Isotopic composition of precipitation at the station Portorož, Slovenia – period 2007–2010

Abstract

The stable isotopic composition of oxygen and hydrogen (δ 18 O and δ 2 H) and the tritium activity (A) were monitored in precipitation at synoptic station Portorož (Slovenia) during the period 2007-2010. Monthly and yearly isotope variations are discussed and compared with those observed over the period 2001-2006 and with the basic meteorological parameters. The mean values for δ 18 O and δ 2 H, weighted by precipitation, are-6.28 ‰ and-41.6 ‰, and these values are 0.35 ‰ and 1.6 ‰ higher but not significantly different than for the period 2001-2006. The reduced major axis (RMA) local meteoric water line (LMWL RMA) for the period 2007-2010 is δ 2 H = (8.14 ± 0.25)×δ 18 O + (8.28 ± 1.64), while the precipitation weighted least square regression (PWLSR) results in LMWL PWLSR δ 2 H = (7.87 ± 0.28)×δ 18 O + (7.97 ± 1.87). The deuterium excess (δ) weighted mean value is 8.6 ‰ and is 1.2 ‰ lower than in 2001-2006, while the temperature coefficient of δ 18 O is 0.21 ‰/°C and is for 0.02 ‰/°C higher than for the previous period. The mean Mediterranean precipitation index (MI) for the period 2007-2010 is 2.3. Lower values of MI and deuterium excess than in the preceding period indicate stronger continental climatic character during observation period, however the differences are not statistically significant. The weighted mean tritium activity is 6.4 TU, which is 0.5 TU lower but not significantly different than in 2001-2006. Izvleček V prispevku obravnavamo izotopsko sestavo kisika in vodika (δ 18 O in δ 2 H) ter aktivnosti tricija (A) v mesečnih vzorcih padavin, ki smo jo spremljali na sinoptični postaji Portorož (Slovenija) v obdobju 2007-2010. Analizirali smo mesečne in letne spremembe izotopske sestave padavin in jih primerjali z nizom podatkov za obdobje 2001-2006 ter z osnovnimi meteorološkimi parametri. Srednje tehtane vrednosti δ 18 O in δ 2 H določene ob upoštevanju izmerjene količine padavin znašajo

Slovenian Network of Isotopes in Precipitation (SLONIP) – a review of activities in the period 1981–2015

“…1). At both stations stable and radioactive water isotopes were monitored on a monthly basis (Vreča et al, 2005(Vreča et al, -2007(Vreča et al, , 2009(Vreča et al, , 2011(Vreča et al, , 2015a. Unfortunately, since 2004, due to the lack of financial support monitoring has been continued only at the Portorož airport.…”

“…At the laboratory impurities (e.g. dust, particles) were removed from the samples collected at the stations Ljubljana-Reaktor, Portorož, Kredarica, Rateče, Bohinjska Češnjica, Zgornja Radovna and Podljubelj by filtration through 12-25 μm pore size ashless filter papers (Grade 589/1 Black Ribbon, Whatman, UK) before taking aliquots for the different isotope analyses (Vreča et al, 2014(Vreča et al, , 2015a. ZavaDlav (2013) reports filtration of samples through 2 μm pore size ashless filters (Grade 589/3, Whatman, UK).…”

“…2). However, different IRMS were used including either a dual inlet Varian MAT 250 at JSI (UrBanc & JaMniK, 1999;PezDič, 1999;LaPanje, 2000;Vreča et al, 2008Vreča et al, , 2011, Finnigan DELTA plus at the Joanneum Research (JR) in Graz, Austria (Mali, 2006;ManDič, 2013;Vreča et al, 2008Vreča et al, , 2011, Thermo Finnigan DELTA plus XP at the University of Rijeka (UR), Croatia (Mance et al, 2014) or a continuous flow IsoPrime IRMS at the JSI (Lojen, personal communication;ZavaDlav, 2013;ZavaDlav et al, 2012;Vreča et al, 2013Vreča et al, , 2014Vreča et al, , 2015aVreča, 2015). Doctor (2002) and TrčeK (2003TrčeK ( , 2005TrčeK ( , 2006 Hydrogen isotope composition (δ 2 H) was determined at 25 locations using different analytical methods.…”

“…2). Measurements were performed on different IRMS like the dual inlet Varian MAT 250 at JSI (PezDič, 1999;Vreča et al, 2008Vreča et al, , 2011 or the Finnigan DELTA plus XP at the JR (Mali, 2006;Vreča et al, 2008Vreča et al, , 2011Vreča et al, , 2014Vreča et al, , 2015a and at the UR (Mance et al, 2014). Doctor (2002) reports that the chromium reduction method (Gehre et al, 1996) was used at the GSF, however similar as in TrčeK (2003TrčeK ( , 2005TrčeK ( , 2006 no information about the type of IRMS used for analysis is reported.…”

Speleothem Stable Isotope Records from Eastern Europe & Turkey

“…Map of the Eastern Europe & Turkey SISAL region, with the modern day δ 18 O/T slopes indicated by circles shaded in greyscale proportionate to the slope (min 0.16‰/°C: white; max 0.36‰/°C: black). The numbers in brackets next to the circles indicate the references for the corresponding studies; Slovenia:[82,90], Serbia:[91], Hungary:[79,83], Slovakia:[84], Romania:[77], Crimea:[92], Turkey:[93].Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 4 December 2018 Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: Environmental controls on speleothem δ C…”