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Temperature Advection (temperature + advection)

Distribution by Scientific Domains
Earth and Environmental Science100%

Selected Abstracts

Remote weather associated with North Pacific subtropical sea level high properties

INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 5 2007
Richard Grotjahn
Abstract Remote events influencing North Pacific (NP) subtropical high properties in monthly and daily data are identified. Variability in the NP during summer is far more strongly dominated by midlatitude events than in South Pacific (SP); low-pass filtering is required to see tropical associations. The dominant pattern in composites, correlations, and regressions is a midlatitude wave train. A stronger NP high was led by higher sea-level pressure (SLP) just east of Japan and lower SLP over central Canada and to a lesser extent over western tropical Pacific. Various mechanisms have been proposed to force the NP high: (1)Heating over southwestern North America (with cooling off the west coast). However, higher temperatures over North America follow stronger SLP over the NP high and occur much further east than postulated. Higher SLP occurs where temperatures are lower over western North America and adjacent ocean. Thermal pattern is consistent with temperature advection between NP high and Canadian low. (2)Precipitation over and near Central America. However, SLP increase on the SE side of the high is led by higher SLP (and higher outgoing longwave radiation (OLR)) along the west coast of Mexico and Central America. Normalized regressions find a very weak lower OLR in North American monsoon preceding stronger NP high, but the region is much smaller in size and magnitude than other significant areas. (3)Precipitation over Indonesia and southeast Asia. Statistics provide some support for lower SLP and OLR over Indonesia preceding higher SLP in the center, west, and northwest sides of NP high. The lower SLP and OLR appear to migrate into southeast Asia, perhaps independently, perhaps from stronger NP high. (4)The NP high has a strong connection to El Niño during winter, but no significant link during summer. Only the south side of NP high appears (weakly) linked to the Madden Julian oscillation (MJO). Copyright © 2006 Royal Meteorological Society [source]

Baroclinic development within zonally-varying flows

THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 626 2007
David M. Schultz
Abstract Previous idealized-modelling studies have shown the importance of across-jet barotropic shear to the resulting evolution of cyclones, anticyclones, surface-based fronts, and upper-level fronts. Meanwhile, many observational studies of cyclones have shown the importance of along-jet variations in the horizontal wind speed (i.e. confluence and diffluence). This study investigates the importance of these along-jet (zonal, for zonally-oriented jets) variations in the horizontal wind speed to the resulting structures and evolutions of baroclinic waves, using idealized models of growing baroclinic waves. An idealized primitive-equation channel model is configured with growing baroclinic perturbations embedded within confluent and diffluent background flows. When the baroclinic perturbations are placed in background confluence, the lower-tropospheric frontal structure and evolution initially resemble the Shapiro,Keyser cyclone model, with a zonally-oriented cyclone, strong warm front, and bent-back warm front. Later, as the baroclinic wave is amplified in the stronger downstream baroclinicity, the warm sector of the cyclone narrows, becoming more reminiscent of the Norwegian cyclone model. The upper-level frontal structure develops with a southwest,northeast orientation, and becomes strongest at the base of the trough, where geostrophic cold advection is occurring. In contrast, when the baroclinic perturbations are placed in background diffluence, the lower-tropospheric frontal structure and evolution resemble the Norwegian cyclone model, with a meridionally-oriented cyclone, strong cold front, and occluded front. The upper-level frontal structure is initially oriented northwest,southeast on the western side of the trough, before becoming zonally oriented. Weak geostrophic temperature advection occurs along its length. These results are compared to those from previous observational and idealized-modelling studies. Copyright © 2007 Royal Meteorological Society [source]

A diagnosis of warm-core and cold-core extratropical cyclone development using the Zwack,Okossi equation

ATMOSPHERIC SCIENCE LETTERS, Issue 4 2009
Roohollah Azad
Abstract In this study, the development of a warm-core and cold-core extratropical cyclone over North Atlantic is examined. The geostrophic relative vorticity tendency used to diagnose the development is calculated utilizing the so-called extended form of the Zwack,Okossi development equation. In both cases, the cyclonic vorticity advection acted to develop the system, but warm-air advection (diabatic heating) made the largest contribution to explosive development in the cold-core (warm-core) case. Further, a vertical cross section of the temperature advection in the warm-core case reveals that the largest values of this contributor are located far and ahead of the cyclone center. Copyright © 2009 Royal Meteorological Society [source]

Scaling of Central England temperature fluctuations?

ATMOSPHERIC SCIENCE LETTERS, Issue 1-4 2001
Joanna Syroka
Abstract Central England temperature fluctuations are found to be monoscaling with long-range dependence. Monoscaling can be explained in terms of the dominance of Gaussian temperature advection. Simulations of the UK Meteorological Office Hadley Centre general circulation model do not capture many of these features. Copyright © 2002 Royal Meteorological Society. [source]