bluuebunny/crossref_metadata_2025 huggingface dataset:
Our Experience with Miniperc XS in the Management of Renal Stones
Authors: Sabale Vilas , Pramanik Prasun , Mane Deepakkumar , Satav Vikram , Shah Avreen Singh , Chaudari Niraj , Kandari Ashwani
Published: January 2019

Objective:

This study was conducted to evaluate the efficacy and safety of Miniperc (MIP) XS (7.5 Fr) nephroscope in the treatment of renal stones up to 20 mm.

Methods:

This was a prospective study that enrolled 65 patients with limited stone burden in calyx or pelvis, which were treated with MIP XS. Primary outcomes included stone-free rates (SFRs), operative time, length of postoperative hospital stay, requirement of analgesic postsurgery, decline in hematocrit, stent requirement, and complications and requirement of ancillary procedure.

Results:

The mean stone size was 17.46 ± 2.9 mm. The patients were treated with MIP XS and had a mean operative time of 38.63 ± 8.4 min, 1.74% drop in hematocrit levels postsurgery and 96.9% SFRs. The length of hospital stay was 55.48 ± 4.6 h. Postoperative fever and nephrostomy leakage occurred in 9 and 1 patients, respectively. Six cases required some drainage procedure (double-J stent/nephrostomy). No patient required blood transfusion.

Conclusion:

This study showed that MIP XS could be considered as an effective treatment option in the treatment of renal stones up to 20 mm as it scores in all the standard parameters used to measure percutaneous nephrolithotripsy outcomes.
Second Repair of Pediatric Inguinal Hernia
Authors: Chen Yi-Sheng , Yang Stephen Shei-Dei , Chen Judy Yi-Chu , Chang Shang-Jen , Chen Ke-Chi
Published: January 2019

Background:

The objective of this nationwide observational study was to report the rate and risk factors for the second repair after pediatric inguinal herniorrhaphy.

Materials and Methods:

Children born from 1998 to 2005 were chosen from a cohort of 1,000,000 cases, which were randomly selected from an insured population of 23 million people in Taiwan (Longitudinal Health Insurance Database 2005). We identified all hernia repairs in the period of 1998–2012 for the sample population and then used a Cox proportional hazards regression model to analyze the risk factors for the second repair after pediatric inguinal herniorrhaphy.

Results:

The total sample population comprised 79,820 children, with a male-to-female ratio of 4.27:1. During a mean observation period of 11.4 ± 2.2 years, 3339 (4.18%) of the children in the sample population received primary inguinal hernia repair. Of the 251 children (7.52%) who underwent a second repair, 220 were boys (8.13%) and 31 were girls (4.9%); 244 (8.62%) underwent primary unilateral hernia repair, and 7 (1.38%) underwent primary bilateral hernia repair. Considering that bilateral hernia involves unilateral hernia on two sides, the expected recurrence rate after primary unilateral hernia repair was calculated as 0.69%. The calculated rates for late occurrence of contralateral hernia after primary unilateral hernia repair were 11.04%, 7.73%, and 3.28% for children aged 0–1, 1–4, and >4 years, respectively. Significant risk factors for second hernia repair were age at first primary hernia repair and unilateral hernia (P < 0.001). Gender and prematurity were not risk factors for second hernia repair.

Conclusions:

The second repair rate after primary unilateral or bilateral hernia repair was 7.52%. The only risk factor that predicted the second repair was age of <4 years at the time of operation. The expected recurrence rate after any hernia was estimated as 0.69%.
Stroke and Lower Urinary Tract Symptoms
Authors: Chou Yu-Cheng , Jiang Yuan-Hong , Harnod Tomor , Lee Hsu-Tung , Kuo Hann-Chorng
Published: January 2019

Lower urinary tract symptoms (LUTSs) are common neurological sequelae of stroke, which negatively impact the mortality of patients with stroke and the quality of life of both patients and their caregivers. There are three hierarchical micturition centers: the sacral spinal center, subconscious structures, and conscious structures. Several brain imaging modalities for micturition studies on humans and animals and neuroanatomical studies on animals have facilitated a better understanding of LUTSs. The urodynamic findings in patients with stroke may vary and tend to evolve with time; the identification of the underlying cause of poststroke voiding dysfunction helps optimize the management of these patients. For patients with stroke with overactive bladders, the first-line treatments include behavioral therapies and the second-line therapies include the use of drugs. Intermittent or indwelling catheterization can be used for patients with stroke with detrusor underactivity. In this article, we discuss the current consensus, relevant assessment modalities, and management of LUTSs in patients with stroke.
Pressure Compression of the Access Tract for Tubeless Percutaneous Nephrolithotomy
Authors: Chang Shun-Kai , Cheong Ian-Seng , Cheng Ming-Chin , Jou Yeong-Chin , Chen Chia-Chun , Hu Min-Min
Published: January 2019

Objective:

To obtain adequate hemostasis, we compressed the access tract at the end of operation for tubeless percutaneous nephrolithotomy (PCNL). The clinical results of 216 consecutive patients were evaluated by retrospective chart review.

Materials and Methods:

After stone extraction, an 8F Foley catheter was inserted into the renal pelvis and was then inflated and gently retracted. The working sheath was withdrawn to the renal capsule, the renal access tract was packed with oxidized regenerated cellulose (SurgicelTM) strips, and the tract was compressed with smaller dilators through the working sheath for 5 min.

