Oceanography and Atmospheric Sciences and Meteorology Commons^™

Worsening Drought Conditions Affect Relay Cropping In Central India, J. L. Chaudhary, A. S. R. A. S. Sastri, D. Naidu, S. K. Srivastava

Drought Network News (1994–2001)

In the Chhattisgarh region of central India (Figure 1), rice is grown on about 3.7 million ha, of which 80% is under rainfed conditions. The rice crop is grown mostly under the broadcast biasi system of cultivation (see Drought Network News, Vol. 5, No. 3 [October 1993], pp. 6–7). The rainy season is the southwest monsoon (June–September) season. Farmers grow traditional local tall varieties of rice, which flower in mid-October and mature by mid- November.

El Niño’S Effect On Southwest Monsoon Rainfall In Andhra Pradesh, India, U. S. Victor, N. N. Srivastava, A. V. M. Subba Rao, B. V. Ramana Rao

Drought Network News (1994–2001)

India is primarily an agricultural country, despite making rapid strides in industrialization in recent decades. The Indian economy is therefore highly dependent on the behavior of the summer monsoon, also known as the southwest monsoon, which occurs during four months (June–September). This accounts for 75% of the annual rainfall over most parts of the country and also generates great demand for rainfall forecasts in different time scales. For nearly a century, Indian meteorologists have been attempting to develop suitable techniques that could be used for preparing long-range forecasts of monsoon rains over India. Walker (1923) has done pioneering work in …

Coping With Exceptional Droughts In Australia, David H. White, Bruce O'Meagher

Drought Network News (1994–2001)

The objectives of Australia’s National Drought Policy (NDP), agreed to by Commonwealth (national), state, and territory ministers in 1992, are to:

• encourage primary producers and other sections of rural Australia to adopt self-reliant approaches to managing the risks stemming from climatic variability;
• maintain and protect Australia’s agricultural and environmental resource base during periods of extreme climate stress; and
• ensure early recovery of agricultural and rural industries consistent with long-term sustainable levels.

Under the NDP, Australian farmers are expected to assume greater responsibility for managing the risks arising from climatic variability. This requires integrating financial and business management …

On The Interpentadal Variability Of The North Atlantic Ocean: Model Simulated Changes In Transport, Meridional Heat Flux And Coastal Sea Level Between 1955-1959 And 1970-1974, Tal Ezer, George L. Mellor, Richard J. Greatbatch

CCPO Publications

Previous studies by Greatbatch et al. (1991) indicate significant changes in the North Atlantic thermohaline structure and circulation between the pentads 1955–1959 and 1970–1974, using data analyzed by Levitus (1989a,b,c) and a simple diagnostic model by Mellor et al. (1982). In this paper these changes are modeled using a three-dimensional, free surface, coastal ocean model. Diagnostic and short-term prognostic calculations are used to infer the dynamically adjusted fields corresponding to the observed hydrographic and wind stress climatology of each pentad. While the results agree with earlier studies indicating that the Gulf Stream was considerably weaker (by about 30 Sv) during …

An Understanding Of Factors Controlling Isotopic Ratios Of Wine As A Potential Surrogate Of Past Precipitation, Eric Alan Caldwell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Precipitation, vapor water, ground water, soil water, grape berry and grape leaf water, grape must, and vintage wines were collected from northern California for stable isotopic analysis. An understanding of factors controlling isotopic ratios of wine allows evaluation of wine as a surrogate of past precipitation. Stable isotopic compositions of grape berry waters collected at Charles Krug Winery in Napa Valley. CA range from -31 to -17 per mil in 8D and +7.2 to +15.3 per mil in 8180, and plot along a transpiration line of slope 2. 7. Grape leaf waters range from -25 to +5 per mil in …

Book Review: Quaternary Geology And Geomorphology Of South America By C. Clapperton, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

Dr. Clapperton is to be commended for having taken on the monumental task of a review of the present state of knowledge of the Quaternary of the entire continent of South America. Quaternary Geology and Geomorphology of South America is a massive, interestingly written, but expensive volume that covers exactly what its title suggests. In spite of the paucity of information on many aspects of the Quaternary geology of this continent, which extends from north of the equator nearly to the Antarctic, the author has succeeded in reviewing and synthesizing most of the material that does exist. To do so …

Drought In The Lower Danube, Ekaterina Koleva

Drought Network News (1994–2001)

Bulgaria is situated on the Balkan Peninsula. Its northern frontier is the lower part of the Danube. The Balkan range, with its zonal situation, is part of a natural climatic frontier, dividing Bulgaria into two parts—north and south.

