The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data

The FLUXNET2015 dataset provides ecosystem-scale data on CO₂, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible.

Measurement(s)	net ecosystem exchange • carbon dioxide • water • energy
Technology Type(s)	eddy covariance • measurement device
Sample Characteristic - Environment	terrestrial biome • atmosphere
Sample Characteristic - Location	Earth (planet)

Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12295910

Contrasting temperature trends across the ice-free part of Greenland

Temperature changes in the Arctic have notable impacts on ecosystem structure and functioning, on soil carbon dynamics, and on the stability of permafrost, thus affecting ecosystem functions and putting man-built infrastructure at risk. Future warming in the Arctic could accelerate important feedbacks in permafrost degradation processes. Therefore it is important to map vulnerable areas most likely to be impacted by temperature changes and at higher risk of degradation, particularly near communities, to assist adaptation to climate change. Currently, these areas are poorly assessed, especially in Greenland. Here we quantify trends in satellite-derived land surface temperatures and modelled air temperatures, validated against observations, across the entire ice-free Greenland. Focus is on the past 30 years, to characterize significant changes and potentially vulnerable regions at a 1 km resolution. We show that recent temperature trends in Greenland vary significantly between seasons and regions and that data with resolutions down to single km² are critical to map temperature changes for guidance of further local studies and decision-making. Only a fraction of the ice-free Greenland seems vulnerable due to warming when analyzing year 2001–2015, but the most pronounced changes are found in the most populated parts of Greenland. As Greenland represents important gradients of north/south coast/inland/distance to large ice sheets, the conclusions are also relevant in an upscaling to greater Arctic areas.

Deltas, freshwater discharge, and waves along the Young Sound, NE Greenland

A wide range of delta morphologies occurs along the fringes of the Young Sound in Northeast Greenland due to spatial heterogeneity of delta regimes. In general, the delta regime is related to catchment and basin characteristics (geology, topography, drainage pattern, sediment availability, and bathymetry), fluvial discharges and associated sediment load, and processes by waves and currents. Main factors steering the Arctic fluvial discharges into the Young Sound are the snow and ice melt and precipitation in the catchment, and extreme events like glacier lake outburst floods (GLOFs). Waves are subordinate and only rework fringes of the delta plain forming sandy bars if the exposure and fetch are optimal. Spatial gradients and variability in driving forces (snow and precipitation) and catchment characteristics (amount of glacier coverage, sediment characteristics) as well as the strong and local influence of GLOFs in a specific catchment impede a simple upscaling of sediment fluxes from individual catchments toward a total sediment flux into the Young Sound.

Toward a statistical description of methane emissions from arctic wetlands

Methane (CH₄) emissions from arctic tundra typically follow relations with soil temperature and water table depth, but these process-based descriptions can be difficult to apply to areas where no measurements exist. We formulated a description of the broader temporal flux pattern in the growing season based on two distinct CH₄ source components from slow and fast-turnover carbon. We used automatic closed chamber flux measurements from NE Greenland (74°N), W Greenland (64°N), and Svalbard (78°N) to identify and discuss these components. The temporal separation was well-suited in NE Greenland, where the hypothesized slow-turnover carbon peaked at a time significantly related to the timing of snowmelt. The temporally wider component from fast-turnover carbon dominated the emissions in W Greenland and Svalbard. Altogether, we found no dependence of the total seasonal CH₄ budget to the timing of snowmelt, and warmer sites and years tended to yield higher CH₄ emissions.

Transitions in high-Arctic vegetation growth patterns and ecosystem productivity tracked with automated cameras from 2000 to 2013

Climate-induced changes in vegetation phenology at northern latitudes are still poorly understood. Continued monitoring and research are therefore needed to improve the understanding of abiotic drivers. Here we used 14 years of time lapse imagery and climate data from high-Arctic Northeast Greenland to assess the seasonal response of a dwarf shrub heath, grassland, and fen, to inter-annual variation in snow-cover, soil moisture, and air and soil temperatures. A late snow melt and start of growing season is counterbalanced by a fast greenup and a tendency to higher peak greenness values. Snow water equivalents and soil moisture explained up to 77 % of growing season duration and senescence phase, highlighting that water availability is a prominent driver in the heath site, rather than temperatures. We found a significant advance in the start of spring by 10 days and in the end of fall by 11 days, resulting in an unchanged growing season length. Vegetation greenness, derived from the imagery, was correlated to primary productivity, showing that the imagery holds valuable information on vegetation productivity.

