The onset of the spring phytoplankton bloom in the coastal North Sea supports the Disturbance Recovery Hypothesis

The spring phytoplankton bloom is a key event in temperate and polar seas, yet the mechanisms that trigger it remain under debate. Some hypotheses claim that the spring bloom onset occurs when light is no longer limiting, allowing phytoplankton division rates to surpass a critical threshold. In contrast, the Disturbance Recovery Hypothesis (DRH) proposes that the onset responds to an imbalance between phytoplankton growth and loss processes, allowing phytoplankton biomass to start accumulating, and this can occur even when light is still limiting. Although many studies have shown that the DRH explains the spring bloom onset in oceanic waters, it is less certain whether and how it also applies to coastal areas. To address this question at a coastal location in the Scottish North Sea, we combined 21 years (1997–2017) of weekly in situ data with meteorological information. The onset of phytoplankton biomass accumulation occurred around the same date each year, 16 ± 11 days (mean ± SD) after the winter solstice, when light limitation for growth was strongest. Also, negative and positive biomass accumulation rates (r) occurred respectively before and after the winter solstice at similar light levels. The seasonal change from negative to positive r was mainly driven by the rate of change in light availability rather than light itself. Our results support the validity of the DRH for the studied coastal region and suggest its applicability to other coastal areas.

Transition Periods in the Udmurt Folk Calendar and Their Spirits

The article investigates the perceptions of time based on lunar and solar cycles, seasonal changes in nature, and the rhythm of agricultural work. The key events of the annual cycle in the Udmurt calendar are winter (vozhodyr/uyvozho) and summer (invozhodyr) solstices. The winter solstice period (vozhodyr, lit: transition time, crossroads / crossroads of time, the time of vozho, the time of evil spirits) and the time of the summer solstice are described. The winter period is dedicated to the winter Christmas period from January 7th to January 19th, and includes the following components: gatherings with songs and games, divination, dressing up, and mumming. The article characterises the most important events, such as mumming and masking, as well as beliefs, rituals and prohibitions connected with the spirits of the transition time. The summer solstice is connected with the image of the Mother/Foremother Invozho (In(‘)vozho-mumy), that descends from heaven to earth at that time of year. During summer solstice period the Udmurt particularly venerated heavenly powers and held calendar festivals (gershyd, gerber, gyron-bydton) in order to glorify blooming nature and peasant farmer’s labour.

Covid Conversations 4: Stacy Klein

The ecology of the rural setting in which Double Edge Theatre lives and works is as integral to its artistic work as to its principles of social justice, and these qualities mark the ensemble’s singular profile not only in the United States but also increasingly on the world theatre map. Stacy Klein co-founded the company in Boston in 1982 as a women’s theatre with a defined feminist programme. In 1997, Double Edge moved its work space to a farm that Klein had bought in Ashfield, Massachusetts, commuting from there back to Boston to show its productions. Within a few years, Klein and her collaborators were acutely aware of their separation from the local community, which necessitated a change of perspective to encompass personal and creative engagement with local people and to develop audiences within the area, while not losing sight of their international links. Carlos Uriona, formerly a popular-theatre activist from Argentina, had joined Double Edge and facilitated the local immersion that ultimately became its lifeline, most visibly during the Covid-19 pandemic, as Klein here observes. Klein, who had been a student of Rena Mirecka in Poland (starting in 1976), has maintained her friendship and professional relations with this founding member of the Teatr Laboratorium led by Jerzy Grotowski, inviting Mirecka to run wokshops at the Double Edge Farm. Collaboration with Gardzienice (also from the Grotowski crucible) through the Consortium of Theatre Practices (1999–2001) extended Klein’s Polish connections. She expanded her research on community cultures in Eastern and Central Europe and developed these experiences in her probing, distinctly imaginative explorations of theatre-making, while taking a new approach to participatory theatre-making in Ashfield. Her highly visual and sensual compositions are driven by her sense of the fantastic, no more strikingly so than in Klein’s Summers Spectacles, which are performed outdoors, in concert with the Farm’s natural environment – fields, trees, water, birds, animals, and heaven’s firmament. Double Edge’s profound commitment in the past decade to what it now terms ‘living culture’ and ‘art justice’ has taken root in multiracial collaborations, primarily with the indigenous peoples of Western Massachusetts. This Conversation took place on the winter solstice, 21 December 2020, a date that Maria Shevtsova, Editor of NTQ, had chosen symbolically. It was transcribed by Kunsang Kelden and edited by Shevtsova. Many thanks are extended to Travis Coe of Double Edge for assembling with such loving care the photographs requested.

About vozho, the Spirit of Transition Time and Holiness among Udmurt and Komi

This article concentrates on one very central character in Udmurt mythology. It is a character typical of the transitional time around the solstices, an ambiguous and liminal time, which requires particular caution from the humans to protect themselves from dangerous interference from the world beyond. This character, whose name, vozho, appears in the Udmurt name of these periods, vozho-dyr, the time of vozho for the winter solstice and invozho, heaven-vozho for the summer solstice, is also a water spirit. I reflect also on other water spirits and on their peculiarities. This analysis leads me to reflect on the origin and the ramifications of the concept behind vozho with its linguistic correlations, the way it is articulated and how it sheds light on the concept of holy in the Permic languages and for the Permians, Udmurt and Komi. This leads me to reflect on the correlations between liminality and holiness, the liminal places and spaces and their value, and the particular characters in the mummery festivities that characterise this transitional time and which are connected both to the spirits of the other world and to the dead ancestors, who are among the main providers of well-being in the Udmurt world.

