bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydroclimatic variability in the Levant during the early last glacial (∼  117–75 ka) derived from micro-facies analyses of deep Dead Sea sediments
Authors: Neugebauer I. , Schwab M. J. , Waldmann N. D. , Tjallingii R. , Frank U. , Hadzhiivanova E. , Naumann R. , Taha N. , Agnon A. , Enzel Y. , Brauer A.
Published: January 2016

Abstract. The new sediment record from the deep Dead Sea basin (ICDP core 5017-1) provides a unique archive for hydroclimatic variability in the Levant. Here, we present high-resolution sediment facies analysis and elemental composition by micro-X-ray fluorescence (µXRF) scanning of core 5017-1 to trace lake levels and responses of the regional hydroclimatology during the time interval from ca. 117 to 75 ka, i.e. the transition between the last interglacial and the onset of the last glaciation. We distinguished six major micro-facies types and interpreted these and their alterations in the core in terms of relative lake level changes. The two end-member facies for highest and lowest lake levels are (a) up to several metres thick, greenish sediments of alternating aragonite and detrital marl laminae (aad) and (b) thick halite facies, respectively. Intermediate lake levels are characterised by detrital marls with varying amounts of aragonite, gypsum or halite, reflecting lower-amplitude, shorter-term variability. Two intervals of pronounced lake level drops occurred at  ∼  110–108 ± 5 and  ∼  93–87 ± 7 ka. They likely coincide with stadial conditions in the central Mediterranean (Melisey I and II pollen zones in Monticchio) and low global sea levels during Marine Isotope Stage (MIS) 5d and 5b. However, our data do not support the current hypothesis of an almost complete desiccation of the Dead Sea during the earlier of these lake level low stands based on a recovered gravel layer. Based on new petrographic analyses, we propose that, although it was a low stand, this well-sorted gravel layer may be a vestige of a thick turbidite that has been washed out during drilling rather than an in situ beach deposit. Two intervals of higher lake stands at  ∼  108–93 ± 6 and  ∼  87–75 ± 7 ka correspond to interstadial conditions in the central Mediterranean, i.e. pollen zones St. Germain I and II in Monticchio, and Greenland interstadials (GI) 24+23 and 21 in Greenland, as well as to sapropels S4 and S3 in the Mediterranean Sea. These apparent correlations suggest a close link of the climate in the Levant to North Atlantic and Mediterranean climates during the time of the build-up of Northern Hemisphere ice shields in the early last glacial period.
Interhemispheric bias in earth's climate response to orbital forcing
Authors: Roychowdhury R. , DeConto R. M.
Published: January 2016

Abstract. The climate response to orbital forcing shows a distinct hemispheric asymmetry due to the unequal distribution of land in the Northern vs. Southern hemispheres. This asymmetry is examined using a Global Climate Model (GCM) and a Land Hemispheric Bias (LHB) is quantified for each hemisphere. The results show how changes in obliquity and precession translate into variations in the calculated LHB. We find that the global climate response to specific past orbits is likely unique and modified by complex climate-ocean-cryosphere interactions that remain poorly known and difficult to model. Nonetheless, these results provide a baseline for interpreting contemporaneous proxy climate data spanning a broad range of latitudes, which maybe especially useful in paleoclimate data-model comparisons, and individual time-continuous records exhibiting orbital cyclicity.
An interactive tool for navigation within a database of water and carbon stable isotope records from natural archives
Authors: Bolliet T. , Brockmann P. , Masson-Delmotte V. , Bassinot F. , Daux V. , Genty D. , Landais A. , Lavrieux M. , Michel E. , Ortega P. , Risi C. , Roche D. M. , Vimeux F. , Waelbroeck C.
Published: January 2016

Abstract. Past climate is an important benchmark to assess the ability of climate models to simulate key processes and feedbacks. Numerous proxy records exist for stable isotopes of water and/or carbon, which are also implemented inside the components of a growing number of Earth system model. Model-data comparisons can help to constrain the uncertainties associated with transfer functions. This motivates the need of producing a comprehensive compilation of different proxy sources. We have put together a global database of proxy records of oxygen (δ18O), hydrogen (δD) and carbon (δ13C) stable isotopes from different archives: ocean and lake sediments, corals, ice cores, speleothems and tree-ring cellulose. Source records were obtained from the georeferenced open access PANGAEA and NOAA libraries, complemented by additional data obtained from a literature survey. About 3000 source records were screened for chronological information and temporal resolution of proxy records. Altogether, this database consists of hundreds of dated δ18O, δ13C and δD records in a standardized simple text format, complemented with a metadata Excel catalog. For coherency with the Paleoclimate Modelling Intercomparison Project (PMIP), we focus on records spanning the past 200 years, the mid-Holocene (MH, 5.5-6.5 ka; calendar kilo years before 1950), and the Last Glacial Maximum (LGM, 19-23 ka), and those spanning the last interglacial period (LIG, 115-130 ka). For the LGM, a quality control flag was implemented to describe age markers and inform on chronological uncertainty. Basic statistics have been applied to characterize anomalies between these different periods. Most changes from the MH to present day, and LIG to MH appear statistically insignificant. Significant global differences are reported from LGM to MH with regional discrepancies in signals from different archives and complex patterns. This compilation effort highlights the need to homogenize the format of datasets and chronological information, and enhance the distribution of published datasets that are currently highly-fragmented and scattered. We also provide an online portal with an intuitive and interactive platform (http://climateproxiesfinder.ipsl.fr/), allowing one to easily select, visualize and download subsets of the homogeneously-formatted records that conform this database, following a choice of search criteria, and to upload new datasets.
Dynamical downscaling of the western North Pacific from CCSM4 simulations during the last glacial maximum and late 20th century using the WRF model: model configuration and validation
Authors: Yoo J. , Galewsky J.
Published: January 2016

