[1] IPCC (Intergovernmental Panel on Climate Change) AR4 (Fourth Assessment Report) GCMs (General Circulation Models) predict a tropical tropospheric warming that increases with height, reaches its maximum at ∼200 hPa, and decreases to zero near the tropical tropopause. This study examines the GCM‐predicted maximum warming in the tropical upper troposphere using satellite MSU (microwave soundin...

[1] The signature of the stratospheric Brewer-Dobson circulation (BDC) in tropospheric cloudiness is investigated in CloudSat and CALIPSO data from June 2006 through April 2011. During the Northern Hemisphere winter, periods of enhanced stratospheric wave driving are associated with increased cloud incidence in the tropical tropopause transition layer (TTL) juxtaposed against decreased cloud in...

[1] A two-dimensional transport model constrained to measured surface CO2 concentrations was used to simulate the spatial and temporal variation of CO2 in the atmosphere for the period from 1975 to 2004. We find that the amplitude, phase and shape of the CO2 seasonal cycle vary as a function of both altitude and latitude. Cross tropopause exchanges, especially the downward branch of the Brewer-...

[1] This paper incorporates the latest improvements in intersatellite calibration, along with a new statistical technique, to determine the diurnal and seasonal cycles and climatic trends of 1978–2004 tropospheric temperature using Microwave Sounding Unit measurements. We also compare the latitudinal distribution of temperature trends from the surface and troposphere with each other and with mo...

Based on the tracking of the movement of the tropopause over the whole year, the extent/depth of stratosphere-troposphere exchange (STE) events and their seasonal variations is investigated. It is found that a stratospheric signature can be observed at pressures as high as 400 hPa in a hemisphere during its winter to spring period, while a tropospheric signature can be observed at pressures as ...

Abstract Analyses of observation data from 1961 to 2014 by using the empirical orthogonal function (EOF) method indicate that primary mode (a monosign pattern) heavy snowfall over northern China in winter shows evident variations a negative polarity positive mid-1990s. Associated with this decadal change, southward displacement polar front jet stream and northward shift subtropical upper tropos...

Seasonality in Titan’s troposphere is driven by latitudinally varying insolation. We show that the latitudinal distributions of insolation in the troposphere and at the surface, based on Huygens DISR measurements, can be approximated analytically with nonzero extinction optical depths s, and are not equivalent to that at the top of the atmosphere (s = 0), as has been assumed previously. This ha...

A number of key problems in atmospheric chemistry are shaped by the strength and character of the various mechanisms acting to move and mix air in the upper troposphere. These transport processes are examined from a mechanistic perspective, with primary emphasis on the tropopause andmiddle-troposphere regions in the extratropics. The roles of vertical and horizontal transport “barriers” are exp...

Though ammonium bisulfate is one of the most common of atmospheric hygroscopic aerosols, knowledge of its interaction with water has, until now, been extremely limited. This paper presents our observations on single isolated ammonium bisulfate aerosol particles, as they interact with water vapor at temperatures ranging from -40 to 30 °C. The complete phase diagram in the temperature/composition...

1. introduction heavy snow hazards, although have less frequency in comparison with extreme weather events such as freezing, but are major hazards in midlatitudes (smith, 2009, 196). heavy snow damages manmade structures, crops, casualties, even between urban and rural ways of blocking.(briant. 69, 2005. ohara et al, 2009, 1611). various definitions have been offered for heavy snow, those are c...