◽  
Long Term Trends

scholarly journals Investigations of long-term trends in the ionosphere with world-wide ionosonde observations*

2005 ◽  
Vol 2 ◽  
pp. 253-258 ◽  
Author(s):  
J. Bremer
Keyword(s):  
Data Series ◽  
Model Calculations ◽  
Maximum Electron Density ◽  
Model Predictions ◽  
Density Values ◽  
Long Term Trends ◽  
Experimental Values ◽  
The Individual ◽  
Global Mean

Abstract. Basing on model calculations by Roble and Dickinson (1989) for an increasing content of atmospheric greenhouse gases in the Earth’s atmosphere Rishbeth (1990) predicted a lowering of the ionospheric F2- and E-regions. Later Rishbeth and Roble (1992) also predicted characteristic longterm changes of the maximum electron density values of the ionospheric E-, F1-, and F2-layers. Long-term observations at more than 100 ionosonde stations have been analyzed to test these model predictions. In the E- and F1-layers the derived experimental results agree reasonably with the model trends (lowering of h'E and increase of ƒoE and ƒoF1, in the E-layer the experimental values are however markedly stronger than the model data). In the ionospheric F2-region the variability of the trends derived at the different individual stations for hmF2 as well as ƒoF2 values is too large to estimate reasonable global mean trends. The reason of the large differences between the individual trends is not quite clear. Strong dynamical effects may play an important role in the F2-region. But also inhomogeneous data series due to technical changes as well as changes in the evaluation algorithms used during the long observation periods may influence the trend analyses.

scholarly journals Long Term Trends in Sulphur and Nitrogen Deposition in Europe and the Cause of Non-linearities

2007 ◽  
Vol 7 (1-3) ◽  
pp. 41-47 ◽  
Author(s):  
David Fowler ◽  
Rognvald Smith ◽  
Jennifer Muller ◽  
John Neil Cape ◽  
Mark Sutton ◽  
...  
Keyword(s):  
Nitrogen Deposition ◽  
Long Term Trends

scholarly journals Chemical footprints of anthropogenic nitrogen deposition on recent soil C : N ratios in Europe

2015 ◽  
Vol 12 (5) ◽  
pp. 4315-4330 ◽  
Author(s):  
C. Mulder ◽  
J.-P. Hettelingh ◽  
L. Montanarella ◽  
M. R. Pasimeni ◽  
M. Posch ◽  
...  
Keyword(s):  
Land Use ◽  
Atmospheric Deposition ◽  
Nitrogen Deposition ◽  
Industrial Revolution ◽  
Terrestrial Ecosystems ◽  
Soil C ◽  
Human Interactions ◽  
Anthropogenic Nitrogen ◽  
Anthropogenic Nitrogen Deposition

Abstract. Long-term human interactions with landscape and nature produced a plethora of trends and patterns of environmental disturbances in time and space. Nitrogen deposition, closely tracking energy and land use, is known to be among the main pollution drivers, affecting both freshwater as terrestrial ecosystems. We investigated the geographical distribution of nitrogen deposition and the impacts of accumulation on recent soil carbon to nitrogen ratios over Europe. After the Second Industrial Revolution (1880–2010), large landscape stretches characterized by different atmospheric deposition caused either by industrialized areas or by intensive agriculture emerged. Nitrogen deposition affects in a still recognizable way recent soil C : N ratios despite the emission abatement of oxidized and reduced nitrogen during the last two decades. Given the seemingly disparate land-use history, we focused on ~ 10 000 unmanaged ecosystems, providing evidence for a rapid response of nature to chronic nitrogen supply by atmospheric deposition.

scholarly journals Long-term trends in pH in Japanese coastal waters

2019 ◽  
Author(s):  
Miho Ishizu ◽  
Yasumasa Miyazawa ◽  
Tomohiko Tsunoda ◽  
Tsuneo Ono
Keyword(s):  
Coastal Waters ◽  
Temporal Trends ◽  
Control Program ◽  
Quality Data ◽  
Anthropogenic Factors ◽  
Water Quality Data ◽  
Anthropogenic Carbon ◽  
Long Term Trends ◽  
Term Data

