scholarly journals Tropical Rainfall Variability on Interannual-to-Interdecadal and Longer Time Scales Derived from the GPCP Monthly Product

2007 ◽  
Vol 20 (15) ◽  
pp. 4033-4046 ◽  
Author(s):  
Guojun Gu ◽  
Robert F. Adler ◽  
George J. Huffman ◽  
Scott Curtis
Keyword(s):  
Rainfall Variability ◽  
Volcanic Eruptions ◽  
Linear Change ◽  
Tropical Ocean ◽  
Tropical Rainfall ◽  
Enso Events ◽  
Time Period ◽  
The Tropics ◽  
The Impact

Abstract Global and large regional rainfall variations and possible long-term changes are examined using the 27-yr (1979–2005) Global Precipitation Climatology Project (GPCP) monthly dataset. Emphasis is placed on discriminating among variations due to ENSO, volcanic events, and possible long-term climate changes in the Tropics. Although the global linear change of precipitation in the dataset is near zero during the time period, an increase in tropical rainfall is noted in the dataset, with a weaker decrease over Northern Hemisphere middle latitudes. Focusing on the Tropics (25°S–25°N), the dataset indicates an upward linear change (0.06 mm day−1 decade−1) and a downward linear change (−0.01 mm day−1 decade−1) over tropical ocean and land, respectively. This corresponds to an about 5.5% increase (ocean) and 1% decrease (land) during the entire 27-yr time period. The year 2005 has the largest annual tropical total precipitation (land plus ocean) for the GPCP record. The five highest years are (in descending order) 2005, 2004, 1998, 2003, and 2002. For tropical ocean the five highest years are 1998, 2004, 2005, 2002, and 2003. Techniques are applied to isolate and quantify variations due to ENSO and two major volcanic eruptions during the time period (El Chichón, March 1982; Mount Pinatubo, June 1991) in order to examine longer-time-scale changes. The ENSO events generally do not impact the tropical total rainfall, but rather induce significant anomalies with opposite signs over tropical land and ocean. The impact of the two volcanic eruptions is estimated to be about a 5% reduction in tropical rainfall over both land and ocean. A modified dataset (with ENSO and volcano effects removed) retains the same approximate linear change slopes, but with reduced variances, thereby increasing the statistical significance levels associated with the long-term rainfall changes in the Tropics. However, although care has been taken to ensure that this dataset is as homogeneous as possible, firm establishment of the existence of the discussed changes as long-term trends may require continued analysis of the input datasets and a lengthening of the observation period.

scholarly journals The Impact of Exchange Rate on Bangladesh’s Export: A Cointegration Approach

2020 ◽  
pp. 22-30
Author(s):  
Takrima Sayeda
Keyword(s):  
Exchange Rate ◽  
Foreign Exchange Market ◽  
Export Performance ◽  
Long Run ◽  
Time Period ◽  
Floating Exchange Rate ◽  
Short Run ◽  
Year 2000 ◽  
The Impact

The purpose of the paper is to see if there is any relationship exist between free floating exchange rate and export performance of Bangladesh. It inspects the monthly data of exchange rate and export value for the time period between year 2000 and 2017. It utilized the Johansen [1] cointegration approach to identify the extent of long run and short run relationship between them. The study could not establish neither any long term trend nor any short term dynamics between the variables. Respective variables are significantly related to their own immediate past values. Distant past values do not have any implications. This study suggests that short run macroeconomic policy would be beneficial to influence the foreign exchange market and eventually the performance of export of Bangladesh.

Managing for rainfall variability: impacts of grazing strategies on perennial grass dynamics in a dry tropical savanna

2011 ◽  
Vol 33 (2) ◽  
pp. 209 ◽  
Author(s):  
D. M. Orr ◽  
P. J. O'Reagain
Keyword(s):  
Carrying Capacity ◽  
Rainfall Variability ◽  
Perennial Grasses ◽  
Heteropogon Contortus ◽  
Heavy Grazing ◽  
Average Rainfall ◽  
Sustainable Grazing ◽  
Grazing Strategies ◽  
The Impact

