scholarly journals Evidence for Increasingly Variable Drought Conditions in the United States Since 1895

2015 ◽  
Author(s):  
Sierra Rayne ◽  
Kaya Forest
Keyword(s):  
United States ◽  
Severity Index ◽  
The United States ◽  
Time Frame ◽  
Drought Severity ◽  
The Pacific ◽  
Rapid Changes ◽  
Increasing Trend ◽  
End Members ◽  
Short Time

Annual and summertime trends towards increasingly variable values of the Palmer Drought Severity Index (PDSI) over a sub-decadal period (five years) were investigated within the contiguous United States between 1895 and the present. For the contiguous U.S. as a whole, there is a significant increasing trend in the five-year running minimum-maximum ranges for the annual PDSI (aPDSI5yr(min|max range)). During this time frame, the averageaPDSI5yr(min|max range)has increased by about one full unit, indicating a substantial increase is drought variability over short time scales across the United States. The end members of the runningaPDSI5yr(min|max range)highlight even more rapid changes in the drought index variability within the past 120 years. This increasing variability in theaPDSI5yr(min|max range)is driven primarily by changes taking place in the Pacific and Atlantic Ocean coastal climate regions, climate regions which collectively comprise one-third the area of the contiguous U.S. Overall, interannual drought patterns are becoming more extreme and difficult to predict, posing a challenge to agricultural and other water-resource related planning efforts.

scholarly journals Adaptation of Irrigation Infrastructure on Irrigation Demands under Future Drought in the United States*

2015 ◽  
Vol 19 (7) ◽  
pp. 1-16 ◽  
Author(s):  
Tianyi Zhang ◽  
Xiaomao Lin ◽  
Danny H. Rogers ◽  
Freddie R. Lamm
Keyword(s):  
United States ◽  
Irrigation Water ◽  
Severity Index ◽  
The United States ◽  
Drought Severity ◽  
Severe Drought ◽  
Surface Irrigation ◽  
Irrigation Depth ◽  
Unit Reduction ◽  
Irrigation Infrastructure

Abstract More severe droughts in the United States will bring great challenges to irrigation water supply. Here, the authors assessed the potential adaptive effects of irrigation infrastructure under present and more extensive droughts. Based on data over 1985–2005, this study established a statistical model that suggests around 4.4% more irrigation was applied in response to a one-unit reduction in the Palmer drought severity index (PDSI), and approximately 5.0% of irrigation water application could be saved for each 10% decrease in the areas supplied by surface irrigation infrastructure. Based on the results, the model-projected irrigation infrastructure has played a greater role in changes in irrigation than drought in most areas under the current climate except some southwestern counties. However, under the predicted future more severe drought in 2080–99 under the representative concentration pathways 4.5 scenario, the model projected that the drought will require 0%–20% greater irrigation amounts assuming the current irrigation efficiency. Under the predicted drought scenario, irrigation depth can be maintained at or below the baseline level in the western United States only when better irrigation infrastructure replaced 40% of the current surface irrigation infrastructure areas. In the northeast United States, limited changes in irrigation depth were predicted under different irrigation infrastructure scenarios because the percentage of surface irrigation area is already low under the baseline climate, and thus there is limited opportunity to adapt to future drought with advanced irrigation infrastructure. These results indicate that other effective solutions are required to complement these measures and aid U.S. agriculture in the future, more extensive drought.

scholarly journals Concurrent and lagged relationships among various drought indices in the United states

MAUSAM ◽  
2021 ◽  
Vol 43 (1) ◽  
pp. 43-50
Author(s):  
PETER T. SOULE
Keyword(s):  
United States ◽  
Supply And Demand ◽  
Severity Index ◽  
Fast Response ◽  
The United States ◽  
Drought Indices ◽  
Drought Severity ◽  
Strongly Correlated ◽  
Entire Study ◽  
Hydrologic Drought

