Trends in Snowfall versus Rainfall in the Western United States

2006 ◽  
Vol 19 (18) ◽  
pp. 4545-4559 ◽  
Author(s):  
Noah Knowles ◽  
Michael D. Dettinger ◽  
Daniel R. Cayan
Keyword(s):  
United States ◽  
West Coast ◽  
Warming Trend ◽  
Western United States ◽  
The West ◽  
Regional Trend ◽  
Study Region ◽  
The Pacific ◽  
Climate Shifts ◽  
The Mean

Abstract The water resources of the western United States depend heavily on snowpack to store part of the wintertime precipitation into the drier summer months. A well-documented shift toward earlier runoff in recent decades has been attributed to 1) more precipitation falling as rain instead of snow and 2) earlier snowmelt. The present study addresses the former, documenting a regional trend toward smaller ratios of winter-total snowfall water equivalent (SFE) to winter-total precipitation (P) during the period 1949–2004. The trends toward reduced SFE are a response to warming across the region, with the most significant reductions occurring where winter wet-day minimum temperatures, averaged over the study period, were warmer than −5°C. Most SFE reductions were associated with winter wet-day temperature increases between 0° and +3°C over the study period. Warmings larger than this occurred mainly at sites where the mean temperatures were cool enough that the precipitation form was less susceptible to warming trends. The trends toward reduced SFE/P ratios were most pronounced in March regionwide and in January near the West Coast, corresponding to widespread warming in these months. While mean temperatures in March were sufficiently high to allow the warming trend to produce SFE/P declines across the study region, mean January temperatures were cooler, with the result that January SFE/P impacts were restricted to the lower elevations near the West Coast. Extending the analysis back to 1920 shows that although the trends presented here may be partially attributable to interdecadal climate variability associated with the Pacific decadal oscillation, they also appear to result from still longer-term climate shifts.

scholarly journals A Climatology of 500-hPa Closed Lows in the Northeastern Pacific Ocean, 1948–2011

2014 ◽  
Vol 53 (6) ◽  
pp. 1578-1592 ◽  
Author(s):  
Nina S. Oakley ◽  
Kelly T. Redmond
Keyword(s):  
United States ◽  
Pacific Ocean ◽  
Interannual Variability ◽  
West Coast ◽  
The United States ◽  
Western United States ◽  
The West ◽  
Reanalysis Dataset ◽  
The Pacific ◽  
Northeastern Pacific

AbstractThe northeastern Pacific Ocean is a preferential location for the formation of closed low pressure systems. These slow-moving, quasi-barotropic systems influence vertical stability and sustain a moist environment, giving them the potential to produce or affect sustained precipitation episodes along the west coast of the United States. They can remain motionless or change direction and speed more than once and thus often pose difficult forecast challenges. This study creates an objective climatological description of 500-hPa closed lows to assess their impacts on precipitation in the western United States and to explore interannual variability and preferred tracks. Geopotential height at 500 hPa from the NCEP–NCAR global reanalysis dataset was used at 6-h and 2.5° × 2.5° resolution for the period 1948–2011. Closed lows displayed seasonality and preferential durations. Time series for seasonal and annual event counts were found to exhibit strong interannual variability. Composites of the tracks of landfalling closed lows revealed preferential tracks as the features move inland over the western United States. Correlations of seasonal event totals for closed lows with ENSO indices, the Pacific decadal oscillation (PDO), and the Pacific–North American (PNA) pattern suggested an above-average number of events during the warm phase of ENSO and positive PDO and PNA phases. Precipitation at 30 U.S. Cooperative Observer stations was attributed to closed-low events, suggesting 20%–60% of annual precipitation along the West Coast may be associated with closed lows.

