scholarly journals Intercomparison of Daily Precipitation Statistics over the United States in Observations and in NCEP Reanalysis Products

2010 ◽  
Vol 23 (17) ◽  
pp. 4637-4650 ◽  
Author(s):  
R. W. Higgins ◽  
V. E. Kousky ◽  
V. B. S. Silva ◽  
E. Becker ◽  
P. Xie
Keyword(s):  
United States ◽  
Daily Precipitation ◽  
Southern Oscillation ◽  
The United States ◽  
Department Of Energy ◽  
Climate Forecast System ◽  
Daily Data ◽  
Environmental Prediction ◽  
New Generation ◽  
Climate Prediction Center

Abstract A comparison of the statistics of daily precipitation over the conterminous United States is carried out using gridded station data and three generations of reanalysis products in use at the National Centers for Environmental Prediction (NCEP). The reanalysis products are the NCEP–NCAR reanalysis (Kalnay et al.), the NCEP–Department of Energy (DOE) reanalysis (Kanamitsu et al.), and the NCEP Climate Forecast System (CFS) reanalysis (Saha et al.). Several simple measures are used to characterize relationships between the observations and the reanalysis products, including bias, precipitation probability, variance, and correlation. Seasonality is accounted for by examining these measures for four nonoverlapping seasons, using daily data in each case. Relationships between daily precipitation and El Niño–Southern Oscillation (ENSO) phase are also considered. It is shown that the CFS reanalysis represents a clear improvement over the earlier reanalysis products, though significant biases remain. Comparisons of the error patterns in the reanalysis products provide a suitable basis for confident conversion of the Climate Prediction Center (CPC) operational monitoring and prediction products to the new generation of analyses based on CFS.

Changes in Observed Daily Precipitation over the United States between 1950–79 and 1980–2009

2013 ◽  
Vol 14 (1) ◽  
pp. 105-121 ◽  
Author(s):  
R. W. Higgins ◽  
V. E. Kousky
Keyword(s):  
United States ◽  
Great Plains ◽  
El Niño ◽  
Daily Precipitation ◽  
El Nino ◽  
Southern Oscillation ◽  
Heavy Precipitation ◽  
The United States ◽  
Enso Cycle ◽  
Precipitation Events

Abstract Changes in observed daily precipitation over the conterminous United States between two 30-yr periods (1950–79 and 1980–2009) are examined using a 60-yr daily precipitation analysis obtained from the Climate Prediction Center (CPC) Unified Raingauge Database. Several simple measures are used to characterize the changes, including mean, frequency, intensity, and return period. Seasonality is accounted for by examining each measure for four nonoverlapping seasons. The possible role of the El Niño–Southern Oscillation (ENSO) cycle as an explanation for differences between the two periods is also examined. There have been more light (1 mm ≤ P < 10 mm), moderate (10 mm ≤ P < 25 mm), and heavy (P ≥ 25 mm) daily precipitation events (P) in many regions of the country during the more recent 30-yr period with some of the largest and most spatially coherent increases over the Great Plains and lower Mississippi Valley during autumn and winter. Some regions, such as portions of the Southeast and the Pacific Northwest, have seen decreases, especially during the winter. Increases in multiday heavy precipitation events have been observed in the more recent period, especially over portions of the Great Plains, Great Lakes, and Northeast. These changes are associated with changes in the mean and frequency of daily precipitation during the more recent 30-yr period. Difference patterns are strongly related to the ENSO cycle and are consistent with the stronger El Niño events during the more recent 30-yr period. Return periods for both heavy and light daily precipitation events during 1950–79 are shorter during 1980–2009 at most locations, with some notable regional exceptions.