Results:

Of the 216 patients, 139 were male and 77 were female. The mean age was 56.0 ± 11.7 years. The stone characteristics were renal stones in 146 patients, ureteral stones in 47 patients, and kidney with ureteral stones in 23 patients. The average stone size was 3.6 ± 2.1 cm, and the average operation time was 80.5 ± 30.1 min. The target stones were all removed in each patient and the overall postoperative stone-free rate was 73.6%. The postoperative blood transfusion rate was 1.4% (three patients). Postoperative fever was noted in 23 patients (10.6%) and sepsis was noted in three patients (1.4%). The average postoperative hospital stay was 3.2 ± 1.4 days.

Conclusion:

Our results suggest that pressure compression may be an alternative method to minimize hemorrhagic complications during tubeless PCNL.
8-week training in partial minimalist shoe reduces impact force during running
Authors: Azevedo Ana P.S. , Mezencio Bruno , Mochizuki Luis , Valvassori Raisa , Amadio Alberto C. , Serrao Julio C.
Published: January 2019

Purpose

Excessive external load is a likely cause of running injuries. Although minimal running has been suggested as a possible approach to reduce impact and injury risk, an abrupt transition from conventional shoes to minimal running is also related to injuries. Therefore, the partial minimalist shoe has been suggested as a training strategy for a safe transition to
minimal running. The study investigated if 8 weeks of training in partial minimalist shoe could improve impact control of shod and barefoot running.

Methods

Recreational runners (12 men, 2 women), inexperienced in minimal running, performed 3 training sessions/week in partial minimalist shoes for 8 weeks. Before and after the intervention, the participants ran on a treadmill at 2.5 m/s under two conditions: in their habitual shoes and barefoot. Vertical ground reaction force (VGRF) was recorded.

Results

After the intervention, reduced values of the first peak (16.7% for shod, 36.7% for barefoot), time to reach the first peak (7.7% for shod, 30.2% for barefoot), and the load rate of the first peak (9.8% for shod, 9.5% for barefoot) were observed for both conditions (p < 0.001). Six subjects dropped out from the intervention.

Conclusions

Partial minimalist training improved VGRF variables related to shock attenuation. Thus, the 8-week running training program with partial minimalist shoes was an effective approach to increase impact control. The intervention reduced the impact force in both shod and barefoot running, arising as a feasible option to progressively transition to minimal running.
Silent Narrative
Authors: Bajoria Rishabh
Published: January 2019

In this article, I describe my public history project seeking to transform a street in Connaught Place, New Delhi, into a militarised Srinagar marketplace. Through this phenomenological project, I aim to make Hindu, middle- class, upper-middle-caste Indians realise that the Indian presence in the Kashmir Valley is a colonial, military occupation. Through this, I want them to reconsider India’s claims of being a secular, liberal-democracy. To contextualise my intervention, I briefly represent the mainstream Indian narrative on Kashmir, both in academia and the wider public space, in the first section of this article. Thus, by highlighting the ‘silences’ in the general understanding of Kashmir, I will demonstrate my project’s contribution to Kashmir’s historiography.

KEYWORDScolonialism; exhibit; phenomenology; India-Occupied Kashmir; historiography; Museum
The significant contribution of HONO to secondary pollutants during a severe winter pollution event in southern China
Authors: Fu Xiao , Wang Tao , Zhang Li , Li Qinyi , Wang Zhe , Xia Men , Yun Hui , Wang Weihao , Yu Chuan , Yue Dingli , Zhou Yan , Zheng Junyun , Han Rui
Published: January 2019

Abstract. Nitrous acid (HONO) can strongly affect atmospheric
photochemistry in polluted regions through the production of hydroxyl
radicals (OHs). In January 2017, a severe pollution episode occurred in the Pearl River
Delta (PRD) of China, with maximum hourly PM2.5, ozone, and HONO levels
reaching 400 µg m−3, 150 ppb, and 8 ppb, respectively, at a
suburban site. The present study investigated the sources
and processes
generating such high HONO concentrations and the role of HONO chemistry in
this severe winter episode. Four recently reported HONO sources were added to
the Community Multiscale Air Quality (CMAQ) model, including RH-dependent
(relative humidity) and light-enhancing effects on heterogeneous reactions, photolysis of
particulate nitrate in the atmosphere, and photolysis of HNO3 and
nitrate on surfaces. The revised model reproduced the observed HONO and
significantly improved its performance for O3 and PM2.5. The
model simulations showed that the heterogeneous generation on surfaces (with
RH and light effects) was the largest contributor (72 %) to the predicted
HONO concentrations, with the RH-enhancing effects more significant at
nighttime and the light-enhancing effects more important in the daytime. The
photolysis of total nitrate in the atmosphere and deposited on surfaces was
the dominant HONO source during noon and afternoon, contributing above 50 %
of the simulated HONO. The HONO photolysis was the dominant contributor to
HOx production in this episode. With all HONO sources, the
daytime average O3 at the Heshan site was increased by 24 ppb (or
70 %), compared to the simulation results without any HONO sources.
Moreover, the simulated mean concentrations of TNO3 (HNO3+
fine particle NO3-) at the Heshan site, which was the key species
for this haze formation, increased by about 17 µg m−3
(67 %) due to the HONO chemistry, and the peak enhancement reached
55 µg m−3. This study highlights the key role of HONO
chemistry in the formation of winter haze in a subtropical environment.
Large increases in Ncn and Nccn together with a nucleation-modeparticle pool over the northwestern Pacific Ocean in the spring of 2014
Authors: Wang Juntao , Shen Yanjie , Li Kai , Gao Yang , Gao Huiwang , Yao Xiaohong
Published: January 2019

