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Drought and desertification / Natural disasters / Agrometeorology / Winter monsoon research / Multi-hazard early warnings / Public weather services / El Niño/La Niña / Wind information from satellites /
Combating land degradation
Moderate-to-severe land degradation occurs on an estimated 24 per cent of cultivated land and 41 per cent of pastureland around the world. An estimated 250 million people are affected and one billion are threatened in over 100, mostly developing, countries.
WMO activities contribute to understanding the links between climate and land degradation through observations of the climate system, improvements in application of meteorological methods in agriculture and proper assessment and management of water resources; and promotion of capacity-building in the application of meteorological and hydrological data and information in drought preparedness and management.
Automatic weather stations (AWS) are cost-effective tools for understanding land-degradation processes and implementing better control measures and land-management practices. A sig-nificant increase in AWS around the world over the past decade has made a major contribution to the understanding of relationships between climate and land degradation. More investment in AWS is needed, especially in developing countries.
Rainfall is the determinant climatic factor in identifying areas at risk from degradation and desertification. Rainfall variability and extremes can lead to soil erosion and accurate data on rainfall intensities are critical to understanding rates at which land degradation takes place. AWS systems can furnish high-quality instantaneous data for rainfall (at one-minute intervals) in a digital format that can be quickly transmitted to interested agencies.
AWS also provide critical data on wind activity. Sand- and duststorms can destroy plant tissue, bury seedlings and blow away nutrient-rich topsoil.
Subregional drought centre
A workshop was organized by the Secretariat of the United Nations Convention to Combat Desertification (UNCCD) and WMO in Sofia, Bulgaria, in April 2006, to consider the establishment of a subregional drought centre in south-eastern Europe.
It was agreed that countries interested in hosting such a centre would send their proposals to UNCCD and WMO for consideration. Countries in the region which are Parties to the UNCCD are Albania, Bosnia and Herzegovina, Bulgaria, Croatia, the Former Yugoslav Republic of Macedonia, Greece, Hungary, the Republic of Moldova, Romania, Slovenia and Turkey.
Early warning systems
An initiative has been launched to harmonize early warning systems and operational instruments for monitoring climate change and desertification in the Mediterranean area. This is being done through a series of training courses. The latest of these concerned early warning systems for impacts of extreme events and the management of drought for sustainable development.
WMO’s World Agrometeorological Information Service (WAMIS) is a dedicated Webserver for disseminating agrometeorological information issued by WMO Members on drought and crop monitoring. WAMIS aids users to evaluate quickly and easily the various bulletins. The Website also hosts a section on tools and resources to help Members improve the quality and presentation and, therefore, the effectiveness of their agrometeorological bulletins.
A task force comprising experts in the fields of meteorology, economics, agriculture and natural disaster management from all WMO Regions met in Pisa, Italy, in May 2006 to consider implementation of a project to assess the impacts of natural disasters on agriculture. It was decided to run case-studies in selected countries in all Regions on drought, tropical cyclones, floods, wildfires, frost and severe local storms.
Agrometeorological modelling is an essential element of software for early warning systems for protecting plants and crops. WMO participates in work on environmental fluid mechanics with respect to agrometeorological modelling in a cross-disciplinary framework. The topics range from basic fluid mechanics to plant health. The aim of such work is to stimulate the interactions of environmental physics and applied biology.
The winter monsoon in the East Asia/Australia region is responsible for cold-air surges that dominate the weather over China and South-East Asia. These surges affect the Australian summer monsoon and the genesis of tropical cyclones in the southern hemisphere. They have also been linked to the development of the El Niño and Southern Oscillation (ENSO) phenomenon. Another significant effect is the explosive development of low-pressure systems (typhoons) over the East China Sea as cold air moves off the continent and over warm water.
Research into the monsoon is, therefore, important for the early warnings of cold surge and tropical cyclone events. Some of the major outcomes of the research promoted by WMO are improved knowledge of the structure and dynamics of the cold surges and their interactions with planetary-scale circulations, the structure and evolution of vortices near the coast of Borneo, the behaviour of cross-equatorial flow and the structure of convective systems.
The diurnal cycle of convection over the southern South China Sea and Malaysian region is now well documented by satel-lite observations and has drawn the attention of the numerical modelling community to the need to improve the simulation of the diurnal cycle of precipitation. Forecasting and predictability of the monsoon, annual cycle and interannual variability, long-term and decadal variations of the monsoon are major foci.