Abstract. Using the Weather Research and Forecasting (WRF) model (version 3.5.1), dynamical downscaling of the Community Climate System Model, version 4 (CCSM4), simulations of the last glacial maximum (LGM) and 20th century (ensemble member #6) run were conducted to simulate ten years of climate over the western North Pacific during the LGM and modern climates, respectively. This paper describes the downscaling procedures for the Weather Research and Forecasting (WRF) model experiments and the quantitative and qualitative model validations comparing with the CCSM4 LGM and 20th century simulations results. Results of the dynamical downscaling of the CCSM4 LGM paleoclimate and twentieth century using the WRF model show not only that the WRF model is capable of long-term simulations in the paleoclimate state of LGM, but also that the WRF model can correct biases in the general circulation model (GCM), producing more realistic spatial distributions of the pressure-level variables. The downscaling of a GCM model using the WRF model (36 km) for the regional climate simulation is considered computationally cost-effective and reliable from the perspectives of model thermodynamics in general, although there are some model errors still existing with dynamic variables.
Last Interglacial climate and sea-level evolution from a coupled ice sheet-climate model
Authors: Goelzer H. , Huybrechts P. , Loutre M.-F. , Fichefet T.
Published: January 2016

Abstract. As the most recent warm period in Earth’s history with a sea-level stand higher than present, the Last Interglacial period (~130 to 115 kyr BP) is often considered a prime example to study the impact of a warmer climate on the two polar ice sheets remaining today. Here we simulate the Last Interglacial climate, ice sheet and sea-level evolution with the Earth system model of intermediate complexity LOVECLIM v.1.3, which includes dynamic and fully-coupled components representing the atmosphere, the ocean and sea ice, the terrestrial biosphere and the Greenland and Antarctic ice sheets. In this set-up, sea-level evolution and climate-ice sheet interactions are modelled in a consistent framework. Surface mass balance changes are the dominant forcing for the Greenland ice sheet, which shows a peak sea-level contribution of 1.4 m at 123 kyr BP in the reference experiment. Our results indicate that ice sheet-climate feedbacks play an important role to amplify climate and sea-level changes in the Northern Hemisphere. The sensitivity of the Greenland ice sheet to surface temperature changes considerably increases when interactive albedo changes are considered. Southern Hemisphere polar and sub-polar ocean warming is limited throughout the Last Interglacial and surface and sub-shelf melting exerts only a minor control on the Antarctic sea-level contribution with a peak of 4.4 m at 125 kyr BP. Retreat of the Antarctic ice sheet at the onset of the LIG is mainly forced by rising sea-level and reduced ice shelf viscosity as the surface temperature increases. Global sea level shows a peak of 5.3 m at 124.5 kyr BP, which includes a minor contribution of 0.35 m from oceanic thermal expansion. Neither the individual contributions nor the total modelled sea-level stand show multi millennial time scale variations as indicated by some reconstructions.
Orbital control on the timing of oceanic anoxia in the Late Cretaceous
Authors: Batenburg S. J. , De Vleeschouwer D. , Sprovieri M. , Hilgen F. J. , Gale A. S. , Singer B. S. , Koeberl C. , Coccioni R. , Claeys P. , Montanari A.
Published: January 2016

Abstract. The oceans at the time of the Cenomanian-Turonian transition were abruptly disturbed by a period of bottomwater anoxia. This led to the brief but widespread deposition of black organic-rich shales, such as the Livello Bonarelli in the Umbria-Marche Basin (Italy). Despite intense studies, the origin and exact timing of this event are still debated. In this study, we assess leading hypotheses about the inception of oceanic anoxia in the Late Cretaceous greenhouse world, by providing a 6-Myr-long astronomically-tuned timescale across the Cenomanian-Turonian boundary. We procure insights in the relationship between orbital forcing and the Late Cretaceous carbon cycle by deciphering the imprint of astronomical cycles on lithologic, geophysical, and stable isotope records, obtained from the Bottaccione, Contessa and Furlo sections in the Umbria-Marche Basin. The deposition of black shales and cherts, as well as the onset of oceanic anoxia, is related to maxima in the 405-kyr cycle of eccentricity-modulated precession. Correlation to radioisotopic ages from the Western Interior (USA) provides unprecedented age control for the studied Italian successions. The most likely tuned age for the Livello Bonarelli base is 94.17 ± 0.15 Ma (tuning #1); however a 405-kyr older age cannot be excluded (tuning #2) due to uncertainties in stratigraphic correlation, radioisotopic dating, and orbital configuration. Our preferred tuning #1 suggests that the exact timing of major carbon cycle perturbations during the Cretaceous may be linked to increased variability in seasonality (i.e. a 405-kyr eccentricity maximum) after the prolonged avoidance of seasonal extremes (i.e. a 2.4-Myr eccentricity minimum). Volcanism was probably the ultimate driver of oceanic anoxia, but the exact timing of carbon cycle perturbations in the Late Cretaceous was likely determined by orbital periodicities. This unites two leading hypotheses about the inception of oceanic anoxia in the Late Cretaceous greenhouse world.
Quantifying late-Holocene climate in the Ecuadorian Andes using a chironomid-based temperature inference model
Authors: Matthews-Bird Frazer , Brooks Stephen  J. , Holden Philip B. , Montoya Encarni , Gosling William D .
Published: January 2016

