Review of Ritter et al. "Isotopic exchange on the diurnal scale between near-surface snow and lower atmospheric water vapor at Kohnen station, East Antarctica"

2016 ◽  
Author(s):  
Bradley Markle
Keyword(s):  
Water Vapor ◽  
Isotopic Exchange ◽  
East Antarctica ◽  
Atmospheric Water Vapor ◽  
Atmospheric Water ◽  
Near Surface ◽  
Surface Snow

scholarly journals Isotopic exchange on the diurnal scale between near-surface snow and lower atmospheric water vapor at Kohnen station, East Antarctica

2016 ◽  
Vol 10 (4) ◽  
pp. 1647-1663 ◽  
Author(s):  
François Ritter ◽  
Hans Christian Steen-Larsen ◽  
Martin Werner ◽  
Valérie Masson-Delmotte ◽  
Anais Orsi ◽  
...  
Keyword(s):  
Water Vapor ◽  
Isotopic Composition ◽  
East Antarctica ◽  
Atmospheric Water Vapor ◽  
Box Model ◽  
Snow Surface ◽  
Atmospheric Water ◽  
Near Surface ◽  
Diurnal Cycles ◽  
Surface Snow

Abstract. Quantifying the magnitude of post-depositional processes affecting the isotopic composition of surface snow is essential for a more accurate interpretation of ice core data. To achieve this, high temporal resolution measurements of both lower atmospheric water vapor and surface snow isotopic composition are required. This study presents continuous measurements of water vapor isotopes performed in East Antarctica (Kohnen station) from December 2013 to January 2014 using a laser spectrometer. Observations have been compared with the outputs of two atmospheric general circulation models (AGCMs) equipped with water vapor isotopes: ECHAM5-wiso and LMDZ5Aiso. During our monitoring period, the signals in the 2 m air temperature T, humidity mixing ratio q and both water vapor isotopes δD and δ18O are dominated by the presence of diurnal cycles. Both AGCMs simulate similar diurnal cycles with a mean amplitude 30 to 70 % lower than observed, possibly due to an incorrect simulation of the surface energy balance and the boundary layer dynamics. In parallel, snow surface samples were collected each hour over 35 h, with a sampling depth of 2–5 mm. A diurnal cycle in the isotopic composition of the snow surface is observed in phase with the water vapor, reaching a peak-to-peak amplitude of 3 ‰ for δD over 24 h (compared to 36 ‰ for δD in the water vapor). A simple box model treated as a closed system has been developed to study the exchange of water molecules between an air and a snow reservoir. In the vapor, the box model simulations show too much isotopic depletion compared to the observations. Mixing with other sources (advection, free troposphere) has to be included in order to fit the observations. At the snow surface, the simulated isotopic values are close to the observations with a snow reservoir of  ∼ 5 mm depth (range of the snow sample depth). Our analysis suggests that fractionation occurs during sublimation and that vapor–snow exchanges can no longer be considered insignificant for the isotopic composition of near-surface snow in polar regions.

scholarly journals Isotopic exchange on the diurnal scale between near-surface snow and lower atmospheric water vapor at Kohnen station, East Antarctica

2016 ◽  
Author(s):  
François Ritter ◽  
Hans Christian Steen-Larsen ◽  
Martin Werner ◽  
Valérie Masson-Delmotte ◽  
Anais Orsi ◽  
...  
Keyword(s):  
Water Vapor ◽  
Isotopic Composition ◽  
East Antarctica ◽  
Atmospheric Water Vapor ◽  
Depth Range ◽  
Snow Surface ◽  
Atmospheric Water ◽  
Near Surface ◽  
Depositional Processes ◽  
Surface Snow

