Oceanography and Atmospheric Sciences and Meteorology Commons^™

Drought In Beijing, 1992-93, Zhuang Xie, Dagang Chen

Drought Network News (1994–2001)

Beijing, located in northeast China, has a semiarid monsoon climate, with summer rainfall providing about 70% of the annual precipitation. This climate is conducive to crop growth, although insufficient summer rainfall in 1992–93 caused reductions in crop yields. Normalized departures of monthly precipitation (DR/R%) are shown in Figure 1. Although some months show above-normal precipitation (for example, November 1992, with a rainfall amount [43.3 mm] 7.5 times the normal), rainfall for the 1993 growing period was marked by negative departures from normal. Of the months of the 1993 growing season, only July recorded above-normal rainfall. Precipitation departures in May, September, …

Drought Classifications And Crop Plans Developed For Tamilnadu, R. Kulandaivelu, K. Jayachandran

Drought Network News (1994–2001)

Drought is defined as inadequate soil moisture to support crop growth and normal yield. The degree of drought for a given location depends on the crop, rainfall and its distribution, soil type, and various management practices. Drought occurs frequently in Tamilnadu—some part of the state experiences drought every year.

The state of Tamilnadu is located in the southernmost tip of peninsular India. It lies between 8°5" and 13°35" latitude north and 76°15" and 80°20" longitude east, covering an area of 0.13 million km2 and including a long coastline (about 1,000 km). The mean annual rainfall is 945 mm, with 45 …

Drought Monitoring And Advisory Services In South Africa, M. V. Laing

Drought Network News (1994–2001)

The normal total rainfall for the summer rainfall areas in South Africa is 664 mm. Since 1963, the country has recorded 16 seasons below normal and 14 above normal. Since the 1982–83 season, 7 seasons have been below normal and 4 have been above normal. Of these last 11 years, two rainy seasons recorded less than 75% of normal rainfall, which is a coarse estimation of severe drought. These seasons were 1982–83, when an average total of only 408 mm was measured, and 1992–93, when the average total was 484 mm. Although 1991–92 has been called the worst drought this …

Persistent Drought In 1993 Affects Bulgarian Agriculture, Nikola Slavov, Vesselin Alexandrov

Drought Network News (1994–2001)

The drought of 1992 persisted through the winter of 1993 (see Drought Network News, Vol. 5, No. 2 [June 1993]:12-15). Figure 1 shows the monthly values of national rainfall in 1993 and their normal averages. National rainfall was 28% and 63%, respectively, of the mean during January and February 1993. During March, rainfall was about normal, but drought conditions persisted because of the rainfall deficit from the summer of 1992. Water supplies increased until 20 April 1993, but after this date, drought conditions returned. At the end of April, the soil moisture in the 0-20 cm layer was 10- 25 …

Economic Impacts Emphasize Need For Greater Drought Planning And Management In El Salvador, Lidia Castillo

Drought Network News (1994–2001)

In terms of drought management and preparedness, El Salvador is one of the most underdeveloped countries. Although the direct and indirect effects of drought are often costly for the country, no official drought policy exists. One of the most important direct effects of drought is the loss of high percentages of basic grains (beans, corn, rice, and a type of sorghum called maicillo); these grains (except for maicillo) form the basic diet. Among the indirect effects of drought is the reduction of national production as an effect of electric power rationing due to drought and sabotage of the national electric …

Geochemical Evidence Of Saharan Dust Parent Material For Soils Developed On Quaternary Limestones Of Caribbean And Western Atlantic Islands, Daniel R. Muhs, Charles A. Bush, Kathleen C. Stewart, Tracy R. Rowland, Russell C. Crittenden

United States Geological Survey: Staff Publications

Most previous workers have regarded the insoluble residues of high-purity Quatemary limestones (coral reefs and oolites) as the most important parent material for well-developed, clay-rich soils on Caribbean and western Atlantic islands, but this genetic mechanism requires unreasonable amounts of limestone solution in Quatemary time. Other possible parent materials from external sources are volcanic ash from the Lesser Antilles island arc and Saharan dust carried across the Atlantic Ocean on the northeast trade winds. Soils on Quatemary coral terraces and carbonate eolianites on Barbados, Jamaica, the Florida Keys (United States), and New Providence Island (Bahamas) were studied to determine which, …

Stable Isotopes Of Oxygen And Hydrogen In The Truckee River-Pyramid Lake Surface-Water System, 2. A Predictive Model Of Δ18O And Δ2H In Pyramid Lake, S. W. Hostetler, Larry Benson