Vegetation phenology gradients along the west and east coasts of Greenland from 2001 to 2015

The objective of this paper is to characterize the spatiotemporal variations of vegetation phenology along latitudinal and altitudinal gradients in Greenland, and to examine local and regional climatic drivers. Time-series from the Moderate Resolution Imaging Spectroradiometer (MODIS) were analyzed to obtain various phenological metrics for the period 2001-2015. MODIS-derived land surface temperatures were corrected for the sampling biases caused by cloud cover. Results indicate significant differences between West and East Greenland, in terms of both observed phenology during the study period, as well as the climatic response. The date of the start of season (SOS) was significantly earlier (24 days), length of season longer (25 days), and time-integrated NDVI higher in West Greenland. The sea ice concentration during May was found to have a significant effect on the date of the SOS only in West Greenland, with the strongest linkage detected in mid-western parts of Greenland.

Greenlandic sheep farming controlled by vegetation response today and at the end of the 21st century

The spatial heterogeneity of vegetation greenness and potential aboveground biomass production for sheep farming has been assessed for Southwest Greenland. A Multi-Criteria Evaluation (MCE) model was set up to identify biophysical constraints on the present spatial distribution of farms and fields based on all existing sheep farms in a detailed study area. Time-integrated NDVI (TI-NDVI) from MODIS and observed temperatures (2000-2012) have been combined with a downscaled regional climate model (HIRHAM5) in order to establish a spatio-temporal model for future TI-NDVI, thus forecasting the dry biomass production available for sheep farming in steps of decades for the next 85 years. The model has been validated against observed biomass production and the present distribution of fields. Future biomass production is used to discuss the expansion of current farms and to identify new suitable areas for sheep farming. Interestingly, new suitable areas are located where sheep farms were situated during the Norse era more than 1000 years ago; areas which have been abandoned for the past 500 years. The study highlights the potential of establishing new areas for sheep farming in Arctic Greenland, where current and future climate changes are markedly amplified compared to global trends. However, for the study area the MCE model clearly indicates that the potential of expansion relies on contemporary infrastructural development.

Clinical and immunological features of Sjögren's syndrome in patients with primary biliary cirrhosis with emphasis on focal sialadenitis

Serological and pathological findings in 21 patients with primary Sjögren's syndrome (primary SS) were compared with those in 32 patients with primary biliary cirrhosis (PBC). In ELISA, anti-SS-B/La antibodies were detected in sera from 14 (67%) of the patients with primary SS, but only from 12 (38%) of those with PBC. With the Ouchterlony test, anti-SS-A/Ro antibodies were found in sera from 15 (71%) of the primary SS patients, but in no PBC patient. Of those PBC patients investigated prospectively with objective tests, four of 11 (36%) had keratoconjunctivitis sicca, and five of 15 (33%) had pathological sialometry results. In contrast, all PBC patients but one (i.e., 14 of 15 or 93%) showed evidence of focal sialadenitis. In immunochemical study of PBC patients, IgM immunoreactivity was found in the stroma, particularly adjacent to excretory ducts and acini in salivary glands (5 of 5), whereas no such IgM deposits were observed in patients with primary SS (3 of 3), nor in healthy controls (n = 20). We conclude that the frequency of anti-SS-A/Ro and anti-SS-B/La antibodies in serum is lower in PBC patients than in patients with primary SS. The incidence of focal sialadenitis is high in PBC, though only one third of the PBC patients studied here showed clinical evidence of glandular dysfunction. With immunochemical techniques, sialadenitis associated with PBC is distinguishable by its significant IgM reaction from sialadenitis in primary SS.

Measuring the size of ulcers by planimetry: a useful method in the clinical setting

OBJECTIVE

The aim of this study was to compare four measurement methods. Digital planimetry was compared with mechanical planimetry, placing the film over graph paper and counting the squares (grid tracing), and multiplying the two maximal perpendicular diameters of the ulcer (diameter product).

METHOD

Twenty patients with 50 chronic leg ulcers of various aetiology and sizes (20 ulcers were < or = 3 cm2, 15 ulcers were > 3 cm2 and < or = 10 cm2, and 15 ulcers were > 10 cm2) were enrolled consecutively into this study. Ulcer area was calculated from film transparency tracings using a digital planimeter, a mechanical planimeter, grid tracing and diameter product.

RESULTS

The mean difference of digital planimetry versus mechanical planimetry, grid tracing and diameter product was 0.51 cm2, 0.72 cm2 and -5.38 cm2, respectively. For all methods difference tended to increase with ulcer size.

CONCLUSION

Digital and mechanical planimetry, together with grid tracing, appear to be appropriate means of obtaining accurate surface area measurements. Digital planimetry is a quick and practical method and could therefore be recommended in the clinical setting.

