ALBERT

Description: Hurricane-induced rainfall over Puerto Rico has characteristic δ 18 O values which are more negative than local rainfall events. Thus, hurricanes may be recorded in speleothems from Larga cave, Puerto Rico, as characteristic oxygen isotope excursions. Samples of 84 local rainfall events between 2012 and 2013 ranged from -6.2 to +0.3 ‰ , whereas nine rainfall samples belonging to a rain band of hurricane Isaac (23-24 August 2012) ranged from -11.8 to -7.1 ‰. Cave monitoring covered the hurricane season of 2014 and investigated the impact of hurricane rainfall on drip water chemistry. δ 18 O values were measured in cumulative monthly rainwater samples above the cave. Inside the cave, δ 18 O values of instantaneous drip water samples were analyzed and drip rates were recorded at six drip sites. Most effective recharge appears to occur during the wet months (April-May and August-November). δ 18 O values of instantaneous drip water samples ranged from -3.5 to -2.4 ‰ . In April 2014 and April 2015 some drip sites showed more negative δ 18 O values than the effective rainfall (-2.9 ‰), implying an influence of hurricane rainfall reaching the cave via stratified seepage flow months to years after the event. Speleothems from these drip sites in Larga cave have a high potential for paleotempestology studies.

Description: The present investigation was initiated to report on species compositions and dynamics in the Norwegian-Greenland Sea during low production phases in spring and early summer. Thus, the distribution patterns of living coccolithophores during June to July, 1990, February and May, 1991, and March to April, 1995 were investigated. In general, the seasonal development of the phytoplankton started after the yearly dark period and coccolithophores increased in abundance when the water column was more stratified and both temperatures and insolation increased. Cell densities reached a maximum of 207x10~c occospheres/l in the southeastern part of the studied area. However, these high cell densities probably resulted from ,,old" populations, drifted to the Norwegian-Greenland Sea from the North Atlantic. Some of the collected samples did not contain any coccolithophores. In total, 15 coccolithophore species were identified. The diversity was generally higher in the eastern part of the Norwegian-Greenland Sea and to the west the coccolithophore communities often were monospecific. Emiliania huxleyi is the dominant species, but Calciopappus caudatus and Algirosphaera robusta also considerably contribute to the communities. High cell densities of C. caudatus were interpreted as the result of a bloom or more probably close to bloom conditions during the general low productive period. In addition, many of the E. huxleyi coccolith from the surface waters of the southeastern Norwegian-Greenland Sea were heavily corroded. These specimens may have drifted within the Atlantic water for a longer time.