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

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.

2013 ◽  
Vol 14 (1) ◽  
pp. 105-121 ◽  
Author(s):  
R. W. Higgins ◽  
V. E. Kousky

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.


Author(s):  
Stanley A. Changnon ◽  
Roger A., Jr. Pielke

Much has been said about El Niño 97-98, some of it profound and some not. Several of the key findings from this assessment are reflected in an excellent short summary published by the World Meteorological Organization (WMO) in January 1999. . . . The 1997/1998 El Niño was probably the strongest in recorded history; it disrupted the lives of millions of people on all the Earth’s inhabited continents. Not all climate extremes and severe weather events of the period, however, can be directly attributed to the El Niño event. Further, not all its impacts were negative, and some regions that were expected to suffer were not seriously affected. (Obasi, 1999) . . . As the WMO found on a global scale, we have documented the profound impacts of El Niño 97-98 in the United States. But, perhaps contrary to conventional wisdom, the impacts in the United States were, in the aggregate, positive. Because El Niño shifted the geographical distribution of seasonal anomalies and because scientists were able to anticipate these shifts, many decision makers were able to profit from the early warnings to take compensatory actions. The accuracy of the predictions, and the successful use by decision makers of those predictions, offers the promise of the development of a more robust climate service in the United States. The remainder of this chapter summarizes the surprises, the lessons learned, and the legacy of El Niño 97-98. Once the rapid onset of El Niño conditions was detected late in the spring of 1997, forecasters successfully predicted the event’s strength and duration. The oceanic predictions reinforced the ensuing seasonal climate forecasts. The official seasonal outlooks issued by the National Oceanic and Atmospheric Administration (NOAA) in the summer of 1997 skillfully predicted the fall, winter, and early spring 1997-1998 conditions in many parts of the United States many months in advance. The seasonal forecasts had an accuracy of greater than 50 percent for temperatures and of between 30 percent and 50 percent for precipitation, the highest levels of accuracy ever attained, a reflection of the benefits of the considerable research and ocean-monitoring efforts directed at the El Niño Southern Oscillation (ENSO) over the past twenty years.


2010 ◽  
Vol 23 (17) ◽  
pp. 4637-4650 ◽  
Author(s):  
R. W. Higgins ◽  
V. E. Kousky ◽  
V. B. S. Silva ◽  
E. Becker ◽  
P. Xie

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.


2021 ◽  
Vol 13 (2) ◽  
pp. 703
Author(s):  
Megan Drewniak ◽  
Dimitrios Dalaklis ◽  
Anastasia Christodoulou ◽  
Rebecca Sheehan

In recent years, a continuous decline of ice-coverage in the Arctic has been recorded, but these high latitudes are still dominated by earth’s polar ice cap. Therefore, safe and sustainable shipping operations in this still frozen region have as a precondition the availability of ice-breaking support. The analysis in hand provides an assessment of the United States’ and Canada’s polar ice-breaking program with the purpose of examining to what extent these countries’ relevant resources are able to meet the facilitated growth of industrial interests in the High North. This assessment will specifically focus on the maritime transportation sector along the Northwest Passage and consists of four main sections. The first provides a very brief description of the main Arctic passages. The second section specifically explores the current situation of the Northwest Passage, including the relevant navigational challenges, lack of infrastructure, available routes that may be used for transit, potential choke points, and current state of vessel activity along these routes. The third one examines the economic viability of the Northwest Passage compared to that of the Panama Canal; the fourth and final section is investigating the current and future capabilities of the United States’ and Canada’s ice-breaking fleet. Unfortunately, both countries were found to be lacking the necessary assets with ice-breaking capabilities and will need to accelerate their efforts in order to effectively respond to the growing needs of the Arctic. The total number of available ice-breaking assets is impacting negatively the level of support by the marine transportation system of both the United States and Canada; these two countries are facing the possibility to be unable to effectively meet the expected future needs because of the lengthy acquisition and production process required for new ice-breaking fleets.


Logistics ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 23
Author(s):  
Rebecca Sheehan ◽  
Dimitrios Dalaklis ◽  
Anastasia Christodoulou ◽  
Megan Drewniak ◽  
Peter Raneri ◽  
...  

The analysis in hand provides a brief assessment of the United States’ and Canada’s marine transportation system and relevant search and rescue (SAR) support in relation to the Northwest Passage, with the purpose of examining to what extent these countries’ relevant infrastructure resources are able to meet the expected growth of shipping operations and business activities in the Arctic. Through an extensive literature review, this assessment will specifically describe the most important influences upon the maritime transportation system, with the issue of certain geographical details and the capabilities of existing ports standing out. Additionally, vessel activity trends and vessel traffic routing measure initiatives will be examined. Furthermore, the SAR infrastructure details and means to render assistance to people in distress along the Northwest Passage will be discussed. The reality remains that port characteristics are limited and vessel traffic routing measure initiatives and upgrades to SAR assets are commendable but slow-paced. It is true that both the United States and Canada are taking proper measures to build up infrastructure needs, but they both may run out of time to put adequate infrastructure in place to deal effectively with the changing environment.


