Variations in tnelt - Iayer frequency in the GISP 2 ice core : itnplications for Holocene sutntner tetnperatures in central Greenland RI CHARD

Th e rare melt feature in the GISP2, central Greenland deep ice core have decreased in frequency over th e most recent 7000 years. Calibration of thi s cha nge in melt frequency against mod ern spatia l va ri a tion of melt freq uency and temperaturc in centra l Green la nd , a nd against mod ern temporal variability of temperatures in ccntra l Green land, indica tes that mean mid-summer temperatures have cooled over th e mos t recent 7000 yea rs, probabl y by slightly more than 1°C if va riability qf summer temperatures has not changed. Comparison to GRIP iso topi c records from central Greenland and to the melt reco rd from the Agassiz Ice Ca p, Arctic Canada , sugges ts some seasonal and reg ional coherence for this cooling signa l, as we ll as for a co ld event a bout 80008500 BP.