Academic literature on the topic 'Interactions surface troposphère'

The Tibetan Plateau (TP) is the largest and highest plateau on Earth. Due to its elevation, it receives much more downward shortwave radiation than other areas, which results in very strong diurnal and seasonal changes of the surface energy components and other meteorological variables, such as surface temperature and the convective atmospheric boundary layer. With such unique land process conditions on a distinct geomorphic unit, the TP has been identified as having the strongest land/atmosphere interactions in the mid-latitudes.Three major TP land/atmosphere interaction issues are presented

The Tibetan Plateau (TP) is subjected to strong interactions among the atmosphere, hydrosphere, cryosphere, and biosphere. The Plateau exerts huge thermal forcing on the mid-troposphere over the mid-latitude of the Northern Hemisphere during spring and summer. This region also contains the headwaters of major rivers in Asia and provides a large portion of the water resources used for economic activities in adjacent regions. Since the beginning of the 1980s, the TP has undergone evident climate changes, with overall surface air warming and moistening, solar dimming, and decrease in wind speed.

Abstract The kinetic theory of gases established that invisible gas molecules are ceaselessly and rapidly moving. Gas pressure is a momentum flux density measured by interaction with surfaces. Motion does not cease at absolute zero because at sufficiently low temperatures all real gases liquefy. By definition the internal energy of an ideal gas is independent of density. Air is mostly empty space. Intermolecular collisions ensure local thermodynamic equilibrium and determine mean free paths of at least thirty molecular diameters. Molecular speeds are distributed about a mean, a decrease of about 7% corresponding to a temperature drop from 20∘C to −20∘C. Relatively fewer molecules drive chemical reactions. Even fewer molecules have sufficient energy to escape Earth’s gravity. Pressure and density decrease exponentially with height in the troposphere with a scale height of around 8 km because of gravity. Earth’s atmosphere is well-mixed up to about 100 km.

Abstract Over some tropical regions and middle-latitude continents during the warmer part of the year, deep convective clouds dominate the thermodynamic structure of the atmosphere. Unlike trade cumuli, deep convection is associated with plentiful precipitation and, therefore, a net release of latent heat integrated through the depth of the troposphere. Consequently, deep convection has strong effects on the dynamics and thermodynamics of the atmospheric circulation systems in which it is embedded. In Chapters 9 and 10, we discussed the local properties of precipitating moist convection, and regarded the clouds as a response to the (given) instability of a thermodynamic sounding. In Section 11.2, however, we pointed out that the global characteristics of moist convecting atmospheres are determined by the destabilization of such atmospheres by large-scale processes such as surface fluxes and radiation and not directly by the character of soundings, which is determined as a response to the forcing. As in stratocumulus and trade-cumulus boundary layers, the vertical structure of density in deep convecting atmospheres represents a compromise between the large­ scale processes, tending to destabilize the atmosphere to convection, and the convection itself, which tends to restore stable or neutral conditions. In this chapter we examine the global characteristics of atmospheres experiencing deep convection, as well as the character of the forcing of deep convection, and explore the nature of the interaction of ensembles of deep convective clouds with large-scale atmospheric circulations.

A major focus of the previous six chapters has been on the chemistry and interactions of the HOx, NOx, and volatile organic compound (VOC) families. Details of the reactions of O3 NO3, and HO that act to initiate VOC oxidation have been presented, as has the ensuing chemistry involving organic peroxy and alkoxy radicals and their interactions with NOx. In this chapter, we complete our discussion of thermal chemical reactions that impact tropospheric ozone. The chapter begins with a discussion of the budgets of two simple (inorganic) carbon-containing species not yet discussed, carbon dioxide (CO2) and carbon monoxide (CO). Although CO2 is not directly involved in ozone-related tropospheric chemistry, it is of course the species most critical to discussions of global climate change, and thus a very brief overview of its concentrations, sources, and sinks is presented. CO is a ubiquitous global pollutant, and its reaction with HO is an essential part of the tropospheric background chemistry. This is followed by a presentation of the tropospheric chemistry of halogen species, beginning with a discussion of inorganic halogen cycles that impact (in particular) the ozone chemistry of the marine boundary layer (MBL) and concluding with a detailed presentation of the reactions of Cl atoms and Br atoms with VOC species. The chapter concludes with an overview of tropospheric sulfur chemistry. The reactions leading to the oxidation of inorganic (SO2 and SO3) as well as organic sulfur compounds (e.g., DMS, CH3SCH3) are detailed, and a brief discussion of the effects of the oxidation of sulfur species on aerosol production in the troposphere and stratosphere is also given. The abundance of CO2 in the atmosphere has obviously received a great deal of attention in recent decades due to the influence of this gas on Earth’s climate system. Indeed, changes in the atmospheric CO2 concentration represent the single largest contributor to changes in radiative forcing since preindustrial times (c. 1750). The atmospheric burden of CO2 is controlled by the processes that make up the global carbon cycle—the exchanges of carbon (mostly in the form of CO2) between various “reservoirs,” including the atmosphere, land (vegetation and soil), the surface ocean, the intermediate and deep ocean, sediment on the ocean floor, and the fossil fuel reservoir (IPCC, 2007).

Significant amounts of stratospheric aerosols can cause a cooling of the earth's surface due to the scattering of solar radiation back into space. Likewise a warming of the stratosphere where the particles reside will occur due to absorption of upwelling infrared radiation [1]. The eruption of the Pinatubo volcano in the Philippines (15.14°N, 120.35°E) on June 15, 1991, produced the largest impact on the stratosphere ever observed by modem airborne, spaceborne, and ground-based scientific instruments. The volcanic aerosols were ejected into the upper troposphere and the stratosphere to heights

The impacts of characteristic weather events and seasonal patterns on infrasound propagation in the Arctic region are simulated numerically. The methodology utilizes wide-angle parabolic equation methods for a windy atmosphere with inputs provided by radiosonde observations and a high-resolution reanalysis of Arctic weather. The calculations involve horizontal distances up to 200 km for which interactions with the troposphere and lower stratosphere dominate. Among the events examined are two sudden stratospheric warmings, which are found to weaken upward refraction by temperature gradients whi