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Articles 1291 - 1320 of 1402

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Continuous Lake-Sediment Records Of Glaciation In The Sierra Nevada Between 52,600 And 12,500 14c Yr B.P., Larry Benson, Howard M. May, Ronald C. Antweiler, Terry I. Brinton, Michaele Kashgarian, Joseph P. Smoot, Steve P. Lund Jan 1998

Continuous Lake-Sediment Records Of Glaciation In The Sierra Nevada Between 52,600 And 12,500 14c Yr B.P., Larry Benson, Howard M. May, Ronald C. Antweiler, Terry I. Brinton, Michaele Kashgarian, Joseph P. Smoot, Steve P. Lund

United States Geological Survey: Staff Publications

The chemistry of the carbonate-free clay-size fraction of Owens Lake sediments supports the use of total organic carbon and magnetic susceptibility as indicators of stadial-interstadial oscillations, Owens Lake records of total organic carbon, magnetic susceptibility, and chemical composition of the carbonate-free, clay-size fraction indicate that Tioga glaciation began ~24,500 and ended by ~13,600 14C yr B.P. Many of the components of glacial rock flour (e.g., TiO2 , MnO, BaO) found in Owens Lake sediments achieved maximum values during the Tioga glaciation when valley glaciers reached their greatest extent. Total organic carbon and Si02 (amorphous) concentrations reached minimum values …


Early Life History Stages Of Gulf Sturgeon In The Suwannee River, Florida, Kenneth J. Sulak, James P. Clugston Jan 1998

Early Life History Stages Of Gulf Sturgeon In The Suwannee River, Florida, Kenneth J. Sulak, James P. Clugston

United States Geological Survey: Staff Publications

Egg sampling confirmed that Suwannee River Gulf sturgeon Acipenser ozyrinchus desotoi, a subspecies of Atlantic sturgeon A. o. oxyrinchus use the same spawning site at river kilometer (rkm) 215 from the mouth of the river each year. Forty-nine eggs were recorded in 1995, and 368 were recorded in 1996. Spawning began 4-7 d after the March new moon in both years and lasted 10-11 d; in 1996, a second 10-d spawning round began on the April new moon. Developmental synchrony among eggs recovered suggested serval discrete spawning events in both years. Total eggs deposited for three 1996 sampling days …


Agrometeorological Aspects Of Crop Production In Temperate Kashmir, Badrul Hasan Jun 1997

Agrometeorological Aspects Of Crop Production In Temperate Kashmir, Badrul Hasan

Drought Network News (1994–2001)

In our recent article on forecasting uncertain weather over temperate Kashmir (India) (Drought Network News, Vol. 9, No. 1, pp. 12–14), we tried to characterize the crop-growing environments by giving long-term means of various agrometeorological parameters (such as air temperature, relative humidity, precipitation, and hours of bright sunshine). Forecast analysis for changes in temperature and precipitation events indicated an overall reliability of about 50%. Changes in minimum temperature could be forecasted relatively more accurately than changes in maximum temperature. Precipitation events were more uncertain during summer (May to October), which happens to be an important season from the …


National Drought Mitigation Center Involved In Development Of Natural Hazards Map, Michael J. Hayes Jun 1997

National Drought Mitigation Center Involved In Development Of Natural Hazards Map, Michael J. Hayes

Drought Network News (1994–2001)

The National Drought Mitigation Center (NDMC) is involved in a project with several other agencies and organizations in Canada, Mexico, and the United States to develop a map of the major natural hazards that threaten North America. Work on the project began in February 1995. Since then, there have been three working group meetings, with the most recent meeting taking place in Guadalajara, Mexico, in February 1997. Project leaders include Dr. Chris Tucker (Emergency Preparedness Canada), Dr. Joe Golden (National Oceanic and Atmospheric Administration [NOAA]), Dr. Rosalind Helz (U.S. Geological Society [USGS]), and Dr. Mario Ordaz- Schroeder (Centro Nacional de …


Workshop On Drought And Desertification: Report On The Workshop And Recommendations, J. Lomas Jun 1997

Workshop On Drought And Desertification: Report On The Workshop And Recommendations, J. Lomas

Drought Network News (1994–2001)

The Workshop on Drought and Desertification was held in Israel from 26 to 30 May 1997. Forty-four participants from Africa, Asia, and Europe took part in the Workshop, which was sponsored by WMO. Three foreign experts provided in-depth analysis on drought and drought preparedness—Dr. O. Brunini (Campinas, Brazil), Prof. S. Mei (CAAS, Beijing, China), and Dr. D. Wilhite (University of Nebraska, USA), in addition to the Israeli lecturers.

