Analysis of the ability of infrared water vapor channel for moisture remote sensing in the lower atmosphere

1998 ◽  
Vol 15 (1) ◽  
pp. 107-112
Author(s):  
Zhao Gaoxiang
2014 ◽  
Vol 31 (11) ◽  
pp. 2462-2481 ◽  
Author(s):  
David Themens ◽  
Frédéric Fabry

AbstractThe ability of different ground-based measurement strategies for constraining thermodynamic variables in the troposphere, particularly at the mesoscale, is investigated. First, a preliminary assessment of the capability of pure-vertical sounders for constraining temperature and water vapor fields in clear-sky conditions to current accuracy requirements is presented. Using analyses over one month from the Rapid Refresh model as input to an optimal estimation technique, it is shown that the horizontal density of a network of nonexisting, ideal vertical profiling instruments must be greater than 30 km in order to achieve accuracies of 0.5 g kg−1 for water vapor and 0.5 K for temperature. Then, an assessment of a scanning microwave radiometer’s capability for retrieving water vapor and temperature fields in a cloud-free environment over two- and three-dimensional mesoscale domains is also presented. The information content of an elevation and azimuthal scanning microwave radiometer is assessed using the same optimal estimation framework. Even though, in any specific pointing direction, the scanning radiometer does not provide much information, it is capable of providing considerably more constraints on thermodynamic fields, particularly water vapor, than a near-perfect vertical sounder. These constraints on water vapor are largely located within 80 km of the radiometer and between 1000- and 7000-m altitude, while temperature constraints are limited to within 35 km of the instrument at altitudes between the ground and 1500 m. The findings suggest that measurements from scanning radiometers will be needed to properly constrain the temperature and especially moisture fields to accuracies needed for mesoscale forecasting.


2011 ◽  
Vol 24 (16) ◽  
pp. 4466-4479 ◽  
Author(s):  
Sun Wong ◽  
Eric J. Fetzer ◽  
Baijun Tian ◽  
Bjorn Lambrigtsen ◽  
Hengchun Ye

Abstract The possibility of using remote sensing retrievals to estimate apparent water vapor sinks and heat sources is explored. The apparent water vapor sinks and heat sources are estimated from a combination of remote sensing, specific humidity, and temperature from the Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit (AIRS) and wind fields from the National Aeronautics and Space Administration (NASA)’s Goddard Space Flight Center (GSFC)’s Modern Era Retrospective-Analysis for Research and Applications (MERRA). The intraseasonal oscillation (ISO) of the Indian summer monsoon is used as a test bed to evaluate the apparent water vapor sink and heat source. The ISO-related northward movement of the column-integrated apparent water vapor sink matches that of precipitation observed by the Tropical Rainfall Measuring Mission (TRMM) minus the MERRA surface evaporation, although the amplitude of the variation is underestimated by 50%. The diagnosed water vapor and heat budgets associated with convective events during various phases of the ISO agree with the moisture–convection feedback mechanism. The apparent heat source moves northward coherently with the apparent water vapor sink associated with the deep convective activity, which is consistent with the northward migration of the precipitation anomaly. The horizontal advection of water vapor and dynamical warming are strong north of the convective area, causing the northward movement of the convection by the destabilization of the atmosphere. The spatial distribution of the apparent heat source anomalies associated with different phases of the ISO is consistent with that of the diabatic heating anomalies from the trained heating (TRAIN Q1) dataset. Further diagnostics of the TRAIN Q1 heating anomalies indicate that the ISO in the apparent heat source is dominated by a variation in latent heating associated with the precipitation.


2013 ◽  
Vol 33 (10) ◽  
pp. 1001001
Author(s):  
程巳阳 Cheng Siyang ◽  
高闽光 Gao Minguang ◽  
徐亮 Xu Liang ◽  
李胜 Li Sheng ◽  
金岭 Jin Ling ◽  
...  

Atmosphere ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1197
Author(s):  
Tingting Ju ◽  
Bingui Wu ◽  
Zhaoyu Wang ◽  
Jingle Liu ◽  
Dehua Chen ◽  
...  

In this study, relationships between low-level jet (LLJ) and low visibility associated with precipitation, air pollution, and fog in Tianjin are investigated based on observational data from January to December, 2016. Statistical results show 55% of precipitation is accompanied by LLJ, and two causes responsible for the relatively high percentage are presented. The result of case analysis shows that some southwesterly LLJs are favorable for the formation of precipitation by transporting water vapor when the water vapor channel from the South China Sea or Bengal Bay to Bohai Rim region is established. Statistical results show 55% of pollution episodes (PEs) are accompanied by LLJs. When pollutions are observed in the southern industrial regions, nocturnal southwesterly LLJ, which can carry polluted air masses from polluted regions to Tianjin and induce turbulent mixing, can enhance surface PM2.5 concentration and is favorable for the formation of surface pollution at night. Nocturnal northerly or southeasterly LLJ leads to clear air masses mixing with polluted air masses and is favorable for increasing visibility. Contributions of southwesterly LLJs to the formation of fog and precipitation are similar, which both rely on establishing the water vapor channel despite occurrence heights of LLJs being different.


2019 ◽  
Vol 100 (1) ◽  
pp. 137-153 ◽  
Author(s):  
Timothy J. Wagner ◽  
Petra M. Klein ◽  
David D. Turner

AbstractMobile systems equipped with remote sensing instruments capable of simultaneous profiling of temperature, moisture, and wind at high temporal resolutions can offer insights into atmospheric phenomena that the operational network cannot. Two recently developed systems, the Space Science and Engineering Center (SSEC) Portable Atmospheric Research Center (SPARC) and the Collaborative Lower Atmosphere Profiling System (CLAMPS), have already experienced great success in characterizing a variety of phenomena. Each system contains an Atmospheric Emitted Radiance Interferometer for thermodynamic profiling and a Halo Photonics Stream Line Doppler wind lidar for kinematic profiles. These instruments are augmented with various in situ and remote sensing instruments to provide a comprehensive assessment of the evolution of the lower troposphere at high temporal resolution (5 min or better). While SPARC and CLAMPS can be deployed independently, the common instrument configuration means that joint deployments with well-coordinated data collection and analysis routines are easily facilitated.In the past several years, SPARC and CLAMPS have participated in numerous field campaigns, which range from mesoscale campaigns that require the rapid deployment and teardown of observing systems to multiweek fixed deployments, providing crucial insights into the behavior of many different atmospheric boundary layer processes while training the next generation of atmospheric scientists. As calls for a nationwide ground-based profiling network continue, SPARC and CLAMPS can play an important role as test beds and prototype nodes for such a network.


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