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 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.

scholarly journals Understanding the Characteristics of Daily Precipitation over the United States Using the North American Regional Reanalysis

2009 ◽  
Vol 22 (23) ◽  
pp. 6268-6286 ◽  
Author(s):  
Emily J. Becker ◽  
Ernesto Hugo Berbery ◽  
R. Wayne Higgins
Keyword(s):  
United States ◽  
Extreme Events ◽  
Daily Precipitation ◽  
Precipitable Water ◽  
Moisture Flux ◽  
The United States ◽  
Moisture Flux Convergence ◽  
The North ◽  
North American Regional Reanalysis ◽  
Regional Reanalysis

Abstract This study examines the seasonal characteristics of daily precipitation over the United States using the North American Regional Reanalysis (NARR). To help understand the physical mechanisms that contribute to changes in the characteristics of daily precipitation, vertically integrated moisture flux convergence (MFC) and precipitable water were included in the study. First, an analysis of the NARR precipitation was carried out because while observed precipitation is indirectly assimilated in the system, differences exist. The NARR mean seasonal amount is very close to that of observations throughout the year, although NARR exhibits a slight systematic bias toward more-frequent, lighter precipitation. Particularly during summer, the precipitation intensity and the probability distribution function (PDF) indicate that NARR somewhat underestimates extremes and overestimates lighter events in the eastern half of the United States. The intensity and PDF of moisture flux convergence exhibit a strong similarity to those of precipitation, suggesting a link between strong MFC and precipitation extremes. On the other hand, the relationship between the precipitable water and precipitation PDFs is weaker, based on the lack of agreement of their gamma distribution parameters. The dependence of the precipitation PDF on the lower-frequency modulation of ENSO was examined. During El Niño winters, the Southwest and central United States, Gulf of Mexico region, and southeastern coast have greater precipitation intensity and extremes than during La Niña, and the Ohio River and Red River basins have lower intensity and fewer extreme events. During summer, the northern Rocky Mountains receive higher intensity precipitation with more extreme events. Most areas where the change in the daily mean precipitation between ENSO phases is large have greater shifts in the extreme tail of the PDF. The ENSO-related response of moisture flux convergence is similar to that of precipitation. ENSO-related shifts in the precipitation PDF do not appear to have a strong relationship to the shifts in precipitable water.

scholarly journals Characterizing the Spatial Scales of Extreme Daily Precipitation in the United States

2018 ◽  
Vol 31 (19) ◽  
pp. 8023-8037 ◽  
Author(s):  
Danielle Touma ◽  
Anna M. Michalak ◽  
Daniel L. Swain ◽  
Noah S. Diffenbaugh
Keyword(s):  
United States ◽  
Extreme Precipitation ◽  
Daily Precipitation ◽  
Spatial Scales ◽  
The United States ◽  
Spatial Extent ◽  
Precipitation Event ◽  
Length Scales ◽  
Precipitation Records ◽  
Northwest Region

The spatial extent of an extreme precipitation event can be important for a basin’s hydrologic response and subsequent flood risk, and may yield insights into underlying atmospheric processes. Using a relaxed moving-neighborhood approach, we develop indicator semivariograms based on precipitation records from the Global Historical Climatology Network–Daily (GHCN-D) station network to directly quantify the climatological length scales of extreme daily precipitation over the United States during 1965–2014. We find that the length scales of extreme (90th percentile) daily precipitation events vary both regionally and seasonally. Over the eastern half of the United States, daily extreme precipitation length scales reach 400 km during the winter months, but are approximately half as large during the summer months. The Northwest region, on the other hand, exhibits little seasonal variation, with extreme precipitation length scales of approximately 150 km throughout the year. By leveraging in situ station measurements, our study avoids some of the uncertainties associated with satellite or interpolated precipitation data, and provides the longest climatological assessment of length scales of extreme daily precipitation over the United States to date. Although the length scales that we calculate can be sensitive to station density, neighborhood size, and neighborhood relaxation, we find that the interregional and interseasonal differences in length scales are relatively robust. Our method could be extended to quantify changes in the spatial extent of extreme daily precipitation in the recent past, and to investigate the underlying causes of any changes that are detected.