Abstract. The updated concentrations of atmospheric particles (Ncn) and the concentrations of cloud condensation nuclei (Nccn) over the northwestern Pacific Ocean (NWPO) were important to accurately evaluate the influence of aerosol outflow from the Asian continent on the climate by considering rapid changes in emissions of air pollutants therein. However, field observations were scarce in the last two decades. We conducted a cruise campaign over the NWPO to simultaneously measure Ncn, Nccn and the size distribution of aerosol particles from DOY 81 to DOY 108 of 2014. The mean values of Nccn at supersaturation (SS) of 0.2 % and 0.4 % were 0.68 ± 0.38×103 cm−3 and 1.1 ± 0.67×103 cm−3, respectively, with an average for Ncn of 2.8 ± 1.0×103 cm−3 during the cruise over the NWPO, which were all approximately one order of magnitude larger than spring observations from two decades ago in the atmosphere of remote marine areas. The higher values, against the marine natural background reported in the literature, implied an overwhelming contribution from continental inputs. The calculated CCN activity ratios were 0.30 ± 0.11 and 0.46 ± 0.19 at SS of 0.2 % and 0.4 %, respectively, which were almost the same as those of upwind semi-urban sites. High Nccn and CCN activities were observed from DOY 98 to 102, when the oceanic zone received even stronger continental inputs. During the whole cruise period with the exclusion of biomass burning and dust aerosols, a good correlation between Nccn at 0.4 % SS and the number concentrations of > 60 nm particles (N> 60 nm), with the slope of 0.98 and R2 = 0.94, was obtained, and the corresponding effective hygroscopicity parameter (k) was estimated as 0.40. The bimodal size distribution pattern of the particle number concentration was generally observed during the entire campaign when the N> 90 nm varied largely. However, the N
Primary and secondary sources of
ambient
formaldehyde
in the
Yangtze River Delta based on OMPS observation
Authors: Su Wenjing , Liu Cheng , Hu Qihou , Zhao Shaohua , Sun Youwen , Wang Wei , Zhu Yizhi , Liu Jianguo , Kim Jhoon
Published: January 2019

Abstract. Formaldehyde (HCHO) in the ambient air not only causes cancer but also is an ideal indicator for volatile organic compounds (VOCs) which are major precursors of ozone (O3) and secondary organic aerosol (SOA) near the surface. It is meaningful to differentiate between direct emission and secondary formation for HCHO pollution control and sensitivity study of O3 production. However, the understanding of the sources of HCHO is still poor in China, due to limited measurements of HCHO in the field, both spatially and temporally. In this study, tropospheric HCHO vertical column densities (VCDs) in the Yangtze River Delta (YRD), East China where HCHO pollution is serious were retrieved from Ozone Mapping and Profiler Suite (OMPS) onboard the Suomi National Polar-orbiting Partnership (Suomi-NPP) satellite from 2014 to 2017, and kept good agreement with the tropospheric HCHO columns measured by ground-based high resolution Fourier transform infrared spectrometry (FTS) with the correlation coefficient (R) of 0.78. Based on this, the cancer risk was estimated nationwide and in the YRD region. At least, 7840 people in the YRD region would develop cancer in their lives due to outdoor HCHO exposure, which occupied 23.4 % of total national cancer risk. Besides, the contributions of primary and secondary sources were apportioned, combining with primary and secondary tracers from surface observation. Overall, HCHO from secondary formation contributed most to ambient HCHO and can be regarded as the indication of the VOCs reactivity in Hangzhou and urban areas of Nanjing and Shanghai from 2015 to 2017, due to strong correlation between total HCHO and secondary HCHO. At industrial sites in Nanjing, primary emission influenced most to ambient HCHO in 2015 and showed an obvious decreasing trend. Seasonally, HCHO from secondary formation reached the maximum in summer and minimum in winter. In the spring, summer, and autumn, secondary formation played a curial effect on variation of ambient HCHO in urban regions of Nanjing, Hangzhou, and Shanghai; while in the winter the contribution from secondary formation became less significant. The understanding of the variation of the primary and secondary contributions to ambient HCHO is in favor for a better understanding the role of HCHO in atmospheric chemistry and formulating effective control measures to decrease HCHO pollution and cancer risk.
Local and regional contributions to fine particulate matter in the 18 cities of
Sichuan Basin, southwestern China
Authors: Qiao Xue , Guo Hao , Tang Ya , Wang Pengfei , Deng Wenye , Zhao Xing , Hu Jianlin , Ying Qi , Zhang Hongliang
Published: January 2019