Leg ulcers in patients with rheumatoid arthritis--a prospective study of aetiology, wound healing and pain reduction after pinch grafting

OBJECTIVE

To study the aetiology of leg ulcers in patients with rheumatoid arthritis (RA) and to study healing and pain relief after pinch grafting.

METHODS

Twenty patients with RA and leg ulcers were studied. Diagnosis of the ulcers was founded on the clinical picture and measurements of the ankle-brachial pressure index. To detect vasculitis, skin biopsies were taken for immunohistochemistry and histopathology. Pain severity was assessed pre- and post-operatively using a visual analogue scale.

RESULTS

Ten of the 20 patients had ulcers with multifactorial aetiology. Fifteen had signs of venous insufficiency, 11 had histopathological evidence of vasculitis, four had reduced arterial circulation and two patients had diabetes. Healing after pinch grafting was found in eight patients, all of whom had an ulcer area less than 15 cm(2). Eleven out of 18 patients had pain reduction after pinch grafting.

CONCLUSION

The causation of leg ulcers in patients with RA was found to be multifactorial, with vasculitis and venous insufficiency as the main determinants. Pinch grafting seems to be a good alternative to conservative treatment for minor leg ulcers for these patients, regarding both wound healing and pain relief.

Pinch grafting in hospital and primary care: a cost analysis

The cost of treating venous leg ulcers with pinch grafting was evaluated for 58 consecutive patients: 29 in hospital care and 29 in primary care. The mean age was 76.8 and 74.3 years and the mean ulcer size 15.1 and 13.5 cm2, respectively. The operation technique, pinch grafting, was the same for all patients but primary care patients were not immobilised postoperatively. Healing rate within 12 weeks was the same for patients in hospital care and primary care (31%). Treatment costs for one week pre-operatively and three weeks postoperatively amounted to 5109 Pounds per patient in hospital care and 870 Pounds per patient in primary care (p < 0.001), and the costs for one week pre-operatively and 12 weeks postoperatively were 6738 Pounds and 1806 Pounds, respectively (p < 0.001). Costs for patients whose ulcers healed within 12 weeks were 5552 Pounds for those receiving hospital care and 1676 Pounds for those receiving primary care (p < 0.001). Pinch grafting in primary care was shown to cost 3.3 to 5.9 times less, with the same healing outcome, than pinch grafting in hospital care.

Wound management for 287 patients with chronic leg ulcers demands 12 full-time nurses. Leg ulcer epidemiology and care in a well-defined population in southern Sweden

OBJECTIVE

To study the prevalence, aetiology and treatment of chronic leg and foot ulcers, and to estimate the nurse's time in wound management.

DESIGN

A structured questionnaire with 19 questions about chronic ulcers and wound management was sent to all district and community nurses in the county during 1 week in March 1998. A similar questionnaire has been administered regularly since 1986.

SETTING

Primary and community care in the county of Blekinge, Sweden, with a population of 1,51,610.

PATIENTS

287 patients with chronic leg and foot ulcers were identified during the week studied.

MAIN OUTCOME MEASURES

Prevalence of leg and foot ulcers, ulcer aetiology, treatment of ulcers and wound management time.

RESULTS

The estimated prevalence of chronic leg and foot ulcers was 0.19%. Venous ulcers were the most common (38%), of which 87% were treated with some form of compression therapy. Seven percent of the nurse's workload was devoted to ulcer care. During the period 1986 to 1998, ulcers with missing or unknown aetiology decreased from 31% to 6% and ulcers with a duration of more than 2 years from 44% to 27%, while treatment time per ulcer decreased from 2.1 to 1.7 hours/week.

CONCLUSION

Monitoring standards for ulcer aetiology through repeated questionnaires seems to ensure more accurate diagnoses. Thorough and detailed information about treatment time documents the workload for wound management.

Pinch graft skin transplantation for leg ulcers in primary care

Pinch grafting offers an alternative approach to conventional management of chronic leg ulcers, and is particularly well suited for venous and diabetic ulcers. Relevant literature from 1872-1998 was reviewed. The method of pinch grafting is described here in detail, and is illustrated by two case reports. Since pinch grafting hastens the healing of granulating wounds, is easy to perform and does not require strict immobilisation, a revival of the method, with adaptation for primary care, should be encouraged.