United States Geological Survey: Staff Publications

A physically based model of variations in δ¹⁸O and δ²H in Pyramid Lake is presented. For inputs, the model uses measurements of liquid water inflows and outflows and their associated isotopic compositions and a set of meteorological data (radiative fluxes, air temperature, relative humidity, and windspced). The model simulates change of lake volume, thermal and isotopic stratification, evaporation, and the isotopic composition of evaporation. A validation of the model for 1987-1989 and 1991 indicates that it can reproduce measured intra- and interannual variations of δ¹⁸O and δ²H. Three applications of the model …

Stable Isotopes Of Oxygen And Hydrogen In The Truckee River-Pyramid Lake Surface-Water System. 1. Data Analysis And Extraction Of Paleoclimatic Information, Larry Benson

United States Geological Survey: Staff Publications

The δ¹⁸O content of streamflow discharge entering Pyramid Lake is a simple mixture of isotopically enriched Lake Tahoe discharge and isotopically depleted snowmelt. The δ¹⁸O value of Pyramid Lake water varies continuously, as isotopically depleted water evaporates from the epilimnion and isotopically depicted water enters the lake as streamflow discharge and on-lake precipitation. In a normal water year, the δ¹⁸O of Pyramid Lake surface water varies seasonally because the components of the hydrologic balance in the Pyramid Lake system are seasonally shifted. The problem of isotopic and thermal heterogeneity can be minimized by analyzing …

Stable Isotopes Of Oxygen And Hydrogen In The Truckee River-Pyramid Lake Surface-Water System, 3: Source Of Water Vapor Overlying Pyramid Lake, Larry Benson, J. W. C. White

United States Geological Survey: Staff Publications

During 1988 and 1989, a series of water-vapor extractions were conducted in the Pyramid Lake basin to determine the source of moisture that overlies the lake. Calculations of the isotopic and water-vapor balances were made from isotopic and meteorological data from the Pyramid Lake and Reno, Nevada, areas. The results indicate that in the warm season, most of the moisture that overlies the lake is derived from evaporation as opposed to advected moisture. Isotopic fluxes at the lake surface can be approximated by climatic data from the lake site, which simplifies the calculation of this input in numerical simulations of …

Probable Glacial Climatic Conditions In Source Areas During Deposition Of Parts Of The Ash Hollow Formation, Ogallala Group (Late Tertiary), Of Western Nebraska, Patricia E. Helland, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Evidence of the climatic conditions in the mountain sediment source areas for the late Tertiary Ash Hollow Formation of the Ogallala Group in western Nebraska has been sought in an SEM (scanning electron microscope) study of surface features on detrital quartz grains from these deposits. The following lines of indirect evidence raised the possibility of glacial conditions: uplift of up to 3500 m in the source areas, paleohydrologic parameters indicative of a transport system analogous to the modern North Saskatchewan River, and possible cold climate surface features on cobbles from the deposits. SEM analysis shows that five of the nine …

The Potential Effects Of Climate Change On Summer Season Dairy Cattle Milk Production And Reproduction, Peggy L. Klinedinst, Donald A. Wilhite, G. Leroy Hahn, Kenneth G. Hubbard

National Drought Mitigation Center: Faculty Publications

The potential direct effects of possible global warming on summer season dairy production and re-production were evaluated for the United States and Europe. Algorithms used for milk production and conception rate were previously developed and validated. Three widely known global circulation models (GISS, GFDL, and UKMO) were used to represent possible scenarios of future climate. Milk production and conception rate declines were highest under the UKMO model scenario and lowest under the GISS model scenario. Predicted declines for the GCM scenarios are generally higher than either “l year in 10” probability-based declines or declines based on the abnormally hot summer …

Global Snow Cover Monitoring: An Update, David A. Robinson, Kenneth F. Dewey, Richard R. Heim Jr.

United States Department of Commerce: Staff Publications

Accurate monitoring of the large-scale dimensions of global snow cover is essential for understanding details of climate dynamics and climate change. Presently, such information is gathered individually from ground station networks and satellite platforms. Efforts are in progress to consolidate and analyze long-term station records from a number of countries. To gain truly global coverage, however, satellite-based monitoring techniques must be employed. A 27-year record of Northern Hemisphere continental snow cover produced by the United States National Oceanic and Atmospheric Administration (NOAA) is the longest such environmental record available. Records of Southern Hemisphere continental cover and snow on top of …

Aminostratigraphy And Oxygen Isotope Stratigraphy Of Marine Terrace Deposits Palos Verdes Hills And San Pedro Areas Los Angeles County California, Daniel R. Muhs, Gifford H. Miller, Joseph F. Whelean, George L. Kennedy

