Central Scandinavian Mountains, 1107–2006 AD, Maximum latewood density, Scots pine, PAGES Euro-Med 2k Version Gunnarson, B.E.; Linderholm, H.W.; Moberg, A. Gunnarson, B.E. Linderholm, H.W. Moberg, A. PAGES 2k Network PAGES Euro-Med 2k PISY Pinus sylvestris L. Scots pine Scotch pine earth science/paleoclimate/tree-ring (Province of Jaemtland, Sweden>LATITUDE 63.1>LONGITUDE 15) Dendroclimatological sampling of Scots pine (Pinus sylvestris L.) has been made in the province of Jämtland, in the west-central Scandinavian mountains, since the 1970s. The tree-ring width (TRW) chronology spans several thousand years and has been used to reconstruct June-August temperatures back to 1632 bc. A maximum latewood density (MXD) dataset, covering the period ad 1107-1827 (with gap 1292-1315) was presented in the 1980s by Fritz Schweingruber. Here we combine these historical MXD data with recently collected MXD data covering ad 1292-2006 into a single reconstruction of April-September temperatures for the period ad 1107-2006. Regional curve standardization (RCS) provides more low-frequency variability than “non-RCS” and stronger correlation with local seasonal temperatures (51% variance explained). The MXD chronology shows a stronger relationship with temperatures than the TRW data, but the two chronologies show similar multi-decadal variations back to ad 1500. According to the MXD chronology, the period since ad 1930 and around ad 1150-1200 were the warmest during the last 900 years. Due to large uncertainties in the early part of the combined MXD chronology, it is not possible to conclude which period was the warmest. More sampling of trees growing near the tree-line is needed to further improve the MXD chronology. STUDY NOTES: The new MXD data (ITRAX), from sites Roertjaern and Furuberget (Fig. 1 of Gunnarson et al., 2011), were obtained using an ITRAX Woodscanner from Cox Analytic System (http://www.coxsys.se). Henceforth, these data are referred to as ITRAX data, and they consist of more than 50 radial measurement series collected from both living and dead trees. Two 10 mm cores, from ~1.3 m above the ground, were collected from each living or standing dead tree. From dead trees, lying on the ground or submerged in water, thick discs were cut from the trunks with a chainsaw at about 1–1.5 m above the root collar. The two MXD chronologies, SH (1107–1827, with a gap between 1292 and 1315) and ITRAX (1292–2006), were combined into a single chronology (1107–2006). This combined chronology consists solely of the SH data before 1292, ITRAX alone for 1292–1315, the average of the two during the period 1316–1827, and ITRAX data alone after 1827. The variance in each chronology was stabilized according to the Briffa RBAR-weighted method implemented in ARSTAN software (Cook and Krusic 2005), in order to compensate for variations in sample depth in the chronologies. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Gunnarson, B.E. Investigator : Linderholm, H.W. Investigator : Moberg, A. 2013-05-15 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/1003408 https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/pages2k/euro-med2k/Gunnarson_et_al_CD_2011.txt https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/pages2k/euro-med2k/Gunnarson_et_al_CD_2011.txt English https://www.ncdc.noaa.gov/paleo/study/1003408 https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/pages2k/euro-med2k/Gunnarson_et_al_CD_2011.txt Björn E. Gunnarson, Hans W. Linderholm, and Anders Moberg. 2011. Improving a tree-ring reconstruction from west-central Scandinavia: 900 years of warm-season temperatures. Climate Dynamics, Vol. 36, Issues 1-2, pp. 97-108. DOI: 10.1007/s00382-010-0783-5 START YEAR: 1107 AD * END YEAR: 2007 AD 15 63.1 15 63.1