Presentations by lecturers and discussions were conducted under the following four main headings:
1. Drought and Desertification Definitions.
2. Drought Causes and Management Response.
3. Drought Monitoring and Mitigation.
4. Assessing Drought …


A Case Study Of The Deficit Spell Index For India’S Semiarid Delhi Region, K. K. Nathan Jun 1997

A Case Study Of The Deficit Spell Index For India’S Semiarid Delhi Region, K. K. Nathan

Drought Network News (1994–2001)

The Delhi region, the national capital region of India, is locked in by adjoining states like Uttar Pradesh and Haryana. Delhi has a characteristic continental type of climate, with extreme dryness, intensely hot summers, and dry cold winters. According to climatologists, this region is classified as semiarid tropical steppe. The monsoon rainfall is very erratic during June–September, which is the kharif crop-growing season. The monsoon breaks over the Delhi region between the first and second week of July and withdraws by the last week of September. The average annual rainfall is about 712.5 mm, of which 80% is contributed by …


Ndmc Conducting Regional Drought Planning Workshops Jun 1997

Ndmc Conducting Regional Drought Planning Workshops

Drought Network News (1994–2001)

The National Drought Mitigation Center is conducting a series of regional workshops, “Planning for the Next Drought,” around the country in 1997 and 1998. The first workshop was in Albuquerque, New Mexico, July 28–30. Plans are underway to conduct similar workshops in other regions. A second workshop will probably be held in Salt Lake City in late 1997, followed by workshops in the Southeast and Midwest in 1998. Because the workshops are sponsored by the U.S. Bureau of Reclamation, there is no registration fee.


Localized Severe Drought During 1996 And Its Impact On Crop Production In Raipur District Of Central India, J. S. Urkurkar, V. K. Koshta, Diwakar Naidu, A. S. R. A. S. Sastri Jun 1997

Localized Severe Drought During 1996 And Its Impact On Crop Production In Raipur District Of Central India, J. S. Urkurkar, V. K. Koshta, Diwakar Naidu, A. S. R. A. S. Sastri

Drought Network News (1994–2001)

In Raipur district, the onset of the monsoon occurred in the 25th standard meteorological week (June 18–24). But after the onset of monsoonal rains, there was a lull in the monsoon for about 2 consecutive weeks. In the 28th week (July 9–15), the district received 77.6 mm of rainfall. This was equal to the normal value for that week. In the following (29th) week, the district received 96.8 mm rainfall, 38.9% more than the normal rainfall for that week.

Thus, the rice, soybean, and other crops sown with the onset of the monsoon in the 25th week suffered from acute …


From The Director: June 1997, Donald A. Wilhite Jun 1997

From The Director: June 1997, Donald A. Wilhite

Drought Network News (1994–2001)

Drought policy continues to be a topic of much discussion in the United States. On June 12, the Western Drought Coordination Council (WDCC) met for the first time and adopted a work plan for 1997–98. The WDCC is committed to improving drought management in the western states through mitigation and preparedness. It is hoped that this Council, representing a partnership between federal, state, local, and tribal government, will serve as a model for other drought-prone regions of the United States. Four working groups (preparedness and mitigation; monitoring, assessment, and prediction; response; and communications) established by the Council will meet in …


Western Drought Coordination Council: Frequently Asked Questions, Donald A. Wilhite Jun 1997

Western Drought Coordination Council: Frequently Asked Questions, Donald A. Wilhite

Drought Network News (1994–2001)

Contents:

What is the Western Drought Coordination Council (WDCC)?

What does the WDCC hope to accomplish?

What prompted the formation of the Council?

Preparedness and Mitigation

Monitoring, Assessment, and Prediction

Response

Communications

To Whom does the WDCC report?

How do I get in touch with the Council?


Announcements: June 1997 Jun 1997

Announcements: June 1997

Drought Network News (1994–2001)

Contents:

Regenerative Agriculture for the 21st Century

4th International Symposium on Environmental Geotechnology and Global Sustainable Development - Call for Abstracts


Announcements: February 1997 Feb 1997

Announcements: February 1997

Drought Network News (1994–2001)

Contents:

Local Authorities Confronting Disasters and Emergencies-Third International Conference

1997 National Conference on Delivering Health and Medical Services in Catastrophic Disasters

Book: Policy Making in an Era of Global Environmental Change


Drought In The United States: 1996 Summary And Historical Perspective, William O. Brown, Richard R. Heim Jr. Feb 1997

Drought In The United States: 1996 Summary And Historical Perspective, William O. Brown, Richard R. Heim Jr.