Abstract. The Sichuan Basin (SCB) is one of the regions suffering from severe air pollution in China, but fewer studies have been conducted for this region than the more developed regions in North and East China. In this study, a source-oriented version of the Community Multi-scale Air Quality (CMAQ) model was used to quantify contributions from nine regions to PM2.5 (i.e., particulate matter (PM) with an aerodynamic diameter less than 2.5 μm) and its components in the 18 cities within the SCB in the winter (December 2014 to February 2015) and summer (June to August, 2015). In the winter, citywide average PM2.5 concentrations are 45~126 μg m−3, with 21~51 % and 39~66 % due to local and non-local emissions, respectively. In the summer, 15~45 % and 25~52 % of citywide average PM2.5 (14~31 μg m−3) are due to local and non-local emissions, respectively. Compared to primary PM (PPM), the inter-region transport of secondary inorganic aerosols (SIA, including ammonia (NH4+), nitrate (NO3−), and sulfate (SO42−)) is greater. The region to the east of SCB (R7) is the largest contributor outside the SCB, and it can contribute approximately 80 % in the northeast, east, and southeast rims of the SCB, but only 10 % in the other regions in both seasons. Under favorable transport conditions, regional transport of air pollutants from R7 could account for up to 35~100 μg m−3 of PM2.5 in each of the SCB cities in the winter. This study demonstrates that it is important to have joint emission control efforts among cities within the SCB and neighbor regions to the east in order to reduce PM2.5 concentrations and prevent high PM2.5 days for the entire basin.
High-resolution (0.05° × 0.05°) NOx emissions in the Yangtze River Delta inferred from OMI
Authors: Kong Hao , Lin Jintai , Zhang Ruixiong , Liu Mengyao , Weng Hongjian , Ni Ruijing , Chen Lulu , Wang Jingxu , Zhang Qiang
Published: January 2019

Abstract. Emission datasets of nitrogen oxides (NOx) at high horizontal resolutions (e.g., 0.05° × 0.05°) are crucial for understanding human influences at fine scales, air quality studies, and pollution control. Yet high-resolution emission data are often lacking or contain large uncertainties especially for the developing regions. Taking advantage of long-term satellite measurements of nitrogen dioxide (NO2), here we develop a computationally efficient method to inverting NOx emissions in major urban areas at the 0.05° × 0.05° resolution. The inversion accounts for the nonlinear effects of horizontal transport, chemical loss, and deposition. We construct a 2-dimensional Peking University High-resolution Lifetime-Emission-Transport (PHLET) model, its adjoint model (PHLET-A), and a Satellite Conversion Metrix approach to relate emissions, simulated NO2, and satellite NO2 data. The inversion method is applied to summer months of 2012–2016 in the Yangtze River Delta area (YRD, 118 °E–123 °E, 29 °N–34 °N), a major polluted region of China, using the POMINO NO2 vertical column density product retrieved from the Ozone Monitoring Instrument. A systematic analysis of inversion errors is performed, including using an Observing System Simulation Experiment-like test. Across the YRD area, the inverted summer average emission ranges from 0 to 12.0 kg km−2 h−1, and the lifetime (due to chemical loss and deposition) from 1.4 to 3.6 h. Our inverted emission dataset reveals fine-scale spatial information tied to nighttime light, population density, road network, and maritime shipping. Many of the inverted fine-scale emission features are not well represented or not included in the widely used Multi-scale Emissions Inventory of China. Our inversion method can be applied to other regions and other satellite sensors such as the TROPOspheric Monitoring Instrument.
Insights into the O : C dependent mechanisms controlling the evaporation of α-pinene secondary organic aerosol particles
Authors: Buchholz Angela , Lambe Andrew T. , Ylisirniö Arttu , Li Zijun , Tikkanen Olli-Pekka , Faiola Celia , Kari Eetu , Hao Liqing , Luoma Olli , Huang Wei , Mohr Claudia , Worsnop Douglas R. , Nizkorodov Sergey A. , Yli-Juuti Taina , Schobesberger Siegfried , Virtanen Annele
Published: January 2019

Abstract. The volatility of oxidation products of volatile organic compounds (VOCs) in the atmosphere is a key factor to determine if they partition into the particle phase contributing to secondary organic aerosol (SOA) mass. Thus, linking volatility and measured particle composition will provide insights into SOA formation and its fate in the atmosphere. We produced a-pinene SOA with three different oxidation levels (characterised by average oxygen to carbon ratio, O : C = 0.53, 0.69, and 0.96) in an oxidation flow reactor. We investigated the particle volatility by isothermal evaporation in clean air as a function of relative humidity (RH
Secondary organic aerosol formation from smoldering and flaming combustion of biomass: a box model parametrization based on volatility basis set
Authors: Stefenelli Giulia , Jiang Jianhui , Bertrand Amelie , Bruns Emily A. , Pieber Simone M. , Baltensperger Urs , Marchand Nicolas , Aksoyoglu Sebnem , Prévôt André S. H. , Slowik Jay G. , El Haddad Imad
Published: January 2019

