scholarly journals Continuous observation of Stable Isotopes of Water Vapor in Atmosphere Using High-Resolution FTIR

2018 ◽  
Author(s):  
Chang-Gong Shan ◽  
Wei Wang ◽  
Cheng Liu ◽  
You-Wen Sun ◽  
Yuan Tian ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Water Vapor ◽  
High Resolution ◽  
Water Cycle ◽  
Back Trajectories ◽  
Mixing Ratios ◽  
Keeling Plot ◽  
Stable Isotopes Of Water ◽  
Observation Period ◽  
Good Agreement

Abstract. Observations of stable isotopes of water vapor provide important information for water cycle. The volume mixing ratios (VMR) of H2O (XH2O) and HDO (XHDO) have been retrieved based on a high-resolution ground-based Fourier transform infrared spectroscopy (FTIR) at Hefei site, and the isotopic composition δD was calculated. Time series of XH2O were compared with the Greenhouse gases Observing Satellite (GOSAT) data, showing a good agreement. The daily averaged δD ranges from −17.02 ‰ to −282.3 ‰ between September 2015 and September 2016. Also, the relationships of meteorological parameters with stable isotopologue were analyzed. δD values showed an obvious positive correlation with temperature and ln(XH2O) and a weak correlation with relative humidity. Further, 51.35 % of airmass at Hefei site comes from the southeast of China, and the main potential sources of δD are in the east of China over the observation period based on the back trajectories model. Furthermore, the δD values of evapotranspiration were calculated based on Keeling plot. Observations of the stable isotopes of water vapor by high-resolution ground-based FTIR provide information on study of the variation of the atmospheric water vapor at Hefei site.

scholarly journals First-Year Operation of a New Water Vapor Raman Lidar at the JPL Table Mountain Facility, California

2008 ◽  
Vol 25 (8) ◽  
pp. 1454-1462 ◽  
Author(s):  
Thierry Leblanc ◽  
I. Stuart McDermid ◽  
Robin A. Aspey
Keyword(s):  
Water Vapor ◽  
Current System ◽  
First Year ◽  
Raman Lidar ◽  
Upper Troposphere ◽  
Mixing Ratios ◽  
Table Mountain ◽  
Lidar Measurements ◽  
Better Than ◽  
Good Agreement

Abstract A new water vapor Raman lidar was recently built at the Table Mountain Facility (TMF) of the Jet Propulsion Laboratory (JPL) in California and more than a year of routine 2-h-long nighttime measurements 4–5 times per week have been completed. The lidar was designed to reach accuracies better than 5% anywhere up to 12-km altitude, and with the capability to measure water vapor mixing ratios as low as 1 to 10 ppmv near the tropopause and in the lower stratosphere. The current system is not yet fully optimized but has already shown promising results as water vapor profiles have been retrieved up to 18-km altitude. Comparisons with Vaisala RS92K radiosondes exhibit very good agreement up to at least 10 km. They also revealed a wet bias in the lidar profiles (or a dry bias in the radiosonde profiles), increasing with altitude and becoming significant near 10 km and large when approaching the tropopause. This bias cannot be explained solely by well-known too-dry measurements of the RS92K in the upper troposphere and therefore must partly originate in the lidar measurements. Excess signal due to residual fluorescence in the lidar receiver components is among the most likely candidates and is subject to ongoing investigation.

scholarly journals Stable Isotopes of Water Vapor in the Vadose Zone: A Review of Measurement and Modeling Techniques

2012 ◽  
Vol 11 (3) ◽  
pp. vzj2011.0165 ◽  
Author(s):  
Keir Soderberg ◽  
Stephen P. Good ◽  
Lixin Wang ◽  
Kelly Caylor
Keyword(s):  
Stable Isotopes ◽  
Water Vapor ◽  
Vadose Zone ◽  
Modeling Techniques ◽  
Stable Isotopes Of Water

scholarly journals High-Resolution Simulation of Hurricane Bonnie (1998). Part II: Water Budget

2006 ◽  
Vol 63 (1) ◽  
pp. 43-64 ◽  
Author(s):  
Scott A. Braun
Keyword(s):  
Boundary Layer ◽  
Water Vapor ◽  
High Resolution ◽  
Mesoscale Model ◽  
Cumulative Effect ◽  
Vapor Source ◽  
Mixing Ratios ◽  
Stratiform Precipitation ◽  
Hurricane Bonnie ◽  
Improved Model

