scholarly journals The Research of Scottish Herring and Mackerel’s Movement Simulation

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Yifan Zhang
Keyword(s):  
Global Warming ◽  
Random Walk ◽  
Marine Species ◽  
Data Sets ◽  
Ocean Temperature ◽  
Interpolation Algorithm ◽  
Movement Simulation ◽  
Species Movement

Global warming has a great effect to marine species. In this paper, the author aims to construct mathematical to simulate the movement of two species, Herring and Mackerel. In order to describe its randomness and the background of global warming, the author improves Random Walk to weighted Random Walk as the model to describe the species movement, and the weight is affected by ocean temperature. Furthermore, to make the results more persuasive, the author uses interpolation algorithm to expand the data sets. After that, the author uses the model and data to simulate the trace of two species in 50 years. The trace is during the next 50 years, Mackerel will move 22.36 kilometers while Scottish Herring will move 29.15 kilometers, which shows that the two species will move a distance that cannot be ignored. Finally, based on above results, the author gets some conclusions and gives some advice to help fisheries companies to deal with it.

scholarly journals Predicting the global warming potential of agro-ecosystems

2007 ◽  
Vol 4 (2) ◽  
pp. 1059-1092 ◽  
Author(s):  
S. Lehuger ◽  
B. Gabrielle ◽  
E. Larmanou ◽  
P. Laville ◽  
P. Cellier ◽  
...  
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Cropping Systems ◽  
C Sequestration ◽  
N2o Emissions ◽  
Data Sets ◽  
Management Scenarios ◽  
Global Warming Impact ◽  
Sequestration Potential ◽  
The Impact

Abstract. Nitrous oxide, carbon dioxide and methane are the main biogenic greenhouse gases (GHG) contributing to the global warming potential (GWP) of agro-ecosystems. Evaluating the impact of agriculture on climate thus requires a capacity to predict the net exchanges of these gases in an integrated manner, as related to environmental conditions and crop management. Here, we used two year-round data sets from two intensively-monitored cropping systems in northern France to test the ability of the biophysical crop model CERES-EGC to simulate GHG exchanges at the plot-scale. The experiments involved maize and rapeseed crops on a loam and rendzina soils, respectively. The model was subsequently extrapolated to predict CO2 and N2O fluxes over an entire crop rotation. Indirect emissions (IE) arising from the production of agricultural inputs and from cropping operations were also added to the final GWP. One experimental site (involving a wheat-maize-barley rotation on a loamy soil) was a net source of GHG with a GWP of 350 kg CO2-C eq ha−1 yr−1, of which 75% were due to IE and 25% to direct N2O emissions. The other site (involving an oilseed rape-wheat-barley rotation on a rendzina) was a net sink of GHG for –250 kg CO2-C eq ha−1 yr−1, mainly due to a higher predicted C sequestration potential and C return from crops. Such modelling approach makes it possible to test various agronomic management scenarios, in order to design productive agro-ecosystems with low global warming impact.

Aggressions of the Socio-Economic System on the Natural Capital

2017 ◽  
pp. 109-140
Author(s):  
Constanţa Popescu ◽  
Constantin Popescu ◽  
Maria Luiza Hrestic
Keyword(s):  
Global Warming ◽  
Adverse Effects ◽  
Economic System ◽  
Acid Rain ◽  
Natural Environment ◽  
Natural Capital ◽  
Marine Species ◽  
Vertebrate Species ◽  
New Beginning ◽  
Almost All

Nearly 250 million years ago, the Earth was shaken by the amplest extinction known so far, which led to the extinction of up to 96% of all the marine species, 70% of the vertebrate species, and almost all the insects. This extinction affected the whole range of biodiversity so much. Nature took almost 10 million years to recover after this event. Life was really in danger on our planet at that moment, due to the dismal conditions that were created, and the current research shows that these dire conditions continued to occur, in the natural environment, after that, triggering numerous outbreaks that occurred for five to six million years following the initial crisis, triggered by the carbon rise and the repeated shortages of oxygen, the increased warming and other such adverse effects, which, once initiated, were uncontrollable and had disastrous effects. When life returned to normal and, gradually, after several million years, a new beginning was possible, the significant elements that caused the disaster - global warming, acid rain - sound strangely familiar to us today.