Drought Network News (1994–2001)

Considerable variation in moisture conditions, on both a spatial and temporal basis, occurred in the contiguous United States during 1996. A tenth or more of the country experienced severe to extreme short-term (i.e., monthly) precipitation deficits during nearly half of the months, but in many months there were also large areas of excessive precipitation, which resulted in overall national conditions averaging near normal to wetter than normal. From a national perspective, long-term drought peaked at mid-year, when severe drought plagued the South and Southwest.


Famine And Drought: The Question Of Food Security In Zimbabwe, Joshua Chigodora Feb 1997

Famine And Drought: The Question Of Food Security In Zimbabwe, Joshua Chigodora

Drought Network News (1994–2001)

From the time that the London Missionary Society first took Zimbabwean rainfall records at Hope Fountain in 1888, the worst droughts on record are the consecutive dry spells from 1911 to 1914, the 1946–47 drought, the 1960 drought, and the 1972–73 rainy season, which was the driest period of colonial Zimbabwe. The country also had serious food shortages in 1903, 1916, 1922, 1933, and 1942. Although the people of precolonial Zimbabwe experienced recurrent droughts, they generally had well-developed coping mechanisms that prevented high death tolls (Iliffe, 1990).


Climatic Uncertainties And Recent Experiences In Medium-Range Weather Forecasting Over Kashmir, Badrul Hasan, Rehana Habib Kanth Feb 1997

Climatic Uncertainties And Recent Experiences In Medium-Range Weather Forecasting Over Kashmir, Badrul Hasan, Rehana Habib Kanth

Drought Network News (1994–2001)

Successful crop management and production require a precise and thorough understanding of agroclimatic conditions of a region. A crop experiences a range of weather conditions during its vegetative and reproductive phases. Although the agronomic inputs at optimum levels decide satisfactory and stable crop yields, the range of weather and climatic optimum prevalent at important crop stages determine the ultimate yields. Thus, even with all inputs at our disposal, we cannot afford to ignore the environmental conditions experienced by the crop. Systematic and continuous measurements of weather elements provide basic data input for tuning any type of computer-based forecasting system. This …


Changing Climatic Scenarios And Strategies For Drought Management In The Indian Arid Region, A. S. Rao, J. P. Gupta, A. S. Faroda Feb 1997

Changing Climatic Scenarios And Strategies For Drought Management In The Indian Arid Region, A. S. Rao, J. P. Gupta, A. S. Faroda

Drought Network News (1994–2001)

Western Rajasthan constitutes 62% of the 0.32 million km2 that make up the hot Indian arid region (Figure 1). The average annual rainfall of the area varies from less than 100 mm (coefficient of variation [CV] = 70%) in the western parts to just above 500 mm (CV = 40%) in the eastern parts of arid Rajasthan. During July and August, the eastern parts of the arid region have an assured crop growing period of 12–15 weeks, whereas the western parts mostly depend on the vagaries of the southwest monsoon. The annual potential evapotranspiration rates are 3–8 times higher …


From The Director: February 1997, Donald A. Wilhite Feb 1997

From The Director: February 1997, Donald A. Wilhite

Drought Network News (1994–2001)

In the October issue of Drought Network News, I briefly discussed two policy initiatives that developed in response to the severe and widespread drought that affected the Southwest and southern Great Plains states in the United States during 1996. The first of these activities, a multistate workshop (and its subsequent report), was coordinated by the Federal Emergency Management Agency. This report was submitted to President Clinton in late August; it contained a series of recommendations that focused on short- and long-term issues. The second initiative, under the leadership of the Western Governors’ Association (WGA), was not available in final …


Ground Water, Robert F. Diffendal Jr. Jan 1997

Ground Water, Robert F. Diffendal Jr.

Department of Earth and Atmospheric Sciences: Faculty Publications

A geologic overview of the groundwater supply underlying Cheyenne County, Nebraska (1997).


Nearly Synchronous Climate Change In The Northern Hemisphere During The Last Glacial Termination, Larry V. Benson, James Burdett, Steve Lund, Michaele Kashgarian, Scott Mensing Jan 1997

Nearly Synchronous Climate Change In The Northern Hemisphere During The Last Glacial Termination, Larry V. Benson, James Burdett, Steve Lund, Michaele Kashgarian, Scott Mensing

United States Geological Survey: Staff Publications

The climate of the North Atlantic region underwent a series of abrupt cold/warm oscillations when the ice sheets of the Northern Hemisphere retreated during the last glacial termination (17,700–11,500 years ago). Evidence for these oscillations, which are recorded in European terrestrial sediments as the Oldest Dryas/Bølling/ Older Dryas/Allerød/Younger Dryas vegetational sequence, has been found in Greenland ice cores. The geographical extent of many of these oscillations is not well known, but the last major cold event (the Younger Dryas) seems to have been global in extent. Here we present evidence of four major oscillations in the hydrological balance of the …