Pinch grafting of leg ulcers in primary care

Treatment of chronic leg ulcers consumes considerable primary care resources. For the patient, it often entails restrictions in everyday life. This study describes the results of 84 skin transplantations on 45 patients with 55 ulcerated limbs, using the pinch graft technique, performed in primary care from 1987-1993. The healing rate after 12 weeks for venous ulcers was 45%, and for neuropathic ulcers 44%. Venous ulcers represented 56% of all the ulcers, while 16% were neuropathic. One year postoperatively, 47% (19/40) of examined ulcers remained healed. The results from our study suggest that venous and neuropathic ulcers may be particularly well suited for skin transplantation, which can easily be performed in primary care.

Lyme borreliosis in rheumatological practice: identification of Lyme arthritis and diagnostic aspects in a Swedish county with high endemicity

To prospectively study the prevalence of Lyme arthritis, 100 consecutive patients referred to a rheumatology out-patient clinic and 115 patients with a classified rheumatological disease were included. Individuals seropositive for antibody against the Borrelia burgdorferi sensu lato complex were examined for clinical signs or a history of Lyme borreliosis. Positive titres against B. burgdorferi s.l. were found in 7/100 and 15/115, respectively. Among the 100 referred patients. Lyme arthritis was diagnosed in five cases. Carpal tunnel syndrome was the presenting clinical feature in two of them. One of the 115 individuals with a previously classified rheumatological disease was re-classified as Lyme arthritis. All cases of Lyme arthritis improved after oral antibiotic treatment. This study revealed Lyme arthritis to be a common disorder in this part of Sweden and the diagnosis should be considered in patients with acute or recurrent episodes of mono- or oligoarthritis.

Polyarteritis nodosa: ischaemic intestinal pain successfully treated with nitroglycerin

Inflammation of medium and small sized arteries caused by polyarteritis nodosa (PAN) sometimes causes acute and life threatening ischaemic intestinal complications. We report a case of PAN presenting with severe abdominal pain successfully treated with nitroglycerin.

Lyme arthritis--a common manifestation in a highly endemic area in Sweden

OBJECTIVE

To study the prevalence and the clinical features of Lyme arthritis in a Swedish area highly endemic for Lyme borreliosis.

METHODS

Sera from 480 of 540 individuals living in a tick endemic area on an island in southern Sweden were tested by ELISA for IgG antibodies against Borrelia burgdorferi. A questionnaire was completed at the time serum was obtained. Antibody positive individuals who reported joint pain were examined by the authors one year later.

RESULTS

Of 90 seropositive individuals, 34 (38%) reported symptoms of chronic or recurrent arthralgia. Of seronegative individuals from the same area 48/390 (12%) reported such complaints (p < 0.001). One year later one of the 34 seropositive patients with arthralgia had died and, of the remaining, 32 still had arthralgia. Lyme arthritis was diagnosed in 11/32 (35%) of these individuals corresponding to a prevalence of 2.3% (95% confidence interval: 1.0-3.6) in the population. The prevalence of other rheumatic disorders did not differ from that found in other areas in South Sweden. Clinical and laboratory findings were in agreement with previous reports of Lyme arthritis. Other manifestations of Lyme borreliosis were found in 6 of the 11 patients with Lyme arthritis. After antibiotic treatment 9/11 (82%) remain free of complaints followed for 6 months or more.

CONCLUSION

Our results indicate that arthritis and musculoskeletal symptoms of Lyme borreliosis are as common in highly endemic areas for Lyme borreliosis in Sweden as in similar areas in North America.

Association of dry eyes and dry mouth with anti-Ro/SS-A and anti-La/SS-B autoantibodies in normal adults

OBJECTIVE

To evaluate the extent to which seemingly healthy, mature adults with mild symptoms of dry eyes or dry mouth share the immunologic features found in patients with Sjögren's syndrome.

METHODS

Of 705 subjects in Malmö, Sweden (age range 52-72 years) who responded to a questionnaire, 35% reported some symptoms of dry eyes or mouth. A random subgroup of the symptomatic subjects (n = 77) and an age- and sex-matched control group from among the asymptomatic subjects (n = 32) were evaluated objectively by serologic testing and by various measures of exocrine gland function.

RESULTS

The symptomatic subjects had relatively impaired exocrine gland function and elevated levels of anti-Ro and anti-La (1.54-2.88-fold increase compared with the asymptomatic subjects, 95% confidence interval [CI] 1.41, 4.03). The 2 autoantibodies correlated with each other (r = 0.64, 95% CI 0.49, 0.78) as well as with selected clinical measures of glandular function.

CONCLUSION

The association between self-reported symptoms of dry eyes or dry mouth and anti-Ro and anti-La, found in more than one-third of mature adults in this study, suggests that the immune abnormalities and exocrine gland dysfunction found in Sjögren's syndrome affect a substantial proportion of the general population.