scholarly journals Evidence for an earlier greenhouse cooling effect in the stratosphere before 1980 over the Northern Hemisphere

2014 ◽  
Vol 14 (15) ◽  
pp. 7705-7720 ◽  
Author(s):  
C. S. Zerefos ◽  
K. Tourpali ◽  
P. Zanis ◽  
K. Eleftheratos ◽  
C. Repapis ◽  
...  
Keyword(s):  
Global Warming ◽  
Northern Hemisphere ◽  
Geopotential Height ◽  
Lower Stratosphere ◽  
Lower Troposphere ◽  
Radiosonde Data ◽  
Data Sets ◽  
Radiative Processes ◽  
Before And After

Abstract. This study provides a new look at the observed and calculated long-term temperature changes from the lower troposphere to the lower stratosphere since 1958 over the Northern Hemisphere. The data sets include the NCEP/NCAR reanalysis, the Free University of Berlin (FU-Berlin) and the RICH radiosonde data sets as well as historical simulations with the CESM1-WACCM global model participating in CMIP5. The analysis is mainly based on monthly layer mean temperatures derived from geopotential height thicknesses in order to take advantage of the use of the independent FU-Berlin stratospheric data set of geopotential height data since 1957. This approach was followed to extend the records for the investigation of the stratospheric temperature trends to the earliest possible time. After removing the natural variability with an autoregressive multiple regression model our analysis shows that the period 1958–2011 can be divided into two distinct sub-periods of long-term temperature variability and trends: before and after 1980. By calculating trends for the summer time to reduce interannual variability, the two periods are as follows. From 1958 until 1979, a non-significant trend (0.06 ± 0.06 °C decade−1 for NCEP) and slightly cooling trends (−0.12 ± 0.06 °C decade−1 for RICH) are found in the lower troposphere. The second period from 1980 to the end of the records shows significant warming (0.25 ± 0.05 °C decade−1 for both NCEP and RICH). Above the tropopause a significant cooling trend is clearly seen in the lower stratosphere both in the pre-1980 period (−0.58 ± 0.17 °C decade−1 for NCEP, −0.30 ± 0.16 °C decade−1 for RICH and −0.48 ± 0.20 °C decade−1 for FU-Berlin) and the post-1980 period (−0.79 ± 0.18 °C decade−1 for NCEP, −0.66 ± 0.16 °C decade−1 for RICH and −0.82 ± 0.19 °C decade−1 for FU-Berlin). The cooling in the lower stratosphere persists throughout the year from the tropics up to 60° N. At polar latitudes competing dynamical and radiative processes reduce the statistical significance of these trends. Model results are in line with reanalysis and the observations, indicating a persistent cooling (−0.33 °C decade−1) in the lower stratosphere during summer before and after 1980; a feature that is also seen throughout the year. However, the lower stratosphere CESM1-WACCM modelled trends are generally lower than reanalysis and the observations. The contrasting effects of ozone depletion at polar latitudes in winter/spring and the anticipated strengthening of the Brewer–Dobson circulation from man-made global warming at polar latitudes are discussed. Our results provide additional evidence for an early greenhouse cooling signal in the lower stratosphere before 1980, which appears well in advance relative to the tropospheric greenhouse warming signal. The suitability of early warning signals in the stratosphere relative to the troposphere is supported by the fact that the stratosphere is less sensitive to changes due to cloudiness, humidity and man-made aerosols. Our analysis also indicates that the relative contribution of the lower stratosphere versus the upper troposphere low-frequency variability is important for understanding the added value of the long-term tropopause variability related to human-induced global warming.

scholarly journals Comparison of ocean datasets by their ability to adequately reproduce winter anomalies in the characteristics of the upper layer ot the north–eastern part of the North Atlantic

2021 ◽  
pp. 137-146
Author(s):  
A.B. Polonsky ◽  
◽  
P.A. Sukhonos ◽  
Keyword(s):  
North Atlantic ◽  
Temperature Anomaly ◽  
Negative Temperature ◽  
Weather Conditions ◽  
Winter Period ◽  
Data Sets ◽  
Ocean Temperature ◽  
The North ◽  
North Eastern ◽  
Upper Mixed Layer