The purpose of this study is to examine the nature of the concurrent and lagged relationships among various drought type-specific measures of drought severity. Monthly values of average temperature (TEMPZ), total precipitation (PREZ), the Palmer moisture anomaly index (ZINX)  the Palmer drought severity index  (PDSl), and the Palmer hydrologic drought seventy Index (PHDI) were examined  from a sample of climatic divisions, in the United States for the period,1931-1985. The relationships are examined at two levels through the use of simple correlations. Level one utilizes data from the entire study period. Data from selected drought   events are employed in level two.   The results show that the strongest relationships are between drought indices with similar rates of response to changes in moisture supply and demand. The correlations also show that lagged values of fast-response drought indices (ZINX, PREZ) arc more strongly correlated with the slow-response PHD1 than concurrent values. Intersite differences between correlated pairs of indices are generally small and follow consistent trends; cross the flow pattern sample for both level one and level two analyses. Intra-site differences are large for some pairs of correlated indices indicating that characteristics of individual droughts can deviate substantially from average or normal conditions

Making Middle Schools Destinations of Choice for Young Adolescents

2021 ◽  
pp. 181-199
Author(s):  
Stacie Pettit ◽  
Laura Rychly ◽  
Milisa Ziegler ◽  
Katie Walker
Keyword(s):  
United States ◽  
Middle School ◽  
Middle Schools ◽  
The United States ◽  
Time Frame ◽  
Middle Level ◽  
Young Adolescents ◽  
Middle Level Education ◽  
Positive Experiences ◽  
Short Time

In this chapter, middle schools are presented metaphorically as layover airports, and the need to see middle schools as more like destinations is explored. How can positive learning experiences in middle schools be created given the short time frame and the transitional nature inherent in even the most effective middle schools? The metaphor of a layover airport that students often enter middle school expecting is juxtaposed to illustrating the characteristics of and potential for middle schools in the United States as destinations. This is done using exemplar experiences and middle schools from vastly different locations with varying characteristics and needs, yet all providing positive experiences for young adolescents. This comparison will be made based on what is known about the developmental nature and needs of young adolescents served in middle schools and also on recommendations for effective middle schools made by the Association for Middle Level Education.

scholarly journals Stochastically Generated North American Megadroughts

2015 ◽  
Vol 28 (5) ◽  
pp. 1865-1880 ◽  
Author(s):  
Samantha Stevenson ◽  
Axel Timmermann ◽  
Yoshimitsu Chikamoto ◽  
Sally Langford ◽  
Pedro DiNezio
Keyword(s):  
United States ◽  
North American ◽  
Land Surface ◽  
Severity Index ◽  
The United States ◽  
Dominant Factor ◽  
Drought Severity ◽  
The North ◽  
Sst Forcing ◽  
Sst Anomalies

Abstract The importance of interannual-to-decadal sea surface temperature (SST) influences on drought in the United States is examined using a suite of simulations conducted with the T31×3 resolution version of the NCAR Community Earth System Model (CESM1.0.3). The model captures tropical Pacific teleconnections to North American precipitation reasonably well, although orographic features are somewhat enhanced at higher resolution. The contribution of SST anomalies is isolated by comparing two idealized, 1000-yr CESM1.0.3 experiments: a fully coupled control and an atmosphere-only (CAM4) run forced with the SST climatology from the control. Droughts are identified using the Palmer Drought Severity Index (PDSI), which is computed over four U.S. regions from the CESM1.0.3 experiments and compared with the North American Drought Atlas (NADA). The CESM1.0.3 reproduces the persistence of NADA droughts quite well, although the model underestimates drought severity. Within the CESM1.0.3 framework, SST forcing does not significantly affect drought intensity or frequency of occurrence, even for very persistent “megadroughts” of 15 yr or more in length. In both the CESM1.0.3 and NADA, with the exception of the Southeast United States, droughts in all regions have intensities, persistence lengths, and occurrence frequencies statistically consistent with a red noise null hypothesis. This implies that SST forcing is not the dominant factor in generating drought and therefore that many decadal megadroughts are caused by a combination of internal atmospheric variability and coupling with the land surface, with SST anomalies playing only a secondary role.