Abstract. Box model simulations based on the volatility basis set (VBS) approach were used to assess secondary organic aerosol (SOA) precursors and volatility distributions from residential wood combustion. Emissions were sampled from three different residential stoves at different combustion conditions (flaming vs. smoldering-dominated), aging temperatures (−10 °C, 2 °C and 15 °C), and emission loads, then exposed to hydroxyl (OH) radicals in a smog chamber. Primary emissions of SOA precursor compounds, organic aerosol and their evolution during aging in the smog chamber were monitored by a comprehensive suite of gas and particle instrumentation, including a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) and a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). SOA precursors were classified according to their chemical composition and the identification of the nature of the precursors revealed useful to better constrain model parameters, in particular SOA production rates and molecular characteristics of the condensable gases formed. The general aim of the model was the determination of the parameters describing the volatility distributions of the oxidation products from the different chemical classes considered and their temperature dependence. Novel parameterization methods based on a genetic algorithm (GA) approach allowed estimation of precursor class contributions to SOA and evaluation of the effect of emission variability on SOA yield predictions. Significant differences were observed in the gas-phase composition between smoldering and flaming emissions. Smoldering phase emissions were dominated by oxidized VOCs with less than six carbon atoms family (OVOCc
The importance of crystalline phases in ice nucleation by volcanic ash
Authors: Maters Elena C. , Dingwell Donald B. , Cimarelli Corrado , Müller Dirk , Whale Thomas F. , Murray Benjamin J.
Published: January 2019

Abstract. Volcanic ash is known to nucleate ice when immersed in supercooled water droplets. This process may impact the properties and dynamics of the eruption plume and cloud, as well as those of meteorological clouds once the ash is dispersed in the atmosphere. However, knowledge of what controls the ice-nucleating effectiveness (INE) of ash remains limited, although it has been suggested that crystalline components in ash may play an important role. Here we adopted a novel approach using nine pairs of tephra and their remelted and quenched glass equivalents to investigate the influence of chemical composition, crystallinity and mineralogy on ash INE in the immersion mode. For all nine pairs studied, the crystal-bearing tephra nucleated ice at higher temperatures than the corresponding crystal-free glass, demonstrating that crystalline phases are key to ash INE. Similar to findings for desert dust from arid and semi-arid regions, the presence of feldspar minerals characterises the four most ice-active tephra samples, although a high INE is observed even in the absence of alkali feldspar in samples bearing plagioclase feldspar and orthopyroxene. There is evidence of a potential indirect relationship between chemical composition and ash INE, whereby a magma of felsic to intermediate composition may generate ash containing ice-active feldspar minerals. This complex interplay between chemical composition, crystallinity, and mineralogy could help partly to explain the variability in volcanic ash INE reported in the literature. Overall, by categorically demonstrating the importance of crystalline phases in the INE of volcanic ash, our study contributes insights essential for better appraising the role of airborne ash in ice formation. Among these is the inference that glass-dominated ash emitted by the largest explosive eruptions may be less effective at impacting ice-nucleating particle populations than crystalline ash generated by smaller, more frequent eruptions.
Improved aerosol correction for OMI tropospheric NO2 retrieval over East Asia: constraint from CALIOP aerosol vertical profile
Authors: Liu Mengyao , Lin Jintai , Boersma K. Folkert , Pinardi Gaia , Wang Yang , Chimot Julien , Wagner Thomas , Xie Pinhua , Eskes Henk , Van Roozendael Michel , Hendrick François , Wang Pucai , Wang Ting , Yan Yingying , Chen Lulu , Ni Ruijing
Published: January 2019

Abstract. Satellite retrieval of vertical column densities (VCDs) of tropospheric
nitrogen dioxide (NO2) is critical for NOx pollution and impact
evaluation. For regions with high aerosol loadings, the retrieval accuracy is
greatly affected by whether aerosol optical effects are treated implicitly
(as additional “effective” clouds) or explicitly, among other factors. Our
previous POMINO algorithm explicitly accounts for aerosol effects to improve
the retrieval, especially in polluted situations over China, by using aerosol
information from GEOS-Chem simulations with further monthly constraints by
MODIS/Aqua aerosol optical depth (AOD) data. Here we present a major
algorithm update, POMINO v1.1, by constructing a monthly climatological dataset of aerosol extinction profiles, based on level 2 CALIOP/CALIPSO data over
2007–2015, to better constrain the modeled aerosol vertical profiles. We find that GEOS-Chem captures the month-to-month variation in CALIOP
aerosol layer height (ALH) but with a systematic underestimate by about 300–600 m
(season and location dependent), due to a too strong negative vertical
gradient of extinction above 1 km. Correcting the model aerosol extinction
profiles results in small changes in retrieved cloud fraction, increases in
cloud-top pressure (within 2 %–6 % in most cases), and increases in
tropospheric NO2 VCD by 4 %–16 % over China on a monthly basis in
2012. The improved NO2 VCDs (in POMINO v1.1) are more consistent with
independent ground-based MAX-DOAS observations (R2=0.80, NMB = −3.4 %, for
162 pixels in 49 days) than POMINO (R2=0.80, NMB = −9.6 %), DOMINO v2 (R2=0.68, NMB = −2.1 %), and QA4ECV
(R2=0.75, NMB = −22.0 %) are. Especially on haze days, R2
reaches 0.76 for POMINO v1.1, much higher than that for POMINO (0.68),
DOMINO v2 (0.38), and QA4ECV (0.34). Furthermore, the increase in cloud
pressure likely reveals a more realistic vertical relationship between cloud
and aerosol layers, with aerosols situated above the clouds in certain
months instead of always below the clouds. The POMINO v1.1 algorithm is a
core step towards our next public release of the data product (POMINO v2), and
it will also be applied to the recently launched S5P-TROPOMI sensor.
Ostracods as ecological and isotopic indicators of lake water salinity changes: The Lake Van example
Authors: McCormack Jeremy , Viehberg Finn , Akdemir Derya , Immenhauser Adrian , Kwiecien Ola
Published: January 2019

