Climate Commons^™

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 …

Government Response To Drought In The United States: With Particular Reference To The Great Plains, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

Drought relief has become an expected response of the federal government to periods of widespread drought in the United States. A wide range of emergency, short-term and long-term drought programs were formulated to deal with the extreme drought of the 1930's. By 1977 there were 40 separate programs administered by 16 different federal agencies. This paper traces the development of federal drought relief bureaucracy, including drought designation criteria and procedures.

Two obvious deficiencies of past drought relief efforts in the United States are noted. First, drought relief organizations and programs have been hastily assembled during periods of crisis. This has …

Changing Fields: Agricultural Land Use Changes In Nebraska 1925-1974, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

The series of graphs and maps which follow illustrate agricultural land use changes in Nebraska from 1925 to 1974. With these graphs and maps, the major agronomic crops of corn (dryland and irrigated), wheat, sorghum and soybeans are analyzed. The purpose of this analysis is to provide a pictorial history of Nebraska's ever-changing cropping system and, hopefully, to stimulate ideas and discussion with regard to trends and future directions. The Nebraska Water Resources Center is deeply interested in both the past and the future of Nebraska's agriculture because of the demands which agriculture places on the state's water resources. An …

Turbulence Spectra Above A Vegetated Surface Under Conditions Of Sensible Heat Advection, Raymond P. Motha, Shashi B. Verma, Norman J. Rosenberg

National Drought Mitigation Center: Faculty Publications

Spectra of vertical and horizontal velocity, air temperature and humidity fluctuations were analyzed from measurements made over a well-watered alfalfa crop under conditions of sensible heat advection. Vertical velocity and air temperature spectra as well as cospectra of momentum, sensible heat and water vapor were found to be dependent on atmospheric thermal stratification. These spectra and cospectra were shifted toward higher frequencies under advective as compared to lapse conditions. These results indicate that the predominant eddy sizes are relatively smaller under advective conditions. Humidity spectra, on the other hand, were independent of daytime thermal stratification conditions but were influenced by …

Extreme Evapotranspiration By Irrigated Alfalfa: A Consequence Of The 1976 Midwestern Drought, Norman J. Rosenberg, Shashi B. Verma

National Drought Mitigation Center: Faculty Publications

The rate of evapotranspiration by irrigated alfalfa at Mead, NE (41°09'Nj 96°30'W, elevation 354 m) reached record levels in 1976. Evapotranspiration was measured with precision weighing lysimeters in a field 1.9 ha in size. Evapotranspiration ranged during the growing season from 4.75 to 14.22 mm day^-l and exceeded 10 mm day^-I on one-third of the days studied. On each day of study the ratio of latent heat flux density (LE) to the sum of the net radiation and soil heat flux densities (Rn+S) was such that LE/ (Rn+S) > 1, indicating the occurrence of significant …

The Growing Season, Department Of Agriculture, Western Australia, Bureau Of Meteorology

Journal of the Department of Agriculture, Western Australia, Series 4

IN AUSTRALIA the seasons of summer, autumn, winter and spring do not have the importance that they have in the Old World, and though summer and winter weather are quite different, there is not the obvious difference in autumn and spring conditions that there is in the colder countries.

This is largely due to the difference in vegetation and in its life cycle in the different places.

Likelihood Of Drought Years In South-Western Australia : How Often Can Droughts Such As That Of 1969 Be Expected In Western Australia's Farming Areas?, Eugene Adsil Fitzpatrick

Journal of the Department of Agriculture, Western Australia, Series 4

Because of the serious consequences of drought to individual farmers and to Western Australia's economy, it is worth making an early appraisal of the 1969 rainfall conditions that led to the State's most recent drought in an attempt to estimate how often such seasons might be expected in the agricultural areas.

1964 Drought In Connecticut, The, Byron E. Janes, Joseph J. Brumbach

Storrs Agricultural Experiment Station

No abstract provided.

Thirsty Cows Are Poor Milkers, S R. Dunstan

Journal of the Department of Agriculture, Western Australia, Series 4

THE HOT summer weather is not far away, and now is a good time for the whole milk producer to attend to those points which will ensure that milk production is maintained at a high level during this period.