Asian American and Pacific Island Modernist Art

2020 ◽  
Author(s):  
Tom Wolf
Keyword(s):  
United States ◽  
New York ◽  
Los Angeles ◽  
San Francisco ◽  
Asian American ◽  
West Coast ◽  
The United States ◽  
The West ◽  
The Pacific ◽  
American Artists

Artists of Asian descent made substantial contributions to the artistic culture of the United States, incorporating practices that were different from the European-based traditions—like painting with water-soluble pigments rather than oil paint, choosing Asian subjects, and signing their works in the Asian fashion. Coming across the Pacific Ocean, some immigrants settled in Hawaii where Isami Doi, born of Japanese parents, became an influential artist. Doi typifies characteristics that are found in many Asian American artists in that he excelled at several media: printmaking, painting, and jewelry design. And he traveled extensively, spending time in Paris and over a decade in New York. The West Coast of the United States became a center for people coming across the Pacific, and major cities like Seattle, San Francisco, and Los Angeles developed Asian communities with active artistic cultures. Chinese immigrants were drawn to the San Francisco area because of the economic boom around the gold rush and the building of the railroads, but they also inspired prejudice, and harsh immigration laws were enacted in 1888. This halted immigration from China and bolstered it from Japan, until another law in 1924 restricted that as well. Yun Gee, of Chinese descent, in San Francisco made aggressively modern, brightly colored, and geometrically abstracted portraits before moving to Paris and then New York where his style became more expressionistic. The Asian communities in Seattle and Los Angeles included artists who worked in photography as well as painting, and some moved further east across the United States to pursue their careers in the Midwest or, more commonly, New York, the artistic center of the country. In the 1920s and 1930s, Yasuo Kuniyoshi became well known in the New York art world for his sensitively handled, sometimes humorous, sometimes erotic paintings and prints. Nevertheless, he and his peers who were born in Asia were forbidden by law from becoming citizens, something he desired, as his entire artistic career was in the United States. The sculptor Isamu Noguchi came to prominence after being nurtured by some of the Japanese American artists in Kuniyoshi’s circle, particularly Itaro Ishigaki. Noguchi is best known for the organically shaped carved stone sculptures he made after World War II, but he was also famous as a designer of modernist furniture and lamps using Japanese materials. Both he and Kuniyoshi suffered after the Japanese bombing of Pearl Harbor in 1941, while on the West Coast Japanese Americans were herded into detention camps, often losing their jobs and their homes in the process. Chiura Obata, for example, was removed from his prestigious teaching position at the University of California at Berkeley and put in a camp where he taught art. There he switched from making luminous landscapes of Yosemite to painting camp scenes of confinement and regimentation—once he was allowed to paint at all. The postwar years were a period of recovery, and new generations of Asian American artists emerged, exploring abstract styles and creating new incarnations of the multicultural art that was pioneered in the works of their Asian American predecessors.

Metamorphic Waters from the Pacific Tectonic Belt of the West Coast of the United States

Science ◽  
1970 ◽  
Vol 168 (3934) ◽  
pp. 973-975 ◽  
Author(s):  
I. Barnes
Keyword(s):  
United States ◽  
West Coast ◽  
The United States ◽  
The West ◽  
The Pacific ◽  
Tectonic Belt

Seasonal Cycle Shifts in Hydroclimatology over the Western United States

2005 ◽  
Vol 18 (2) ◽  
pp. 372-384 ◽  
Author(s):  
Satish Kumar Regonda ◽  
Balaji Rajagopalan ◽  
Martyn Clark ◽  
John Pitlick
Keyword(s):  
United States ◽  
Pacific Northwest ◽  
Snow Water Equivalent ◽  
Warming Trend ◽  
Winter Precipitation ◽  
Western United States ◽  
Temperature And Precipitation ◽  
The Pacific ◽  
Snow Water ◽  
Northwest Region

Abstract Analyses of streamflow, snow mass temperature, and precipitation in snowmelt-dominated river basins in the western United States indicate an advance in the timing of peak spring season flows over the past 50 years. Warm temperature spells in spring have occurred much earlier in recent years, which explains in part the trend in the timing of the spring peak flow. In addition, a decrease in snow water equivalent and a general increase in winter precipitation are evident for many stations in the western United States. It appears that in recent decades more of the precipitation is coming as rain rather than snow. The trends are strongest at lower elevations and in the Pacific Northwest region, where winter temperatures are closer to the melting point; it appears that in this region in particular, modest shifts in temperature are capable of forcing large shifts in basin hydrologic response. It is speculated that these trends could be potentially a manifestation of the general global warming trend in recent decades and also due to enhanced ENSO activity. The observed trends in hydroclimatology over the western United States can have significant impacts on water resources planning and management.

