For the WRF model, the sensitivity of driving data and physics parametrization for the water and energy budgets has been addressed by several studies: Flaounas et al. () found that the type of planetary boundary and convective parametrization scheme affects precipitation amounts and patterns in a simulation for the the West African Monsoon. A study by Borge et al. () investigated viable setups of WRF for the Iberian peninsula. A more general work by Kim and Hong () comes to the conclusion that differences in modeled sea air interaction can considerably affect the water budgets of regional atmospheric models. Heikkilä et al. () examined the skill of 30 and 10 km downscaling with WRF for the Scandinavian region. The higher resolution simulations further improved the quality of the downscaling. A study by Berg et al. () and Wagner et al. () comparing different RCMs for Germany found that by dynamical downscaling, precipitation biases of the global circulation model (GCM) typically propagate to the RCM results. However, they state that the examined RCMs are able to add value to the precipitation intensity distributions with respect to the GCMs. Miguez-Macho et al. () pointed out that dynamic downscaling models can develop unrealistic circulation patterns if only the lateral boundaries are considered for global input. By applying a nudging term to the model’s prognostic equations, important large-scale features can be preserved within the dynamic downscaling process.
In our study we investigate the sensitivity and performance of different configurations for the dynamic downscaling model WRF-ARW (Advanced Research WRF) with respect to the water budget of long-term simulations for continental scale hydrological basins of 2–5 million km2 extent. The analysis is based on a monthly time-scale and covers four years from 2003 to 2006. The sensitivity analysis encompasses (1) two different global driving models, (2) two alternative convective parametrization schemes, (3) gridded nudging, and (4) time-variant and invariant sea-surface temperature (SST). Four globally distributed study regions are selected to cover different climatic conditions. The results of the regional atmospheric downscaling and the respective fields of the global driving models are evaluated with a range of independent global observation data sets for (1) precipitation, (2) ground level temperature, (3) evapotranspiration, and basin discharge.
2003–2006 mean BIAS and RMSE for P, Ea, R (mm month−1), and T2 (K) for the combined basins of Lena and Yenisei
The physicians involved in orthopedic sports medicine often were looked on as M.D.s that simply couldnt compete in the world of "real" medicine, and the lay people involved as trainers and support personnel to the performing athletes were regarded as would-be athletes with the same disabilities.
The arctic winterly cold climate is represented by the Siberia domain, combining the two river catchments of Yenissei and Lena with a total area of around 5 × 106 km2. The Africa domain covers different climatic zones ranging from desert in the North to tropics and monsoon influenced conditions on the Western and the Central continent. For this study we analyze the water budgets of the Sahara desert, the Niger basin and the Lake Chad catchment. The Australian continent is completely surrounded by the ocean and has very steep climatic gradients from the coast to the center. The Central Australian Plane is considered for the water budget analysis. The tropical climate domain of the Amazon region shows very strong variations of the annual water cycle.
"The ability to have access to, operate in, and dominate the aerospace environment has become the key to military success in modern, high-technology warfare. Indeed, as will be discussed below, space dominance may become so essential to the preservation of American military preeminence that it may require a separate service. How well the Air Force rises to the many challenges it faces – even should it receive increased budgets – will go far toward determining whether U.S. military forces retain the combat edge they now enjoy" (pp. 38-39).
Only one article provided any deviation from the pattern, and that was one that originated in Australia and drew distinctions between "elite" and "non-elite" without actually managing to define the terms.
"American landpower remains the essential link in the chain that translates U.S. military supremacy into American geopolitical preeminence. Even as the means for delivering firepower on the battlefield shift – strike aircraft have realized all but the wildest dreams of air power enthusiasts, unmanned aerial vehicles promise to extend strike power in the near future, and the ability to conduct strikes from space appears on the not-too-distant horizon – the need for ground maneuvers to achieve decisive political results endures. Regimes are difficult to change based upon punishment alone. If land forces are to survive and retain their unique strategic purpose in a world where it is increasingly easy to deliver firepower precisely at long ranges, they must change as well, becoming more stealthy, mobile, deployable and able to operate in a dispersed fashion. The U.S. Army, and American land forces more generally, must increasingly complement the strike capabilities of the other services. Conversely, an American military force that lacks the ability to employ ground forces that can survive and maneuver rapidly on future battlefields will deprive U.S. political leaders of a decisive tool of diplomacy" (p. 30).
"In general terms, it seems likely that the process of transformation will take several decades and that U.S. forces will continue to operate many, if not most, of today’s weapons systems for a decade or more. Thus, it can be foreseen that the process of transformation will in fact be a two-stage process: first of transition, then of more thoroughgoing transformation. The break-point will come when a preponderance of new weapons systems begins to enter service, perhaps when, for example, unmanned aerial vehicles begin to be as numerous as manned aircraft. In this regard, the Pentagon should be very wary of making large investments in new programs – tanks, planes, aircraft carriers, for example – that would commit U.S. forces to current paradigms of warfare for many decades to come" (p. 13).
2 m temperature The lower panel of Fig. gives the deviations for T2 with respect to the 2003–2006 mean temperature of CRUT. A significant warm bias is experienced for all the WRF model runs (Table ). In contrast, the global fields seem to be more closely related to CRUT. Despite of the bias, the spatial deviation patterns are very similar for the regional and the global fields. Between the center and the west of the domain, the models suggest a larger temperature gradient than it is observed with CRUT.
"Although the no-fly-zone air operations over northern and southern Iraq have continued without pause for almost a decade, they remain an essential element in U.S. strategy and force posture in the Persian Gulf region. Ending these operations would hand Saddam Hussein an important victory, something any American leader would be loath to do. Likewise, withdrawing from the Balkans would place American leadership in Europe – indeed, the viability of NATO – in question. While none of these operations involves a mortal threat, they do engage U.S. national security interests directly, as well as engaging American moral interests" (p. 11).
"The end of the Cold War leaves the U.S. Navy in a position of unchallenged supremacy on the high seas, a dominance surpassing that even of the British Navy in the 19th and early parts of the 20th century. With the remains of the Soviet fleet now largely rusting in port, the open oceans are America’s, and the lines of communication open from the coasts of the United States to Europe, the Persian Gulf and East Asia. Yet this very success calls the need for the current force structure into question. Further, the advance of precision-strike technology may mean that naval surface combatants, and especially the large-deck aircraft carriers that are the Navy’s capital ships, may not survive in the high-technology wars of the coming decades. Finally, the nature and pattern of Navy presence missions may be out of synch with emerging strategic realities. In sum, though it stands without peer today, the Navy faces major challenges to its traditional and, in the past, highly successful methods of operation" (p. 39).