scholarly journals Evaluation of the Perspective of ERA-Interim and ERA5 Reanalyses for Calculation of Drought Indicators for Uzbekistan

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 527
Author(s):  
Natella Rakhmatova ◽  
Mikhail Arushanov ◽  
Lyudmila Shardakova ◽  
Bakhriddin Nishonov ◽  
Raisa Taryannikova ◽  
...  
Keyword(s):  
High Spatial Resolution ◽  
Limited Data ◽  
Near Surface ◽  
Weather Forecasts ◽  
Mountain Ranges ◽  
Medium Range ◽  
Drought Indicators ◽  
High Level ◽  
Level Of Agreement ◽  
Arid And Semiarid

The arid and semiarid regions of Uzbekistan are sensitive and vulnerable to climate change. However, the sparse and very unevenly distributed meteorological stations within the region provide limited data for studying the region’s climate variation. The aim of this work was to evaluate the performance of the European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA)-Interim and ERA5 products for the fields of near-surface temperature, humidity, and precipitation over Uzbekistan from 1981 to 2018 using observations from 74 meteorological stations. Major results suggested that the reanalysis datasets match well with most of the observed climate records, especially in the plain areas. While ERA5, with a high spatial resolution of 0.1°, is able more accurately reproduce mountain ranges and valleys. Compared to ERA-Interim, the climatological biases in temperature, humidity, and total precipitation from ERA5 are clearly reduced, and the representation of inter-annual variability is improved over most regions of Uzbekistan. Both reanalyses show a high level of agreement with observations on the standardized precipitation evaporation index (SPEI) with a correlation coefficient of 0.7–0.8.Although both of these ECMWF products can be successfully implemented for the calculation of atmospheric drought indicators for Uzbekistan and adjacent regions of Central Asia, the newer and advanced ERA5 is preferred.

scholarly journals Evento de Precipitação Intensa Associado às Perturbações Ondulatórias dos Alísios Sobre o Estado de Alagoas.

2020 ◽  
Vol 13 (07) ◽  
pp. 3195
Author(s):  
Matheus José Arruda Lyra ◽  
Ismael Guidson Farias Freitas ◽  
Dimas De Barros Santiago
Keyword(s):  
Reanalysis Data ◽  
Wave Disturbance ◽  
Precipitation Event ◽  
Trade Winds ◽  
Climatological Data ◽  
Weather Forecasts ◽  
Global Era ◽  
Medium Range ◽  
Strong Convection ◽  
High Level

O estudo teve como objetivo analisar a forte convecção provocada por uma Perturbação Ondulatória dos Alísios (POA) sobre o estado de Alagoas no dia 27 de maio de 2017. A análise e previsão de sistemas dessa magnitude desperta interesse devido os fenômenos adversos provocados e consequências à população. Foram utilizados dados de reanálise global ERA Interim fornecidos pelo European Centre for Medium-Range Weather Forecasts (ECMWF) com resolução espacial de 0,75º de latitude x 0,75º de longitude. Estes dados foram utilizados no software OpenGrADS para plotagem dos campos meteorológicos para a análise sinótica. Os dados referentes à precipitação acumulada foram fornecidos pela Secretaria de Estado do Meio Ambiente e dos Recursos Hídricos (SEMARH) a partir de 25 estações meteorológicas espalhadas por Alagoas. A perturbação se desenvolveu após a passagem de um sistema frontal que atingiu o Nordeste do Brasil alguns dias antes. O sistema sinótico pôde ser observado no campo de pressão à nível do mar e através das linhas de correntes em baixos níveis (925 e 850hPa) entre os dias 26 e 27, onde o eixo do cavado se concentrou sobre o estado de Alagoas. Os campos do fluxo de umidade integrado na vertical indicaram valores bastante elevados provenientes do Atlântico, adentrando Alagoas entre os dias 25 e 27. Através da análise da série de dados climatológica, maio de 2017 registrou o terceiro maior pico de pluviometria (692mm/24h), onde somente no dia 27 foram registrados 173mm/24h, o que correspondeu à cerca de 25% da média histórica. Intense Precipitation Event Provoked by the Wave Disturbance of Trade Winds Over the Alagoas State A B S T R A C TThe main objective of this study was to analyze the Wave Disturbance of Trade Winds (WDTW) dynamics that provoked strong rainfall over the Alagoas state on May 27 of 2017. The analysis and systems forecasting of this magnitude arouses interest due to the adverse phenomena caused and consequences to the population. Global ERA Interim reanalysis data was provided by the European Center for Medium-Range Weather Forecasts (ECMWF) with spatial resolution of 0.75º latitude x 0.75º longitude. This dataset was used in conjunction with OpenGrADS software to the meteorological fields plot for synoptic analysis. Precipitation dataset were collected from 25 meteorological stations spread across the Alagoas state provided by the State Secretary for the Environment and Water Resources (SEMARH). The disturbance developed after a frontal system passage that reached BNE a few days earlier. The synoptic system could be observed in the pressure at sea level field and through the streamlines at low levels (925 and 850hPa) between 26 and 27 of May, where the Trough axis was concentrated over Alagoas. The strong convection was also driven by a high-level Trough, lasted from 30ºS. The vertical integrated moisture flow fields indicated very high values from the Atlantic Ocean, reaching Alagoas between 25th and 27 of May. Through the analysis of climatological data, in May 2017 was registered the third highest peak of rainfall (692 mm/24h), where only on the 27th 173 mm/24h was recorded, which corresponded to the fence 25% of the historical average.Keywords: WDTW; Adverse Phenomena, Alagoas.