Primary Sjögren's syndrome in patients with multiple sclerosis

The relationship between multiple sclerosis (MS) and primary Sjögren's syndrome (PSS) is ambiguous; it was suggested that some patients diagnosed with MS may instead have PSS. In a recent epidemiologic study, the prevalence of PSS was 2.7% in southern Sweden. We randomly selected 30 patients with definite MS from our patient population and investigated them for evidence of PSS according to the Copenhagen criteria. One patient had clinical symptoms compatible with PSS and also fulfilled the Copenhagen criteria. In addition, five patients had keratoconjunctivitis sicca, one had xerostomia, and three had histopathologic evidence of sialadenitis in the lower lip salivary glands. However, one of these findings alone is not sufficient to support the diagnosis of PSS. We conclude that MS and PSS may coexist in the same individual, but PSS is not more common among MS patients than expected in the general population.

High prevalence of autoimmune liver disease in patients with multiple nuclear dot, anti-centromere, and mitotic spindle antibodies

We used HEp-2 cells to compare the occurrence of multiple nuclear dot (MND), anti-centromere (ACA), and mitotic spindle antibodies (MSA) in patients with primary biliary cirrhosis (PBC) (n = 32) and primary Sjögren's syndrome (n = 50). The predictive value of these antibodies for autoimmune liver disease was evaluated among patients with chronic liver or inflammatory connective tissue diseases. MND were found in 6%, ACA in 10%, and MSA in 6% of PBC sera. Among patients with primary Sjögren's syndrome, ACA were found in one, whereas another had both MND and MSA. MND were also detected in 1 of 25 sera from patients with other chronic inflammatory connective tissue diseases. Reexamination of these three patients showed evidence of PBC in two. In a blinded study of sera from 356 patients with chronic liver diseases, MND were detected in 10 (3%), ACA in 2 (0.9%), and MSA in 4 (1.2%). All patients with MND or ACA and two of four with MSA had PBC or autoimmune chronic active hepatitis, particularly of the cholestatic type. In four of these patients the liver disease had not previously been classified. We conclude that these antibodies have low sensitivity but high predictive value for autoimmune, cholestatic liver disease.

Autoimmune thyroiditis and primary Sjögren's syndrome: clinical and laboratory evidence of the coexistence of the two diseases

The prevalence of primary Sjögren's syndrome (primary SS) among patients with autoimmune thyroiditis (AT), and that of AT among patients with primary SS were studied prospectively. Of 63 patients with AT, one had precipitating antibodies against SS-A/Ro antigen together with objectively verified primary SS, and none had precipitating anti-SS-B/La antibodies; in contrast 17/63 (27%) had above normal values of anti-SS-B/La antibodies, as tested with ELISA. Of 19 AT patients tested objectively for xerostomia and keratoconjunctivitis sicca, six (32%) had keratoconjunctivitis sicca together with xerostomia and four (21%) had autoimmune sialadenitis. The prevalence of AT in patients with primary SS (n = 28) was 18%; of the 28 patients, 64% had an enlarged or abnormal thyroid gland on palpation and four of them (14%) had cytology verified AT. Ten (36%) had anti-thyroglobulin and/or antimicrosomal autoantibodies. Based upon the present investigation we conclude that the prevalence of primary SS is ten times higher among patients with AT, and that of AT is nine times higher among patients with primary SS, compared with the general population.

Dry eyes or mouth--an epidemiological study in Swedish adults, with special reference to primary Sjögren's syndrome

The prevalence of dry eyes or dry mouth, and of primary Sjögren's syndrome (primary SS) according to the Copenhagen criteria were established in 705 randomly selected subjects, aged 52-72 years who answered a simple questionnaire, and of whom 247 (35%) reported symptoms. A subgroup with symptoms (n = 77) and a matched asymptomatic control group (n = 32) were examined with the Schimer-1 test (S1t), tear film break-up time (BUT), van Bijsterveld score (vB), unstimulated whole sialometry (Sialo) and, in about 40% of them labial salivary gland (LSG) biopsy and salivary gland scintigraphy. Apart from four cases of keratoconjunctivitis sicca (KCS) among controls, cases of KCS (15), xerostomia (12), autoimmune sialoadenitis (6) and primary SS (6) were exclusively confined to the symtomatic group. The calculated frequencies (with 95% confidence intervals) for the whole population were 14.9 (7.3-22.6)% for KCS, 5.5(3.0-7.9)% for xerostomia and 2.7 (1.0-4.5)% for autoimmune sialoadenitis and primary SS. The serum levels of ANA and RF were similar in the two groups, though those of anti-SS-B/La antibodies were higher in the group with symptoms (P less than 0.01).