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>

Evaluating the ecological effects of Mediterranean marine protected areas: habitat, scale and the natural variability of ecosystems

2000 ◽  
Vol 27 (2) ◽  
pp. 159-178 ◽  
Author(s):  
J.A. GARCÍA CHARTON ◽  
I.D. WILLIAMS ◽  
A. PÉREZ RUZAFA ◽  
M. MILAZZO ◽  
R. CHEMELLO ◽  
...  
Keyword(s):  
Protected Areas ◽  
Marine Protected Areas ◽  
Multiple Scales ◽  
Natural Variability ◽  
Data Sets ◽  
Nested Designs ◽  
Spatio Temporal ◽  
Habitat Scale ◽  
Physical Elements

The capability to detect and predict the responses of marine populations and communities to the establishment of marine protected areas (MPAs) depends on the ability to distinguish between the influences of management and natural variability due to the effects of factors other than protection. Thus, it is important to understand and quantify the magnitude and range of this natural variability at each scale of observation. Here we review the scale of responses of target populations and communities to protection within Mediterranean MPAs, against their ‘normal’ spatio-temporal heterogeneity, and compare those with documented cases from other temperate and tropical marine ecosystems. Additionally, we approach the problem of the relative importance of habitat structure, considered as a set of biological and physical elements of the seascape hierarchically arranged in space at multiple scales, to drive natural variability. We conclude that much more effort has to be made to characterize heterogeneity in relation to Mediterranean MPAs, and to quantify and explain relationships between target species and their habitats as sources of such variability. These studies should be based on sound sampling designs, which (1) generate long-term data sets, and would ideally (2) be based on a Mediterranean-wide comparison of a number of protected and unprotected localities, (3) be designed from a multi-scaled perspective, and (4) control for factors other than protection, in order to avoid their confounding effects. The need for appropriate spatial and temporal replication, nested designs and power analysis is advocated.

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 A Phase Locking Perspective on Rossby Wave Amplification and Atmospheric Blocking Downstream of Recurving Western North Pacific Tropical Cyclones

2019 ◽  
Vol 147 (2) ◽  
pp. 567-589 ◽  
Author(s):  
Jacopo Riboldi ◽  
Christian M. Grams ◽  
Michael Riemer ◽  
Heather M. Archambault
Keyword(s):  
Tropical Cyclones ◽  
Rossby Wave ◽  
North Pacific ◽  
Western North Pacific ◽  
Phase Locking ◽  
Storm Track ◽  
Propagation Speed ◽  
Atmospheric Blocking ◽  
Wave Amplification ◽  
Upper Level

Abstract The extratropical transition (ET) of tropical cyclones (TCs) can significantly influence the evolution of the midlatitude flow. However, the interaction between recurving TCs and upstream upper-level troughs features a large and partly unexplained case-to-case variability. In this study, a synoptic, feature-based climatology of TC–trough interactions is constructed to discriminate recurving TCs that interact with decelerating and accelerating troughs. Upper-level troughs reducing their eastward propagation speed during the interaction with recurving TCs exhibit phase locking with lower-level temperature anomalies and are linked to pronounced downstream Rossby wave amplification. Conversely, accelerating troughs do not exhibit phase locking and are associated with a nonsignificant downstream impact. Irrotational outflow near the tropopause associated with latent heat release in regions of heavy precipitation near the transitioning storm can promote phase locking (via enhancement of trough deceleration) and further enhance the downstream impact (via advection of air with low potential vorticity in the direction of the waveguide). These different impacts affect the probability of atmospheric blocking at the end of the Pacific storm track, which is generally higher if a TC–trough interaction occurs in the western North Pacific. Blocking in the eastern North Pacific is up to 3 times more likely than climatology if an interaction between a TC and a decelerating trough occurs upstream, whereas no statistical deviation with respect to climatology is observed for accelerating troughs. The outlined results support the hypothesis that differences in phase locking can explain the observed variability in the downstream impact of ET.

scholarly journals Timescales and Magnitude of Water Quality Change in Three Texas Estuaries Induced by Passage of Hurricane Harvey

2020 ◽  
Author(s):  
Lily M. Walker ◽  
Paul A. Montagna ◽  
Xinping Hu ◽  
Michael S. Wetz
Keyword(s):  
Water Quality ◽  
Tropical Cyclones ◽  
Storm Surge ◽  
Storm Track ◽  
Wind Speeds ◽  
Low Salinity ◽  
Water Quality Change ◽  
Before And After ◽  
Estuarine Water Quality

Abstract Tropical cyclones represent a substantial disturbance to water quality in coastal ecosystems via storm surge, winds, and flooding. However, evidence to date suggests that the impacts of tropical cyclones on water quality are generally short-lived (days-months) and that the magnitude of the disturbance is related to proximity to storm track. Discrete and continuous water samples were collected in three Texas estuaries before and after Hurricane Harvey made landfall in 2017. Of the three estuaries, the Guadalupe Estuary and its watershed received the highest rainfall totals and wind speeds. An ephemeral increase in salinity was observed (mean of 9.8 on 24 August 2017 to a peak of 32.1 on 26 August 2017) due to storm surge and was followed by a rapid decrease to < 1 as floodwaters reached the estuary. Salinity returned to pre-storm levels within 1 month. During the low salinity period, bottom water hypoxia developed and lasted for 9 days. In all three estuaries, there was an increase in inorganic nutrients post-Harvey, but the nutrients largely returned to pre-storm baseline levels by winter. The lack of long-term water quality impacts from Harvey despite its severity corroborates previous findings that estuarine water quality tends to return to baseline conditions within days to a few months after storm passage.