Abstract. Presented here is the first chironomid calibration dataset for tropical South America. Surface sediments were collected from 59 lakes across Bolivia (15 lakes), Peru (32 lakes) and Ecuador (12 lakes) between 2004 and 2013 over an altitudinal gradient from 150 m above sea level (a.s.l) to 4655 m a.s.l, between 0-­17°S and 64-­78°W. The study sites cover a mean annual temperature (MAT) gradient of 25°C. In total, 55 chironomid taxa were identified in the 59 calibration data-­set lakes. When used as a single explanatory variable, MAT explains 12.9% of the variance (λ1/λ2= 1.431). Two inference models were developed using weighted averaging and Bayesian methods. The best performing model using conventional statistical methods was a WA (inverse) model (R2jack= 0.890, RMSEPjack= 2.404, Mean biasjack= -­0.017, Max biasjack= 4.665). The Bayesian method produced a model with R2jack= 0.909, RMSEPjack= 2.373, Mean biasjack= 0.598, Max biasjack= 3.158. Both models were used to infer past temperatures from a c. 3000 yr record from the tropical Andes of Ecuador, Laguna Pindo. Inferred temperatures fluctuated around modern day conditions but showed significant departures at certain intervals (c. 1600 cal yr BP; c. 3000-­2500 cal yr BP). Both methods (WA/Bayesian) showed similar patterns of temperature variability; however, the magnitude of fluctuations differed. In general the WA method was more variable often inferring unrealistically cold temperatures (c. -­7±2.5°C relative to the modern). The Bayesian method provided temperature anomaly estimates for cool periods that lay within the expected range of the Holocene (c. -­3±3.4°C). The chironomid-­based MAT recon struction from the Laguna Pindo fossil record suggests that periods of low solar output not only affect the tropics through changes in precipitation, but also directly affect tropical temperatures. Inferred temperatures were 2-­3°C colder relative to the modern during the widely recognised 3500-­2500 cal yr BP cooling event. Long-­term cooling during the late-­Holocene culminating in the Little Ice Age (LIA) is not apparent in the Laguna Pindo record. A cooling by 1-­2°C relative to the modern during the LIA is recorded in a single fossil sa
Influence of proxy data uncertainty on data assimilation for the past climate
Authors: Matsikaris Anastasios , Widmann Martin , Jungclaus Johann
Published: January 2016

Abstract. Data assimilation (DA) is an emerging topic in palaeoclimatology and one of the key challenges in this field. Assimilating proxy-based continental mean temperature reconstructions into the MPI-ESM model showed a lack of information propagation to small spatial scales (Matsikaris et al., 2015b). Here, we investigate whether this lack of regional skill is due to the methodology or to errors in the assimilated reconstructions. Error separation is fundamental, as it can lead to improvements in DA methods. We address the question by performing a new set of simulations, using two different sets of target data; the proxy-based PAGES 2K reconstructions (DA-P scheme), and the HadCRUT3v instrumental observations (DA-I scheme). Again, we employ ensemble-member selection DA using the MPI-ESM model, and assimilate NH continental mean tempera- tures; the simulated period is 1850-1949 AD. Both DA schemes follow the large-scale target and observed climate variations well, but the assimilation of instrumental data improves the performance. This improvement cannot be seen for Asia, where the limited instrumental coverage leads to errors in the target data and low skill for the DA-I scheme. No skill on small spatial scales is found for either of the two DA schemes, demonstrating that errors in the assimilated data are not the main reason for the unrealistic representation of the regional temperature variability. It can thus be concluded that assimilating continental mean temperatures is not ideal for providing skill on small spatial scales.
Last Glacial Maximum and Deglacial Abyssal Seawater Oxygen Isotopic Ratios
Authors: Wunsch Carl
Published: January 2016