Abstract. In recent decades, acidification of the open ocean has shown consistent increases. However, analysis of long-term data in coastal waters shows that the pH is highly variable because of coastal processes and anthropogenic carbon inputs. It is therefore important to understand how anthropogenic carbon inputs and other natural or anthropogenic factors influence the temporal trends in pH in coastal waters. Using water quality data collected at 1481 monitoring sites as part of the Water Pollution Control Program, we determined the long-term trends in pH in Japanese coastal waters at ambient temperature from 1978 to 2009. We found that pH decreased (i.e., acidification) at between 70 % and 75 % of the sites and increased (i.e., basification) at between 25 % and 30 % of the sites. The rate of decrease varied seasonally and was, on average, −0.0014 yr−1 in summer and −0.0024 yr−1 in winter, but with relatively large deviations from these average values. While the overall trends reflect acidification, watershed processes might also have contributed to the large variations in pH in coastal waters. The seasonal variation in the average pH trends reflects variability in warming trends, while regional differences in pH trends are partly related to heterotrophic water processes induced by nutrient loadings.

scholarly journals Shift of subtropical transport barriers explains observed hemispheric asymmetry of decadal trends of age of air

2017 ◽  
Author(s):  
Gabriele P. Stiller ◽  
Federico Fierli ◽  
Felix Ploeger ◽  
Chiara Cagnazzo ◽  
Bernd Funke ◽  
...  
Keyword(s):  
Circulation Pattern ◽  
Transport Time ◽  
Model Calculations ◽  
Model Predictions ◽  
Southward Shift ◽  
Transport Barriers ◽  
Long Term Trends ◽  
The Mean ◽  
Middle Stratosphere

Abstract. In response to global warming the Brewer–Dobson circulation in the stratosphere is expected to accelerate and the mean transport time of air along this circulation to decrease. This would imply a negative stratospheric age of air trend, i.e. an air parcel would need less time to travel from the tropopause to any point in the stratosphere. Age of air as inferred from tracer observations, however, shows zero to positive trends in the Northern midlatitude stratosphere and zonally asymmetric patterns. Using satellite 5 observations and model calculations we show that the observed latitudinal and vertical patterns of the decadal changes of age of air in the lower to middle stratosphere during 2002–2012 are predominantly caused by a southward shift of the circulation pattern of about 5 degrees. After correction for this shift, the observations reveal a hemispherically almost symmetric decrease of age of air in the lower to middle stratosphere up to 800 K of up to −0.25 years over the 2002–2012 period with strongest decrease in the Northern tropics. This net change is consistent with long-term trends from model predictions.

scholarly journals Long-term variations of the mesospheric wind field at mid-latitudes

2007 ◽  
Vol 25 (8) ◽  
pp. 1779-1790 ◽  
Author(s):  
D. Keuer ◽  
P. Hoffmann ◽  
W. Singer ◽  
J. Bremer
Keyword(s):  
Solar Activity ◽  
Wind Field ◽  
Meridional Wind ◽  
Time Interval ◽  
Wind Component ◽  
Model Calculations ◽  
Measuring Techniques ◽  
Long Term Trends ◽  
Solar Influence

Abstract. Continuous MF radar observations at the station Juliusruh (54.6° N; 13.4° E) have been analysed for the time interval between 1990 and 2005, to obtain information about solar activity-induced variations, as well as long-term trends in the mesospheric wind field. Using monthly median values of the zonal and the meridional prevailing wind components, as well as of the amplitude of the semidiurnal tide, regression analyses have been carried out with a dependence on solar activity and time. The solar activity causes a significant amplification of the zonal winds during summer (increasing easterly winds) and winter (increasing westerly winds). The meridional wind component is positively correlated with the solar activity during summer but during winter the correlation is very small and non significant. Also, the solar influence upon the amplitude of the semidiurnal tidal component is relatively small (in dependence on height partly positive and partly negative) and mostly non-significant. The derived trends in the zonal wind component during summer are below an altitude of about 83 km negative and above this height positive. During the winter months the trends are nearly opposite compared with the trends in summer (transition height near 86 km). The trends in the meridional wind components are below about 85 km positive in summer (significant) and near zero (nonsignificant) in winter; above this height during both seasons negative trends have been detected. The trends in the semidiurnal tidal amplitude are at all heights positive, but only partly significant. The detected trends and solar cycle dependencies are compared with other experimental results and model calculations. There is no full agreement between the different results, probably caused by different measuring techniques and evaluation methods used. Also, different heights and observation periods investigated may contribute to the detected differences.

scholarly journals Shift of subtropical transport barriers explains observed hemispheric asymmetry of decadal trends of age of air