Relationships between Climate Variability and Fluctuations in Daily Precipitation over the United States

2007 ◽  
Vol 20 (14) ◽  
pp. 3561-3579 ◽  
Author(s):  
R. W. Higgins ◽  
V. B. S. Silva ◽  
W. Shi ◽  
J. Larson
Keyword(s):  
United States ◽  
Climate Variability ◽  
Climate Models ◽  
Daily Precipitation ◽  
Southern Oscillation ◽  
Heavy Precipitation ◽  
The United States ◽  
Global Scale ◽  
The Arctic ◽  
Teleconnection Patterns

Abstract Fluctuations in the frequency of daily precipitation occurrence and in the intensity of daily precipitation over the United States during the period 1948–2004 are identified and linked to leading sources of interannual and interdecadal climate variability. The El Niño–Southern Oscillation (ENSO) phenomena are implicated in interannual fluctuations while the Pacific decadal oscillation (PDO) and the Arctic Oscillation (AO) are linked to recent interdecadal fluctuations. For the conterminous United States as a whole there have been increases in the annual frequency of occurrence of wet days and heavy precipitation days and in the mean daily and annual total precipitation over the past several decades, though these changes have not been uniform. The possibility of significant natural forcing of these interdecadal variations in precipitation is explored. It is shown that the PDO is associated with these fluctuations over the western and southern United States, while the AO is also associated with them but to a much lesser extent over the southeastern United States. Because the interdecadal fluctuations are linked to changes in the global-scale circulation and sea surface temperatures associated with the PDO, the results imply that a significant portion of the skill of climate models in anticipating fluctuations in daily precipitation statistics over the United States will arise from an ability to forecast the temporal and spatial variability of the interdecadal shifts in tropical precipitation and in the associated teleconnection patterns into the midlatitudes.

scholarly journals Análise comparativa de dados de precipitação gerados pelo “Climate Prediction Center – CPC” versus dados observados para o Sul do Brasil (Comparative analysis of precipitation data generated by Climate Prediction Center – CPC versus data observed ...)

2017 ◽  
Vol 10 (4) ◽  
pp. 1180 ◽  
Author(s):  
Camila De Souza Cardoso ◽  
Mário Francisco Leal de Quadro
Keyword(s):  
Statistical Analysis ◽  
Climate Prediction ◽  
Precipitation Data ◽  
Southern Brazil ◽  
Mountainous Regions ◽  
Daily Data ◽  
Observation Network ◽  
Environmental Prediction ◽  
New Generation ◽  
Climate Prediction Center

Com o aumento significativo da rede de observação pluviométrica no Brasil, a partir da instalação de estações meteorológicas automáticas, cada vez mais se tem a necessidade de uniformizar, tanto no espaço como no tempo, as séries diárias de precipitação. Em função disso, este estudo tem por objetivo analisar o desempenho da nova geração de dados de precipitação do Climate Prediction Center (CPC) para região Sul do Brasil, comparando com dados observados em estações meteorológicas. Neste trabalho, são utilizados dados acumulados diários de precipitação fornecidos pelo CPC/NCEP/NOAA (Climate Prediction Center/National Centers for Environmental Prediction/national Oceanic and Atmospheric Administration), que possui resolução espacial de 0.5°x0.5°, no período de 01 de janeiro de 1979 a 31 de dezembro de 2015. As análises foram realizadas através de técnicas estatísticas comparando com dados de precipitação observados em 81 estações localizadas nos três estados da região Sul do Brasil, disponibilizados pela Agência Nacional de Águas (ANA) e Instituto Nacional de Meteorologia (INMET). A etapa de consistência dos dados observados mostrou que as séries observadas possuem falhas à nível diário, mensal e anual, que podem ter alterado o padrão climatológico da precipitação no Sul do Brasil. A análise estatística dos dados mostrou que o CPC possui bom desempenho em representar a precipitação no Sul do Brasil, com tendência a subestimar a precipitação em regiões montanhosas e os maiores erros ocorreram nas regiões oeste e litorâneas do Sul do Brasil.  A B S T R A C TWith the significant increase of the rainfall observation network in Brazil, with the installation of automatic meteorological stations, there is an increasing need to standardize, both in space and in time, the daily series of precipitation. Therefore, this study aims to analyze the performance of the new generation of precipitation data from the Climate Prediction Center (CPC) for the southern region of Brazil, comparing with data observed in meteorological stations. This work uses daily cumulative precipitation data provided by the CPC/NCEP/NOAA (Climate Prediction Center/National Centers for Environmental Prediction/National Oceanic and Atmospheric Administration), which has spatial resolution of 0.5°x0.5°, considering the period from January 1st, 1979 to December 31st, 2015. The analyzes were performed by using statistical techniques to make a comparison with precipitation data observed in 81 stations located in the three southern states of Brazil, made available by the National Water Agency (ANA) and the National Institute of Meteorology (INMET). The stage of consistency of the observed data showed that the evaluated series have daily, monthly and annual faults that may have altered the precipitation climatological pattern in southern Brazil. The statistical analysis of the data showed that CPC has a good performance in representing precipitation in southern Brazil, with a trend to underestimate precipitation in mountainous regions, and the major errors occurred in the western and coastal regions of southern Brazil.Keywords: Precipitation daily data, statistical analysis, Southern Brazil. 