One of the main features of the climate in the Danube Plain (northern Bulgaria) is insufficient precipitation—a tendency toward dryness and frequent droughts. The annual amount of precipitation is 500–600 mm. The highest monthly values are measured in June (in some places in May), with 55–75 mm. February (in some places, March) is the driest month. Absence of precipitation can occur in …

Summer Drought Ravages Crops In Middle China, Huajie Tai

Drought Network News (1994–2001)

Drought affected China’s agricultural production in spring, summer, and fall 1994. The summer drought was very severe in the middle part of China, especially in Anhui and Jiansu provinces.

Relating United States Crop Land Use To Natural Resources And Climate Change, K. G. Hubbard, F. J. Flores-Mendoza

National Drought Mitigation Center: Faculty Publications

Crop production depends not only on the yield but also on the area harvested. The yield response to climate change has been widely examined, but the sensitivity of crop land use to hypothetical climate change has not been examined directly. Crop land-use regression models for estimating crop area indices (CAIs) - the percent of land used for corn, soybean, wheat, and sorghum production - are presented. Inputs to the models include available water-holding capacity of the soil, percent of land available for rain-fed agricultural production, annual precipitation, and annual temperature. The total variance of CAI explained by the models ranged …

Description And Vorticity Analysis Of 50-Day Oscillations In The Western Tropical Region Of The Cme Model, Julie L. Mcclean, John M. Klinck

CCPO Publications

The WOCE Community Modeling Effort (CME) general circulation model of the North Atlantic was used to investigate the behavior, nature, and dynamics of 50-day oscillations seen in the meridional component of velocity between 5 degrees and 11 degrees N, 35 degrees and 55 degrees W. Oscillations of the meridional component of velocity, with a period of about 50 days, appear as the seasonal meander pattern of the North Equatorial Countercurrent starts to break down in December. They appear first near 35 degrees W and are advected westward. They have a westward phase velocity of about 0.1 m s(-1), wavelength of …

Land Management Report For The Kent River Catchment, Sue Kelly

Natural resources published reports

The Kent River Catchment is located in the South-West of Western Australia, approximately between latitudes 34° 15' and 35° 10' South and longitudes 116° 45" and 117° 50° East. The north-eastern boundary of the catchment stretches to the Albany Highway at Tenterden, and from there the catchment curves towards Rocky Gully before continuing to the South Coast (Figure 1.1.1). The catchment is located within the Shires of Cranbrook, Plantagenet and Denmark.

The Kent River Catchment is part of Basin 604, which is the Water Authority descriptor for the Kent, Bow and Kordabup River catchments collectively. Basin 604 has a total …

A Guide To Floodplain Cattle Fencing, Department Of Agriculture, Western Australia, Main Roads, Western Australia

Animal production and livestock published reports

A seminar and workshop was held at Fitzroy Crossing in October 1993 to address the consequences of flooding to landholders and communities.

Damage to flood plain fencing was identified as one of the major concerns to landholders.

An outcome from the workshop was the decision to draw on local knowledge and collate information on options for fence and floodgate designs.

This information was to be made available to land holders and other interested parties - hence this publication.