Abstract. An earlier analysis of pore water salinity/chlorinity in two deep-sea cores, using terminal constraint methods of control theory, concluded that although a salinity amplification in the abyss was possible during the LGM, it was not required by the data. Here the same methodology is applied to δ18Ow in the upper 100 m of four deep-sea cores. An ice volume amplification to the isotopic ratio is, again, consistent with the data but not required by it. In particular, results are very sensitive, with conventional diffusion values, to the assumed initial conditions at −100 ky. If the calcite values of δ18O are fully reliable, then inferred enriched values of the ratio in sea water are necessary to preclude sub-freezing temperatures, but the sea water δ18O in pore waters does not independently support the conclusion.
Shower heat exchanger: reuse of energy from heated drinking water for CO2 reduction
Authors: Deng Z. , Mol S. , van der Hoek J. P.
Published: January 2016

Abstract. The heating of drinking water in households contributes significantly to the emission of greenhouse gases. As a water utility aiming to operate at a climate neutral level by 2020, Waternet needs to reduce its CO2 emission by 53 kton yr−1. To contribute to this ambition, a pilot project was carried out in Uilenstede, Amstelveen, the Netherlands, to recover the shower heat energy with a shower heat exchanger from Dutch Solar Systems. An experimental setup was built in the Waternet laboratory to evaluate the claimed efficiencies. The energy recovery efficiency observed in the lab was 61–64 % under winter conditions and 57–62 % under summer conditions, while the energy recovery efficiency observed in Uilenstede was 57 % in December 2014. Based on the observations, 4 % of the total energy consumption of households in Amsterdam (electricity and gas) can be recovered with a shower heat exchanger installed in all households in Amsterdam, which also means a 54 kton year−1 CO2 emission reduction can be achieved.
Lifetime of soil moisture perturbations in a coupled land–atmosphere simulation
Authors: Stacke T. , Hagemann S.
Published: January 2016

Abstract. In order to evaluate whether the initialization of soil moisture has the potential to improve the prediction skill of earth system models (ESMs) on seasonal to decadal timescales, an elaborate experiment was conducted. For this task a coupled land–atmosphere model with prescribed ocean was utilized. The experiment design considered soil moisture initialization in different seasons and years and yielded information about the lifetime (memory) of extreme yet realistic soil moisture perturbations. Our analyses were focused on root zone soil moisture (RootSM) as it comprises the part of the soil that directly interacts with the atmosphere via bare-soil evaporation and transpiration. We found that RootSM memory differs not only spatially but also depends on the time of initialization. A long memory of up to 1 year is evident mostly for dry soil moisture regimes after heavy precipitation periods or prior to snow covered conditions. Short memory below 2 weeks prevails in wet soil moisture regimes and prior to distinct precipitation periods or snowmelt. Furthermore, RootSM perturbations affect other land surface states, e.g. soil temperature and leaf carbon content, and even induce anomalies with specific memory in these variables. Especially for deep-layer soil temperature, these anomalies can last for up to several years. As long as RootSM memory is evident, we found that anomalies occur periodically in other land surface states whenever climate conditions allow for interactions between that state and RootSM. Additionally, anomaly recurrence is visible for RootSM itself. This recurrence is related to the thickness of the soil layer below the root zone and can affect RootSM for several years. From our findings we conclude that soil moisture initialization has the potential to improve the predictive skill of climate models on seasonal scales and beyond. However, a sophisticated, multilayered soil hydrology scheme is necessary to allow for the interactions between RootSM and the deep-soil layer reservoir.
Topology of sustainable management of dynamical systems with desirable states: from defining planetary boundaries to safe operating spaces in the Earth system
Authors: Heitzig J. , Kittel T. , Donges J. F. , Molkenthin N.
Published: January 2016

Abstract. To keep the Earth system in a desirable region of its state space, such as defined by the recently suggested "tolerable environment and development window", "guardrails", "planetary boundaries", or "safe (and just) operating space for humanity", one needs to understand not only the quantitative internal dynamics of the system and the available options for influencing it (management) but also the structure of the system's state space with regard to certain qualitative differences. Important questions are, which state space regions can be reached from which others with or without leaving the desirable region, which regions are in a variety of senses "safe" to stay in when management options might break away, and which qualitative decision problems may occur as a consequence of this topological structure? In this article, we develop a mathematical theory of the qualitative topology of the state space of a dynamical system with management options and desirable states, as a complement to the existing literature on optimal control which is more focussed on quantitative optimization and is much applied in both the engineering and the integrated assessment literature. We suggest a certain terminology for the various resulting regions of the state space and perform a detailed formal classification of the possible states with respect to the possibility of avoiding or leaving the undesired region. Our results indicate that, before performing some form of quantitative optimization such as of indicators of human well-being for achieving certain sustainable development goals, a sustainable and resilient management of the Earth system may require decisions of a more discrete type that come in the form of several dilemmas, e.g. choosing between eventual safety and uninterrupted desirability, or between uninterrupted safety and larger flexibility. We illustrate the concepts and dilemmas drawing on conceptual models from climate science, ecology, coevolutionary Earth system modelling, economics, and classical mechanics, and discuss their potential relevance for the climate and sustainability debate, in particular suggesting several levels of planetary boundaries of qualitatively increasing safety.
The sensitivity of landscape evolution models to spatial and temporal rainfall resolution
Authors: Coulthard T. J. , Skinner C. J.
Published: January 2016