2017 ◽  
Vol 17 (18) ◽  
pp. 11177-11192 ◽  
Author(s):  
Gabriele P. Stiller ◽  
Federico Fierli ◽  
Felix Ploeger ◽  
Chiara Cagnazzo ◽  
Bernd Funke ◽  
...  
Keyword(s):  
Circulation Pattern ◽  
Transport Time ◽  
Model Calculations ◽  
Model Predictions ◽  
Southward Shift ◽  
Transport Barriers ◽  
Long Term Trends ◽  
The Mean ◽  
Middle Stratosphere

Abstract. In response to global warming, the Brewer–Dobson circulation in the stratosphere is expected to accelerate and the mean transport time of air along this circulation to decrease. This would imply a negative stratospheric age of air trend, i.e. an air parcel would need less time to travel from the tropopause to any point in the stratosphere. Age of air as inferred from tracer observations, however, shows zero to positive trends in the northern mid-latitude stratosphere and zonally asymmetric patterns. Using satellite observations and model calculations we show that the observed latitudinal and vertical patterns of the decadal changes of age of air in the lower to middle stratosphere during the period 2002–2012 are predominantly caused by a southward shift of the circulation pattern by about 5°. After correction for this shift, the observations reveal a hemispherically almost symmetric decrease of age of air in the lower to middle stratosphere up to 800 K of up to −0.25 years over the 2002–2012 period with strongest decrease in the northern tropics. This net change is consistent with long-term trends from model predictions.

Hohokam to Akimel O’Odham: Obsidian Acquisition at the Historic Period Sacate Site (GR-909), Gila River Indian Community, Arizona

2013 ◽  
Vol 78 (2) ◽  
pp. 266-284 ◽  
Author(s):  
Chris R. Loendorf ◽  
Craig M. Fertelmes ◽  
Barnaby V. Lewis
Keyword(s):  
Temporal Trends ◽  
Cultural Patterns ◽  
Historic Period ◽  
South Central ◽  
Phoenix Basin ◽  
Long Term Trends ◽  
Akimel O'odham ◽  
The Relationship ◽  
The Phoenix

AbstractObsidian provenance studies within the Phoenix Basin of south-central Arizona have become increasingly comprehensive during the last four decades. As a result, broad regional and temporal trends have been defined regarding Preclassic (ca. A.D. 650–1150) and Classic period (ca.A.D. 1150–1450) socioeconomic interactions in the Hohokam core area. However, Historic period patterns are still poorly understood, and these data are essential for understanding the relationship between the prehistoric Hohokam and historical Akimel O’Odham. The association between the Akimel O’Odham and Hohokam has been debated since Euro-Americans first visited the area in the late 1600s, yet this issue is still not fully resolved. This article presents analyses of historical obsidian from the Sacate site that suggest that long-term trends in cultural patterns within the Phoenix Basin continued unbroken into the Historic period. These continuities provide another line of evidence that the Akimel O’Odham are the direct cultural descendants of the Hohokam.

scholarly journals Chemical footprints of anthropogenic nitrogen deposition on recent soil C : N ratios in Europe

2015 ◽  
Vol 12 (13) ◽  
pp. 4113-4119 ◽  
Author(s):  
C. Mulder ◽  
J.-P. Hettelingh ◽  
L. Montanarella ◽  
M. R. Pasimeni ◽  
M. Posch ◽  
...  
Keyword(s):  
Land Use ◽  
Atmospheric Deposition ◽  
Nitrogen Deposition ◽  
Industrial Revolution ◽  
Terrestrial Ecosystems ◽  
Nitrogen Emissions ◽  
Soil C ◽  
Human Interactions ◽  
Anthropogenic Nitrogen

Abstract. Long-term human interactions with the natural landscape have produced a plethora of trends and patterns of environmental disturbances across time and space. Nitrogen deposition, closely tracking energy and land use, is known to be among the main drivers of pollution, affecting both freshwater and terrestrial ecosystems. We present a statistical approach for investigating the historical and geographical distribution of nitrogen deposition and the impacts of accumulation on recent soil carbon-to-nitrogen ratios in Europe. After the second Industrial Revolution, large swaths of land emerged characterized by different atmospheric deposition patterns caused by industrial activities or intensive agriculture. Nitrogen deposition affects soil C : N ratios in a still recognizable way despite the abatement of oxidized and reduced nitrogen emissions during the last 2 decades. Given a seemingly disparate land-use history, we focused on ~ 10 000 unmanaged ecosystems, providing statistical evidence for a rapid response of nature to the chronic nitrogen supply through atmospheric deposition.

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