Drought Vulnerability Of Rainfed Crops In Semiarid Tropics In India: New Methods Of Determining Rainfall Variability, U. S. Victor, N. N. Srivastava, P. Vijay Kumar

Drought Network News (1994–2001)

In dryland areas of India, rainfall is the main source of water for raising crops. For these areas, the greatest problem is not water shortage per se, but rather the tremendous variability in rainfall from year to year and season to season. In planning for the coming season, we currently have little or no ability to predict the date of the onset of rains or their amount, distribution, or duration. However, uncertainty about rainfall is lessened when information is available concerning the possible variability and frequencies of historical occurrences of rainfall. This information can be obtained by coupling water use …

Rainfall Patterns For India’S Karnataka State Show Above-Normal Precipitation For 1994-98, M. B. Rajegowda, D. M. Gowda

Drought Network News (1994–2001)

The Karnataka state, confined roughly within 11.5° N and 18.5° N latitude and 74° E and 78.5° E longitude, is situated on a table land at the point where the western and eastern Ghat range enclose the Nilgiri hill complex. It is enclosed by chains of mountains to its west, east, and south. The state consists mainly of plateau, with a higher elevation of 600 to 900 m amsl in small portions of the extreme north and northwest Karnataka and the whole of the southern half, an elevation of 300 to 600 m amsl in the north, and an elevation …

Ozone Heating And The Destabilization Of Traveling Waves During Summer, Terrence R. Nathan, Eugene Cordero, Long Li

Faculty Publications, Meteorology and Climate Science

The effects of ozone heating on the linear stability of lower stratospheric traveling waves of the summertime, extratropical circulation are examined. Based on coupled equations for the quasigeostrophic potential vorticity and ozone volume mixing ratio, it is shown that the diabatic heating arising from ozone advection can offset the damping due to Newtonian cooling, leading to wave amplification and significant changes in the structure and zonally rectified fluxes of the wave fields in both the lower stratosphere and troposphere. The vertical profile of the zonal mean wind plays a crucial role in determining whether the ozone heating destabilizes eastward and/or …

Drought Profile: Haryana State In North India, K. Kailasa Nathan

Drought Network News (1994–2001)

Haryana state is considered the breadbasket of India, along with the Punjab state. The effects of drought (and mitigation of those effects) are therefore of considerable importance for the state. This article considers the state’s drought “profile” through a study of six drought years in Haryana.

Haryana has a semiarid climate in the southwest and a Gangetic plain environment in the rest of the state. About 50% of the state has a moisture deficit. One of the reasons for adverse crop production in the state during June–September is the early withdrawal or late onset of monsoon rains, which contribute nearly …

Droughts Over Homogeneous Regions Of India: 1871–-1990, B. Parathasarathy, A. A. Munot, D. R. Kothawale

Drought Network News (1994–2001)

The summer monsoon (June through September), or southwest seasonal rains, contribute 78% of India’s annual rainfall. It is the greatest climatic water resource of India. The country’s agriculture and food production depend on these rains. Rainfed farming areas in India account for about 70% of the total arable land in the country, with nearly 100 million ha depending on the monsoon rains. The rains also contribute to power generation and industrial production.

Hydrometeorological Considerations For Rainwater Management During Drought Years In Peninsular India, J. B. Singh, B. V. Ramana Rao, J. C. Katyal

Drought Network News (1994–2001)

Peninsular India is located in the tropics; its climate ranges from arid conditions in the rain shadow region (under the influence of Eastern Ghats along the east coast and Western Ghats along the west coast) to humid conditions in regions adjoining the west coast. The average annual rainfall in the region varies from about 500 mm in the interior parts to more than 3000 mm on the crest of Western Ghats. The rainy season commences during the month of June because of the onset of the southwest monsoon near the tip of peninsular India. The southwest monsoon ends during September. …

Drought And Southern Africa: A Note From The Harare Regional Drought Monitoring Centre, Leonard S. Uganai

Drought Network News (1994–2001)

Drought is a normal part of southern Africa’s climate and one of the most important natural disasters in southern Africa. In fact, it is becoming increasingly unusual for drought not to occur somewhere in southern Africa each year. The dependence of most southern African economies on rainfed agriculture emphasizes the importance of drought early warning products for short- and long-term decision making in various sectors of the national economies of the region. Following the 1991–92 drought, which ravaged more than 80% of southern Africa, many in southern Africa now realize the value of meteorological information in weather-sensitive decisions. Requests for …