Mafias on the Move

2011 ◽  
Author(s):  
Federico Varese
Keyword(s):  
United States ◽  
New York ◽  
Organized Crime ◽  
The United States ◽  
The West ◽  
Market Expansion ◽  
The North ◽  
Economic Transformations ◽  
At Will

Organized crime is spreading like a global virus as mobs take advantage of open borders to establish local franchises at will. That at least is the fear, inspired by stories of Russian mobsters in New York, Chinese triads in London, and Italian mafias throughout the West. As this book explains, the truth is more complicated. The author has spent years researching mafia groups in Italy, Russia, the United States, and China, and argues that mafiosi often find themselves abroad against their will, rather than through a strategic plan to colonize new territories. Once there, they do not always succeed in establishing themselves. The book spells out the conditions that lead to their long-term success, namely sudden market expansion that is neither exploited by local rivals nor blocked by authorities. Ultimately the inability of the state to govern economic transformations gives mafias their opportunity. In a series of matched comparisons, the book charts the attempts of the Calabrese 'Ndrangheta to move to the north of Italy, and shows how the Sicilian mafia expanded to early twentieth-century New York, but failed around the same time to find a niche in Argentina. The book explains why the Russian mafia failed to penetrate Rome but succeeded in Hungary. A pioneering chapter on China examines the challenges that triads from Taiwan and Hong Kong find in branching out to the mainland. This book is both a compelling read and a sober assessment of the risks posed by globalization and immigration for the spread of mafias.

scholarly journals “The Future of Archaeology Is Antiracist”: Archaeology in the Time of Black Lives Matter

2021 ◽  
pp. 1-20
Author(s):  
Ayana Omilade Flewellen ◽  
Justin P. Dunnavant ◽  
Alicia Odewale ◽  
Alexandra Jones ◽  
Tsione Wolde-Michael ◽  
...  
Keyword(s):  
United States ◽  
North American ◽  
The United States ◽  
Heritage Preservation ◽  
Social Unrest ◽  
Black Lives Matter ◽  
The North ◽  
Road Map ◽  
The Social ◽  
The Future

This forum builds on the discussion stimulated during an online salon in which the authors participated on June 25, 2020, entitled “Archaeology in the Time of Black Lives Matter,” and which was cosponsored by the Society of Black Archaeologists (SBA), the North American Theoretical Archaeology Group (TAG), and the Columbia Center for Archaeology. The online salon reflected on the social unrest that gripped the United States in the spring of 2020, gauged the history and conditions leading up to it, and considered its rippling throughout the disciplines of archaeology and heritage preservation. Within the forum, the authors go beyond reporting the generative conversation that took place in June by presenting a road map for an antiracist archaeology in which antiblackness is dismantled.

Allied High Commission for Germany

1951 ◽  
Vol 5 (4) ◽  
pp. 825-832
Keyword(s):  
United States ◽  
North Atlantic ◽  
Foreign Minister ◽  
The United States ◽  
Scrap Metal ◽  
German Federal Republic ◽  
The North ◽  
The United Kingdom ◽  
The North Atlantic ◽  
Contractual Agreements

With the development of certain administrative frictions (concerning coal quotas, occupation costs, and the scrap metal treaty) between the western occupying powers and the German Federal Republic, early indications were that if the talk of “contractual agreements” did materialize it would reserve, for the occupying powers, wide controls over important areas of west Germany's internal and external affairs. In Washington, however, a general modification of approach was noted during the September discussions between the United States Secretary of State (Acheson), the United Kingdom Foreign Secretary (Morrison), and the French Foreign Minister (Schuman), preparatory to the Ottawa meetings of the North Atlantic Council.

A SYNOPSIS OF THE NORTH AMERICAN SPECIES OF SYNDIPNUS (HYMEN., ICHNEUMONIDAE)

1940 ◽  
Vol 72 (7) ◽  
pp. 135-145 ◽  
Author(s):  
G. Stuart Walley
Keyword(s):  
United States ◽  
North American ◽  
The United States ◽  
North American Species ◽  
National Museum ◽  
United States National Museum ◽  
The North

As noted below the two North American species described in Syndipnus by workers appear to belong in other genrra. In Europe the gunus is represented by nearly a score of species and has been reviewed in recent years by two writers (1, 2). North American collections contain very few representatives of the genus; after combining the material in the National Collection with that from the United States National Museum, the latter kindly loaned to me by Mr. R. A. Cushman, only thirty-seven specimens are available for study.

War stimulus: The Japanese threat and rebirth of the North America Pacific Coast shipbuilding industry, 1937-1946

2021 ◽  
Vol 33 (2) ◽  
pp. 382-411
Author(s):  
Chris Madsen
Keyword(s):  
United States ◽  
Supply Chain ◽  
Pacific Coast ◽  
The United States ◽  
Pearl Harbor ◽  
Shipbuilding Industry ◽  
The North ◽  
The Pacific ◽  
Before And After ◽  
Strategic Procurement

Henry Eccles, in classic studies on logistics, describes the dynamics of strategic procurement in the supply chain stretching from home countries to military theatres of operations. Naval authorities and industrialists concerned with Japanese aggression before and after Pearl Harbor looked towards developing shipbuilding capacity on North America’s Pacific Coast. The region turned into a volume producer of merchant vessels, warships and auxiliaries destined for service in the Pacific and Indian Oceans. Shipbuilding involved four broad categories of companies in the United States and Canada that enabled the tremendous production effort.

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