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This paper traces the history of the use of ships' logbooks in climatological studies from the earliest days of the 17th century to the present day. Although early theories concerning global air circulations by Halley and Hadley were based on information gathered by mariners and recorded in their logbooks, it has only been in the last two decades that interest has returned to this important, but long-overlooked, source of climatic information. Attention is drawn to the many advantages offered by logbooks, in particular the long period of time that they collectively cover, their near-global geographic range, the large number of such documents that have survived, and the degree of detailed and reliable record that they provide. Before the mid-19th century, much of the recorded information is noninstrumental in character but its scientific potential is reflected in the variety of approaches and methods that have been used in its analysis and in the equally wide range of outcomes, from databases to synoptic charts and long-time series indices that have emerged from the most recent research. Attention is also drawn to the benefits to be derived from old and more recent instrumental logbook data. As only a small percentage of the tens of thousands of logbooks that have been preserved have thus far been examined, the potential for yet further development is enormous. [ABSTRACT FROM AUTHOR]

Cut-off low pressure systems (COLs) are defined as closed lows in the upper troposphere that have become completely detached from the main westerly current. These slow-moving systems often affect the weather conditions at the earth's surface and also work as a mechanism of mass transfer between the stratosphere and the troposphere, playing a significant role in the net flow of tropospheric ozone. In the first part of this work we provide a comprehensive summary of results obtained in previous studies of COLs. Following this, we present three long-term climatologies of COLs. The first two climatologies are based on the conceptual model of a COL, using European Centre for Medium-range Weather Forecasts (ECMWF) analyses (1958–2002) and National Centers for Environmental Prediction–National Center for Atmospheric Research (1948–2006) reanalysis data sets. The third climatology uses a different method of detection, which is based on using potential vorticity as the physical parameter of diagnosis. This approach was applied only to the ECMWF reanalysis data. The final part of the paper is devoted to comparing results obtained by these different climatologies in terms of areas of preferential occurrence, life span, and seasonal cycle. Despite some key differences, the three climatologies agree in terms of the main areas of COL occurrence, namely (1) southwestern Europe, (2) the eastern north Pacific coast, and (3) the north China–Siberian region. However, it is also shown that the detection of these areas of main COL occurrence, as obtained using the potential vorticity approach, depends on the level of isentropic analysis used. [ABSTRACT FROM AUTHOR]

Transition mechanisms characterizing changes from hurricanes to midlatitude cyclones and vice-versa (extratropical and tropical transition) have become a topic of increasing interest, partially because of their association with recent unusual storms that have developed in different ocean basins of both hemispheres. The aim of this work is to discuss some recent cases of transition and highly unusual hurricane developments and to address some of their wider implications for climate science. Frequently those dramatic cyclones are responsible for severe weather, potentially causing significant damage to property and infrastructure. An additional manifestation discussed here is their association with cold surges, a topic that has been very little explored in the literature. In the Southern Hemisphere, the first South Atlantic hurricane, Catarina, developed in March 2004 under very unusual large-scale conditions. That exceptional cyclone is viewed as a case of tropical transition facilitated by a well-developed blocking structure. A new index for monitoring tropical transition in the subtropical South Atlantic is discussed. This “South Atlantic index” is used to show that the unusual flow during and prior to Catarina's genesis can be attributed to tropical/extratropical interaction mechanisms. The “Donald Duck” case in Australia and Vince in the North Atlantic have also been examined and shown to belong to a category of hybrid-transitioning systems that will achieve at least partial tropical transition. While clearly more research is needed on the topic of transition, as we gain further insight, it is becoming increasingly apparent that features of large-scale circulation do play a fundamental role. A complex interaction between an extratropical transition case and an extreme summer cold surge affecting southeastern Australia is discussed as an example of wider climate implications. [ABSTRACT FROM AUTHOR]

The Northern Hemisphere annular mode, also known as the Arctic Oscillation/North Atlantic Oscillation (AO/NAO) is a dominant atmospheric mode in the Northern Hemisphere winter that influences climate fluctuations from the eastern seaboard of the United States to Siberia and from the Arctic to the subtropical Atlantic. After almost a century of scientific investigation, the fundamental mechanisms determining the evolution of the AO/NAO are not yet completely understood. The ocean is favored as the most likely forcing of atmospheric variability, given the time scales of oceanic circulation and its large heat capacity. Our analyses of snow cover, soil temperatures, zonal winds, and geopotential heights identify the effect of land–atmosphere interaction over Eurasia on Northern Hemisphere atmospheric circulation, explaining the predictive signal that links fluctuations of April–October snow cover with the following winter AO/NAO phases. [ABSTRACT FROM AUTHOR]

We review recent advances in classifications of circulation patterns as a specific research area within synoptic climatology. The review starts with a general description of goals of classification and the historical development in the field. We put circulation classifications into a broader context within climatology and systematize the varied methodologies and approaches. We characterize three basic groups of classifications: subjective (also called manual), mixed (hybrid), and objective (computer-assisted, automated). The roles of cluster analysis and principal component analysis in the classification process are clarified. Several recent methodological developments in circulation classifications are identified and briefly described: the introduction of nonlinear methods, objectivization of subjective catalogs, efforts to optimize classifications, the need for intercomparisons of classifications, and the progress toward an optimum, if possible unified, classification method. Among the recent tendencies in the applications of circulation classifications, we mention a more extensive use in climate studies, both of past, present, and future climates, innovative applications in the ensemble forecasting, increasing variety of synoptic–climatological investigations, and steps above from the troposphere. After introducing the international activity within the field of circulation classifications, the COST733 Action, we briefly describe outputs of the inventory of classifications in Europe, which was carried out within the Action. Approaches to the evaluation of classifications and their mutual comparisons are also reviewed. A considerable part of the review is devoted to three examples of applications of circulation classifications: in historical climatology, in analyses of recent climate variations, and in analyses of outputs from global climate models. [ABSTRACT FROM AUTHOR]

Systematic conservation planning provides a structured, target-driven approach to ensuring the long-term maintenance of biodiversity. However, reviews of how well the steps of such a planning process are applied in different regions are scant; some steps may be implemented although there is no formal systematic conservation planning process taking place. Here we conduct such a review for Europe. Taking in turn the six recognized steps of systematic conservation planning, for this region: (i) The availability of data on biodiversity remains a significant constraint on conservation planning because, although species occurrences have often been better mapped in Europe than elsewhere, there is a continuing mismatch between the spatial resolution at which data coverage is adequate and that of habitat fragmentation. (ii) Although there are important legal frameworks for conservation planning, explicit quantitative goals for the representation and persistence of biodiversity are largely lacking. (iii) Assessment of the effectiveness of existing protected area systems is patchy and rather ill developed, with a substantial gulf between the work being conducted in more academic and policy-oriented arenas. (iv) Nonetheless, particularly through the Natura 2000 process, there has been an extraordinary program to select additional protected areas. (v) Although it has taken longer than originally envisaged, this program is resulting in a substantial expansion of the protected area system. (vi) There are significant concerns over the extent to which existing protected area systems can maintain their biodiversity values, particularly given the small size of many of these areas and likely impacts of climate change. [ABSTRACT FROM AUTHOR]