Rainfall variability remains a major challenge to sustainable grazing management in northern Australia with perennial grasses the key to the stability of the resources that maintain a sustainable grazing industry. This paper describes the dynamics of five perennial grasses – Bothriochloa ewartiana (Domin) C.E. Hubb., Chrysopogon fallax S.T. Blake, Aristida spp., Panicum effusum R. Br. and Heteropogon contortus (L.) P. Beauv. ex Roem. & Schult. in relation to three grazing strategies – moderate stocking at long-term carrying capacity, heavy stocking and rotational wet season spelling. The research was conducted in permanent quadrats on the predominant land type in an extensive grazing study in an Aristida-Bothriochloa pasture in north Australia between 1998 and 2010. Summer rainfall was above average for two periods – 1998 – 2001 and 2008 – 2010 with drought and below-average rainfall from 2002 to 2007. Low rainfall affected the dynamics of all grasses by reducing survival and basal area through its effect on plant size; this impact was most noticeable for the shorter-lived Aristida spp., P. effusum and H. contortus. The impact of grazing was greatest on the long-lived B. ewartiana and C. fallax; this effect was accentuated by the 2002–07 drought. Heavy grazing during this period further reduced the survival and size of B. ewartiana in comparison with the moderate stocking and rotational spell treatments. In contrast, the survival of C. fallax was reduced in the moderate stocking and rotational spelling treatment during drought, relative to that under heavy grazing. The density of B. ewartiana declined even under moderate grazing and despite two sequences of above-average rainfall because seedling recruitment failed to offset mature plant death. Results from this study emphasised the importance of maintaining the existing populations of key long-lived species such as B. ewartiana through good management. These results also supported the overall findings from the grazing study indicating that stocking at the long-term carrying capacity is sustainable in managing for climate variability.

scholarly journals The use of QBO, ENSO, and NAO perturbations in the evaluation of GOME-2 MetOp A total ozone measurements

2019 ◽  
Vol 12 (2) ◽  
pp. 987-1011
Author(s):  
Kostas Eleftheratos ◽  
Christos S. Zerefos ◽  
Dimitris S. Balis ◽  
Maria-Elissavet Koukouli ◽  
John Kapsomenakis ◽  
...  
Keyword(s):  
Satellite Data ◽  
Total Ozone ◽  
Southern Oscillation ◽  
Model Calculations ◽  
Ozone Data ◽  
Ozone Monitoring ◽  
Mean Differences ◽  
The Tropics ◽  
The Impact

Abstract. In this work we present evidence that quasi-cyclical perturbations in total ozone (quasi-biennial oscillation – QBO, El Niño–Southern Oscillation – ENSO, and North Atlantic Oscillation – NAO) can be used as independent proxies in evaluating Global Ozone Monitoring Experiment (GOME) 2 aboard MetOp A (GOME-2A) satellite total ozone data, using ground-based (GB) measurements, other satellite data, and chemical transport model calculations. The analysis is performed in the frame of the validation strategy on longer time scales within the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) Satellite Application Facility on Atmospheric Composition Monitoring (AC SAF) project, covering the period 2007–2016. Comparison of GOME-2A total ozone with ground observations shows mean differences of about -0.7±1.4 % in the tropics (0–30∘), about +0.1±2.1 % in the mid-latitudes (30–60∘), and about +2.5±3.2 % and 0.0±4.3 % over the northern and southern high latitudes (60–80∘), respectively. In general, we find that GOME-2A total ozone data depict the QBO–ENSO–NAO natural fluctuations in concurrence with the co-located solar backscatter ultraviolet radiometer (SBUV), GOME-type Total Ozone Essential Climate Variable (GTO-ECV; composed of total ozone observations from GOME, SCIAMACHY – SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY, GOME-2A, and OMI – ozone monitoring instrument, combined into one homogeneous time series), and ground-based observations. Total ozone from GOME-2A is well correlated with the QBO (highest correlation in the tropics of +0.8) in agreement with SBUV, GTO-ECV, and GB data which also give the highest correlation in the tropics. The differences between deseazonalized GOME-2A and GB total ozone in the tropics are within ±1 %. These differences were tested further as to their correlations with the QBO. The differences had practically no QBO signal, providing an independent test of the stability of the long-term variability of the satellite data. Correlations between GOME-2A total ozone and the Southern Oscillation Index (SOI) were studied over the tropical Pacific Ocean after removing seasonal, QBO, and solar-cycle-related variability. Correlations between ozone and the SOI are on the order of +0.5, consistent with SBUV and GB observations. Differences between GOME-2A and GB measurements at the station of Samoa (American Samoa; 14.25∘ S, 170.6∘ W) are within ±1.9 %. We also studied the impact of the NAO on total ozone in the northern mid-latitudes in winter. We find very good agreement between GOME-2A and GB observations over Canada and Europe as to their NAO-related variability, with mean differences reaching the ±1 % levels. The agreement and small differences which were found between the independently produced total ozone datasets as to the influence of the QBO, ENSO, and NAO show the importance of these climatological proxies as additional tool for monitoring the long-term stability of satellite–ground-truth biases.