United States Geological Survey: Staff Publications

Amino acid and oxygen isotope data for fossils from terraces of the Palos Verdes Hills and San Pedro areas in Los Angeles County California shed new light on the ages of terraces sea level history marine paleotemperatures and late Quaternary tectonics in this region Low terraces on the Palos Verdes peninsula correlate with the 80 ka and 125 ka sea level highstands that are also recorded as terraces on other coasts In San Pedro the Palos Verdes sand the deposit on what is mapped as the first terrace by Woodring and others 1946 was previously thought to be a single …

The Last Interglacial-Glacial Transition In North America: Evidence From Uranium-Series Dating Of Coastal Deposits, Daniel R. Muhs

United States Geological Survey: Staff Publications

Considerable uncertainty exists as to whether the last interglacial was relatively "short" (~10 ka) or "long" (-20-60 ka), although most investigators generally agree that the last interglacial correlates with all or part of deep-sea oxygen-isotope stage 5. A compilation of reliable U-series ages of marine terrace corals from deposits that have been correlated with isotope stage 5 indicates that there were three relatively high sea-level stands at ca 125-120 ka, ca. 105 ka, and ca. 85-80 ka, and these ages agree with the times of high sea level predicted by the Milankovitch orbital-forcing theory. At a number of localities, however, …

Sr-Isotope Record Of Quaternary Marine Terraces On The California Coast And Off Hawaii, Kenneth R. Ludwig, Daniel R. Muhs, Kathleen R. Simmons, James G. Moore

United States Geological Survey: Staff Publications

Strontium-isotopic ratios of dated corals have been obtained from submerged reefs formed during Quaternary glacial periods off the Hawaiian islands. These data, combined with data from deep-sea sediments, tightly constrain the secular variation of marine ⁸⁷Sr/⁸⁶Sr for the past 800,000 yr. Although long-term trends are apparent, no significant (>0.02‰), rapid (<100,000 yr) excursions in ⁸⁷Sr/⁸⁶Sr were resolved nor did we observe any samples with ⁸⁷Sr/⁸⁶Sr greater than that of modern seawater. Strontium in mollusks from elevated marine terraces formed during interglacial periods on the southern California coast show resolvable and consistent variations in …

Reservoir Sedimentation Studies, D C. Boudurant, R H. Livesey

United States Army Corps of Engineers, Omaha District

It must be recognized that, when a reservoir is constructed on a stream, all or most of the sediment transported into the reservoir by the stream will be deposited there. With few exceptions, there is no practical method for reducing or eliminating the sediment inflow; thus it is necessary to anticipate and to provide for resulting problems. The major problem is, of course, the accumulative loss of storage capacity. Other items of importance include the distribution of the sediment with respect to various storage increments, the effect on the chemical or physical quality of the water, ecological effects, and the …

Potential Impacts Of Biomass Production In The United States On Biological Diversity, James H. Cook, Jan Beyea, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

Biomass could be a renewable source of energy and chemicals that would not add CO₂ to the atmosphere. It will become economically competitive as its cost decreases relative to energy costs, and biotechnology is expected to accelerate this trend by increasing biomass productivity. Pressure to slow global warming may also make biomass more attractive. Substantial dependence on biomass would entail massive changes in land use, risking serious reductions in biodiversity through destruction of habitat for native species. Forests could be managed and harvested more intensively, and virtually all arable land unsuitable for high-value agriculture or silviculture might be used …

Loss Of Biological Diversity: A Global Crisis Requiring International Solutions: A Report To The National Science Board, Craig Call Black, Perry L. Adkisson, Gardner Mallard Brown, Rita Rossi Colwell, Charles E. Hess, James B. Holderman, K. June Lindstedt-Siva, William A. Nierenberg, Peter Hamilton Raven, Theodore M. Smith, Edward O. Wilson, W. Franklin Harris

Harold W. Manter Laboratory of Parasitology: Library Materials

Executive Summary

Biological diversity refers to the variety and variability among living organisms and the ecological complexes in which they occur. Diversity can be defined as the number of different items and their relative frequency. For biological diversity, these items are organized at many levels, ranging from complete ecosystems to the chemical structures that are the molecular basis of heredity. Thus, the term encompasses different ecosystems, species, genes, and their relative abundance (OTA, 1987).