Analysis of the BDGIM Performance in BDS Single Point Positioning

The broadcast ionospheric model is mainly used to correct the ionospheric delay error for single-frequency users. Since the BeiDou global ionospheric delay correction model (BDGIM) is a novel broadcast ionospheric model for BDS-3, its performance was analyzed through single point positioning (SPP) in this study. Twenty-two stations simultaneously receiving B1C, B2a, B1I and B3I signals were selected from the International GNSS Service (IGS) and the International GNSS Monitoring and Assessment System (iGMAS) tracking networks for the SPP experiments. The differential code bias (DCB) parameters were used to correct the hardware delays in the signals of B1C and B2a. The results showed that the BDGIM performs the best in high-latitude areas, and can effectively improve the positioning accuracy compared with the Klobuchar model. The average 3D positioning accuracy of the four civil signals can reach 3.58 m in high-latitude areas. The positioning accuracies with the BDGIM in the northern hemisphere are better than those in the southern hemisphere, and the global average 3D positioning accuracy of the four civil signals is 4.60 m. The performance of the BDGIM also shows some seasonal differences. The BDGIM performs better than the Klobuchar model on the days of spring equinox and winter solstice, while the opposite is true on the days of summer solstice and autumn equinox. On the day of winter solstice, the average 3D accuracies with the BDGIM on the signals of B1C, B2a, B1I and B3I are 4.13 m, 5.32 m, 4.40 m and 4.49 m, respectively. Although the SPP accuracies are to some extent affected by the geomagnetic storm, the BDGIM generally performs better and are more resistant to the geomagnetic storm than the Klobuchar model.

Meteorology and climatology of historical weekly wind and solar power resource droughts over western North America in ERA5

Wind and solar electricity generation is projected to expand substantially over the next several decades due both to rapid cost declines as well as regulation designed to achieve climate targets. With increasing reliance on wind and solar generation, future energy systems may be vulnerable to previously underappreciated synoptic-scale variations characterized by low wind and/or surface solar radiation. Here we use western North America as a case study region to investigate the historical meteorology of weekly-scale “droughts” in potential wind power, potential solar power and their compound occurrence. We also investigate the covariability between wind and solar droughts with potential stresses on energy demand due to temperature deviations away human comfort levels. We find that wind power drought weeks tend to occur in late summer and are characterized by a mid-level atmospheric ridge centered over British Columbia and high sea level pressure on the lee side of the Rockies. Solar power drought weeks tend to occur near winter solstice when the seasonal minimum in incoming solar radiation co-occurs with the tendency for mid-level troughs and low pressure systems over the U.S. southwest. Compound wind and solar power drought weeks consist of the aforementioned synoptic pattern associated with wind droughts occurring near winter solstice when the solar resource is at its seasonal minimum. We find that wind drought weeks are associated with high solar power (and vice versa) both seasonally and in terms of synoptic meteorology, which supports the notion that wind and solar power generation can play complementary roles in a diversified energy portfolio at synoptic spatiotemporal scales over western North America.

Ecological Feedback Effects Affecting Arctic Biodiversity in Response to Glacial Melt

A changing Arctic The Arctic is a geographic region situated in the northernmost part of earth. It marks the latitude above which the sun does not set on the summer solstice and does not rise on the winter solstice. The Arctic is considered an area within the Arctic Circle that draws an imaginary line that …

The Impacts of Climate Variability on the Wind Erosion Potentials in the Western Region of Makran Coastal Plain, Iran

Coastal plains are prone to various degrees of wind erosion due to their characteristics. This study aimed to investigate the effect of climatic factors in the western region of Makran coastal plain in a southeastern region of Iran on the wind erosion potential. The study period was 1993-2018. First, the data related to wind velocities, relative humidity and precipitation, and the granulometric data of plain surface sediments were obtained. Then, the wind erosion threshold velocity in humid air conditions was determined. Finally, the Mann-Kendall test was applied to analyze the probability of wind erosion and its temporal variability. The results indicated that the wind erosion threshold, in terms of humidity changes, varied from 7.21 to 12.31 meters per second during the study period. The highest probability of wind erosion was in February, March, and April, with 24.69%, 21.51%, and 20.41%, respectively. The lowest probability of wind erosion was in October, November, and September with 4.00%, 4.12%, and 6.00%, respectively. Finally, the erosion trend analysis indicated that wind erosion was a temporal phenomenon that increased significantly in January (winter solstice) and July (summer solstice). These months were characterized by an increase in the wind blowing at speed above the threshold. Otherwise, the months were not different from other months of the year in terms of precipitation or the number of dry days. Therefore, wind erosion is expected to maximize in the early winter and the early summer.