Effects of Arctic ozone on the stratospheric spring onset and its surface response

Ozone in the Arctic stratosphere is subject to large interannual variability, driven by both chemical ozone depletion and dynamical variability. Anomalies in Arctic stratospheric ozone become particularly important in spring, when returning sunlight allows them to alter stratospheric temperatures via shortwave heating, thus modifying atmospheric dynamics. At the same time, the stratospheric circulation undergoes a transition in spring with the final stratospheric warming (FSW), which marks the end of winter. A causal link between stratospheric ozone anomalies and FSWs is plausible and might increase the predictability of stratospheric and tropospheric responses on sub-seasonal to seasonal timescales. However, it remains to be fully understood how ozone influences the timing and evolution of the springtime vortex breakdown. Here, we contrast results from chemistry climate models with and without interactive ozone chemistry to quantify the impact of ozone anomalies on the timing of the FSW and its effects on surface climate. We find that ozone feedbacks increase the variability in the timing of the FSW, especially in the lower stratosphere. In ozone-deficient springs, a persistent strong polar vortex and a delayed FSW in the lower stratosphere are partly due to the lack of heating by ozone in that region. High-ozone anomalies, on the other hand, result in additional shortwave heating in the lower stratosphere, where the FSW therefore occurs earlier. We further show that FSWs in high-ozone springs are predominantly followed by a negative phase of the Arctic Oscillation (AO) with positive sea level pressure anomalies over the Arctic and cold anomalies over Eurasia and Europe. These conditions are to a significant extent (at least 50 %) driven by ozone. In contrast, FSWs in low-ozone springs are not associated with a discernible surface climate response. These results highlight the importance of ozone–circulation coupling in the climate system and the potential value of interactive ozone chemistry for sub-seasonal to seasonal predictability

Evaluation of Three Commercial Interferon-γ Assays in a Bovine Tuberculosis Free Population

The interferon-γ assay has been used worldwide as an ancillary test for the diagnosis of bovine tuberculosis (bTB). This study aimed to describe, based on the bTB-free status in Switzerland, the difference of applying a more stringent cutoff point of 0.05 compared with 0.1 for bTB surveillance. Moreover, the effect of time between blood collection and stimulation, culture results, optical density values, and the influence of testing different breeds were evaluated. Blood samples from a total of 118 healthy cows older than 6 months were tested with three commercial interferon-gamma assays. To confirm the bTB-free status of the tested animals and to investigate potential cross-reactions with nontuberculous mycobacteria, pulmonary and abdominal lymph nodes in addition to ileal mucosa from each cattle were used for the detection of viable Mycobacteria spp. by specific culture. Significant differences regarding the proportion of false-positive results between the two Bovigam tests and between Bovigam 2G and ID Screen were found. Samples analyzed with Bovigam 2G were 2.5 [95% confidence interval (CI) 1.6–3.9] times more likely to yield a false-positive test result than samples analyzed with Bovigam TB. Similarly, the odds ratio (OR) for testing samples false-positive with ID Screen compared with Bovigam TB was 1.9 (95% CI 1.21–2.9). The OR for testing false-positive with ID Screen compared with Bovigam 2G was less to equally likely with an OR of 0.75 (95% CI 0.5–1.1). When using a cutoff of 0.05 instead of 0.1, the OR for a false-positive test result was 2.2 (95% CI 1.6–3.1). Samples tested after 6 h compared with a delayed stimulation time of 22–24 h were more likely to yield a false-positive test result with an OR of 3.9 (95% CI 2.7–5.6). In conclusion, applying a more stringent cutoff of 0.05 with the Bovigam 2G kit generates a questionable high number of false-positive results of one of three tested animals. Furthermore, specific breeds might show an increased risk to result false-positive in the Bovigam 2G and the ID Screen assays

AGTEC-Org Agronomy Handbook of Methods

A common handbook was conceived in the CORE Organic AGTEC-Org project in order to give some elements of field trial monitoring

New challenges to improve organic bread wheat production in Europe

The total organic area in the EU-27 had an annual average growth rate of nearly 15% from 1998 to 2006 with winter wheat being the most important cereal crop. Wheat yield in organic farming is around 30% to 70% of yield of conventional farming but higher premia for organic wheat may to some extent compensate for this. Bread wheat is grown in a variety of crop rotations and farming systems and four basic organic crop production systems have been defined. Nitrogen deficiency and weed infestation are considered to be the most serious threat in organic wheat production. Organic wheat producers will have to fulfil the technological needs of bakers although the requirements differ widely from small artisan bakers to large enterprises handling the organic bread processing. To maintain and expand organic wheat production, there is a need to control weed population, manage nitrogen nutrition and maintain crop diversity in the cropping system. In order to obtain a share in the premium price of organic wheat products, farmers may involve in further processing and marketing

Coupling of Arctic ozone and stratospheric dynamics and its influence on surface climate : the role of CFC concentrations