Abstract. Climate is one of the main drivers for landscape evolution models (LEMs), yet its representation is often basic with values averaged over long time periods and frequently lumped to the same value for the whole basin. Clearly, this hides the heterogeneity of precipitation – but what impact does this averaging have on LEM outcomes? This paper examines the sensitivity of the CAESAR-Lisflood LEM to different spatial and temporal precipitation resolutions – as well as how this interacts with different size drainage basins over short and long time scales. A range of simulations were carried out varying rainfall from 0.25 hour, 5 km to 24 hour lumped resolution over three different sized basins for 30 year durations. Results showed that there was a sensitivity to temporal and spatial resolution, with the finest leading to > 100 % increases in basin sediment yields. To look at how these interactions manifested over longer time scales, several simulations were carried out to model a 1000 year period. These showed a systematic bias towards greater erosion in uplands and deposition in valley floors with the highest spatial and temporal resolution data. Further tests showed that this effect was due solely to the data resolution, not from other (e.g. orographic) factors. The implications of these findings are that past and present LEMs may be under-predicting basin sediment yields, as well upland erosion and downstream deposition - that may have significant impacts on the modelled basin profile and shape.
Network response to disturbances in large sand-bed braided rivers
Authors: Schuurman F. , Kleinhans M. G. , Middelkoop H.
Published: January 2016

Abstract. The reach-scale effects of human-induced disturbances on the channel network in large braided rivers are a challenge to understand and to predict. In this study, we simulated different types of disturbances in a large braided river to get insight into the propagation of disturbances through a braided channel network. The results showed that the disturbances initiate an instability that propagates in the downstream direction by means of alteration of water and sediment division at bifurcations. These adjustments of the bifurcations change the migration and shape of bars, with a feedback to the upstream bifurcation and alteration of the approaching flow to the downstream bifurcation. This way, the morphological effect of a disturbance amplifies in the downstream direction. Thus, the interplay of bifurcation instability and asymmetrical reshaping of bars was found to be essential for propagation of the effects of a disturbance. The study also demonstrated that the large-scale bar statistics are hardly affected.
The westernmost occurrence of Gnathorhiza in the Triassic, with a discussion of the stratigraphic and palaeogeographic distribution of the genus
Authors: Skrzycki P.
Published: January 2016

Abstract. The paper refines the taxonomic assignment of the only representative of the dipnoan genus Gnathorhiza from the Lower Triassic of Poland. It is assigned here to Gnathorhiza otschevi on the basis of morphological and biometrical similarity with the tooth plates from coeval strata of the European part of Russia. The material is comprised solely of tooth plates, both the upper and the lower ones. It comes from karst deposits of the Czatkowice 1 locality (southern Poland) dated to late Olenekian, Lower Triassic. The presence of G. otschevi in southern Poland widens its palaeobiogeographic Triassic record by more than 2000 km to the west. Czatkowice 1 locality is the only known occurrence of gnathorhizids within the Germanic Basin. G. otschevi from Czatkowice 1 shows petrodentine in the tooth plate. Its presence is proved for the first time in a Triassic gnathorhizid. Gnathorhiza was most widely distributed during the Permian and restricted to Europe in the Triassic. Tooth plates of both Early Triassic European and Late Permian Brazilian gnathorhizids are more similar to each other than to Permo-Carboniferous American ones.
Scale morphology and specialized dorsal scales of a new teleosteomorph fish from the Aptian of West Gondwana
Authors: Giordano P. G. , Arratia G. , Schultze H.-P.
Published: January 2016

Abstract. Scales of a new species of Teleosteomorpha from the continental Aptian of the south of South America are studied. These neopterygians are from the La Cantera Formation in central Argentina, and were previously identified as Pholidophoriformes. They present ganoid scales; most of them are rhombic with well-developed peg-and-socket articulations and possessing a smooth surface. They have a straight posterior margin, but occasionally, some scales of the flank have a sinuous posterior margin with one or two serrations. The shape of the scales varies along the body from large, rectangular and deeper than long scales behind the head to the preanal region to smaller and rhomboidal scales in the caudal region. There are a few horizontal rows along the flank and about 32 lateral line scales. Thick, round ganoid scales are present in the prepelvic region close to the ventral margin. The round and rhombic scales present growth lines, which form concentric ridges on the external side. A characteristic row of deep scales forms the dorsal margin on each side of the body; a row of median ridge scales is not present. This is a unique feature of the studied fishes. Scutes covered with unornamented ganoine precede the pelvic, dorsal, and anal fins, as well as the dorsal and ventral margins of the caudal fin. The posterior margin of the dorsal lobe of the caudal fin is formed by a single line of scales, which continues and covers the base of the first principal caudal ray. Histological studies reveal a lepisosteoid-scale type with multiple ganoine layers, lack of dentine, and the presence of canaliculi of Williamson. The macro- and micromorphology of the scales shows features that are found in other teleosteomorphs, but also in other neopterygians.
Vehicular networking and road weather related research in Sodankylä
Authors: Sukuvaara T. , Mäenpää K. , Ylitalo R.
Published: January 2016