Correlation Of Late-Pleistocene Lake-Level Oscillations In Mono Lake, California, With North Atlantic Climate Events, Larry Benson, Steve P. Lund, James W. Burdett, Michaele Kashgarian, Timothy P. Rose, Joseph P. Smoot, Martha Schwartz Jan 1997

Correlation Of Late-Pleistocene Lake-Level Oscillations In Mono Lake, California, With North Atlantic Climate Events, Larry Benson, Steve P. Lund, James W. Burdett, Michaele Kashgarian, Timothy P. Rose, Joseph P. Smoot, Martha Schwartz

United States Geological Survey: Staff Publications

Oxygen-18 (18O) values of sediment from the Wilson Creek Formation, Mono Basin, California, indicate three scales of temporal variation (Dansgaard-Oeschger, Heinrich, and Milankovitch) in the hydrologic balance of Mono Lake between 35,400 and 12,900 14C yr B.P. During this interval, Mono Lake experienced four lowstands each lasting from 1000 to 2000 yr. The youngest low stand, which occurred between 15,500 and 14,000 14C yr B.P., was nearly synchronous with a desiccation of Owens Lake, California. Paleomagnetic secular variation (PSV) data indicate that three of four persistent low stands occurred at the same times as Heinrich events …


Food Security In The Southern African Development Community States, Joshua Chigodora Oct 1996

Food Security In The Southern African Development Community States, Joshua Chigodora

Drought Network News (1994–2001)

The 1995–96 cereal harvest in the Southern African Development Community (SADC) is the best within the last ten years. Provisional assessments project a regional maize surplus of 2.08 million tons, a 72% increase in production over the previous year’s harvest. Overall cereal production substantially increased in all countries except Tanzania, where the current cereal forecast of 3.73 million tons is a 14% drop from last year’s output of 4.34 million tons. Of special note are the exceptionally large increases in the area planted in cereals in war-ravaged Angola and Mozambique, for the first time in many years. Production trebled in …


Assessing The Impacts Of El Niño And Non-El Niño-Related Droughts Over India, R. H. Kripalani, Ashwini Kulkarni Oct 1996

Assessing The Impacts Of El Niño And Non-El Niño-Related Droughts Over India, R. H. Kripalani, Ashwini Kulkarni

Drought Network News (1994–2001)

It has now been recognized that the single most important key to the earth’s year-to-year climate variability is the El Niño/Southern Oscillation (ENSO) phenomenon. El Niño episodes directly affect the climate of at least half the planet and in many instances result in heavy loss of life and resources. The global impacts of El Niño events have been summarized in a review article by Bigg (1990), while the role of ENSO in Indian monsoon rainfall variability is given in Krishna Kumar et al. (1995). During the ENSO warm/ cold extremes—i.e., El Niño/La Niña events—the majority of the episodes induce below/above-normal …


Moisture Deficit Index Evaluated For Dry Regions Of India, K. K. Nathan, S. K. Sinha Oct 1996

Moisture Deficit Index Evaluated For Dry Regions Of India, K. K. Nathan, S. K. Sinha

Drought Network News (1994–2001)

In India, about 70% of the cultivable land is rainfed. This includes areas where crops are rarely affected by drought and areas where crops experience moisture stress and often fail. The regions with the latter characteristics are often called dryland areas and the agriculture so practiced there is known as dryland agriculture. About 35% of the total cultivable land belongs in this category. To determine the magnitude of water deficiency in these regions, the moisture deficit index (MDI) has been evaluated for dryland stations in India. The MDI is usually determined on the basis of annual precipitation and annual potential …


Exploring The Potential For Using Enso Forecasts In The U.S. Corn Belt, Jennifer G. Phillips, Cynthia Rosenzweig, Mark Cane Oct 1996

Exploring The Potential For Using Enso Forecasts In The U.S. Corn Belt, Jennifer G. Phillips, Cynthia Rosenzweig, Mark Cane

Drought Network News (1994–2001)

Interannual climate variability poses the greatest risk that farmers face. Until recently, seasonal climate forecasts have been weak and therefore rarely observed by farmers in making management decisions. Farm management is generally based on long-term mean expectations of climate and crop responses to local edaphic conditions. Currently, significant progress is being made in the skill level of predictions of seasonal to interannual climate, primarily because of new understanding of the teleconnections between ocean circulation and atmospheric processes. The El Niño/Southern Oscillation (ENSO) refers to fluctuations in both sea-surface temperatures (SSTs) in the eastern equatorial Pacific and in sea-level pressures in …