Arctic stratospheric ozone has been shown to exert a statistically significant influence on Northern Hemispheric surface climate. This suggests that Arctic ozone is not only passively responding to dynamical variability in the stratosphere, but actively feeds back into the circulation through chemical and radiative processes. However, the extent and causality of the chemistry-dynamics coupling is still unknown. Since many state-of-the-art climate models lack a sufficient representation of ozone-dynamic feedbacks, a quantification of this coupling can be used to improve intra-seasonal weather and long-term climate forecasts. We assess the importance of the ozone-dynamics coupling by performing simulations with and without interactive chemistry in two Chemistry Climate Models. The chemistry-dynamics coupling was examined in two different sets of time-slice simulations: one using pre-industrial, and one using year-2000 boundary conditions. We focus on the impact of sudden stratospheric warmings (SSW) and strong vortex events on stratosphere-troposphere coupling, since these go along with strong ozone anomalies and therefore an intensified ozone feedback. We compare the runs with and without interactive chemistry. For pre-industrial conditions, simulations without interactive ozone show a more intense and longer lasting surface signature of SSWs compared to simulations with interactive chemistry. Conversely, for year-2000 conditions, the opposite effect is found: interactive chemistry amplifies the surface signature of SSWs. Following these results, atmospheric CFC concentrations, which differ greatly in the pre-industrial and year-2000 runs, determine the sign of the ozone-circulation feedback, and thus have a strong impact on chemistry-climate coupling. Implications for modeling of stratosphere-troposphere coupling and future projections are discussed

The Mannheim Corona study: Life in Germany in a state of emergency : Report for March 20 to July 09, 2020

We are all affected by the corona pandemic and the measures taken by the federal government to decelerate the spread of the virus. At the University of Mannheim, we have developed a survey instrument over the past eight years which we can use to quickly examine the social implications of the pandemic in Germany. To the best of our knowledge, our study is the only one in Germany which can assess how the corona crisis is affecting people’s lives in Germany on a daily basis. That is why we consider it as our social duty to contribute to a better understanding of how the corona crisis is affecting the population and to inform the public as well as decision-makers in politics and business about current developments. The Mannheim Corona Study started on Friday, March 20. The study is carried out daily and reports on life in Germany during the corona crisis. We examine social and economic aspects (such as childcare, employment situations, and disposable income), the influence of political measures on social interactions, anxiety as well as public acceptance of the measures taken to contain the pandemic. Between 411 und 643 (on average 489) respondents take part in the study every day

The Mannheim Corona study: life in Germany in a state of emergency : report for March 20 to May 28, 2020, English translation of the original report (in German)

We are all affected by the corona pandemic and the measures taken by the federal government to decelerate the spread of the virus. At the University of Mannheim, we have developed a survey instrument over the past eight years which we can use to quickly examine the social implications of the pandemic in Germany. To the best of our knowledge, our study is the only one in Germany which can assess how the corona crisis is affecting people’s lives in Germany on a daily basis. That is why we consider it as our social duty to contribute to a better understanding of how the corona crisis is affecting the population and to inform the public as well as decision-makers in politics and business about current developments. The Mannheim Corona Study started on Friday, March 20. The study is carried out daily and reports on life in Germany during the corona crisis. We examine social and economic aspects (such as childcare, employment situations, and disposable income), the influence of political measures on social interactions, anxiety as well as public acceptance of the measures taken to contain the pan

The Mannheim Corona Study: Life in Germany in a state of emergency : Report for March 20 to June 30, 2020 ; English translation of the original report (in German)

We are all affected by the corona pandemic and the measures taken by the federal government to decelerate the spread of the virus. At the University of Mannheim, we have developed a survey instrument over the past eight years which we can use to quickly examine the social implications of the pandemic in Germany. To the best of our knowledge, our study is the only one in Germany which can assess how the corona crisis is affecting people’s lives in Germany on a daily basis. That is why we consider it as our social duty to contribute to a better understanding of how the corona crisis is affecting the population and to inform the public as well as decision-makers in politics and business about current developments

Evaluation of Three Commercial Interferon-γ Assays in a Bovine Tuberculosis Free Population

The interferon-γ assay has been used worldwide as an ancillary test for the diagnosis of bovine tuberculosis (bTB). This study aimed to describe, based on the bTB-free status in Switzerland, the difference of applying a more stringent cutoff point of 0.05 compared with 0.1 for bTB surveillance. Moreover, the effect of time between blood collection and stimulation, culture results, optical density values, and the influence of testing different breeds were evaluated. Blood samples from a total of 118 healthy cows older than 6 months were tested with three commercial interferon-gamma assays. To confirm the bTB-free status of the tested animals and to investigate potential cross-reactions with nontuberculous mycobacteria, pulmonary and abdominal lymph nodes in addition to ileal mucosa from each cattle were used for the detection of viable Mycobacteria spp. by specific culture. Significant differences regarding the proportion of false-positive results between the two Bovigam tests and between Bovigam 2G and ID Screen were found. Samples analyzed with Bovigam 2G were 2.5 [95% confidence interval (CI) 1.6–3.9] times more likely to yield a false-positive test result than samples analyzed with Bovigam TB. Similarly, the odds ratio (OR) for testing samples false-positive with ID Screen compared with Bovigam TB was 1.9 (95% CI 1.21–2.9). The OR for testing false-positive with ID Screen compared with Bovigam 2G was less to equally likely with an OR of 0.75 (95% CI 0.5–1.1). When using a cutoff of 0.05 instead of 0.1, the OR for a false-positive test result was 2.2 (95% CI 1.6–3.1). Samples tested after 6 h compared with a delayed stimulation time of 22–24 h were more likely to yield a false-positive test result with an OR of 3.9 (95% CI 2.7–5.6). In conclusion, applying a more stringent cutoff of 0.05 with the Bovigam 2G kit generates a questionable high number of false-positive results of one of three tested animals. Furthermore, specific breeds might show an increased risk to result false-positive in the Bovigam 2G and the ID Screen assays