A Data Pretreatment Method about Power System Load Modeling

2012 ◽  
Vol 263-266 ◽  
pp. 125-130
Author(s):  
Yan Ping Wang
Keyword(s):  
Power System ◽  
High Speed ◽  
Load Forecasting ◽  
Multiple Time ◽  
Load Modeling ◽  
Time Period ◽  
Data Pretreatment ◽  
Load Increase ◽  
The Impact

Short-term load forecasting is one of the most important routine works for power dispatch departments. The accuracy of load forecasting will exert direct effects on the safety, economy and stabilization of the power system running. Portrait and transverse comparability are employed to distinguish and correct bad load data, while wavelet analysis and multiple-time-period analysis used to eliminate long-term increasing weights, thus reducing the impact of the high-speed load increase on the accuracy of load forecasting.

scholarly journals Yet another lockdown? A large-scale study on people's unwillingness to be confined during the first 5 months of the COVID-19 pandemic in Spain

2021 ◽  
Author(s):  
Marina Martinez-Garcia ◽  
Alejandro Rabasa ◽  
Xavier Barber ◽  
Kristina Polotskaya ◽  
Kristof Roomp ◽  
...  
Keyword(s):  
Large Scale ◽  
Psychological Impact ◽  
Important Variable ◽  
Decision Makers ◽  
Policy Makers ◽  
Time Period ◽  
Economic Support ◽  
Gender And Age ◽  
The Impact

Population confinements have been one of the most widely adopted non-pharmaceutical interventions (NPIs) implemented by governments across the globe to help contain the spread of the SARS-CoV-2 virus. While confinement measures have been proven to be effective to reduce the number of infections, they entail significant economic and social costs. Thus, different policy makers and social groups have exhibited varying levels of acceptance of this type of measures. In this context, understanding the factors that determine the willingness of individuals to be confined during a pandemic is of paramount importance, particularly, to policy and decision-makers. In this paper, we study the factors that influence the unwillingness to be confined during the COVID-19 pandemic by means of a large-scale, online population survey deployed in Spain. We apply both quantitative (logistic regression) and qualitative (automatic pattern discovery) methods and consider socio-demographic, economic and psychological factors, together with the 14-day cumulative incidence per 100,000 inhabitants. Our analysis of 109,515 answers to the survey covers data spanning over a 5-month time period to shed light on the impact of the passage of time. We find evidence of pandemic fatigue as the percentage of those who report an unwillingness to be in confinement increases over time; we identify significant gender differences, with women being generally less likely than men to be able to sustain long-term confinement of at least 6 months; we uncover that the psychological impact was the most important factor to determine the willingness to be in confinement at the beginning of the pandemic, to be replaced by the economic impact as the most important variable towards the end of our period of study. Our results highlight the need to design gender and age specific public policies, to implement psychological and economic support programs and to address the evident pandemic fatigue as the success of potential future confinements will depend on the population's willingness to comply with them.

scholarly journals Towards Financial Valuation in Data-Driven Companies

2016 ◽  
Vol 12 (2) ◽  
pp. 28-33
Author(s):  
M. Eugenia Pérez-Pons ◽  
Alfonso González-Briones ◽  
Juan M. Corchado
Keyword(s):  
Economic Value ◽  
Indirect Costs ◽  
Added Value ◽  
Data Driven ◽  
Financial Valuation ◽  
External Data ◽  
Time Period ◽  
The Impact ◽  
A Company

The following work presents a methodology of determining the economic value of the data owned by a company in a given time period. The ability to determine the value of data at any point of its lifecycle, would make it possible to study the added value that data gives to a company in the long term. Not only external data should be considered but also the impact that the internal data can have on company revenues. The project focuses on data-driven companies, which are different to the data-oriented ones, as explained below. Since some studies affirm that data-driven companies are more profitable, the indirect costs of using those data must be allocated somewhere to understand their financial value14 and to present a possible alternative for measuring the financial impact of data on the revenue of companies.

Volcanic aerosol heating in the tropical tropopause region and associated water vapour changes

2021 ◽  
Author(s):  
Clarissa Kroll ◽  
Hauke Schmidt ◽  
Claudia Timmreck
Keyword(s):  
Water Vapour ◽  
Volcanic Eruptions ◽  
Aerosol Layer ◽  
Volcanic Aerosol ◽  
Surface Warming ◽  
Tropical Tropopause ◽  
Tropopause Region ◽  
Cold Point ◽  
The Impact