Abstract The fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) is used to simulate Hurricane Bonnie at high resolution (2-km spacing) in order to examine budgets of water vapor, cloud condensate, and precipitation. Virtually all budget terms are derived directly from the model (except for the effects of storm motion). The water vapor budget reveals that a majority of the condensation in the eyewall occurs in convective hot towers, while outside of the eyewall most of the condensation occurs in weaker updrafts, indicative of a larger role of stratiform precipitation processes. The ocean source of water vapor in the eyewall region is only a very small fraction of that transported inward in the boundary layer inflow or that condensed in the updrafts. In contrast, in the outer regions, the ocean vapor source is larger owing to the larger area, counters the drying effect of low-level subsidence, and enhances the moisture transported in toward the eyewall. In this mature storm, cloud condensate is consumed as rapidly as it is produced. Cloud water peaks at the top of the boundary layer and within the melting layer, where cooling from melting enhances condensation. Unlike in squall lines, in the hurricane, very little condensate produced in the eyewall convection is transported outward into the surrounding precipitation area. Most of the mass ejected outward is likely in the form of small snow particles that seed the outer regions and enhance in situ stratiform precipitation development through additional growth by vapor deposition and aggregation. This study also examines artificial source terms for cloud and precipitation mass associated with setting to zero negative mixing ratios that arise from numerical advection errors. Although small at any given point and time, the cumulative effect of these terms contributes an amount of mass equivalent to 13% of the total condensation and 15%–20% of the precipitation. Thus, these terms must be accounted for to balance the model budgets, and the results suggest the need for improved model numerics.

scholarly journals Estimating the size of a methane emission point-source at different scales: from local to landscape

2016 ◽  
Author(s):  
Stuart N. Riddick ◽  
Sarah Connors ◽  
Andrew D. Robinson ◽  
Alastair J. Manning ◽  
Pippa S. D. Jones ◽  
...  
Keyword(s):  
Point Sources ◽  
Back Trajectories ◽  
Mixing Ratios ◽  
Ch4 Production ◽  
Emission Point ◽  
Landfill Emissions ◽  
Gaussian Plume ◽  
Isotopic Measurements ◽  
Good Agreement ◽  
Modelling Approach

Abstract. High methane (CH4) mixing ratios (up to 4 ppm) have occurred sporadically at our measurement site in Haddenham, Cambridgeshire since July 2012. Isotopic measurements and back trajectories show that the source is the Waterbeach Waste management park 7 km SE of Haddenham. To investigate this further, measurements were made on June 30th and July 1st 2015 at other locations nearer to the source. Landfill emissions have been estimated using three different approaches (WindTrax, Gaussian plume, and NAME InTEM inversion) applied to the measurements made close to source and at Haddenham. The emission estimates derived using the WindTrax and Gaussian plume approaches agree well for the period of intense observations. Applying the Gaussian plume approach to all periods of elevated measurements seen at Haddenham produces year-round and monthly landfill emission estimates. The estimated annual emissions vary between 11.6 and 13.7 Gg CH4 yr−1. The monthly emission estimates are highest in winter (2160 kg hr−1 in February) and lowest in summer (620 kg hr−1 in July). These data identify the effects of environmental conditions on landfill CH4 production and highlight the importance of year-round measurement to capture seasonal variability in CH4 emission. We suggest the landscape inverse modelling approach described in this paper is in good agreement with more labour-intensive near-source approaches and can be used to identify point-sources within an emission landscape to provide high-quality emission estimates.

scholarly journals Profiling water vapor mixing ratios in Finland by means of a Raman lidar, a satellite and a model

2017 ◽  
Author(s):  
Maria Filioglou ◽  
Anna Nikandrova ◽  
Sami Niemelä ◽  
Holger Baars ◽  
Tero Mielonen ◽  
...  
Keyword(s):  
Water Vapor ◽  
High Resolution ◽  
Weather Prediction ◽  
Microwave Radiometer ◽  
Limited Area ◽  
Raman Lidar ◽  
Model Data ◽  
Mixing Ratios ◽  
Field Campaigns ◽  
Satellite Product

Abstract. We present tropospheric water vapor profiles measured with a Raman lidar during three field campaigns held in Finland. Co-located radio soundings are available throughout the period for the calibration of the lidar signals. We investigate the possibility of calibrating the lidar water vapor profiles in the absence of co-existing on site soundings using water vapor profiles from the combined Advanced Infrared Sounder (AIRS) and the Advanced Microwave Radiometer (AMSU) satellite product; the Aire Limitee Adaptation dynamique Development International and High Resolution Limited Area Model (ALADIN HIRLAM) numerical weather prediction (NWP) system, and the nearest radio sounding station located 100 km away from the lidar site (only for the permanent location of the lidar). The uncertainties of the calibration factor derived from the soundings, the satellite and the model data are

scholarly journals Stable Isotopes of Water Vapor in the Vadose Zone: A Review of Measurement and Modeling Techniques

2013 ◽  
Vol 12 (1) ◽  
pp. vzj2011.0165er
Author(s):  
Keir Soderberg ◽  
Stephen P. Good ◽  
Lixin Wang ◽  
Kelly Caylor
Keyword(s):  
Stable Isotopes ◽  
Water Vapor ◽  
Vadose Zone ◽  
Modeling Techniques ◽  
Stable Isotopes Of Water
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