This article analyzes the reproducibility of the reemergence of temperature and upper mixed layer (UML) depth anomalies in the northeastern North Atlantic during severe weather conditions observed in the Atlantic-European region in the winter of 2009/2010 and 2010/2011. The data of re-analyzes ORA-S3, GFDL, GODAS, GLORYS2v4 and objective analyzes Ishii, EN4.1.1 are used. It is confirmed that the formation of the negative temperature anomaly in UML in winter 2010/2011 is largely due to the reemergence of the ocean temperature anomaly that occurred in the winter of 2009/2010. Interannual UML depth anomalies in the northeastern North Atlantic from the ORA-S3 and GODAS reanalysis datasets from March 2009 to November 2011 are in satisfactory agreement. The best description of the evolution of temperature anomalies in the 10–550 m layer in 2010, in accordance with the hypothesis of the reemergence of the ocean temperature anomaly, was obtained for the UML depth from the indicated data sets. An assessment of the statistical features of the case of the reemergence of anomalies in the UML characteristics at a significant level showed the occurrence of the UML depth anomaly in the winter of 2010/2011, formed in the last autumn-winter period. Moreover, such specific conditions could not have formed in the early 2000s.

scholarly journals Analysis of the Spatial Differences in Canopy Height Models from UAV LiDAR and Photogrammetry

2020 ◽  
Vol 12 (18) ◽  
pp. 2884
Author(s):  
Qingwang Liu ◽  
Liyong Fu ◽  
Qiao Chen ◽  
Guangxing Wang ◽  
Peng Luo ◽  
...  
Keyword(s):  
Point Cloud ◽  
Forest Canopy ◽  
Point Clouds ◽  
Canopy Height ◽  
Central China ◽  
Data Sets ◽  
Interpolation Algorithm ◽  
Data Set ◽  
Spatial Differences ◽  
Mean Square Errors

Forest canopy height is one of the most important spatial characteristics for forest resource inventories and forest ecosystem modeling. Light detection and ranging (LiDAR) can be used to accurately detect canopy surface and terrain information from the backscattering signals of laser pulses, while photogrammetry tends to accurately depict the canopy surface envelope. The spatial differences between the canopy surfaces estimated by LiDAR and photogrammetry have not been investigated in depth. Thus, this study aims to assess LiDAR and photogrammetry point clouds and analyze the spatial differences in canopy heights. The study site is located in the Jigongshan National Nature Reserve of Henan Province, Central China. Six data sets, including one LiDAR data set and five photogrammetry data sets captured from an unmanned aerial vehicle (UAV), were used to estimate the forest canopy heights. Three spatial distribution descriptors, namely, the effective cell ratio (ECR), point cloud homogeneity (PCH) and point cloud redundancy (PCR), were developed to assess the LiDAR and photogrammetry point clouds in the grid. The ordinary neighbor (ON) and constrained neighbor (CN) interpolation algorithms were used to fill void cells in digital surface models (DSMs) and canopy height models (CHMs). The CN algorithm could be used to distinguish small and large holes in the CHMs. The optimal spatial resolution was analyzed according to the ECR changes of DSMs or CHMs resulting from the CN algorithms. Large negative and positive variations were observed between the LiDAR and photogrammetry canopy heights. The stratified mean difference in canopy heights increased gradually from negative to positive when the canopy heights were greater than 3 m, which means that photogrammetry tends to overestimate low canopy heights and underestimate high canopy heights. The CN interpolation algorithm achieved smaller relative root mean square errors than the ON interpolation algorithm. This article provides an operational method for the spatial assessment of point clouds and suggests that the variations between LiDAR and photogrammetry CHMs should be considered when modeling forest parameters.