Abstract. Quantifying the magnitude of post-depositional processes affecting the isotopic composition of surface snow is essential for a more accurate interpretation of ice core data. To achieve this, high temporal resolution measurements of both lower atmospheric water vapor and surface snow isotopic composition are required. This study presents the first continuous measurements of water vapor isotopes performed in East Antarctica (Kohnen station) from December 2013 to January 2014 using a laser spectrometer. During our monitoring period, the synoptic variability of the water vapor isotopic composition is found to be low compared to the diurnal cycle and we therefore concentrate our study on interaction between the isotopic composition of the vapor and the snow surface on a diurnal timescale. The peak-to-peak amplitude of the snow surface isotopic composition over 24 h reaches 3 ‰ for δD, in phase with the diurnal variations of δD in surface vapor, which itself has an amplitude of 36 ‰. A simple box model treated as a closed system has been developed to study the exchange of water molecules between an air and a snow reservoir. In the vapor, the simulations show too much isotopic depletion compared to the observations. Mixing with other sources (wind advection, free troposphere) has to be included in order to fit the observations. At the snow surface, the simulated isotopic values are close to the observations with a snow reservoir of ∼5 mm depth (range of the snow sample depth). Our analysis suggests that vapor-snow exchanges can no longer be considered insignificant for the isotopic composition of near surface snow in central Antarctica.

scholarly journals Effect of atmospheric water vapor on modification of stable isotopes in near-surface snow on ice sheets

2008 ◽  
Vol 113 (D24) ◽  
Author(s):  
Michael S. Town ◽  
Stephen G. Warren ◽  
Von P. Walden ◽  
Edwin D. Waddington
Keyword(s):  
Stable Isotopes ◽  
Water Vapor ◽  
Ice Sheets ◽  
Atmospheric Water Vapor ◽  
Atmospheric Water ◽  
Near Surface ◽  
Surface Snow

Near-surface atmospheric water vapor enhancement at the Mars Phoenix lander site

Icarus ◽  
2020 ◽  
Vol 343 ◽  
pp. 113624
Author(s):  
Leslie K. Tamppari ◽  
Mark T. Lemmon
Keyword(s):  
Water Vapor ◽  
Atmospheric Water Vapor ◽  
Atmospheric Water ◽  
Near Surface

Stable isotopic composition of near surface atmospheric water vapor and rain–vapor interaction in Taipei, Taiwan

2014 ◽  
Vol 519 ◽  
pp. 2091-2100 ◽  
Author(s):  
Amzad H. Laskar ◽  
Jr-Chuan Huang ◽  
Shih-Chieh Hsu ◽  
Sourendra K. Bhattacharya ◽  
Chung-Ho Wang ◽  
...  
Keyword(s):  
Water Vapor ◽  
Isotopic Composition ◽  
Atmospheric Water Vapor ◽  
Atmospheric Water ◽  
Near Surface ◽  
Stable Isotopic Composition ◽  
Stable Isotopic

scholarly journals Exploring the elevated water vapor signal associated with the free tropospheric biomass burning plume over the southeast Atlantic Ocean

2021 ◽  
Vol 21 (12) ◽  
pp. 9643-9668
Author(s):  
Kristina Pistone ◽  
Paquita Zuidema ◽  
Robert Wood ◽  
Michael Diamond ◽  
Arlindo M. da Silva ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Carbon Monoxide ◽  
Water Vapor ◽  
Biomass Burning ◽  
Sea Water ◽  
Source Region ◽  
Atmospheric Water Vapor ◽  
Atmospheric Water ◽  
Near Surface ◽  
Aerosol Effects

