First observational record of Siberian weasel Mustela sibirica Pallas, 1773 in Dhorpatan Hunting Reserve, Nepal

Siberian weasel Mustela sibirica Pallas, 1773 is one of the least known small carnivores in Nepal. Only a few authenticated localities of Siberian weasel are known to exist in Nepal. In March 2021, a week-long field trip to the Dhorpatan Valley documented the first confirmed record of Siberian weasel in Dhorpatan Hunting Reserve in Western Nepal.

A spatial ecological analysis of the reintroduction of the Eurasian beaver

As ‘nature’s ecological engineers’ beavers can intentionally modify their habitat by building structures. This ability can have wider environmental benefits, including benefits for other habitats and species. However, this ability to modify the environment can sometimes be destructive, bringing beavers into conflict with land managers and others. To understand the complex connections between Eurasian beavers and ecosystems, this study was based on R language analysis tool that used land cover types, river network distribution and observational record studies of Eurasian beavers to find their most preferred environmental resources and potential habitats. The results found that reintroduced Eurasian beavers have a high potential for settlement and dispersal in restored areas.

Deciphering Solar Magnetic Activity: 140 Years of the ‘Extended Solar Cycle’ – Mapping the Hale Cycle

We investigate the occurrence of the “extended solar cycle” (ESC) as it occurs in a host of observational data spanning 140 years. Investigating coronal, chromospheric, photospheric, and interior diagnostics, we develop a consistent picture of solar activity migration linked to the 22-year Hale (magnetic) cycle using superposed epoch analysis (SEA) and previously identified Hale cycle termination events as the key time for the SEA. Our analysis shows that the ESC and Hale cycle, as highlighted by the terminator-keyed SEA, is strongly recurrent throughout the entire observational record studied, some 140 years. Applying the same SEA method to the sunspot record confirms that Maunder’s butterfly pattern is a subset of the underlying Hale cycle, strongly suggesting that the production of sunspots is not the fundamental feature of the Hale cycle, but the ESC is. The ESC (and Hale cycle) pattern highlights the importance of $55^{\circ }$ 55 ∘ latitude in the evolution, and possible production, of solar magnetism.

Paleohydrological context for recent floods and droughts in the Fraser River Basin, British Columbia, Canada

The recent intensification of floods and droughts in the Fraser River Basin of British Columbia has had profound cultural, ecological, and economic impacts that are expected to be exacerbated further by anthropogenic climate change. In part due to short instrumental runoff records, the long-term stationarity of hydroclimatic extremes in this major North American watershed remains poorly understood, highlighting the need to use high-resolution paleoenvironmental proxies to inform on past streamflow. Here we use a network of tree-ring proxy records to develop 11 subbasin-scale, complementary flood- and drought-season reconstructions, the first of their kind. The reconstructions explicitly target management-relevant flood and drought seasons within each basin, and are examined in tandem to provide an expanded assessment of extreme events across the Fraser River Basin with immediate implications for water management. We find that past high flood-season flows have been of greater magnitude and occurred in more consecutive years than during the observational record alone. Early 20th century low flows in the drought season were especially severe in both duration and magnitude in some subbasins relative to recent dry periods. Our Fraser subbasin-scale reconstructions provide long-term benchmarks for the natural flood and drought variability prior to anthropogenic forcing. These reconstructions demonstrate that the instrumental streamflow records upon which current management is based likely underestimate the full natural magnitude, duration, and frequency of extreme seasonal flows in the Fraser River Basin, as well as the potential severity of future anthropogenically forced events.

Deciphering Solar Magnetic Activity: 140 Years Of The ‘Extended Solar Cycle’ – Mapping the Hale Cycle

We investigate the occurrence of the ``extended solar cycle'' (ESC) as it occurs in a host observational data spanning 140 years. Investigating coronal, chromospheric, photospheric and interior diagnostics we develop a consistent picture of solar activity migration linked to the 22-year Hale (magnetic) cycle using superposed epoch analysis (SEA) using previously identified Hale cycle termination events as the key time for the SEA. Our analysis shows that the ESC and Hale cycle, as highlighted by the terminator-keyed SEA, is strongly recurrent throughout the entire observational record studied, some 140 years. Applying the same SEA method to the sunspot record confirms that Maunder's butterfly pattern is a subset of the underlying Hale cycle, strongly suggesting that the production of sunspots is not the fundamental feature of the Hale cycle, but the ESC is. The ESC (and Hale cycle) pattern highlights the importance of 55\degree\ latitude in the evolution, and possible production, of solar magnetism.

