Developing a western Siberia reference site for tropospheric water vapour isotopologue observations obtained by different techniques (in situ and remote sensing)

Abstract

Abstract. Water stable isotopologues provide integrated tracers of the atmospheric water cycle, affected by changes in air mass origin, non-convective and convective processes and continental recycling. Novel remote sensing and in situ measuring techniques have recently offered opportunities for monitoring atmospheric water vapour isotopic composition. Recently developed infrared laser spectrometers allow for continuous in situ measurements of surface water vapour δD v and δ 18 O v . So far, very few intercomparisons of measurements conducted using different techniques have been achieved at a given location, due to difficulties intrinsic to the comparison of integrated with local measurements. Nudged simulations conducted with high-resolution isotopically enabled general circulation models (GCMs) provide a consistent framework for comparison with the different types of observations. Here, we compare simulations conducted with the ECHAM5-wiso model with two types of water vapour isotopic data obtained during summer 2012 at the forest site of Kourovka, western Siberia: hourly ground-based FTIR total atmospheric columnar δD v amounts, and in situ hourly Picarro δD v measurements. There is an excellent correlation between observed and predicted δD v at surface while the comparison between water column values derived from the model compares well with FTIR estimates.

Variations of oxygen-18 in West Siberian precipitation during the last 50 years

“…This allows us to compute the columnintegrated δD values that GOSAT would retrieve if it was flying in ECHAM5-wiso's simulated atmosphere (Risi et al, 2012a). Gribanov et al (2014) showed that the ECHAM5-wiso simulation results agree well with observations from Kourovka Observatory and the surrounding area for the year 2012. Total column water vapour values of δD, according to ECHAM5-wiso and to GOSAT satellite retrievals, are shown in Fig.…”

A posteriori calculation of δ<sup>18</sup>O and δD in atmospheric water vapour from ground-based near-infrared FTIR retrievals of H<sub>2</sub><sup>16</sup>O, H<sub>2</sub><sup>18</sup>O, and HD<sup>16</sup>O

“…Additional fractionation processes of equilibrium and non-equilibrium conditions are defined for the water isotope variables whenever a phase change of the "normal" water occurs in ECHAM5. ECHAM5-wiso has been validated with observations of isotope concentrations in precipitation and water vapour (Langebroeck et al, 2011;Werner et al, 2011;Gribanov et al, 2014). On a global and European scale, annual and seasonal ECHAM5-wiso simulation results are in good agreement with available observations from the Global Network of Isotopes in Precipitation, GNIP (IAEA-WMO, 2006).…”

“…Using the isotopic version of the LMD model, Risi et al (2013) have investigated the role of continental recycling, while Gryazin et al (2014) have suggested that the difficulty of this model in simulating the water cycle over western Siberia may be due to a problem in the large-scale advection or to insufficient surface evaporation. Also interesting is the fact that the δD of the total water column is highly correlated with δD near surface values as shown by Gribanov et al (2014) for a site in western Siberia. In turn, such recent studies point both to the usefulness of total column integrated δD, which could be easily extended to the study of seasonal and intraseasonal variations when sufficiently long time series will be available, and to the possibility of comparing and possibly combining such data with in situ δD measurements in ground level water vapour at sites like Kourovka where both FTIR and PICARRO measurements are performed.…”

“…For comparison with FTIR, vertical profiles of H 16 2 O, H 18 2 O and HDO from the model were smoothed by the averaging kernels from the retrieval to take into account different vertical sensitivity (according to Gribanov et al, 2014;Wunch et al, 2010) (see Fig. 2), vertically integrated to get total column values, and then isotopic ratios were calculated.…”

Moisture origin as a driver of temporal variabilities of the water vapour isotopic composition in the Lena River Delta, Siberia

“…More recently, continuous water vapour isotopic observations have been conducted in western Russia, at the Kourovka observatory (Bastrikov et al, 2014;Gribanov et al, 2014) and at Labytnangy (Konstantin Gribanov and Jean Jouzel, personal communication). Observations from the Kourovka station depicted seasonal and synoptic variations as well as strong diurnal variations in summer on the first and second order vapour isotopic signals.…”