Regional Seismic Networks Operating along the West Coast of the United States of America

2020 ◽  
Vol 91 (2A) ◽  
pp. 695-706 ◽  
Author(s):  
Margaret Hellweg ◽  
Paul Bodin ◽  
Jayne M. Bormann ◽  
Hamid Haddadi ◽  
Egill Hauksson ◽  
...  
Keyword(s):  
United States ◽  
West Coast ◽  
Warning System ◽  
The United States ◽  
The West ◽  
Waveform Data ◽  
Earthquake Early Warning System ◽  
Seismic Waveform ◽  
The Pacific ◽  
Seismic Networks

Abstract The Pacific coast of the contiguous United States hosts the highest seismic risk in the country due to the intersection of high-seismic hazard and the high densities of population and infrastructure. The regional seismic networks in Washington, Oregon, Nevada, and California have operated for many years and have collected long catalogs and large amounts of seismic waveform data in a variety of formats, including digital records. These data are available for engineering purposes and research into earthquakes, other natural and man-made seismic sources, and the Earth’s structure. The West Coast networks are closely coordinating as they embark on the implementation of West Coast ShakeAlert, an earthquake early warning system.

scholarly journals Uncovering the role of the East Asian jet stream and heterogeneities in atmospheric rivers affecting the western United States

2018 ◽  
Vol 115 (5) ◽  
pp. 891-896 ◽  
Author(s):  
Wei Zhang ◽  
Gabriele Villarini
Keyword(s):  
United States ◽  
West Coast ◽  
Southern Oscillation ◽  
East Asian ◽  
Teleconnection Pattern ◽  
Western United States ◽  
Atmospheric Rivers ◽  
Climate Modes ◽  
The Pacific ◽  
The Us

Atmospheric rivers (ARs) exert major socioeconomic repercussions along the US West Coast by inducing heavy rainfall, flooding, strong winds, and storm surge. Despite the significant societal and economic repercussions of these storms, our understanding of the physical drivers responsible for their interannual variability is limited, with different climate modes identified as possible mechanisms. Here we show that the Pacific-Japan (PJ) teleconnections/patterns and the East Asian subtropical jet (EASJ) exhibit a strong linkage with the total frequency of ARs making landfall over the western United States, much stronger than the other potential climate modes previously considered. While our findings indicate that the PJ pattern and EASJ are the most relevant climate modes driving the overall AR activity, we also uncover heterogeneities in AR tracks. Specifically, we show that not all ARs making landfall along the West Coast come from a single population, but rather that it is possible to stratify these storms into three clusters. While the PJ pattern and EASJ are major drivers of AR activity for two clusters, the cluster that primarily affects the US Southwest is largely driven by other climate modes [El Niño Southern Oscillation (ENSO), the Atlantic meridional mode (AMM), the Pacific-North America (PNA) teleconnection pattern, and the North Pacific Gyre Oscillation (NPGO)]. Therefore, important regional differences exist and this information can substantially enhance our ability to predict and prepare for these storms and their impacts.

scholarly journals Wildfires Threaten West Coast’s Seismic Network

Eos ◽  
2020 ◽  
Vol 101 ◽  
Author(s):  
Alka Tripathy-Lang
Keyword(s):  
United States ◽  
West Coast ◽  
Seismic Network ◽  
Western United States ◽  
The West

A dense seismic network keeps vigil over the western United States, sensing quakes soon after they begin so people nearby can brace themselves. How do wildfires affect these guardians of the West Coast?

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