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, …

On The Low-Frequency Current And Temperature Fluctuations Along The Shelf Break In The South Atlantic Bight, Sunny Yu Wu

OES Theses and Dissertations

Current and temperature data collected along the shelf edge in the South Atlantic Bight were analyzed using a spectral analysis technique. The power spectra of both alongshore currents and temperatures (upon removal of seasonal trends) in the mid- to lower water column suggest a significant energy peak at 28 days. The spatial characteristics of the fluctuations around this period band were determined using the frequency domain empirical orthogonal function (EOF) analysis applied to the concurrent current and temperature records. Consistent results were obtained from the upstream side of the Charleston Bump. Around the 28-day period, temperature seems to have little …

Miscellaneous Publication 10/94 - The Climate And Soils Of South-Western Australia In Relation To Vine Growing, J. S. Gladstones

Viticulture research reports

The vine industry in Western Australia is at present located mainly in the Swan Valley, some 15 miles inland from Perth. It produces currants for export, wine grapes, and table grapes for both local and export markets, in approximately that order of importance.

Climatically, the Swan Valley is well suited to vine fruit production. With an annual rainfall of about 34 inches, it has a mild, wet, almost frost-free winter, and a warm, dry summer. Olmo (1956) concluded that the Swan was especially well suited to the production of currants, table grapes and sweet dessert wines. However, he considered that …

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 …

The Importance Of Understanding Climate And The Use Of Climate Information, Stanley A. Changnon

Journal of the Minnesota Academy of Science

In this paper, the interrelated issues of understanding climate and its importance are addressed through consideration of three factors. Considered first are the general views of climate, as seen by three principal groups who deal with climatic conditions; the public, the weather-sensitive sectors, and the scientific community. The second consideration is how the atmospheric sciences community and climatologists specifically, have helped society function. Finally, activities and knowledge of climate which are changing over time, are assessed. I want to stress these are views· developed over 43 years as an atmospheric scientist. I have had the privilege of conducting a wide …

Continuous Assimilation Of Geosat Altimeter Data Into A Three-Dimensional Primitive Equation Gulf Stream Model, Tal Ezer, George L. Mellor

CCPO Publications

A three-dimensional data assimilation scheme is described and tested, using the Geosat altimeter data and a high-resolution, primitive equation, numerical ocean model of the Gulf Stream region. The assimilation scheme is based on an optimal interpolation approach in which data along satellite tracks are continuously interpolated horizontally and vertically into the model grid and assimilated with the model prognostic fields. Preprocessed correlations between surface elevation anomalies and subsurface temperature and salinity anomalies are used to project surface information into the deep ocean; model and data error estimates are used to optimize the assimilation. Analysis fields derived from the Navy's Optimum …

Invariant Manifolds Of A Toy Climate Model, Michael Toner

Mathematics & Statistics Theses & Dissertations

According to astronomical theory, ice ages are caused by variations in the Earth's orbit. However, ice core data shows strong fluctuations in ice volume at a low frequency not significantly present in orbital variations. To understand how this might occur, the dynamics of a two dimensional nonlinear differential equation representing glacier/temperature interaction of an idealized climate was studied. Self sustained oscillation of the autonomous equation was used to model the internal mechanisms that could produce these fluctuations. Periodic parametric modulation of a damped internal oscillation was used to model periodic climate response at double the external modulation period. Both phenomena …

Periodic And Homoclinic Orbits In A Toy Climate Model, M. Toner, A. D. Kirwan Jr.

Mathematics & Statistics Faculty Publications

A two dimensional system of autonomous nonlinear ordinary differential equations models glacier growth and temperature changes on an idealized planet. We apply standard perturbative techniques from dynamical systems theory to study small amplitude periodic orbits about a constant equilibrium. The equations are put in cononical form and the local phase space topology is examined. Maximum and minimum periods of oscillation are obtained and related to the radius of the orbit. An adjacent equilibrium is shown to have saddle character and the inflowing and outflowing manifolds of this saddle are studied using numerical integration. The inflowing manifolds show the region of …