scholarly journals Validation and Error Characterization of the GPCP-1DD Precipitation Product over the Contiguous United States

2005 ◽  
Vol 6 (4) ◽  
pp. 441-459 ◽  
Author(s):  
James McPhee ◽  
Steven A. Margulis
Keyword(s):  
United States ◽  
Daily Precipitation ◽  
Ground Truth ◽  
Global Precipitation Climatology Project ◽  
The United States ◽  
Precipitation Event ◽  
Precipitation Product ◽  
The North ◽  
Error Characterization ◽  
Environmental Prediction

Abstract A validation and error characterization study of the Global Precipitation Climatology Project, 1 degree daily (GPCP-1DD) precipitation product over the contiguous United States is presented. Daily precipitation estimates over a 1° grid are compared against aggregated precipitation values obtained from the forcing field of the North American Land Data Assimilation System (LDAS). LDAS daily values are consistent with the National Centers for Environmental Prediction Climate Prediction Center (CPC) gauge-based daily precipitation product and hence are regarded as realistic ground-truth values with full coverage of the United States. Continuous and categorical measures of skill are presented, so that both the ability of GPCP-1DD to identify a precipitation event and its accuracy in determining cumulative precipitation amounts are evaluated. Daily values are aggregated into seasonal averages, and spatial averages are computed for five arbitrarily defined zones that cover most of the study area. Results show that in general there is good agreement between GPCP-1DD and LDAS values, except for areas where GPCP-1DD is unable to identify high-intensity events, particularly the Pacific coast north of parallel 40°N. Computation of continuous statistics shows that average bias is negligible in most areas of the United States except for humid regions north of parallel 40°N. However, the rmse statistics shows that differences in estimated precipitation for individual 1° cells can be significant, exceeding in most cases the magnitude of the average precipitation. Beyond the validation, the error characterization presented here can significantly enhance the utility of the GPCP-1DD product by providing necessary inputs for ensemble hydrologic modeling and forecasting.

scholarly journals Comparison of Daily Precipitation Statistics for the United States in Observations and in the NCEP Climate Forecast System

2008 ◽  
Vol 21 (22) ◽  
pp. 5993-6014 ◽  
Author(s):  
R. W. Higgins ◽  
V. B. S. Silva ◽  
V. E. Kousky ◽  
W. Shi
Keyword(s):  
United States ◽  
Lead Time ◽  
Daily Precipitation ◽  
The United States ◽  
Climate Forecast ◽  
Forecast System ◽  
Climate Forecast System ◽  
Station Data ◽  
Forecast Lead Time ◽  
Ncep Climate Forecast System

Abstract An intercomparison of the statistics of daily precipitation within seasonal climate over the conterminous United States is carried out using gridded station data and output from the NCEP Climate Forecast System (CFS). Differences in the occurrence of daily precipitation between the observations and a set of CFS reforecasts are examined as a function of forecast lead time for 1982–2005. Difference patterns show considerable evolution depending on season and lead time, with positive biases in CFS at most locations and leads except along the southern tier of states during the spring and summer months. An examination of differences in daily precipitation statistics by ENSO phase and in the frequencies of wet and dry spells is also conducted using a longer period of gridded daily station data (1948–2006) and a pair of 100-yr CFS coupled simulations. These comparisons expose additional details of the regional and seasonal dependence of the bias in the CFS simulations and reforecasts over the conterminous United States. The analysis motivates additional synoptic studies aimed at improving the linkage between daily precipitation and related circulation features in CFS. Prospects for using this information to develop more reliable ensemble-based probabilistic forecasts in real time at leads of 2–4 weeks (e.g., risks of heavy rain events) are also considered.