Aggressions of the Socio-Economic System on the Natural Capital

2020 ◽  
pp. 108-131
Author(s):  
Constanţa Popescu ◽  
Constantin Popescu ◽  
Maria Luiza Hrestic
Keyword(s):  
Global Warming ◽  
Adverse Effects ◽  
Economic System ◽  
Acid Rain ◽  
Natural Environment ◽  
Natural Capital ◽  
Marine Species ◽  
Vertebrate Species ◽  
New Beginning ◽  
Almost All

Nearly 250 million years ago, the Earth was shaken by the amplest extinction known so far, which led to the extinction of up to 96% of all the marine species, 70% of the vertebrate species, and almost all the insects. This extinction affected the whole range of biodiversity so much. Nature took almost 10 million years to recover after this event. Life was really in danger on our planet at that moment, due to the dismal conditions that were created, and the current research shows that these dire conditions continued to occur, in the natural environment, after that, triggering numerous outbreaks that occurred for five to six million years following the initial crisis, triggered by the carbon rise and the repeated shortages of oxygen, the increased warming and other such adverse effects, which, once initiated, were uncontrollable and had disastrous effects. When life returned to normal and, gradually, after several million years, a new beginning was possible, the significant elements that caused the disaster - global warming, acid rain - sound strangely familiar to us today.

Long-Term Trends of Extra-Tropical Cyclones in the Extended ERA5 Reanalysis

2021 ◽  
Author(s):  
Alexia Karwat ◽  
Christian L. E. Franzke ◽  
Richard Blender
Keyword(s):  
Global Warming ◽  
Tropical Cyclones ◽  
Storm Track ◽  
Propagation Speed ◽  
Life Cycles ◽  
Natural Variability ◽  
Change Point Analysis ◽  
Systematic Change ◽  
Data Sets

<p>Long-term reanalysis data sets are needed to determine the natural variability of extra-tropical cyclone tracks and for the assessment of the response to global warming. Using a systematic change-point analysis we provide evidence that the pre-satellite ERA5 data of the Backward Extension (ERA5-BE, covering 1950-1978) is highly compatible with the standard ERA5 (1979-2021) data sets. We observe that the joint ERA5 data from 1950 to 2021 is consistent in all storm-related quantities, allowing long-term studies. Despite the high inter-annual variability, a trend analysis suggests that the intensity of extra-tropical cyclones has increased significantly in the Northern Hemisphere from 1950 to 2021. The propagation speed of extra-tropical cyclones has notably decreased and the North Atlantic cyclone track, in particular, has shifted northward. Furthermore, the number of North Pacific storms increased significantly; these storms exhibit longer life cycles and travel larger distances, while they also grow more slowly. From 1979 to 2021 we find increases in wind gusts and cyclone-related precipitation. The central geopotential height, a measure for storminess, has decreased in both storm track areas. The observed changes originating from potential changes in the atmospheric circulation are the result of natural variability and anthropogenic global warming. Future storm adaptation planning should consider the observed increase in storm-related impacts.</p>

scholarly journals Depth-mediated reversal of the effects of climate change on long-term growth rates of exploited marine fish

2007 ◽  
Vol 104 (18) ◽  
pp. 7461-7465 ◽  
Author(s):  
Ronald E. Thresher ◽  
J. A. Koslow ◽  
A. K. Morison ◽  
D. C. Smith
Keyword(s):  
Climate Change ◽  
Deep Water ◽  
Growth Rates ◽  
Global Climate ◽  
Marine Species ◽  
Data Sets ◽  
Otolith Analysis ◽  
Deep Water Species ◽  
Biological Impacts

The oceanographic consequences of climate change are increasingly well documented, but the biological impacts of this change on marine species much less so, in large part because of few long-term data sets. Using otolith analysis, we reconstructed historical changes in annual growth rates for the juveniles of eight long-lived fish species in the southwest Pacific, from as early as 1861. Six of the eight species show significant changes in growth rates during the last century, with the pattern differing systematically with depth. Increasing temperatures near the ocean surface correlate with increasing growth rates by species found in depths <250 m, whereas growth rates of deep-water (>1,000 m) species have declined substantially during the last century, which correlates with evidence of long-term cooling at these depths. The observations suggest that global climate change has enhanced some elements of productivity of the shallow-water stocks but also has reduced the productivity, and possibly the resilience, of the already slow-growing deep-water species.

Sign in / Sign up

Export Citation Format

Share Document