There is an ongoing, unprecedented loss of the variety as well as absolute numbers of organisms-from the smallest microorganism to the largest and most spectacular of …

The Uranium-Trend Dating Method: Principles And Application For Southern California Marine Terrace Deposits, Daniel R. Muhs, John N. Rosholt, Charles L. Bush

United States Geological Survey: Staff Publications

Uranium-trend dating is an open-system method for age estimation of Quaternary sediments, using disequilibrium in the ²³⁸U–²³⁴U–²³⁰Th decay series. The technique has been applied to alluvium, colluvium, loess, till, and marine sediments, in this study we tested the U-trend dating method on calcareous marine terrace deposits from the Palos Verdes Hills and San Nicolas Island, California. Independent age estimates indicate that terraces in these areas range from –80 ka to greater than 1.0 Ma. Two low terraces on San Nicolas Island yielded U-trend plots that have a clustered array of points and the ages of …

Drought Management: The Role Of Near- Real Time Weather Data, Donald A. Wilhite, Kenneth G. Hubbard

National Drought Mitigation Center: Faculty Publications

The ability to collect weather data in near-real time has improved because of technological advances, enabling weather data users to obtain more weather data over wider areas, and in a more timely fashion. The number of near-real time climate networks is increasing as new applications are found for climate data. More than fifteen states in the United States have established automated weather station networks. This paper presents an overview of recent developments in automated weather data collection in the United States and gives a detailed description of the network in Nebraska.

Near-real time weather data has many applications in agricultural …

Cropstatus--A Computer Program To Assess The Effects Of Seasonal Weather Changes On Nebraska's Agriculture, R. E. Neild, Donald A. Wilhite, K. G. Hubbard

National Drought Mitigation Center: Faculty Publications

CROPSTATUS is a series of programs residing in Nebraska's AGNET system using daily weather data to assess seasonal changes in crops, livestock, and other agricultural conditions. Assessments are based on parameters developed from accumulations of current daily temperature and precipitation data collected from a network of synoptic, climate, and automated micrometeorological stations in Nebraska in comparison with daily normals. The daily normals were derived from monthly summaries using multiple regression models to compute daily values as a function of Julian day numbers. Crop phenology models based on growing degree days were used to monitor and forecast the progress of different …

Improving Projected Potential Evapotranspiration Estimates Using National Weather Service Forecasts, Steven J. Meyer, Kenneth G. Hubbard, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

In a recent survey conducted by the University of Nebraska's Center for Agricultural Meteorology and Climatology of Agricultural Network (AGNET) users, the results of potential evapotranspiration (ET_p) projections (calculated using the Blaney-Criddle approach, which employs "normal" climatic data to project ET_p estimates up to three days into the future) were labeled "unrealistic." To improve these projections, National Weather Service (NWS) forecast variables were used as input into the Blaney-Criddle and Penman equations. ET_p projections calculated according to the Penman equation, with data measured by automated weather stations as input, were assumed to represent the "best" …

The Nebraska Agricultural Climate Situation Committee, R. E. Neild, K. G. Hubbard, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

The Nebraska Agricultural Climate Situation Committee consisting of an interdisciplinary group of extension specialists provides up-to-date information and advice on seasonal changes in crop/ weather conditions. The committee meets each Monday during the growing season to review:

1. Maps and tabular data developed by a computer program CIS /Crop Weather Information System/ that is linked to a network of weather stations and computer terminals in county agent offices.

2. Insect, plant disease and weed surveys.

3. Weekly weather and crop reports from the State/Federal System.

4. Weather outlooks from the National Weather Service.

5. Climate probabilities.

Situation reports and advisories …

A Preliminary Study Of The Hydrogeology Of The Dakota Formation In Douglas, Sarpy And Washington Counties, Eastern Nebraska, Thomas Mark O'Connor

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

This study provides preliminary information on the hydrogeology of the Dakota Formation within a 1,000 square-mile area in eastern Nebraska. Isopach maps of the Dakota Formation and individual sand and gravel beds were constructed using a computer contouring program. Hydraulic conductivity values for water-bearing sand beds in the Dakota were estimated using the equation for calculating the specific capacity of wells and results from a grain-size analysis. Concentrations of major dissolved species were determined for samples collected from twenty five wells. The Dakota Formation is characterized by an increase in thickkness and an increase in percentage of clay versus sand …

Genesis Of Marine Terrace Soils, Barbados, West Indies: Evidence From Mineralogy And Geochemistry, Daniel R. Muhs, Russell C. Crittenden, John N. Rosholt, Charles A. Bush, Kathleen C. Stewart