Abstract. Vehicular networking and especially safety-related wireless vehicular services have been under intensive research for almost a decade now. Only in recent years, also the road weather information has been acknowledged to play an important role when aiming to reduce traffic accidents and fatalities via Intelligent Transport Systems (ITS). Part of the progress can be seen as a result of Finnish Meteorological Institute's (FMI) long-term research work in Sodankylä within the topic, originally started in 2006. Within multiple research projects, FMI Arctic Research Centre has been developing wireless vehicular networking and road weather services, in co-operation with FMI meteorological services team in Helsinki. At the beginning the wireless communication was conducted with traditional Wi-Fi type local area networking, but during the development the system has been evolved to hybrid communication system of combined Vehicular area Networking (VANET) system with special IEEE 802.11p protocol and supporting cellular networking based on 3G commercial network, not forgetting support for Wi-Fi-based devices also. For the piloting purposes and further research, we have established a special combined road weather station (RWS) and roadside unit (RSU), to interact with vehicles as a service hotspot. In the RWS/RSU we have chosen to build support to all major approaches, IEEE 802.11, traditional Wi-Fi and cellular 3G. We employ road weather systems of FMI, RWS and vehicle data gathered from vehi20 cles, into the up-to-date localized weather data delivered in real-time. IEEE 802.11p vehicular networking is supported with Wi-Fi and 3G communications. This paper briefly introduces the research work related vehicular networking and road weather services conducted in Sodankylä, as well as the research project involved in this work. The current status of instrumentation, available services and capabilities are presented in order to formulate the clear general view of the research field.
Bipolar long-term high temporal resolution broadband measurement system for incoming and outgoing solar UV radiation, and snow UV albedo, at Sodankylä (67°N) and Marambio (64°S)
Authors: Meinander O. , Aarva A. , Poikonen A. , Kontu A. , Suokanerva H. , Asmi E. , Neitola K. , Rodriguez E. , Sanchez R. , Mei M. , de Leeuw G. , Kyrö E.
Published: January 2016

Abstract. The polar regions of the Earth are characterized with low solar elevation angles, cold temperatures and large amount of snow and ice. Under the harsh polar conditions, good quality in situ measurements of incoming and outgoing solar radiation, and surface albedo, is a major challenge. Both in the Arctic and Antarctic, the solar radiation at the wavelengths of ultraviolet (UV) has been of particular interest due to the polar stratospheric ozone depletion, which increases UV radiation on the ground (with multiple effects, such as UV-induced DNA-damage). In the presence of light absorbing impurities (OC/BC/dust) in snow, albedo can be most affected at the wavelengths of UV. Here we provide, for the first time, the description, comparison and evaluation of our bipolar measurement design, instrumentation and data system, calibration assessment, as well as challenges, for measuring incoming and outgoing UV radiation (from which snow albedo is calculated) at the Sodankylä Arctic Research Centre (67°N) and at the Marambio Antarctic Research Station (64°S). Both stations are members of the Global Atmosphere Watch GAW programme of the World Meteorological Organization WMO and have personnel available year-round. The Sodankylä snow UV albedo measurements were started in 2007, as part of the International Polar Year IPY (2007–2008). The Marambio surface UV albedo measurements, since February 2013, are part of the Argentinian-Finnish scientific co-operation on meteorological and atmospheric observations. The paper aims to give a comprehensive insight into our bipolar measurement system, and to create an understanding needed for a successful scientific utilization of these data, including satellite and modeling approaches. We also present a literature review of our previous publications on Sodankylä snow UV albedo data.
FTS measurements of column CO2 at Sodankylä
Authors: Kivi R. , Heikkinen P.
Published: January 2016

Abstract. Fourier Transform Spectrometer (FTS) observations at Sodankylä have been per formed since early 2009. The FTS instrument is participating in the Total Carbon Column Observing Network (TCCON) and has been optimized to measure abundances of the key greenhouse gases in the atmosphere. Here we report the measured CO2 time series over a six year period (2009–2014) and provide a description of the FTS system and data processing at Sodankylä. We find the lowest monthly column CO2 values in August and the highest monthly values during the February to May season. Inter-annual variability is the highest in June–September period, which correlates with the growing season. During the time period of FTS measurements from 2009 until 2014 we have observed a 2.4 ± 0.3 ppm increase per year in column CO2. The monthly mean column CO2 values have exceeded 400 ppm level for the first time in February 2014.
Practical considerations for enhanced-resolution coil-wrapped Distributed Temperature Sensing
Authors: Hilgersom K. P. , van Emmerik T. H. M. , Solcerova A. , Berghuijs W. R. , Selker J. S. , van de Giesen N. C.
Published: January 2016