Abstract. In southern Africa, widespread agricultural fires produce substantial biomass burning (BB) emissions over the region. The seasonal smoke plumes associated with these emissions are then advected westward over the persistent stratocumulus cloud deck in the southeast Atlantic (SEA) Ocean, resulting in aerosol effects which vary with time and location. Much work has focused on the effects of these aerosol plumes, but previous studies have also described an elevated free tropospheric water vapor signal over the SEA. Water vapor influences climate in its own right, and it is especially important to consider atmospheric water vapor when quantifying aerosol–cloud interactions and aerosol radiative effects. Here we present airborne observations made during the NASA ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign over the SEA Ocean. In observations collected from multiple independent instruments on the NASA P-3 aircraft (from near-surface to 6–7 km), we observe a strongly linear correlation between pollution indicators (carbon monoxide (CO) and aerosol loading) and atmospheric water vapor content, seen at all altitudes above the boundary layer. The focus of the current study is on the especially strong correlation observed during the ORACLES-2016 deployment (out of Walvis Bay, Namibia), but a similar relationship is also observed in the August 2017 and October 2018 ORACLES deployments. Using reanalyses from the European Centre for Medium-Range Weather Forecasts (ECMWF) and Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), and specialized WRF-Chem simulations, we trace the plume–vapor relationship to an initial humid, smoky continental source region, where it mixes with clean, dry upper tropospheric air and then is subjected to conditions of strong westward advection, namely the southern African easterly jet (AEJ-S). Our analysis indicates that air masses likely left the continent with the same relationship between water vapor and carbon monoxide as was observed by aircraft. This linear relationship developed over the continent due to daytime convection within a deep continental boundary layer (up to ∼5–6 km) and mixing with higher-altitude air, which resulted in fairly consistent vertical gradients in CO and water vapor, decreasing with altitude and varying in time, but this water vapor does not originate as a product of the BB combustion itself. Due to a combination of conditions and mixing between the smoky, moist continental boundary layer and the dry and fairly clean upper-troposphere air above (∼6 km), the smoky, humid air is transported by strong zonal winds and then advected over the SEA (to the ORACLES flight region) following largely isentropic trajectories. Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT) back trajectories support this interpretation. This work thus gives insights into the conditions and processes which cause water vapor to covary with plume strength. Better understanding of this relationship, including how it varies spatially and temporally, is important to accurately quantify direct, semi-direct, and indirect aerosol effects over this region.

scholarly journals Exploring the elevated water vapor signal associated with the free-tropospheric biomass burning plume over the southeast Atlantic Ocean

2021 ◽  
Author(s):  
Kristina Pistone ◽  
Paquita Zuidema ◽  
Robert Wood ◽  
Michael Diamond ◽  
Arlindo M. da Silva ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Carbon Monoxide ◽  
Water Vapor ◽  
Biomass Burning ◽  
Sea Water ◽  
Source Region ◽  
Atmospheric Water Vapor ◽  
Atmospheric Water ◽  
Near Surface ◽  
Aerosol Effects

Abstract. In southern Africa, widespread agricultural fires produce substantial biomass burning (BB) emissions over the region. The seasonal smoke plumes associated with these emissions are then advected westward over the persistent stratocumulus cloud deck in the Southeast Atlantic (SEA) Ocean, resulting in aerosol effects which vary with time and location. Much work has focused on the effects of these aerosol plumes, but previous studies have also described an elevated free-tropospheric water vapor signal over the SEA. Water vapor influences climate in its own right, and it is especially important to consider atmospheric water vapor when quantifying aerosol-cloud interactions and aerosol radiative effects. Here we present airborne observations made during the NASA ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign over the SEA Ocean. In observations collected from multiple independent instruments on the NASA P-3 aircraft (from near-surface to 6–7 km), we observe a strongly linear correlation between pollution indicators (carbon monoxide (CO) and aerosol loading) and atmospheric water vapor content, seen at all altitudes above the boundary layer. The focus of the current study is on the especially strong correlation observed during the ORACLES-2016 deployment (out of Walvis Bay, Namibia), but a similar relationship is also observed in the August 2017 and October 2018 ORACLES deployments. Using ECMWF and MERRA-2 reanalyses and specialized WRF-Chem simulations, we trace the plume-vapor relationship to an initial humid, smoky continental source region, where it is subjected to conditions of strong westward advection, namely the South African Easterly Jet (AEJ-S). Our analysis indicates that airmasses likely left the continent with the same relationship between water vapor and carbon monoxide as was observed by aircraft. This linear relationship developed over the continent due to daytime convection within a deep continental boundary layer (up to 5–6 km) which produced fairly consistent vertical gradients in CO and water vapor, decreasing with altitude and varying in time, but does not originate as a product of the BB combustion itself. Due to a combination of conditions and mixing between the smoky, moist continental boundary layer and the dry and fairly clean upper-troposphere air above (~6 km), the smoky, humid air is transported by strong zonal winds and then advected over the SEA (to the ORACLES flight region) following largely isentropic trajectories. HYSPLIT back trajectories support this interpretation. Better understanding of the conditions and processes which cause the water vapor to covary with plume strength is important to accurately quantify direct, semi-direct, and indirect aerosol effects in this region.

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