Meteorological Drought In Turkey: A Historical Perspective, 1930-–93, Murat Türkes Oct 1996

Meteorological Drought In Turkey: A Historical Perspective, 1930-–93, Murat Türkes

Drought Network News (1994–2001)

The climate of Turkey, which is mainly characterized by the Mediterranean macro climate, results from the seasonal alternation of frontal depressions with polar air masses and subtropical high pressures with subsiding maritime tropical and continental tropical air masses. Continental tropical airstreams from the northern African and Arabian deserts particularly dominate throughout the summer, by causing long-lasting warm (hot) and dry conditions over Turkey (except the Black Sea region and northeastern Anatolia). Turkey has an area of 779,452 km2 and an average elevation of 1,132 m.

This study outlines some spatial and temporal characteristics of Turkey’s rainfall, particularly in terms …


Drought Continues In Hungary In 1995, Attila Bussay, Csaba Szinell Aug 1996

Drought Continues In Hungary In 1995, Attila Bussay, Csaba Szinell

Drought Network News (1994–2001)

In 1995, Hungary again suffered from serious drought. Fortunately, drought has not extended over the whole country. It is primarily centered in the southeast, a plain area with significant agricultural production.

Meteorological conditions have been the most important factors in the evolution of the drought. The start of 1995 was not ideal; dry conditions during 1994 resulted in poor soil moisture at the beginning of the season. In Figure 1, the water shortage is indicated using the Palmer Drought Severity Index (PDSI), revealing the extraordinarily dry winter conditions in the east.


A Prototype National Drought Alert Strategic Information System For Australia, Ken D. Brook, John O. Carter Aug 1996

A Prototype National Drought Alert Strategic Information System For Australia, Ken D. Brook, John O. Carter

Drought Network News (1994–2001)

Defining and categorizing drought in a quantitative and scientific manner are important national issues for Australian state and Commonwealth governments, landholders, and agribusiness. The challenge for modelers of Australia’s grasslands is to integrate biological models, geographic information systems (GIS), satellite imagery, economics, climatology, and visual high-performance computing into an Internet-deliverable application that can provide easily understood monitoring and prediction advice in near real-time— a national drought alert strategic information system.

Although NOAA satellite-derived imagery has been somewhat useful in the broad-scale spatial assessment of green cover, especially the spatial response of vegetation to rainfall events (Smith, 1994; Dudgeon et al., …


Simulation The Shift In Position Of Hinge Lines Between Two, Shallow, Flow-Through Lakes, Mohan J. Khisty Aug 1996

Simulation The Shift In Position Of Hinge Lines Between Two, Shallow, Flow-Through Lakes, Mohan J. Khisty

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Groundwater flow between two hypothetical, shallow, flow-through lakes was numerically simulated in steady state and transient conditions for two cases. In the first case the lakes are at identical surface water elevations and in the second case there is a small difference in surface water elevations between them. Simulation results from both cases indicate a direct relation between movement of hinge lines, which indicate changes in the direction of groundwater-lake seepage components, and the seasonal persistence and decline of a groundwater mound that exists between the two lakes. A comparison between steady-state simulation results for both cases indicates that a …


Changes In Drought Policies In New Zealand, Heather J. Keen, Lynmore Rotorua Jun 1996

Changes In Drought Policies In New Zealand, Heather J. Keen, Lynmore Rotorua

Drought Network News (1994–2001)

New Zealand, lying in the South Pacific Ocean approximately 1,200 miles east of Australia, is subject to recurring droughts. Its two main islands are long and narrow, with high mountain ranges and hill country bisecting them from north to south. The predominant westerly winds, along with the mountain ranges and hill country, produce a marked orographic effect. Thus, the western side of the country, in general, records significantly higher annual average rainfall totals than does land on the eastern side.

The country has experienced a number of severe droughts throughout its history, especially in the east, where a number of …


Recent Advances In Seasonal Forecasting In Southern Africa, Leonard S. Uganai Jun 1996

Recent Advances In Seasonal Forecasting In Southern Africa, Leonard S. Uganai

Drought Network News (1994–2001)

Climatic uncertainty posed by the looming possibility of unprecedented climatic change is presenting society with new challenges the world over. In recent years, demand for long-range seasonal to interannual climate forecasts has been on the rise as society grapples with climatic risk management in southern Africa. Although more investment is still required to bring weather services in the region to a level advanced enough to handle the emerging complex and economically justified user needs for climatic services and products, some commendable progress has already been made, particularly in providing seasonal forecasts in addition to the other traditional core services and …