scholarly journals Choices in the Verification of S2S Forecasts and Their Implications for Climate Services

2020 ◽  
Vol 148 (10) ◽  
pp. 3995-4008
Author(s):  
Andrea Manrique-Suñén ◽  
Nube Gonzalez-Reviriego ◽  
Verónica Torralba ◽  
Nicola Cortesi ◽  
Francisco J. Doblas-Reyes
Keyword(s):  
Skill Score ◽  
Climate Services ◽  
Near Surface ◽  
Weather Forecasts ◽  
Probabilistic Evaluation ◽  
Skill Scores ◽  
Medium Range ◽  
The Impact ◽  
Start Dates

AbstractSubseasonal predictions bridge the gap between medium-range weather forecasts and seasonal climate predictions. This time scale is crucial for operations and planning in many sectors such as energy and agriculture. For users to trust these predictions and efficiently make use of them in decision-making, the quality of predicted near-surface parameters needs to be systematically assessed. However, the method to follow in a probabilistic evaluation of subseasonal predictions is not trivial. This study aims to offer an illustration of the impact that the verification setup might have on the calculation of the skill scores, thus providing some guidelines for subseasonal forecast evaluation. For this, several forecast verification setups to calculate the fair ranked probability skill score for tercile categories have been designed. These setups use different number of samples to compute the fair RPSS as well as different ways to define the climatology, characterized by different time periods to average (week or month). These setups have been tested by evaluating 2-m temperature in ECMWF-Ext-ENS 20-yr hindcasts for all of the initializations in 2016 against the ERA-Interim reanalysis. Then, the implications on skill score values of each of the setups are analyzed. Results show that to obtain a robust skill score several start dates need to be employed. It is also shown that a constant monthly climatology over each calendar month may introduce spurious skill score associated with the seasonal cycle. A weekly climatology bears similar results to a monthly running-window climatology; however, the latter provides a better reference climatology when bias adjustment is applied.

Strong Trends in the Skill of the ERA-40 and NCEP–NCAR Reanalyses in the High and Midlatitudes of the Southern Hemisphere, 1958–2001*

2004 ◽  
Vol 17 (23) ◽  
pp. 4603-4619 ◽  
Author(s):  
David H. Bromwich ◽  
Ryan L. Fogt
Keyword(s):  
Satellite Data ◽  
Austral Winter ◽  
Weather Forecasts ◽  
Atmospheric Research ◽  
June July August ◽  
Medium Range ◽  
Height Fields ◽  
Environmental Prediction ◽  
June July ◽  
High Level

Abstract The European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) and the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis (NCEP1) data are compared with Antarctic and other mid- to high-latitude station observations for the complete years of overlap, 1958–2001. Overall, it appears that ERA-40 more closely follows the observations; however, a more detailed look at the presatellite era reveals many shortcomings in ERA-40, particularly in the austral winter. By calculating statistics in 5-yr moving windows for June–July–August (JJA), it is shown that ERA-40 correlations with observed MSLP and surface (2 m) temperatures are low and even negative during the mid-1960s. A significant trend in skill in ERA-40 is observed in conjunction with the assimilation of satellite data during winter, eventually reaching a high level of skill after 1978 that is superior to NCEP1. NCEP1 shows consistency in its correlation with observations throughout time in this season; however, the biases in the NCEP1 MSLP fields decrease significantly with time. Similar problems are also found in the 500-hPa geopotential height fields above the direct influences of the mountainous topography. The height differences between ERA-40 and NCEP1 over the South Pacific are substantial before the modern satellite era throughout the depth of the troposphere. The ability for ERA-40 to be more strongly constrained by the satellite data compared to NCEP1, which is largely constrained by the station observational network, suggests that the differing assimilation schemes between ERA-40 and NCEP1 lead to the large discrepancies seen here. Thus, both reanalyses must be used with caution over high southern latitudes during the nonsummer months prior to the assimilation of satellite sounding data.