Long-Term Increase in Hibernating Bats in Swedish Mines — Effect of Global Warming?

2019 ◽  
Vol 20 (2) ◽  
pp. 421 ◽  
Author(s):  
Jens Rydell ◽  
Johan Eklöf ◽  
Hans Fransson ◽  
Sabine Lind
Keyword(s):  
Global Warming

Asian Americans and Pacific Islanders: Employment Issues in the United States

2011 ◽  
Vol 9 (1-2) ◽  
pp. 58-69
Author(s):  
Marlene Kim
Keyword(s):  
United States ◽  
Asian Americans ◽  
The United States ◽  
Current Data ◽  
Pacific Islanders ◽  
Native Hawaiians ◽  
Data Sets ◽  
High Poverty ◽  
Unemployment Rates

Asian Americans and Pacific Islanders (AAPIs) in the United States face problems of discrimination, the glass ceiling, and very high long-term unemployment rates. As a diverse population, although some Asian Americans are more successful than average, others, like those from Southeast Asia and Native Hawaiians and Pacific Islanders (NHPIs), work in low-paying jobs and suffer from high poverty rates, high unemployment rates, and low earnings. Collecting more detailed and additional data from employers, oversampling AAPIs in current data sets, making administrative data available to researchers, providing more resources for research on AAPIs, and enforcing nondiscrimination laws and affirmative action mandates would assist this population.

Epidemiological Evidence that Maternal Influenza Contributes to the Aetiology of Schizophrenia

1993 ◽  
Vol 163 (4) ◽  
pp. 522-534 ◽  
Author(s):  
W. Adams ◽  
R. E. Kendell ◽  
E. H. Hare ◽  
P. Munk-Jørgensen
Keyword(s):  
Data Sets ◽  
Time Lags ◽  
Epidemiological Evidence ◽  
Intrauterine Development ◽  
Increased Risk ◽  
Schizophrenic Patients ◽  
The Relationship ◽  
Monthly Incidence ◽  
Maternal Influenza

The epidemiological evidence that the offspring of women exposed to influenza in pregnancy are at increased risk of schizophrenia is conflicting. In an attempt to clarify the issue we explored the relationship between the monthly incidence of influenza (and measles) in the general population and the distribution of birth dates of three large series of schizophrenic patients - 16 960 Scottish patients born in 1932–60; 22 021 English patients born in 1921–60; and 18 723 Danish patients born in 1911–65. Exposure to the 1957 epidemic of A2 influenza in midpregnancy was associated with an increased incidence of schizophrenia, at least in females, in all three data sets. We also confirmed the previous report of a statistically significant long-term relationship between patients' birth dates and outbreaks of influenza in the English series, with time lags of - 2 and - 3 months (the sixth and seventh months of pregnancy). Despite several other negative studies by ourselves and others we conclude that these relationships are probably both genuine and causal; and that maternal influenza during the middle third of intrauterine development, or something closely associated with it, is implicated in the aetiology of some cases of schizophrenia.

scholarly journals Effect of Barley Sowing Density on the Integrated Weed Management of Lolium rigidum (Annual Ryegrass) in Mediterranean Dryland: A Modeling Approach

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1565
Author(s):  
María Belén D’Amico ◽  
Guillermo R. Chantre ◽  
Guillermo L. Calandrini ◽  
José L. González-Andújar
Keyword(s):  
Weed Management ◽  
Life Cycles ◽  
Integrated Weed Management ◽  
Future Research ◽  
Seed Removal ◽  
Weed Infestation ◽  
High Control ◽  
Weed Dynamics ◽  
The Impact

Population models are particularly helpful for understanding long-term changes in the weed dynamics associated with integrated weed management (IWM) strategies. IWM practices for controlling L. rigidum are of high importance, mainly due to its widespread resistance that precludes chemical control as a single management method. The objective of this contribution is to simulate different IWM scenarios with special emphasis on the impact of different levels of barley sowing densities on L. rigidum control. To this effect, a weed–crop population model for both L. rigidum and barley life cycles was developed. Our results point out: (i) the necessity of achieving high control efficiencies (>99%), (ii) that the increase of twice the standard sowing density of barley resulted in a reduction of 23.7% of the weed density, (iii) non-herbicide-based individual methods, such as delayed sowing and weed seed removal at harvest, proved to be inefficient for reducing drastically weed population, (iv) the implementation of at least three control tactics (seed removal, delay sowing and herbicides) is required for weed infestation eradication independently of the sowing rate, and (v) the effect of an increase in the sowing density is diluted as a more demanding weed control is reached. Future research should aim to disentangle the effect of different weed resistance levels on L. rigidum population dynamics and the required efficiencies for more sustainable IWM programs.

scholarly journals Influence of the Environment on the Reliability of Security Magnetic Contacts

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 401
Author(s):  
Martin Boros ◽  
Andrej Velas ◽  
Viktor Soltes ◽  
Jacek Dworzecki
Keyword(s):  
Global Warming ◽  
Extreme Conditions ◽  
Alarm System ◽  
Test Device ◽  
Reaction Distance ◽  
Ambient Temperatures ◽  
Thermal Chamber

Magnetic contacts are one of the basic components of an alarm system, providing access to buildings, especially windows and doors. From long-term reliability tests, it can be concluded that magnetic contacts show sufficient reliability. Due to global warming, we can measure high as well as low ambient temperatures in the vicinity of magnetic contacts, which can directly affect their reliability. As part of partial tests, research into the reliability of magnetic contacts, we created a test device with which their reaction distance was examined under extreme conditions simulated in a thermal chamber. The results of the practical tests have yielded surprising results.

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