Abstract. Ostracods are common lacustrine calcitic microfossils. Their faunal assemblage and morphological characteristics are important ecological proxies, while their valves are archives of geochemical information related to palaeoclimatic and palaeohydrological changes. In an attempt to assess ostracod ecology (taxonomic diversity and valve morphology) combined with valve geochemistry (δ18O and δ13C) as palaeosalinity indicators, we analysed material from terminal and alkaline Lake Van (Turkey) covering the last 150 kyr. Despite a low species diversity, the ostracod faunal assemblage reacted sensitive to changes in the concentration of total dissolved salts in their aquatic environment. Limnocythere inopinata is present throughout the studied interval, while Limnocythere sp. A is restricted to the Last Glacial period and related to increased lake water salinity and alkalinity. The presence of species belonging to the genus Candona is limited to periods of lower salinity. Valves of limnocytherinae species (incl. L. inopinata) display nodes (hollow protrusions) during intervals of increased salinity. Both the amount of noded valves and the number of nodes per valve appear to increase with rising salinity, suggesting that node formation is related to hydrological changes (salinity and/or alkalinity). In contrast to Lake Van's inorganic δ18O record, the δ18O values of ostracod valves do record relative changes of the lake volume, with lower values during high lake level periods. The δ13C values of different species reflect ostracod habitat preferences (i.e., infaunal versus epifaunal) but are less sensitive to hydrological changes. However, combined with other proxies, decreasing Holocene δ13C values may indicate a freshening of the lake water compared to the low lake level during the Last Glacial period. The Lake Van example underscores the significance and value of coupling ostracod ecology and valve geochemistry in palaeoenvironmental studies of endorheic lakes basins.
Spatial changes in soil stable isotopic composition in response to carrion decomposition
Authors: Keenan Sarah W. , Schaeffer Sean M. , DeBruyn Jennifer M.
Published: January 2019

Abstract. Decomposition provides a critical mechanism for returning nutrients to the surrounding environment. In terrestrial systems, animal carcass, or carrion, decomposition results in a cascade of biogeochemical changes. Soil microbial communities are stimulated, resulting in transformations of carbon (C) and nitrogen (N) sourced from the decaying carrion soft tissues, changes to soil pH and electrical conductivity as microbial communities release CO2 and mineralize organic N, and significant changes to oxygen availability. Over time, microbial communities transform ammonium to nitrate and potentially N2O through nitrification and denitrification. While many of the rapid changes to soil biogeochemistry observed during carrion decomposition return to background or starting conditions shortly after soft tissues are degraded, some biogeochemical parameters, particularly bulk soil stable δ15N isotopic composition, have the potential to exhibit prolonged perturbations, extending for several years. The goal of this study was to evaluate the lateral and vertical changes to soil stable isotopic composition one year after carrion decomposition in a forest ecosystem. Lateral transects extending 140 cm from three decomposition hotspots were sampled at 20 cm intervals, and subsurface cores were collected beneath each hotspot to a depth of 50 cm. Bulk soil stable isotopic composition (δ15N and δ13C) indicated that one year after complete soft tissue removal and decay, soils were significantly 15N-enriched compared to control soils up to 60 cm from the hotspot center, and enrichment extended to a depth of 10 cm. Our results demonstrate that carrion decomposition has the potential to result in long-term changes to soil biogeochemistry, up to at least one year after soft tissue degradation, and to contribute to bulk soil stable isotopic composition.
Organic signatures in Pleistocene cherts from Lake Magadi (Kenya), analogs for early Earth hydrothermal deposits
Authors: Reinhardt Manuel , Goetz Walter , Duda Jan-Peter , Heim Christine , Reitner Joachim , Thiel Volker
Published: January 2019

Abstract. Organic matter in Archean hydrothermal cherts may provide an important archive for molecular traces of earliest life on Earth. The geobiological interpretation of this archive, however, requires a sound understanding of organic matter preservation and alteration in hydrothermal systems. Here we report on organic matter (including molecular biosignatures) enclosed in hydrothermally influenced cherts of the Pleistocene Lake Magadi (Kenya; High Magadi Beds and Green Beds) – important analogs for Archean cherts. The Magadi cherts contain low organic carbon (
A reconstruction of warm water inflow to Upernavik Isstrøm since AD 1925 and its relation to glacier retreat
Authors: Vermassen Flor , Andreasen Nanna , Wangner David J. , Thibault Nicolas , Seidenkrantz Marit-Solveig , Jackson Rebecca , Schmidt Sabine M. , Kjær Kurt H. , Andresen Camilla S.
Published: January 2019