scholarly journals Prediction of Summer Maximum and Minimum Temperature over the Central and Western United States: The Roles of Soil Moisture and Sea Surface Temperature

2006 ◽  
Vol 19 (8) ◽  
pp. 1407-1421 ◽  
Author(s):  
Eric J. Alfaro ◽  
Alexander Gershunov ◽  
Daniel Cayan
Keyword(s):  
United States ◽  
Soil Moisture ◽  
Short Range ◽  
Large Scale ◽  
Severity Index ◽  
Time Frame ◽  
Western United States ◽  
Drought Severity ◽  
Explanatory Variables ◽  
Predictive Skill

Abstract A statistical model based on canonical correlation analysis (CCA) was used to explore climatic associations and predictability of June–August (JJA) maximum and minimum surface air temperatures (Tmax and Tmin) as well as the frequency of Tmax daily extremes (Tmax90) in the central and western United States (west of 90°W). Explanatory variables are monthly and seasonal Pacific Ocean SST (PSST) and the Climate Division Palmer Drought Severity Index (PDSI) during 1950–2001. Although there is a positive correlation between Tmax and Tmin, the two variables exhibit somewhat different patterns and dynamics. Both exhibit their lowest levels of variability in summer, but that of Tmax is greater than Tmin. The predictability of Tmax is mainly associated with local effects related to previous soil moisture conditions at short range (one month to one season), with PSST providing a secondary influence. Predictability of Tmin is more strongly influenced by large-scale (PSST) patterns, with PDSI acting as a short-range predictive influence. For both predictand variables (Tmax and Tmin), the PDSI influence falls off markedly at time leads beyond a few months, but a PSST influence remains for at least two seasons. The maximum predictive skill for JJA Tmin, Tmax, and Tmax90 is from May PSST and PDSI. Importantly, skills evaluated for various seasons and time leads undergo a seasonal cycle that has maximum levels in summer. At the seasonal time frame, summer Tmax prediction skills are greatest in the Midwest, northern and central California, Arizona, and Utah. Similar results were found for Tmax90. In contrast, Tmin skill is spread over most of the western region, except for clusters of low skill in the northern Midwest and southern Montana, Idaho, and northern Arizona.

scholarly journals THE MEDITERRANEAN FLOUR MOTH, EPHESTIA KUEHNIELLA, Zeller, STILL IN CANADA.

1896 ◽  
Vol 28 (1) ◽  
pp. 13-13
Author(s):  
W. G. Johnson
Keyword(s):  
United States ◽  
New York ◽  
Local Government ◽  
Pacific Coast ◽  
New York State ◽  
The United States ◽  
Ephestia Kuehniella ◽  
York State ◽  
The Pacific ◽  
Short Time

The determined and energetic fight carried on by the miller, the entomologist, and the Local Government in 1889, to stamp out this destructive mill pest in Ontario, is too fresh in the memory of those who witnessed that outbreak to warrant a repetition of the particulars. Suffice it to say that the flour moth is still very abundant in certain Canadian mills. I have received it recently in flour sent me direct from a milling firm in Valleyfield, Quebec, with an urgent appeal for help. The mill has been obliged to shut down several times during the present year to clean out the enormous accumulations of matted flour and webs in the spouts and elevator legs. The mill is a new one and has been running a very short time. It is said the pest came from a neighboring firm. My experience with this moth in California and other places convinces me that it is the worst pest millers have to combat, and this note should be a signal warning to all those interested in the milling business. I have also recently discovered the same pest in Southwestern New York State, where it has done considerable mischief this year, and is still spreading. It has occasioned much loss on the Pacific Coast also the present season. If something is not done to arrest and destroy thisadvancing enemy in the United States and Canada, I predict very serious results to the milling industries of both countries.

scholarly journals Spatial–Temporal Patterns of Historical, Near-Term, and Projected Drought in the Conterminous United States

Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 136
Author(s):  
Susan M. Kotikot ◽  
Olufemi A. Omitaomu
Keyword(s):  
United States ◽  
Spatial Scale ◽  
Climate Models ◽  
Global Climate ◽  
Severity Index ◽  
The United States ◽  
Global Climate Models ◽  
Drought Severity ◽  
Near Term ◽  
Local Variability

