A comparison between VEGA 1, 2 and Giotto flybys of comet 1P/Halley: implications for Rosetta Annales Geophysicae DOI 10.5194/angeo-32-1441-2014 28 November 2014 We discuss three flybys (within a time span of 8 days) of comet 1P/Halley by VEGA 1, 2 and Giotto. Looking at two different plasma phenomena: mirror mode waves and field line draping; we study the differences in SW-comet interaction between these three flybys. We find that on this time scale (comparable to Rosetta’s orbits) there is a significant difference, both caused by changing outgassing rate of the comet and changes in the solar wind. We discuss implications for Rosetta RPC observations. Read more
Correlations between climate network and relief data Nonlinear Processes in Geophysics DOI 10.5194/npg-21-1127-2014 27 November 2014 In the past few years, complex networks have been extensively applied to climate sciences, yielding the new field of climate networks. Here, we generalize climate network analysis by investigating the influence of altitudes in network topology. More precisely, we verified that nodes group into different communities corresponding to geographical areas with similar relief properties. This new approach may contribute to obtaining more complete climate network models. Read more
Path independence of climate and carbon cycle response over a broad range of cumulative carbon emissions Earth System Dynamics DOI 10.5194/esd-5-409-2014 24 November 2014 Recent studies have identified an approximately proportional relationship between global warming and cumulative carbon emissions. This relationship – referred to as the transient climate response to cumulative carbon emissions (TCRE) – is useful for climate policy applications. We show that the TCRE is constant for cumulative emissions lower than ~1500 GtC, but declines for higher cumulative emissions. We also find the TCRE to decrease with increasing emission rate. Read more
Long-term trends at the Boknis Eck time series station (Baltic Sea), 1957–2013: does climate change counteract the decline in eutrophication? Biogeosciences DOI 10.5194/bg-11-6323-2014 24 November 2014 A time series of 9 oceanic parameters from the coastal time series station Boknis Eck (BE, South Western Baltic Sea) in the period of 1957-2013 is analysed with respect to seasonal cycles and longterm trends. Most striking was a paradoxical decreasing trend in oxygen with a simultaneous decline in eutrophication. Possible reasons for this paradox, e.g. processes related to warming temperatures such as increased decomposition of organic matter or altered ventilation, are discussed. Read more
Detailed ice loss pattern in the northern Antarctic Peninsula: widespread decline driven by ice front retreats The Cryosphere DOI 10.5194/tc-8-2135-2014 24 November 2014 This study of one of the most rapidly changing glacier regions on Earth – the Antarctic Peninsula – uses two types of satellite data to measure the rates of ice loss in detail for the individual glaciers. The satellite data is laser altimetry from ICESat and stereo image DEM differences. The results show that 24..9 ± 7.8 billion tons of ice are lost from the region north of 66°S on the Peninsula each year. The majority of the data cover 2003-2008. Read more
The global monsoon across timescales: coherent variability of regional monsoons Climate of the Past DOI 10.5194/cp-10-2007-2014 21 November 2014 It remains a debated issue as to what extent and at which timescales the global monsoon can be viewed as a major mode of climate variability. For this purpose, a PAGES (Past Global Changes) working group (WG) was set up to investigate the concept of the global monsoon and its future research directions. The WG’s synthesis is presented here. Read more
Complex networks for streamflow dynamics Hydrology and Earth System Sciences DOI 10.5194/hess-18-4565-2014 20 November 2014 This study introduces the theory of networks, and in particular complex networks, to examine connections in streamflow dynamics. Monthly streamflow data from a network of 639 stations in the United States are studied. The connections are examined primarily using the concept of clustering coefficient, which quantifies the network’s tendency to cluster. The clustering coefficient analysis is performed with several different threshold levels based on correlations in streamflow between the stations. Read more
Missing SO2 oxidant in the coastal atmosphere? – observations from high-resolution measurements of OH and atmospheric sulfur compounds Atmospheric Chemistry and Physics DOI 10.5194/acp-14-12209-2014 20 November 2014 Sulfuric acid plays a major role in the formation of aerosol particles and clouds. Measurements at the west coast of Ireland reveal that oxidation of SO2 by OH explains only 20%, on average, of H2SO4 formation in coastal marine air. Additional sources may be oxidation by Criegee intermediates produced photolytically and/or formation from SO3 instead of SO2 in the oxidation of dimethyl sulfide suggesting an important role of marine emissions in the self-cleaning power of the atmosphere. Read more
Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap system Hydrology and Earth System Sciences DOI 10.5194/hess-18-4529-2014 17 November 2014 This paper analyses the historical water levels of the Mekong River and Tonle Sap system by comparing pre- and post-1991 daily observations from six stations along the Mekong mainstream from Chiang Saen (northern Thailand), to Stung Treng (Cambodia), and the Prek Kdam station on the Tonle Sap River. Read more
Changes in extreme regional sea surface height due to an abrupt weakening of the Atlantic meridional overturning circulation Ocean Science DOI 10.5194/os-10-881-2014 7 November 2014 As an extreme scenario of dynamical sea level changes, regional sea surface height (SSH) changes that occur in the North Atlantic due to an abrupt weakening of the Atlantic meridional overturning circulation (AMOC) are simulated. Two versions of the same ocean-only model are used to study the effect of ocean model resolution on these SSH changes. Read more
