Climate Commons^™

Data Assimilation Experiments In The Gulf Stream Region: How Useful Are Satellite-Derived Surface Data For Nowcasting The Subsurface Fields?, Tal Ezer, George L. Mellor

CCPO Publications

Satellite-derived surface data have become an important source of information for studies of the Gulf Stream system. The question of just how useful these datasets are for nowcasting the subsurface thermal fields, however, remains to be fully explored. Three types of surface data-sea surface temperature (SST), sea surface height (SSH), and Gulf Stream position (GSP)-are used here in a series of data assimilation experiments to test their usefulness when assimilated into a realistic primitive equation model. The U.S. Navy's analysis fields from the Optimal Thermal Interpolation System are used to simulate the surface data and to evaluate nowcast errors. Correlation …

An Analysis Of Tropical Transport: Influence Of The Quasi-Biennial Oscillation, Eugene C. Cordero, S. Randolph Kawa, Mark R. Schoeberl

Faculty Publications, Meteorology and Climate Science

An analysis of over 4 years of Upper Atmosphere Research Satellite (UARS) measurements of CH₄, HF, O₃, and zonal wind are used to study the influence of the quasi-biennial oscillation (QBO) on constituent transport in the tropics. At the equator, spectral analysis of the Halogen Occultation Experiment (HALOE) and Microwave Limb Sounder (MLS) observations reveals QBO signals in constituent and temperature fields at altitudes between 20 and 45 km. Between these altitudes, the location of the maximum QBO amplitude roughly corresponds with the location of the largest vertical gradient in the constituent field. Thus, at 40 …

Simulations Of The Atlantic Ocean With A Free Surface Sigma Coordinate Ocean Model, Tal Ezer, George L. Mellor

CCPO Publications

A sigma coordinate, free surface numerical model with turbulence dynamics has been implemented for the Atlantic Ocean and the Greenland Sea, from 80°S to 80°N. It is driven at the surface by monthly mean sea surface temperature and wind stress climatologies and is executed for 30 years. This is the first time that a model of this type, previously used mostly for coastal and regional simulations, has been implemented for the entire Atlantic Ocean and run for a long period of time. The model horizontal circulation, thermohaline overturning circulation, and meridional heat fluxes are described; the results are compared with …

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

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

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

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

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

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

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

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

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

Wind Climatology At 87 Km Above The Rocky Mountains At Bear Lake Observatory--Fabry-Perot Observations Of Oh, V. B. Wickwar, I K. Monson, C M. Vadnais, D Rees

Reports

This paper presents the neutral -wind climatology at approximately 87-km 53 altitude from Utah State University's Bear Lake Observatory (BLO). a mid-latitude site 54 situated in the middle of the Rocky Mountains. The winds were determined using a very 55 sensitive Fabry-Perot interferometer (FPI) observing the OH Me inel (6-2) PI (3) line al 56 843 nm. The climatology. determined from monthly averages of the nightly evolution of 57 the geographic meridional and zonal wind components over forty· five months, has three 58 distinct seasonal patterns: winter (November- February), summer (May-Jul y), and late 59 Slimmer (August and September). The …

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.

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

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

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

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

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 …

Potential Regional Impacts Of Global Warming On Precipitation In The Western United States, United States Department Of The Interior, Bureau Of Reclamation

Meterology

Snow and melting of the snowpack provide the principal supply of water to much of the Western United States. Whether global warming threatens this water supply is the focus of this research. This study builds upon a previous Global Climate Change Response Program investigation. Charts were generated of four geopotential height parameters for a domain covering the eastern North Pacific Ocean and western North America. Out of 131 total winter months (from 1946-89), 35 were selected as analogues.

Monthly mean precipitation values for areas in western Montana, northern Utah, and east central Arizona were compared with median values for the …

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 …