<p>Large volcanic eruptions affect the distribution of atmospheric water vapour, for instance through cooling of the surface, warming of the lowermost stratosphere, and increasing the upwelling in the tropical tropopause region.</p><p>To better understand the volcanic impact on the tropical tropopause region and associated changes in the water vapour distribution in the stratosphere we employ a combination of short term convection-resolving global simulations with ICON and long term low resolution ensemble simulations with the MPI-ESM1.2-LR EVAens<strong>, </strong>both with prescribed volcanic forcing. With the EVAens a long term statistical analysis of the water vapour trends during the build-up and decay of a volcanic aerosol layer is made possible. The impact of the heating in the cold point regions is studied for five different eruption magnitudes. Stratospheric water vapour changes are analyzed in simulations with synthetic and observation based aerosol profiles showing that the distance of the aerosol profile from the cold point region can be more important for the water vapour entry into the stratosphere than the emitted amount of sulfur.</p><p>Whereas the EVAens is ideal to investigate the slow ascent of water vapour into the stratosphere the 10 km high resolution simulations with ICON allow insights into the convective changes after volcanic eruptions going beyond the limitations parameterizations usually impose on the model data.</p>

Recent evolution of stratospheric aerosol load from ground-based lidars and satellites: impact of volcanic eruptions and wildfires.

2020 ◽  
Author(s):  
Sergey Khaykin ◽  
Sophie Godin-Beekmann ◽  
Ghassan Taha ◽  
Artem Feofilov ◽  
Adam Bourassa ◽  
...  
Keyword(s):  
Large Scale ◽  
Background Level ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Satellite Observations ◽  
Eastern Australia ◽  
Stratospheric Circulation ◽  
The Tropics ◽  
Global Mean

<p>    During the last 2 years (2018-2019) a series of volcanic eruptions led to remarkable enhancements in stratospheric aerosol load. These are eruptions of <strong>Ambae</strong> (July 2018, Vanuatu), <strong>Raikoke</strong> (June 2019, Russia) and <strong>Ulawun</strong> (July 2019, Papua New Guinea). In this study we examine the evolution of the stratospheric aerosol bulk optical properties following these events in consideration of large-scale stratospheric circulation. We use long-term aerosol records by <strong>ground-based lidars</strong> in both hemispheres together with global observations by various satellite missions (<strong>OMPS-LP, SAGE III, OSIRIS, CALIOP</strong>) and discuss the consistency between these datasets.  In addition, we evaluate the preliminary lower stratosphere aerosol product by ESA <strong>Aeolus</strong> mission through intercomparison with ground-based lidars.</p><p>   The 28-yr Observatoire de Haute Provence (<strong>OHP) lidar record</strong> shows that<strong> Raikoke eruption has led to the strongest enhancement of stratospheric aerosol optical depth (SAOD) in the northern extratropics since Pinatubo eruption</strong>. Satellite observations suggest that the stratospheric plume of Raikoke has dispersed throughout the entire Northern hemisphere and ascended up to 27 km altitude. The eruption of Ulawun in the tropics has further boosted the stratospheric aerosol load and by Fall 2019, the <strong>global mean SAOD was a factor of 2.5 higher than its background level</strong>.</p><p>    At the turn of the year 2020, while both Raikoke and Ulawun aerosols were still present in the stratosphere, a dramatic bushfire event accompanied by vigorous fire-induced thunderstorms (PyroCb) in eastern Australia caused a massive injection of smoke into the stratosphere. The early detections of stratospheric smoke by OMPS-LP suggest that the zonal-mean SAOD perturbation caused by this event<strong> exceeds the previous record-breaking PyroCb-related perturbation</strong> after the British Columbia fires in August 2017. We use satellite observations of aerosol and trace gases (H2O, CO) to characterize the stratospheric impact of the wildfires and contrast it with that of volcanic eruptions.</p>

scholarly journals Impact of the economic crisis and contractions within the European long-term care systems

2021 ◽  
pp. 1-17
Author(s):  
Esther Albesa Jové
Keyword(s):  
Economic Crisis ◽  
Financial Crises ◽  
Long Term Care ◽  
Term Care ◽  
Development Level ◽  
Time Period ◽  
The World ◽  
Care Systems ◽  
The Impact

Abstract In 2008, the world underwent one of its worst economic and financial crises, whose consequences are still visible in some countries. This paper aims to analyse the impact of the crisis within the long-term care systems of Germany, England, Sweden and Spain from a comparative perspective. The time period analysed spans from the outset of the crisis in 2008, up to 2017. This article starts off from the thesis of the divergent impact of the economic crisis in these countries and the convergence between the impact of the crisis and long-term care contractions in the most afflicted countries. The outcome highlights the power of economic and financial pressures in order to explain the contractions within the care policies. Equally, it emphasizes the contradictions between the formal development level of the care systems and their practical institutional implementation in the field.

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