Conclusion

2015 ◽  
Author(s):  
Udi Greenberg
Keyword(s):  
United States ◽  
The United States ◽  
West Germany ◽  
Student Movements ◽  
Left Wing ◽  
State Institutions ◽  
Small Organizations ◽  
New Vision ◽  
The 1960S ◽  
New Generation

This chapter considers the new vision of democracy ushered in by the generation of the 1960s. Unlike the architects of the postwar order, left-wing students challenged, rather than celebrated, the legitimacy of elected institutions and party politics. Parliaments were merely stages for oligarchies, tools for self-perpetuating elites. In both West Germany and the United States, students claimed that state institutions inevitably reinforced rigid hierarchies and oppressive norms. A “true” democracy could not be built by state agencies. Rather, it would emerge from “autonomy,” from small organizations, student movements, NGOs, and, later, human rights organizations. When the frustration and anger of this new generation exploded in protest in the late 1960s, German émigrés were among its main targets. Student journals and pamphlets frequently attacked and ridiculed the leading thinkers of the older generation. Such criticism was especially ferocious in West Germany, where returning émigrés came to represent Cold War ties with an amoral and depraved United States.

“Every Brother on a Rooftop Can Quote Fanon”

2017 ◽  
Author(s):  
Sean L. Malloy
Keyword(s):  
United States ◽  
Black Americans ◽  
The United States ◽  
Malcolm X ◽  
Amiri Baraka ◽  
The Third ◽  
The 1960S ◽  
The Third World ◽  
Lorraine Hansberry ◽  
New Generation

This chapter examines the intersection of the domestic and international developments that shaped the creation of black-led movements that looked beyond the borders of the United States for support and legitimacy in the 1960s. By the mid-1960s, the notion that black Americans should seek solidarity with the Third World rather than looking to Washington for help had attracted advocates ranging from Williams to Malcolm X, Lorraine Hansberry, Amiri Baraka, Vicki Garvin, Harold Cruse, and groups such as the Revolutionary Action Movement (RAM). The successes—and failures—of these pioneering figures helped pave the way for a new generation of activists, including key figures in the birth and development of the Black Panther Party.

National regeneration and the education of the Latin American elites

2018 ◽  
pp. 86-115
Author(s):  
Michela Coletta
Keyword(s):  
United States ◽  
Latin American ◽  
Direct Contact ◽  
The United States ◽  
National Character ◽  
Spanish American ◽  
Anglo Saxon ◽  
Spatial Direction ◽  
New Generation ◽  
Cultural Connotations

Given the essentially cultural connotations of the notion of ‘Latin race’, education was widely perceived as a key tool for bringing about a process of national and regional regeneration. ‘The problem of the race’ was closely linked to ‘the problem of education’. What characterised the debate on education in all three countries was a deep concern with the need for a regeneration of the national character. This chapter explores the debates around Latin and Anglo-Saxon education models and the ways in which major contemporary theories of education were incorporated. Intellectual exchanges with the Spanish ‘regeneracionistas’ were key in the case of the pedagogical strand of Krausismo in the River Plate and especially in Uruguay. What approach to education best suited the Spanish American nations? Was ‘Latin’ education the best model to adopt? The ‘spatial’ direction of these exchanges is in itself revealing of the different national tendencies: while the Chileans ostensibly and increasingly looked towards the United States, the River Plate was largely part of a revival of Krausismo through direct contact with a new generation of Spanish krausistas. 

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