scholarly journals Brief communication: Interest of a regional climate model against ERA5 to simulate the near-surface climate of the Greenland ice sheet

2019 ◽  
Author(s):  
Alison Delhasse ◽  
Christoph Kittel ◽  
Charles Amory ◽  
Stefan Hofer ◽  
Xavier Fettweis
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Regional Climate ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Regional Climate Models ◽  
Near Surface ◽  
Weather Forecasts ◽  
Surface Climate ◽  
Medium Range

Abstract. The ERA5 reanalysis, recently made available by the European Centre for Medium-Range Weather Forecasts (ECMWF), is a new reanalysis product at a higher resolution which will replace ERA-Interim, considered to be the best reanalysis over Greenland until now. However, so far very little is known about the performance of ERA5 when compared to ERA-Interim over the Greenland Ice Sheet (GrIS). This study shows (1) that ERA5 improves not significantly the ERA-Interim comparison with near-surface climate observations over GrIS, (2) polar regional climate models (e.g. MAR) are still a useful tool to study the GrIS climate compared to ERA5, in particular in summer, and (3) that MAR results are not sensitive to the forcing used at its lateral boundaries (ERA5 or ERA-Interim).

scholarly journals Addressing model error through atmospheric stochastic physical parametrizations: impact on the coupled ECMWF seasonal forecasting system

2014 ◽  
Vol 372 (2018) ◽  
pp. 20130290 ◽  
Author(s):  
Antje Weisheimer ◽  
Susanna Corti ◽  
Tim Palmer ◽  
Frederic Vitart
Keyword(s):  
Time Scales ◽  
Weather Prediction ◽  
Seasonal Forecasting ◽  
Near Surface ◽  
Weather Forecasts ◽  
European Centre ◽  
Medium Range ◽  
Forecasting System ◽  
The Impact ◽  
Stochastically Perturbed

The finite resolution of general circulation models of the coupled atmosphere–ocean system and the effects of sub-grid-scale variability present a major source of uncertainty in model simulations on all time scales. The European Centre for Medium-Range Weather Forecasts has been at the forefront of developing new approaches to account for these uncertainties. In particular, the stochastically perturbed physical tendency scheme and the stochastically perturbed backscatter algorithm for the atmosphere are now used routinely for global numerical weather prediction. The European Centre also performs long-range predictions of the coupled atmosphere–ocean climate system in operational forecast mode, and the latest seasonal forecasting system—System 4—has the stochastically perturbed tendency and backscatter schemes implemented in a similar way to that for the medium-range weather forecasts. Here, we present results of the impact of these schemes in System 4 by contrasting the operational performance on seasonal time scales during the retrospective forecast period 1981–2010 with comparable simulations that do not account for the representation of model uncertainty. We find that the stochastic tendency perturbation schemes helped to reduce excessively strong convective activity especially over the Maritime Continent and the tropical Western Pacific, leading to reduced biases of the outgoing longwave radiation (OLR), cloud cover, precipitation and near-surface winds. Positive impact was also found for the statistics of the Madden–Julian oscillation (MJO), showing an increase in the frequencies and amplitudes of MJO events. Further, the errors of El Niño southern oscillation forecasts become smaller, whereas increases in ensemble spread lead to a better calibrated system if the stochastic tendency is activated. The backscatter scheme has overall neutral impact. Finally, evidence for noise-activated regime transitions has been found in a cluster analysis of mid-latitude circulation regimes over the Pacific–North America region.

ИССЛЕДОВАНИЯ АКУСТИЧЕСКИХ ХАРАКТЕРИСТИК ВЕРХНЕГО СЛОЯ МОРЯ МЕТОДОМ МНОГОЧАСТОТНОГО АКУСТИЧЕСКОГО ЗОНДИРОВАНИЯ

2020 ◽  
Author(s):  
V.A. Bulanov ◽  
I.V. Korskov ◽  
A.V. Storozhenko ◽  
S.N. Sosedko
Keyword(s):  
High Frequency ◽  
Wave Motion ◽  
High Spatial Resolution ◽  
Wind Waves ◽  
Acoustic Parameter ◽  
Sea Surface ◽  
Near Surface ◽  
Acoustical Properties ◽  
Acoustic Spectroscopy ◽  
Sea Bottom