Abstract. The mass loss from the Greenland Ice Sheet has increased over the past two decades. Marine-terminating glaciers contribute significantly to this mass loss due to increased melting and ice discharge. Rapid retreat periods of these tidewater glaciers have been linked to the concurrent inflow of warm, Atlantic derived waters. However, little is known about the variability of Atlantic-derived waters within these fjords, due to a lack of multi-annual, in situ measurements. Thus, to better understand the potential role of ocean warming on glacier retreat, reconstructions that characterize the variability of Atlantic water inflow to these fjords are required. Here, we investigate foraminiferal assemblages in a sediment core from Upernavik Fjord, West Greenland, in which the major ice stream Upernavik Isstrøm terminates. We investigate the environmental characteristics that control species diversity and derive that it is predominantly controlled by changes in bottom water variability. Hence, we provide a reconstruction of Atlantic water inflow to Upernavik Fjord, spanning the period 1925–2012. This reconstruction reveals peak Atlantic water inflow during the 1930s and again after 2000, a pattern that is similar to the Atlantic Multidecadal Oscillation (AMO). We compare these results to historical observations of front positions of Upernavik Isstrøm. This reveals that inflow of warm, Atlantic-derived waters indeed likely contributed to high retreat rates in the 1930s and after 2000. However, moderate retreat rates of Upernavik Isstrøm also prevailed in the 1960s/1970s, showing that retreat continued despite reduced Atlantic water inflow, albeit at a lower rate. Considering the link between bottom water variability and the AMO in Upernavik Fjord and the fact that a persistent negative phase of the AMO is expected for the next decade, Atlantic water inflow into the fjord may decrease in the next ~ 10 years.
Merits of novel high-resolution estimates and existing long-term estimates of humidity and incident radiation in a complex domain
Authors: Erlandsen Helene Birkelund , Tallaksen Lena Merete , Kristiansen Jørn
Published: January 2019

Abstract. To provide better and more robust estimates of evaporation and snow-melt in a changing climate, hydrological and ecological modelling practices are shifting towards solving the surface energy balance. In addition to precipitation and near-surface temperature (T2), which often is available at high resolution by national providers, high quality estimates of 2-meter humidity, surface incident shortwave (SW ↓) and longwave (LW ↓) radiation are also required. Novel, gridded estimates of humidity and incident radiation are constructed using a methodology similar to that used in the development of the WATCH forcing data, however, a national 1 × 1 km gridded, observation-based T2 data is consulted in the downscaling rather than the 0.5 × 0.5 degree CRU T2 data. The novel dataset, HySN, is archived in Zenodo (https://doi.org/10.5281/zenodo.1970170). The HySN estimates, existing estimates from reanalysis data, post-processed reanalysis data, and VIC-type forcing data are compared with observations from the Norwegian mainland between 1982 and 2000. Humidity measurements from 84 stations are used, and, by employing quality control routines and including agricultural stations, SW ↓ observations from 10 stations are made available. Meanwhile, only two stations have observations of LW ↓. Vertical gradients, differences when compared at common altitudes, daily correlations, sensitivities to air mass type, and, where possible, trends and geographical gradients in seasonal means are assessed. At individual stations differences in seasonal means from the observations are as large as 7 °C for Td, 62 W m−2 for SW ↓, and 24 W m−2 for LW ↓. Most models overestimate SW ↓, and underestimate LW ↓. Horizontal resolution is not a predictor of the model's efficiency. Daily correlation is better captured in the products based on newer reanalysis data. Certain model estimates show different dependencies on geographical features, diverging trends, or a different sensitivity to air mass type than the observations.
Fifty years of recorded hillslope runoff on seasonally-frozen ground: The Swift Current, Saskatchewan, Canada dataset
Authors: Coles Anna E. , McDonnell Jeffrey J. , McConkey Brian G.
Published: January 2019

Abstract. Long records of hillslope runoff and nutrients are rare – on seasonally frozen ground they are almost non-existent. The Swift Current hillslopes at the Swift Current Research and Development Centre on the Canadian Prairies provide such a long-term hydrological record. Runoff, runoff nutrient concentration, snowpack, soil moisture, and soil nutrient concentration were monitored on the three 5 ha hillslopes over a 50-year period (1962–2011). Runoff from the hillslopes was generated episodically during snowmelt and occasional rainfall events. Edge-of-field runoff was measured with a 0.61 m H-flume. Daily runoff nutrient concentration data are available for nitrate (March 1971–April 2011), ammonium (February 1996–April 2011), and orthophosphate (March–April 1971; June 1991–April 2011). Snowpack data (snowpack depth, density and water equivalent) were determined via manual snow surveys carried out several times each winter, between January and March, between 1965 and 2011 Gravimetric soil moisture content was measured in October and April each year between 1971 and 2011 at five depth intervals (0–15, 15–30, 30–60, 60–90, and 90–120 cm) at nine points on each hillslope. We summarize these hillslope data in two publically-available repositories: 1) 1962–2011 data on runoff, runoff nutrients, snowpack, soil moisture, soil nutrients, and crop and tillage practices at https://doi.org/10.23684/hhn5-rz52; and 2) digital elevation data at https://doi.org/10.20383/101.011. Complete climate data recorded at a Environment and Climate Change Canada meteorological station located 390 m from the three hillslopes are publically-available at http://climate.weather.gc.ca/.
Snow cover variability across glaciers in Nordenskiöldland (Svalbard) from point measurements in 2014–2016
Authors: Möller Marco , Möller Rebecca
Published: January 2019