Polar Record ◽  
1961 ◽  
Vol 10 (67) ◽  
pp. 365-371
Author(s):  
T. A. Harwood

In 1946 the United States Weather Bureau and the Canadian Meteorological Service installed the first of the Joint Arctic Weather Stations at Resolute Bay. The network of satellite stations was extended into the Arctic archipelago in the following years on roughly a 275-mile spacing to Mould Bay, Isachsen, Eureka and Alert.


2016 ◽  
Vol 97 (6) ◽  
pp. 1033-1056 ◽  
Author(s):  
Taneil Uttal ◽  
Sandra Starkweather ◽  
James R. Drummond ◽  
Timo Vihma ◽  
Alexander P. Makshtas ◽  
...  

Abstract International Arctic Systems for Observing the Atmosphere (IASOA) activities and partnerships were initiated as a part of the 2007–09 International Polar Year (IPY) and are expected to continue for many decades as a legacy program. The IASOA focus is on coordinating intensive measurements of the Arctic atmosphere collected in the United States, Canada, Russia, Norway, Finland, and Greenland to create synthesis science that leads to an understanding of why and not just how the Arctic atmosphere is evolving. The IASOA premise is that there are limitations with Arctic modeling and satellite observations that can only be addressed with boots-on-the-ground, in situ observations and that the potential of combining individual station and network measurements into an integrated observing system is tremendous. The IASOA vision is that by further integrating with other network observing programs focusing on hydrology, glaciology, oceanography, terrestrial, and biological systems it will be possible to understand the mechanisms of the entire Arctic system, perhaps well enough for humans to mitigate undesirable variations and adapt to inevitable change.


2021 ◽  
Vol 1 (10) ◽  
pp. 149-166
Author(s):  
Dmitry V. Gordienko ◽  

The paper examines the interests of Russia, the United States and China in the regions of the world and identifies the priorities of Russia's activities in Europe, Central Asia and the Caucasus, the Asia-Pacific region, the Arctic, Africa, the Middle East and Latin America, their comparative assessment with the interests of the United States and China. An approach to assessing the impact of possible consequences of the activities of the United States and China on the realization of Russia's interests is proposed. This makes it possible to identify the priorities of the policy of the Russian Federation in various regions of the world. The results of the analysis can be used to substantiate recommendations to the military-political leadership of our country. It is concluded that the discrepancy between the interests of the United States and China is important for the implementation of the current economic and military policy of the Russian Federation.


2021 ◽  
Author(s):  
Brandi Gamelin ◽  
Jiali Wang ◽  
V. Rao Kotamarthi

<p>Flash droughts are the rapid intensification of drought conditions generally associated with increased temperatures and decreased precipitation on short time scales.  Consequently, flash droughts are responsible for reduced soil moisture which contributes to diminished agricultural yields and lower groundwater levels. Drought management, especially flash drought in the United States is vital to address the human and economic impact of crop loss, diminished water resources and increased wildfire risk. In previous research, climate change scenarios show increased growing season (i.e. frost-free days) and drying in soil moisture over most of the United States by 2100. Understanding projected flash drought is important to assess regional variability, frequency and intensity of flash droughts under future climate change scenarios. Data for this work was produced with the Weather Research and Forecasting (WRF) model. Initial and boundary conditions for the model were supplied by CCSM4, GFDL-ESM2G, and HadGEM2-ES and based on the 8.5 Representative Concentration Pathway (RCP8.5). The WRF model was downscaled to a 12 km spatial resolution for three climate time frames: 1995-2004 (Historical), 2045-2054 (Mid), and 2085-2094 (Late).  A key characteristic of flash drought is the rapid onset and intensification of dry conditions. For this, we identify onset with vapor pressure deficit during each time frame. Known flash drought cases during the Historical run are identified and compared to flash droughts in the Mid and Late 21<sup>st</sup> century.</p>


Author(s):  
Amanda Henton ◽  
Thanos Tzounopoulos

Tinnitus is a pervasive public health issue that affects approximately 15% of the United States population. Similar estimates have also been shown on a global scale, with similar prevalence found in Europe, Asia, and Africa. The severity of tinnitus is heterogeneous, ranging from mildly bothersome to extremely disruptive. In the United States, approximately 10-20% of individuals who experience tinnitus report symptoms that severely reduce their quality of life. Due to the huge personal and societal burden, in the last twenty years a concerted effort on basic and clinical research has significantly advanced our understanding and treatment of this disorder. Yet, neither full understanding, nor cure exists. We know that tinnitus is the persistent involuntary phantom percept of internally-generated non-verbal noises and tones, which in most cases is initiated, by acquired hearing loss and maintained only when this loss is coupled with distinct neuronal changes in auditory and extra-auditory brain networks. Yet, the exact mechanisms and patterns of neural activity that are necessary and sufficient for the perceptual generation and maintenance of tinnitus remain incompletely understood. Combinations of animal model and human research will be essential in filling these gaps. Nevertheless, the existing progress in investigating the neurophysiological mechanisms has improved current treatment and highlighted novel targets for drug development and clinical trials. The aim of this review is to thoroughly discuss the current state of human and animal tinnitus research, outline current challenges, and highlight new and exciting research opportunities.


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