Major droughts in the United States have heavily impacted the hydrologic system, negatively effecting energy and food production. Improved understanding of historical drought is critical for accurate forecasts. Data from global climate models (GCMs), commonly used to assess drought, cannot effectively evaluate local patterns because of their low spatial scale. This research leverages downscaled (~4 km grid spacing) temperature and precipitation estimates from nine GCMs’ data under the business-as-usual scenario (Representative Concentration Pathway 8.5) to examine drought patterns. Drought severity is estimated using the Palmer Drought Severity Index (PDSI) with the Thornthwaite evapotranspiration method. The specific objectives were (1) To reproduce historical (1966–2005) drought and calculate near-term to future (2011–2050) drought patterns over the conterminous USA. (2) To uncover the local variability of spatial drought patterns in California between 2012 and 2018 using a network-based approach. Our estimates of land proportions affected by drought agree with the known historical drought events of the mid-1960s, late 1970s to early 1980s, early 2000s, and between 2012 and 2015. Network analysis showed heterogeneity in spatial drought patterns in California, indicating local variability of drought occurrence. The high spatial scale at which the analysis was performed allowed us to uncover significant local differences in drought patterns. This is critical for highlighting possible weak systems that could inform adaptation strategies such as in the energy and agricultural sectors.

scholarly journals Influence of the Pacific Decadal Oscillation on Winter Precipitation and Drought during Years of Neutral ENSO in the Western United States

2007 ◽  
Vol 22 (1) ◽  
pp. 116-124 ◽  
Author(s):  
Gregory B. Goodrich
Keyword(s):  
United States ◽  
Pacific Northwest ◽  
Pacific Decadal Oscillation ◽  
Severity Index ◽  
Winter Precipitation ◽  
Western United States ◽  
Drought Severity ◽  
The Pacific ◽  
Area Of Influence ◽  
Hydroclimatic Variables

Abstract The influence of the Pacific decadal oscillation (PDO) on important hydroclimatic variables during years of neutral ENSO for 84 climate divisions in the western United States is analyzed from 1925 to 1998. When the 34 neutral ENSO years are split by cold (12 yr) and warm (22 yr) PDOs, the resulting winter precipitation patterns are spatially similar to those that occur during years of La Niña–cold PDO and, to a lesser extent, years of El Niño–warm PDO, respectively, although the characteristic ENSO dipole is not evident. The PDO influence is similar when the winter Palmer drought severity index is analyzed, although the core area of influence moves from the Southwest to the northern Rockies. Correlations between Niño-3.4 SSTs and the hydroclimatic variables reverse sign when the neutral ENSO years are split by PDO phase. The greatest difference between correlations occurs in the characteristic dipole between the Pacific Northwest and the desert Southwest. Since seasonal forecast guidance based on ENSO conditions in the tropical Pacific often yields a forecast of “equal chances” during years of neutral ENSO, forecasters may be able to improve their forecasts for the southwestern United States depending on if the PDO is known to be in the cold (drier than normal) or warm (wetter than normal) phase. However, this can be difficult to implement considering the current uncertainty of the phase of the PDO.

Petrels collected by Titian Ramsay Peale in the Pacific Ocean during the United States Exploring Expedition of 1838–1842

2008 ◽  
Vol 35 (1) ◽  
pp. 143-149 ◽  
Author(s):  
W. R. P. BOURNE
Keyword(s):  
United States ◽  
Pacific Ocean ◽  
The United States ◽  
Important Type ◽  
The Pacific ◽  
The Pacific Ocean

The report by Titian Ramsay Peale on birds encountered during the Wilkes Expedition was withdrawn for inaccuracy when few copies had been distributed, and re-written by John Cassin. A survey of the accounts of the petrels shows that this was not an improvement. Two important type localities for Procellaria brevipes and Thalassidroma lineata are probably wrong, and could be exchanged.

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