Abstract. Snow depths and bulk densities of the annual snow layer were measured at 69 different locations on glaciers across Nordenskiöldland, Svalbard, during the spring seasons of the period 2014–2016. Sampling locations lie along nine transects extending over 17 individual glaciers. Several of the locations were visited repeatedly, leading to a total of 109 point measurements, on which we report in this study. Snow water equivalents were calculated for each point measurement. In the dataset, snow depth and density measurements are accompanied by appropriate uncertainties which are rigorously transferred to the calculated snow water equivalents using a straightforward Monte Carlo simulation-style procedure. The final dataset can be downloaded from the Pangaea data repository (https://www.pangaea.de; https://doi.org/10.1594/PANGAEA.896581). Snow cover data indicate a general and statistically significant increase of snow depths and water equivalents with terrain elevation. A significant increase of both quantities with decreasing distance towards the east coast of Nordenskiöldland is also evident, but shows distinct interannual variability. Snow density does not show any characteristic spatial pattern.
Determining the Optimal Grid Resolution for Topographic Analysis on an Airborne Lidar Dataset
Authors: Smith Taylor , Rheinwalt Aljoscha , Bookhagen Bodo
Published: January 2019

Abstract. Digital Elevation Models (DEMs) are a gridded representation of the surface of the earth and typically contain uncertainties due to data collection and processing. The topographic metrics slope and aspect contain errors and uncertainties inherited both from the representation of a continuous surface as a grid (referred to as truncation error, TE), and from any DEM uncertainty. We analyze in detail the impacts of TE and propagated elevation uncertainty (PEU) on slope and aspect. Using synthetic data as a control, we define functions to quantify both TE and PEU for arbitrary grids. We then develop a quality metric which captures the combined impact of both TE and PEU on the calculation of topographic metrics. Our quality metric allows us to examine the spatial patterns of error and uncertainty in topographic metrics, and to compare calculations on DEMs of different sizes and accuracies. Using lidar data with point density of ~ 10 pts/m2 covering Santa Cruz Island in southern California, we are able to generate DEMs and uncertainty estimates at several grid resolutions. Slope (aspect) errors on the one-meter dataset are on average 0.3° (0.9°) from TE, and 5.5° (14.5°) from PEU. We calculate an optimal DEM resolution for our SCI lidar dataset of four meters that minimizes the error bounds on topographic metric calculations due to the combined influence of TE and PEU for both slope and aspect calculations over the entire SCI. Average slope (aspect) errors from the four meter DEM are 0.25° (0.75°) from TE and 5° (12.5°) from PEU. While the smallest grid resolution possible from the high-density SCI lidar is not necessarily optimal for calculating topographic metrics, high point-density data are essential for measuring DEM uncertainty across a range of resolutions.
A low-cost autonomous rover for polar science
Authors: Hoffman Andrew O. , Steen-Larsen Hans Christian , Christianson Knut , Hvidberg Christine
Published: January 2019

Abstract. We present the developmental considerations, design, and deployment of an autonomous modular terrestrial rover for ice-sheet exploration that is inexpensive, easy to construct, and allows for instrumentation customization. Total construction cost for this rover is less than $3000, approximately one tenth the cost of existing platforms, and it can be built using facilities frequently available at academic institutions (machine shop, 3D printer, open-source hardware and software). Instrumentation deployed on this rover can be customized; the rover presented in this study was equipped with a dual-frequency GPS receiver and a digital SLR camera for constructing digital elevation models using structure-from motion (SfM) photogrammetry. We deployed this prototype rover on the Northeast Greenland Ice Stream to map local variations in snow accumulation and surface topography. The rover conducted four autonomous missions based out of the East Greenland Ice Core Project (EGRIP) camp during July 2017, measuring surface elevation transects across the hazardous ice-stream shear margins. During these missions, the rover proved capable of driving over 20 km on a single charge with a drawbar pull of 25°N, sufficient to tow commercial ground-penetrating radars. The rover also acquired photographs that were subsequently used to construct digital elevation models of a site monitored for spatiotemporal variability in snow accumulation, demonstrating adequate stability for high-resolution imaging applications. Due to its low cost, low-power requirements, and simple modular design, mass deployments of this rover design are practicable. Furthermore, operation of the rover in hazardous areas circumvents substantial expense and risk to personnel associated with conventional, crewed deployments. Thus, this rover is an investigatory platform that enables direct exploration of polar environments considered too hazardous for conventional field expeditions.
Calibration and analysis of the uncertainty in downscaling global land use and land cover projections from GCAM
Authors: Chen Min , Vernon Chris R. , Huang Maoyi , Calvin Katherine V. , Kraucunas Ian P.
Published: January 2019

Abstract. Demeter is a community spatial downscaling model that disaggregates land use and land cover changes projected by integrated human-Earth system models. Demeter has not been intensively calibrated, and we still lack a good knowledge about its sensitivity to key parameters and the parameter uncertainties. We used long-term global satellite-based land cover records to calibrate key Demeter parameters. The results identified the optimal parameter values and showed that the parameterization substantially improved the model’s performance. The parameters of intensification ratio and selection threshold were the most sensitive and needed to be carefully tuned, especially for regional applications. Further, small parameter uncertainties after calibration can be inflated when propagated into future scenarios, suggesting that users should consider the parameterization equifinality to better account for the uncertainties in the Demeter downscaled products. Our study provides a key reference for Demeter users, and ultimately contribute to reducing the uncertainties in Earth system model simulations.