United States Geological Survey: Staff Publications

Well-developed, clay-rich soils dominated by interstratified kaolinite-smectite are found on the uplifted coral reef terraces on the island of Barbados. The reef limestone is unlikely to have been the soil parent material however, because it is 98 per cent CaCO, and geomorphic evidence argues against the 20 m of reef solution required to produce the soils by this process. The mineralogy of the sand, silt, and clay fractions of the soils, and trace element geochemistry, suggest that aeolian materials carried on the trade winds from Africa, volcanic ash from the island of St. Vincent, and quartz from Tertiary bedrock on …

Cliff-Height And Slope-Angle Relationships In A Chronosequence Of Quaternary Marine Terraces, San Clemente Island, California, Russell Crittenden, Daniel R. Muhs

United States Geological Survey: Staff Publications

Zusammenfassung. Eine Abfolge quartarer Strandterrassen auf ~an Clemente Island, Kalifornien, liefert einen Rahmen fur die quantitative Analyse der Anderungen an vom Meer verlassenen Kustenkliffen als Funktion der Zeit. Es wurde eine Abschatzung der Anwendbarkeit von BUCKNAM & ANDERSON (1979) log-lin~arer Beziehung zwischen Wandhohe und Hangwinkel durchgefuhrt, indem Brandungskliffhohe und maximale Hangwinkel verwendet wurden. Die Ergebnisse zeigen eine regelhafte Zunahme des Hangwinkels mit dem Logarithmus der Kliffhohe, und Kliffe einer bestimmten Hohe zeigen m,it der Zeit eine Abnahmedes maximalen Hangwinkels. 1m ganzen waren die Relationen schwacher als fur FluBterrassen und Bruchstufen in unverfestigten Materialen, aber die Methode kann wahrscheinlich verwendet werden, …

Reconnaissance Bathymetry Of Basins Occupied By Pleistocene Lake Lahontan, Nevada And California, Larry Benson, M. D. Mifflin

United States Geological Survey: Staff Publications

Beginning about 12,500 years B.P., Lake Lahontan began to decline (fig. 1: Black Rock Desert data from Davis [1983]; Truckee River Delta data from Born [1972]; tufa data from Benson [1981]; packrat-midden data from Thompson and others [1985]) . As water levels declined, their altitudes fell below sill altitudes (table 1); locations of these sills are shown in figure 2. Today, five surface-water bodies (Black Rock Playa, Humboldt-Carson Sink, Walker Lake, Pyramid Lake, Honey Lake) exist in four of the seven subbasins (fig. 2).

The collective surface area of the modern lakes today (1985) totals less than 1,600 km2 . …

Soils And The Location Of Cacao Orchards At A Maya Site In Western Belize, Daniel R. Muhs, Robert R. Kautz, J. Jefferson Mackinnon

United States Geological Survey: Staff Publications

Cacao was one of the most important crops of the lowland Maya. Ethnohistoric sources document that the Postclassic-Colonial Period Maya settlement of Tipu in western Belize was an important cacao-growing center, yet evidence of where the cacao was grown is not apparent. We analysed the suitability of floodplain, terrace, and bedrock soils for cacao cultivation. Our results indicate that the soils most likely to have been used for cacao growth were those on the modem floodplain of the Macal River, based on their suitable physical and chemical properties. In addition, buried stone walls of Late Classic or Postclassic age that …

An Evaluation Of Uranium-Series Dating Of Fossil Echinoids From Southern California Pleistocene Marine Terraces, Daniel R. Muhs, Los Angeles County Museum Of Natural History, Los Angeles, Ca

United States Geological Survey: Staff Publications

Fossil sea urchins (Strongylocentrotus) from Pleistocene marine terraces on the southern California Channel Islands have been dated by the uranium-series method in order to test the suitability of echinoids for dating marine terraces. Results indicate that urchin plates and spines do not behave as closed systems with respect to both uranium and thorium. Calculated ages based on these data do not agree with uranium-series ages (120,000 and 127,000 yrs) obtained previously from corals from the same localities. Thus, fossil sea urchins (Strongylocentrotus) are not considered suitable for uranium-series dating of Pleistocene marine terrace deposits.

J. P. Finley: The First Severe Storms Forecaster, Joseph G. Galway

National Oceanographic and Atmospheric Administration: Technical Reports and Related Materials

During the 19th century, while others were debating about the theory and morphology of tornadoes, Finley set out to prove that tornadoes, like other weather phenomena, could be forecast. He developed forecast rules and made experimental forecasts. His forecasting and analysis activities made him the center of controversy during most of his professional life and led to open debate in the literature, but he set precedents in meteorological forecasting that are still valid today. His career as a meteorologist started while he was a private in the United States Army. His interest continued even when he had achieved the rank …