Abstract. Fibre optic Distributed Temperature Sensing (DTS) is widely applied in earth sciences. Many applications require a spatial resolution higher than the provided by the DTS instrument. Measurements at these higher resolutions can be achieved with a fibre optic cable helically wrapped on a cylinder. The effect of the probe construction, such as its material, shape, and diameter, on the performance has been poorly understood. In this article, we study datasets obtained from a laboratory experiment using different cable and construction diameters, and three field experiments using different construction characteristics. This study shows that the construction material, shape, diameter, and cable attachment method can have a significant influence on DTS temperature measurements. We present a qualitative and quantitative approximation of errors introduced through the choice of auxiliary construction, influence of solar radiation, coil diameter, and cable attachment method. Our results provide insight into factors that influence DTS measurements, and we present a number of solutions to minimize these errors. These practical considerations allow designers of future DTS measurement setups to improve their environmental temperature measurements.
The co-condensation of semi-volatile organics into multiple aerosol particle modes
Authors: Crooks Matthew , Connolly Paul , Topping David , McFiggans Gordon
Published: January 2016

Abstract. An existing equilibrium partitioning model for calculating the equilibrium gas/particle concentrations of multiple semi-volatile organics within a bulk aerosol is extended to allow for multiple core aerosol modes of different sizes and chemical compositions. In the bulk aerosol problem the partitioning coefficient determines the fraction of the total concentration of semi-volatile material that is in the condensed phase on the aerosol. This work modifies this definition for multiple polydisperse aerosol modes to account for multiple condensed concentrations; one for each semivolatile on each core aerosol mode. The pivotal assumption in this work is that each aerosol mode contains a core constituent which is involatile thus overcoming the potential problem of smaller particles evaporating completely and then condensing on the larger particles to create a monodisperse aerosol at equilibrium. The resulting coupled non-linear system is approximated by a simpler set of equations in which the organic mole fraction in the partitioning coefficient is set to be the same across all modes. By perturbing the condensed masses about this approximate solution a correction term is derived which accounts for much of the removed complexities. This method offers a greatly increased efficiency in calculating the solution without significant loss in accuracy, thus allowing its inclusion into large scale models feasable.
Representation of the Community Earth System Model (CESM1) CAM4-chem within the Chemistry-ClimateModel Initiative (CCMI)
Authors: Tilmes S. , Lamarque J.-F. , Emmons L. K. , Kinnison D. E. , Marsh D. , Garcia R. R. , Smith A. K. , Neely R. R. , Conley A. , Vitt F. , Val Martin M. , Tanimoto H. , Simpson I. , Blake D. R. , Blake N.
Published: January 2016

Abstract. The Community Earth System Model, CESM1 CAM4-chem has been used to perform the Chemistry Climate Model Initiative (CCMI) reference and sensitivity simulations. In this model, the Community Atmospheric Model Version 4 (CAM4) is fully coupled to tropospheric and stratospheric chemistry. Details and specifics of each configuration, including new developments and improvements are described. CESM1 CAM4-chem is a low top model that reaches up to approximately 40 km and uses a horizontal resolution of 1.9° latitude and 2.5° longitude. For the specified dynamics experiments, the model is nudged to Modern-Era Retrospective Analysis For Research And Applications (MERRA) reanalysis. We summarize the performance of the three reference simulations suggested by CCMI, with a focus on the observed period. Comparisons with elected datasets are employed to demonstrate the general performance of the model. We highlight new datasets that are suited for multi-model evaluation studies. Most important improvements of the model are the treatment of stratospheric aerosols and the corresponding adjustments for radiation and optics, the updated chemistry scheme including improved polar chemistry and stratospheric dynamics, and improved dry deposition rates. These updates lead to a very good representation of tropospheric ozone within 20 % of values from available observations for most regions. In particular, the trend and magnitude of surface ozone has been much improved compared to earlier versions of the model. Furthermore, stratospheric column ozone of the Southern Hemisphere in winter and spring is reasonably well represented. All experiments still underestimate CO most significantly in Northern Hemisphere spring and show a significant underestimation of hydrocarbons based on surface observations.
Atmosphere-only GCM simulations with prescribed land surface temperatures
Authors: Ackerley D. , Dommenget D.
Published: January 2016

Abstract. General circulation models (GCMs) are valuable tools for understanding how the global ocean-atmosphere-land surface system interacts and are routinely evaluated relative to observational datasets. Conversely, observational datasets can also be used to constrain GCMs in order to identify systematic errors in their simulated climates. One such example is to prescribe sea surface temperatures (SSTs) such that 70% of the Earth’s surface temperature ﬁeld is observationally constrained (known as an Atmospheric Model Intercomparison Project, AMIP, simulation). Nevertheless, in such simulations, land surface temperatures are typically allowed to vary freely and therefore any errors that develop over the land may affect the global circulation. In this study therefore, a method for prescribing the land surface temperatures within a GCM (the Australian Community Climate and Earth System Simulator, ACCESS) is presented. Simulations with this prescribed land temperature model produce a mean climate state that is comparable to a simulation with freely varying land temperatures; for example the diurnal cycle of tropical convection is maintained. The model is then developed further to incorporate a selection of "proof of concept" sensitivity experiments where the land surface temperatures are changed globally and regionally. The resulting changes to the global circulation in these sensitivity experiments are found to be consistent with other idealised model experiments described in the wider scientific literature. Finally, a list of other potential applications are described at the end of the study to highlight the usefulness of such a model to the scientiﬁc community.
Integration of nitrogen dynamics into the Noah-MP land surface model v1.1 for climate and environmental predictions
Authors: Cai X. , Yang Z.-L. , Fisher J. B. , Zhang X. , Barlage M. , Chen F.
Published: January 2016

