Relationship Between Atmospheric Teleconnections And The Northern Hemisphere\u27S Circumpolar Vortex

The Northern Hemispheric circumpolar vortex (NHCPV) is the hemispheric-scale, middle- and upper-tropospheric wind belt circumnavigating the North Pole. It is delineated by the well-known polar front jet stream, and it bends poleward at ridges and equatorward at troughs at various amplitudes and positions over time. Previous work assessed the accuracy of representing the NHCPV using a new technique through correlations to air-sea teleconnections known to be related to broad-scale, extratropical steering circulation at the monthly scale. Results of that work suggested that the method allows for notable improvements in the calculation of area and circularity of the 500-hPa manifestation of the NHCPV. Because using monthly averaged data to represent the NHCPV may oversimplify analyses, especially for identifying meteorological impacts, this research employs the same technique for identifying the daily NHCPV. Results suggest that CPV area and circularity are even more closely related to variability in the North Atlantic Oscillation (NAO), Pacific/North American pattern, and (especially) Arctic Oscillation (AO) teleconnections, and the El Nino/Southern Oscillation phenomenon at the daily scale than at the monthly scale. A principal components analysis reveals the extent of the interrelationships between the teleconnections and NHCPV area and circularity. Results generally affirm that both the individual teleconnections, especially the NAO and AO, and interdependencies among these teleconnections and others, are strongly related to the NHCPV area and circularity. These findings are important because low- and high-frequency variability in the amplitudes and positions of the undulations in the broad-scale flow influence weather systems that exert important impacts on society. Plain Language Summary The broad-scale, west-to-east, upper-level atmospheric flow separates the frigid polar air from the much more moderate temperate air over the middle latitudes. Popularly known as the polar vortex, this circumpolar vortex (CPV) expands equatorward and contracts poleward, and becomes quasi-circular at times and wavier (with south-to-north or north-to-south components of flow) at other times on its general west-to-east trek around the North Pole. Previous work has defined the CPV\u27s position at a given time using a predetermined, one-size-fits-all elevation at which 500 hPa of atmospheric pressure occurs. Our approach introduced in a previous study is based on the steepest gradient of that elevation. In this study, we demonstrate the effectiveness of this new delineation by showing that the CPV\u27s area and waviness are linked at the daily scale to several known atmospheric circulation features that have been shown previously to be associated with the CPV. Two atmospheric flow patterns-the so-called Arctic Oscillation and the related North Atlantic Oscillation-are particularly closely linked to the Northern Hemisphere\u27s CPV (NHCPV), and the El Nino/Southern Oscillation phenomenon is associated less directly with NHCPV variability. Results will help atmospheric scientists as they use model output of the CPV\u27s position to identify steering patterns that affect daily weather

Globally Extended Kppen-Geiger Climate Classification and Temporal Shifts in Terrestrial Climatic Types

Increasing awareness of the impacts of global climate change on marine ecosystems and concerns about shifting bioclimatic and agricultural zones necessitate a reassessment of the geographical distribution of Earths climate types. In recent years, the availability of truly global data-sets has allowed for the application of climatic types, including the Kppen-Geiger system, over the oceans. This research uses NCAR Reanalysis data to create a global Extended Kppen-Geiger climate classification, including the world ocean, for the 1981-2010 averaging period. The percentages of Earths surface covered by tropical rainforest (Af), tropical monsoon (Am), and (especially) the mesothermal-mild summer (Cfc) climate types are much larger than in the terrestrial only analysis. Expanding and contracting terrestrial climate zones are also identified based on the differences in the total area through comparison with maps produced for 1901-1925, 1926-1950, 1951-1975, 1976-2000 and model-output-based predicted Kppen-Geiger types for 2076-2100. Results suggest that hot desert (BWh), hot semi-arid (BSh), and Af climatic types are projected to expand, while the tundra and most mesothermal and microthermal types will decrease in area. These results assist in projecting global impacts of climatic change

Strategies for ideal indoor environments towards low/zero carbon buildings through a biomimetic approach

Biomimicry is a relatively new discipline of applied science that seeks inspiration from natural systems for innovative solutions to human problems. Taking nature as ‘model, mentor and measure’ receives wide acceptance in the field of architecture but predominantly in conceptualising novel forms. The biomimicry concept is comprehensively analysed for its ability to provide more sustainable and possibly even regenerative built environments. As part of this study, first, various frameworks for approaching ‘biomimicry’ in general are discussed and then relevant examples pertaining to architecture are evaluated. Case studies are critiqued with respect to varied levels of sustainability achieved and its causative factors. In the second part, an approach model for ‘biomimetic architecture’ in the context of Mumbai is presented and applicable strategies based on climatic adaptation are suggested using local biodiversity as a library of organisms. The generic example of ‘human skin’ addressing the same adaptation is analysed and complemented by a state-of-the-art case study on similar lines. The results achieved clearly reveal that biomimicry is a successful approach to design and operate the sustainable built environments for the buildings of the future

Exploring physical geography

xxviii, 603 p. : col. ill. ; 27 cm