Meteorology and climatology: some challenges for this century
With the development of powerful new supercomputers like the Earth Simulator in Japan, numerical modeling of the atmosphere can reach unprecedented accuracy. This is not only due to the enhanced spatial and temporal resolution of the grids employed, but also because these more powerful machines can model the Earth as an integrated climate system, where atmosphere, ocean, vegetation, and man-made influences depend on each other realistically. The goal in global meteorological modeling can thus currently be termed Earth System Modeling, with a growing number of models of various processes coupled to each other. Predictions for global effects like Global Warming and El Niño are expected to benefit substantially from these advancements.
Regional models are also becoming more interesting as the resolution of global models increases and with the observed increase in regional weather disasters such as the Elbe flooding in 2002 and the European heat wave in 2003. Decision makers expect from these models accurate assessments about the possible increase of these natural hazards in specific regions and countermeasures (such as dikes or areas that are intentionally flooded to decrease the flooding somewhere else) that might be effective in preventing or at least attenuating them.
For models at all scales, increased model resolution means less reliance on parameterizations , which are empirically derived expressions for processes that cannot be resolved on the model grid. For example, in mesoscale models individual clouds can now be resolved, removing the need for formulations that average over a grid box. In global modeling, atmospheric waves such as gravity waves with short temporal and spatial scales can be represented without resorting to often overly simplified parameterizations.
Possibilities for future improvements
With model output approaching observational data (e.g. from satellite soundings) in resolution, the sheer size of the datasets means that data mining and data management will become equally important considerations in meteorological computing. In light of the decrease in density of surface and rawinsonde observations, new algorithms have to be developed to extract similarly accurate information from satellite data, for example about cloud type and distribution. Data management will become more global in nature, with some central archives storing a large number of numerical experiments from various institutions. This data needs to have a sufficient amount of metadata attached and can then be conveniently retrieved by a WWW interface from anywhere. These new archives will alleviate the important task of comparing experiments conducted with different models, which is instrumental for their further improvement. Also, grid computing may be an interesting way to harness the power of meteorological supercomputers more effectively. Of course international cooperation is nothing unusual in modeling, but grid computing might automate the process of running a model where the right amount of computing resources are currently available and leave scientists more time for analyzing the results.
Meteorological instrumentation that is used at the surface or in airplanes also has room for improvement. Radar and lidar show precipitation and clouds by their effects on emitted monospectral electromagnetic waves. If radar measurements can be used to accurately determine the amount of precipitation (which as of now is only possible with rain gauges), this would be beneficial for numerical weather prediction. Lidar can be used to study clouds that are so thin that they cannot be seen by the naked eye such as certain types of cirrus filaments. Researchers continue to find new atmospheric details such as high-altitude clouds that can form from contrails, which suggest that air travel may affect regional weather.
Aside from weather and climate prediction, weather modification has been (often covertly) attempted since the 1950s---often by the military, but also at airports. But even without consideration of anecdotal evidence of trying to use weather modification as a "weapon" (such as the supposed cloud seeding by US troops during the Vietnam conflict), it is clear that unilateral weather modification may lead to political tensions. Especially in the Middle East, the possibility of wars about water supply looms for this century (Hussein's Iraq used surface engineering to block water from entering the land of the Marsh Arabs). While many of the proposed systems for modification of the water cycle belong more to the domain of engineering than to meteorology, it is clear that meteorology has taken on additional political dimensions such as the IPCC climate change mitigation proposals, and the UNFCCC pollution control limits with climate support payments from industrialized countries to developing countries.
Finally, meteorologists must educate the public more about weather and climate in general. Scientifically accurate and understandable information about topics like the ozone layer, climate change, the effects of deforestation, or sea level rise must be disseminated and misinformation by special-interest groups be countered. Particularly in Europe, which may see an increase in extreme weather events as it already has in the 1990s, the population must be educated to pay closer attention to severe weather warnings or information about other detrimental health factors such as high tropospheric ozone concentration or high levels of UV radiation. Similarly, a better infrastructure to deal with natural disasters must be developed akin to similar services in the US. Political decision makers should rely on scientific assessment and properly prepare for weather events and climate effects.
Meteorological topics and phenomena