Abstract. Climate and terrestrial biosphere models consider nitrogen an important factor in limiting plant carbon uptake, while operational environmental models view nitrogen as the leading pollutant causing eutrophication in water bodies. The community Noah land surface model with multi-parameterization options (Noah-MP) is unique in that it is the next-generation land surface model for the Weather Research and Forecasting meteorological model and for the operational weather/climate models in the National Centers for Environmental Prediction. In this study, we add a capability to Noah-MP to simulate nitrogen dynamics by coupling the Fixation and Uptake of Nitrogen (FUN) plant model and the Soil and Water Assessment Tool (SWAT) soil nitrogen dynamics. This model development incorporates FUN's state-of-the-art concept of carbon cost theory and SWAT's strength in representing the impacts of agricultural management on the nitrogen cycle. Parameterizations for direct root and mycorrhizal-associated nitrogen uptake, leaf retranslocation, and symbiotic biological nitrogen fixation are employed from FUN, while parameterizations for nitrogen mineralization, nitrification, immobilization, volatilization, atmospheric deposition, and leaching are based on SWAT. The coupled model is then evaluated at the Kellogg Biological Station – a Long Term Ecological Research site within the US Corn Belt. Results show that the model performs well in capturing the major nitrogen state/flux variables (e.g., soil nitrate and nitrate leaching). Furthermore, the addition of nitrogen dynamics improves the modeling of net primary productivity and evapotranspiration. The model improvement is expected to advance the capability of Noah-MP to simultaneously predict weather and water quality in fully coupled Earth system models.
Geothermometric evaluation of geothermal resources in southeastern Idaho
Authors: Neupane G. , Mattson E. D. , McLing T. L. , Palmer C. D. , Smith R. W. , Wood T. R. , Podgorney R. K.
Published: January 2016

Abstract. Southeastern Idaho exhibits numerous warm springs, warm water from shallow wells, and hot water from oil and gas test wells that indicate a potential for geothermal development in the area. We have estimated reservoir temperatures from chemical composition of thermal waters in southeastern Idaho using an inverse geochemical modeling technique (Reservoir Temperature Estimator, RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. The temperature estimates in the region varied from moderately warm (59°C) to over 175°C. Specifically, hot springs near Preston, Idaho, resulted in the highest reservoir temperature estimates in the region.
Diagnosing hydrological limitations of a land surface model: application of JULES to a deep-groundwater chalk basin
Authors: Le Vine N. , Butler A. , McIntyre N. , Jackson C.
Published: January 2016

Abstract. Land surface models (LSMs) are prospective starting points to develop a global hyper-resolution model of the terrestrial water, energy, and biogeochemical cycles. However, there are some fundamental limitations of LSMs related to how meaningfully hydrological fluxes and stores are represented. A diagnostic approach to model evaluation and improvement is taken here that exploits hydrological expert knowledge to detect LSM inadequacies through consideration of the major behavioural functions of a hydrological system: overall water balance, vertical water redistribution in the unsaturated zone, temporal water redistribution, and spatial water redistribution over the catchment's groundwater and surface-water systems. Three types of information are utilized to improve the model's hydrology: (a) observations, (b) information about expected response from regionalized data, and (c) information from an independent physics-based model. The study considers the JULES (Joint UK Land Environmental Simulator) LSM applied to a deep-groundwater chalk catchment in the UK. The diagnosed hydrological limitations and the proposed ways to address them are indicative of the challenges faced while transitioning to a global high resolution model of the water cycle.
Climatological characteristics of raindrop size distributions in Busan, Republic of Korea
Authors: Suh S.-H. , You C.-H. , Lee D.-I.
Published: January 2016

Abstract. Raindrop size distribution (DSD) characteristics within the complex area of Busan, Republic of Korea (35.12° N, 129.10° E), were studied using a Precipitation Occurrence Sensor System (POSS) disdrometer over a 4-year period from 24 February 2001 to 24 December 2004. Also, to find the dominant characteristics of polarized radar parameters, which are differential radar reflectivity (Zdr), specific differential phase (Kdp) and specific attenuation (Ah), T-matrix scattering simulation was applied in the present study. To analyze the climatological DSD characteristics in more detail, the entire period of recorded rainfall was divided into 10 categories not only covering different temporal and spatial scales, but also different rainfall types. When only convective rainfall was considered, mean values of mass-weighted mean diameter (Dm) and normalized number concentration (Nw) values for all these categories converged around a maritime cluster, except for rainfall associated with typhoons. The convective rainfall of a typhoon showed much smaller Dm and larger Nw compared with the other rainfall categories. In terms of diurnal DSD variability, we analyzed maritime (continental) precipitation during the daytime (DT) (nighttime, NT), which likely results from sea (land) wind identified through wind direction analysis. These features also appeared in the seasonal diurnal distribution. The DT and NT probability density function (PDF) during the summer was similar to the PDF of the entire study period. However, the DT and NT PDF during the winter season displayed an inverse distribution due to seasonal differences in wind direction.