[1] Water vapor in the subtropical troposphere plays an important role in the radiative balance, the distribution of precipitation, and the chemistry of the Earth’s atmosphere. Measurements of the water vapor mixing ratio paired with stable isotope ratios provide unique information on transport processes and moisture sources that is not available with mixing ratio data alone. Measurements of th...

Several lines of evidence concerning the vertical abundance profile of water in the atmosphere of Venus lead to strikingly unusual distributions (the water vapor abundance decreases sharply in the immediately vicinity of the surface) or to serious conflicts in the profiles (different infrared bands suggest water abundances that are discrepant by a factor of 2.5 to 10). These data sets can be re...

Two methods for the measurement of the column water vapor in the atmosphere are compared with respect to their usefulness for imaging spectrometer campaigns. First, in situ measurements of 26 radiosonde launches are integrated with height to obtain the water vapor column. Second, simultaneous ground irradiance measurements using a sun photometer are inverted to column water vapor amounts. An ex...

Moist patches are areas in the subcloud layer characterized by a positive water vapor anomaly compared to the environment and are considered important in triggering new convective cells. A correct understanding of the origin of the water vapor in these patches is, thus, essential to improving existing convective parameterizations. Recent studies have addressed this problem and have shown that c...

Recent progress is reviewed in the understanding of convective interaction with water vapor, and changes associated with water vapor in warmer climates. Progress includes new observing techniques (including isotopic methods) that are helping to illuminate moistureconvection interaction, better-observed humidity trends, new modeling approaches, and clearer expectations as to the hydrological con...

An algorithm based on the radiance transfer model (RM) and a dynamic learning neural network (NN) for estimating water vapor content from moderate resolution imaging spectrometer (MODIS) 1B data is developed in this paper. The MODTRAN4 is used to simulate the sun-surface-sensor process with different conditions. The dynamic learning neural network is used to estimate water vapor content. Analys...

The paper deals with application of GPS radio occultation (RO) measurements aboard CHAMP for the retrieval of tropospheric water vapor profiles. The GPS RO technique provides a powerful tool for atmospheric sounding which requires no calibration, is not affected by clouds, aerosols or precipitation, and provides an almost uniform global coverage. We briefly overview data processing and retrieva...

Air may cross the tropical tropopause either by gradual ascent or in localized episodes associated with convection. While observations demonstrate that water vapor mixing ratios of air entering the tropical stratosphere are consistent with the mean tropical tropopause temperature, they do not resolve key mechanistic questions, such as the relative contribution of gradual or episodic transport, ...

Microtribological measurements of a hydrogenated diamondlike carbon film in controlled gaseous environments show that water vapor plays a significant role in the friction coefficient. These experiments reveal an initial high friction transient behavior that does not reoccur even after extended periods of exposure to low partial pressures of H2O and O2. Experiments varying both water vapor press...

In recent years techniques have been developed to obtain integrated water vapor along slant paths between ground-based Global Positioning System (GPS) receivers and the GPS satellites. Results are presented of an observing system simulation (OSS) to determine whether three-dimensional water vapor fields could be recovered from a high-resolution network (e.g., with 40-km spacing) of GPS receiver...