Описано применение акустического зондирования для исследования акустических характеристик верхнего слоя моря с использованием широкополосных остронаправленных инвертированных излучателей,устанавливаемых на дно. В основу метода положен принцип регистрации обратного рассеяния и отраженияот поверхности моря акустических импульсов с различной частотой, позволяющий одновременно измерятьрассеяние и поглощение звука и нелинейный акустический параметр морской воды. Многочастотное зондирование позволяет реализовать акустическую спектроскопию пузырьков в приповерхностных слоях моря,проводить оценку газосодержания и получать данные о спектре поверхностного волнения при различных состояниях моря вплоть до штормовых. Применение остронаправленных высокочастотных пучков ультразвукапозволяет разделить информацию о планктоне и пузырьках и определить с высоким пространственным разрешением структуру пузырьковых облаков, образующихся при обрушении ветровых волн, и структуру планктонных сообществ. Участие планктона в волновом движении в толще морской воды позволяет определитьпараметры внутренних волн спектр и распределение по амплитудам в различное время.This paper represents the application of acoustic probingfor the investigation of acoustical properties of the upperlayer of the sea using broadband narrow-beam invertedtransducers that are mounted on the sea bottom. Thismethod is based on the principle of the recording of thebackscattering and reflections of acoustic pulses of differentfrequencies from the sea surface. That simultaneouslyallows measuring scattering and absorption of the soundand non-linear acoustic parameter of seawater. Multifrequencyprobing allows performing acoustic spectroscopy ofbubbles in the near-surface layer of the sea, estimating gascontent, and obtaining data on the spectrum of the surfacewaves in various states of the sea up to a storm. Utilizationof the high-frequency narrow ultrasound beams allows us toseparate the information about plankton and bubbles and todetermine the structure of bubble clouds, created during thebreaking of wind waves, along with the structure of planktoncommunities with high spatial resolution. The participationof plankton in the wave motion in the seawater columnallows determining parameters of internal waves, such asspectrum and distribution of amplitudes at different times.

scholarly journals Agreement between different recall periods in drug utilization studies

2017 ◽  
Vol 20 (2) ◽  
pp. 324-334 ◽  
Author(s):  
Cassia Garcia Moraes ◽  
Sotero Serrate Mengue ◽  
Tatiane da Silva Dal Pizzol
Keyword(s):  
Drug Use ◽  
Drug Utilization ◽  
Recall Period ◽  
Percent Agreement ◽  
Drug Utilization Studies ◽  
24 Hour Recall ◽  
High Level ◽  
Continuous Use ◽  
First Interview ◽  
Level Of Agreement

ABSTRACT: Objective: To assess the agreement between three recall periods for self-reported drug use using a 24-hour recall period as reference. Methods: Participants were allocated into three groups with different recall periods of 7, 14 and 30 days and were interviewed at two different times. A 24-hour recall questionnaire was answered during the first interview, and a questionnaire on drug use over the different recall periods tested was answered during the second interview. The agreement between the questionnaires was evaluated using percent agreement and kappa. Results: For continuous drugs, percent agreement varied between 92 and 99% and kappa varied between 0.71 and 0.97 for three periods tested. For drugs of occasional use, percent agreement varied between 63 and 81% and kappa varied between 0.27 and 0.52. The prevalence of drugs, particularly those of occasional use, increases with time. Conclusions: The high level of agreement between the three recall periods suggests that all of them are valid for the investigation of drugs of continuous use.

Impact of planetary waves on infrasound propagation uncertainties

2021 ◽  
Author(s):  
Elisabeth Blanc ◽  
Patrick Hupe ◽  
Bernd Kaifler ◽  
Natalie Kaifler ◽  
Alexis Le Pichon ◽  
...  
Keyword(s):  
Wave Activity ◽  
Atmospheric Dynamics ◽  
Planetary Waves ◽  
Data Sets ◽  
Atmospheric Models ◽  
Period Range ◽  
Weather Forecasts ◽  
Atmospheric Disturbances ◽  
Medium Range ◽  
Model Improvement

<p>The uncertainties in the infrasound technology arise from the middle atmospheric disturbances, which are partly underrepresented in the atmospheric models such as in the European Centre for Medium-Range Weather Forecasts (ECMWF) products used for infrasound propagation simulations. In the framework of the ARISE (Atmospheric dynamics Research InfraStructure in Europe) project, multi-instrument observations are performed to provide new data sets for model improvement and future assimilations. In an unexpected way, new observations using the autonomous CORAL lidar showed significant differences between ECMWF analysis fields and observations in Argentina in the period range between 0.1 and 10 days. The model underestimates the wave activity, especially in the summer. During the same season, the infrasound bulletins of the IS02 station in Argentina indicate the presence of two prevailing directions of the detections, which are not reflected by the simulations. Observations at the Haute Provence Observatory (OHP) are used for comparison in different geophysical conditions. The origin of the observed anomalies are discussed in term of planetary waves effect on the infrasound propagation.</p>

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