Scientists from operational forecast centres and research institutions are investigating ways in which international cooperation could contribute to progress towards accurate extended and seasonal forecasts and their applications.
It is important to bridge the gap between academia and operational centres. Meteorological centres of the region have been urged to organize the collection and archival of their monsoon data and to cooperate in the devel-opment of improved monsoon-prediction systems.
See also Symposium on Asian Winter Monsoon in Recent events.
A high priority for WMO is assisting countries in identifying, assessing and monitoring disaster risks and enhancing early warnings within an integrated, multi-hazard approach.
Early warning systems for all natural hazards need to be established worldwide, building on existing national and regional capacities to complement broader disaster-preparedness and mitigation initiatives.
Progress has been made but early warning systems still need to be integrated in disaster-risk reduction strategies, especially in countries with few resources.
WMO convened a symposium to address these issues in May 2006. Participants representing a number of international and regional organizations discussed policy, development and financing, science and technology, humanitarian affairs, education and capacity-building and community-based planning relating to the different aspects of early warning systems.
The outcome of the Symposium provided guidance for better understanding of the concept of a “multi-hazard approach” to early warning systems. It will also be used to stimulate partnerships and a more coordinated approach towards strengthening capacity at all levels.
WMO works to strengthen public weather services in developing countries in support of disaster prevention and mitigation.
Ongoing work includes promoting the availability of public weather forecasts and warnings on the Internet, raising the visibility of public weather services, the early warning process, cross-border exchange and the application of nowcasting to warnings.
A survey was carried out in January 2006 to assess the deficiencies and needs of NMHSs in severe weather warning services. The results identified rain as the hazard of most concern and some 40 per cent of the responses cited forecasting accuracy.
To improve warnings of short-term severe weather phenomena, especially rainstorms, nowcasting as a decision-support tool is called for. A workshop on nowcasting is being planned for the transfer of technology from researchers and advanced centres to developing countries.
The sign that a warning has been successful is a change in people’s behaviour—and education is crucial. Reaching out to decision-makers, as well as the public, to help them understand the meaning of warnings and enhance their ability to translate them into action is a major aim for WMO.
Another outcome of the above-mentioned survey is that developing countries will be provided with examples of successful initiatives of NMHSs to improve disaster prevention and mitigation, together with examples of measures taken to rectify identified deficiencies.
Close partnerships between NMHSs and emergency managers or civil protection are necessary, as is the need to communicate crucial information on high-impact weather in an understandable and timely way.
A set of best practices will be developed on effectively communicating forecast uncertainty and confidence. It will include examples of presenting information to emergency managers and will help NMHSs maintain this important partnership.
Other best-practice examples will be cases of raising the visibility of NMHSs by, for example, using their logos on graphical products and services, and the verbal attribution of their services as part of TV and radio weather presentations.
According to WMO’s latest El Niño/La Niña update (20 June 2006), conditions were neutral in the central and eastern equatorial Pacific, with no rapid changes expected over the next few months.
There is, however, a small likelihood of El Niño development in the latter part of the year, and an even lesser likelihood that a La Niña may develop. The uncertainty of these projections will diminish as we move into a time of year when El Niño/La Niña predictions are known to have greater accuracy.
Changes in prevailing El Niño or La Niña conditions are not the only source of major regional climate anomalies. Other aspects of tropical sea-surface temperatures (such as the currently warmer-than-normal ones in the tropical North Atlantic Ocean and the south-western tropical Pacific Ocean) can substantially alter the likelihood of unusual climate patterns in adjacent regions.
These and other potential sources of unusual climate conditions illustrate the importance of considering regionally and locally specific seasonal climate forecasts as provided by National Meteorological and Hydrological Services.
See also: http://www.elnino.noaa.gov/
An international workshop on winds was held in Beijing, China, in April 2006. The main focus was the processing and utilization of atmospheric motion vector and other satellite-based observing platforms which are producing, or are planned to produce, wind information. Topics covered wind characteristics retrieval methods and data assimilation.
A similar workshop is being planned to address precipitation estimates using satellite data, including those from the advanced TIROS operational vertical sounder.
The TIROS Operational Vertical Sounder (TOVS) equipped aboard NOAA's TIROS series of polar orbiting satellites consists of three instruments: the High Resolution Infrared Radiation Sounder (HIRS), the Microwave Sounding Unit (MSU) and the Stratospheric Sounding Unit (SSU). The MSU and SSU have been replaced with improved instruments, the AMSU-A and AMSU-B, on the newer satellites (image courtesy: NOAA).
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