Reassessing Ireland's Hottest Temperature Record

The highest currently recognised air temperature (33.3 °C) ever recorded in the Republic of Ireland was logged at Kilkenny Castle in 1887. The original observational record however no longer exists. Given that Ireland is now the only country in Europe to have a national heat record set in the 19th century, a reassessment of the verity of this record is both timely and valuable. The present analysis undertakes a fundamental reassessment of the plausibility of the 1887 temperature record using methods similar to those used to assess various weather extremes under WMO auspices over recent years. Specifically, we undertake an inter-station reassessment using sparse available records and make recourse to the new and improved 20CRv3 sparse-input reanalysis product. Neither surrounding available stations nor the reanalysis offer substantive support for the Kilkenny record of 33.3 °C being correct. Moreover, recent data rescue efforts have uncovered several earlier extreme values, one of which exceeds the Kilkenny value (33.5 °C on 16th July 1876 recorded at the Phoenix Park). However, the sparsity of early observational networks, a distinct lack of synoptic support from 20CRv3 for many of the extreme heat values, and the fact that these measurements were obtained using non-standard exposures leads us to conclude that there is grossly insufficient evidence to support any of these 19th Century extremes as robust national heat record candidates. Data from the early 20th Century onwards benefits from a denser network of stations undertaking measurements in a more standardised manner, many under the direct auspices of Met Éireann and its predecessors, adhering to WMO guidance and protocols. This enables more robust cross-checking of records. We argue that the Met Éireann recognised 20th Century heat record from Boora in 1976 verifies as the most plausible robust national temperature record based upon the synoptic situation and comparisons with nearby neighbouring stations. This measurement of 32.5 °C thus likely constitutes the highest reliably recorded temperature measurement in the Republic of Ireland. Ultimately, the formal decision on any reassessment and reassignment of the national record rests with the national meteorological service, Met Éireann.

Seasonality modulates wind-driven mixing pathways in a large lake

Turbulent mixing controls the vertical transfer of heat, gases and nutrients in stratified water bodies, shaping their response to environmental forcing. Nevertheless, due to technical limitations, the redistribution of wind-derived energy fuelling turbulence within stratified lakes has only been mapped over short (sub-annual) timescales. Here we present a year-round observational record of energy fluxes in the large Lake Geneva. Contrary to the standing view, we show that the benthic layers are the main locus for turbulent mixing only during winter. Instead, most turbulent mixing occurs in the water-column interior during the stratified summer season, when the co-occurrence of thermal stability and lighter winds weakens near-sediment currents. Since stratified conditions are becoming more prevalent –possibly reducing turbulent fluxes in deep benthic environments–, these results contribute to the ongoing efforts to anticipate the effects of climate change on freshwater quality and ecosystem services in large lakes.

Persistence and variability of Earth’s inter-hemispheric albedo symmetry in 19 years of CERES EBAF observations

Despite the unequal partitioning of land and aerosol sources between the hemispheres, Earth’s albedo is observed to be persistently symmetric about the equator. This symmetry is determined by the compensation of clouds to the clear-sky albedo. Here, the variability of this inter-hemispheric albedo symmetry is explored by decomposing observed radiative fluxes in the CERES EBAF satellite data record into components reflected by the atmosphere, clouds, and the surface. We find that the degree of inter-hemispheric albedo symmetry has not changed significantly throughout the observational record. The variability of the inter-hemispheric difference in reflected solar radiation (asymmetry) is strongly determined by tropical and subtropical cloud cover, particularly those related to non-neutral phases of the El Niño-Southern Oscillation (ENSO). As the ENSO is the most significant source of interannual variability in reflected radiation on a global scale, this underscores the inter-hemispheric albedo symmetry as a robust feature of Earth’s current annual mean climate. Comparing this feature in observations with simulations from coupled models reveals that the degree of modeled albedo symmetry is mostly dependent on biases in reflected radiation in the midlatitudes, and that models that overestimate its variability the most have larger biases in reflected radiation in the tropics. The degree of model albedo symmetry is improved when driven with historical sea surface temperatures, indicating that the degree of symmetry in Earth’s albedo is dependent on the representation of cloud responses to coupled ocean-atmosphere processes.

Multidecadal Analysis of an Engineered River System Reveals Challenges for Model-Based Design of Human Interventions

Hydraulic models were used in practice to predict the effect of human intervention during extreme conditions. However, the accuracy of such predictions remains untested. In this study, we compare a simulated trend in water levels covering a twenty-year period of large-scale human intervention with a thirty-year observational record. The results show that the observed water levels display a linearly decreasing trend attributed to channel bed erosion. A deviation from this trend, which would be an indication of the effect of human intervention, was not observed. We propose that the most likely explanation for this is that any effect observable at lower discharge is hidden in the uncertainty of the rating curve. Given the inherent uncertainties associated with making predictions about a changing system for conditions with a low period of return, we argue that model uncertainty should be considered in intervention design.