EUREC⁴A observations from the SAFIRE ATR42 aircraft

As part of the EUREC4A (Elucidating the role of cloud-circulation coupling in climate) field campaign, which took place in January and February 2020 over the western tropical Atlantic near Barbados, the French SAFIRE ATR42 research aircraft conducted 19 flights in the lower troposphere. Each flight followed a common flight pattern that sampled the atmosphere around the cloud-base level, at different heights of the subcloud layer, near the sea surface and in the lower free troposphere. The aircraft's payload included a backscatter lidar and a Doppler cloud radar that were both horizontally oriented, a Doppler cloud radar looking upward, microphysical probes, a cavity ring-down spectrometer for water isotopes, a multiwavelength radiometer, a visible camera and multiple meteorological sensors, including fast rate sensors for turbulence measurements. With this instrumentation, the ATR characterized the macrophysical and microphysical properties of trade-wind clouds together with their thermodynamical, turbulent and radiative environment. This paper presents the airborne operations, the flight segmentation, the instrumentation, the data processing and the EUREC4A datasets produced from the ATR measurements. It shows that the ATR measurements of humidity, wind and cloud-base cloud fraction measured with different techniques and samplings are internally consistent, that meteorological measurements are consistent with estimates from dropsondes launched from an overflying aircraft (HALO), and that water isotopic measurements are well correlated with data from the Barbados Cloud Observatory. This consistency demonstrates the robustness of the ATR measurements of humidity, wind, cloud-base cloud fraction and water isotopic composition during EUREC4A. It also confirms that through their repeated flight patterns, the ATR and HALO measurements provided a statistically consistent sampling of trade-wind clouds and of their environment. The ATR datasets are freely available at the locations specified in Table 11.

PIRATARIA FLUVIAL NA SERRA DO ESPIGÃO: DIVISÓRIA DOS RIOS URUGUAI E IGUAÇU-AMÉRICA DO SUL

Stream capture is a drainage rearrangement where a flux transference occurs and a contribution area from a drainage basin is incorporated to another. It is about expanding a river system over another one, caused by erosive advantage earned by conditioning factors such as lithostructure, pluviometric regime, topographic gradient, and base level. However, in the southern region of Brazil, a rare dynamic of stream piracy was verified between the drainage basins of the Uruguay and Iguazu (Paraná) rivers. Stream captures were observed along the Serra of Espigão, part of the drainage divide between the two basins. Still, it was not possible to identify which basin was advancing over the other. This paper investigated the occurrence of stream captures, identifying which factors are responsible for this atypical stream dynamic. Mapping the stream captures by remote sensing and further validation with fieldwork, it was verified that there is stream piracy for both sides of the drainage divide. Still, it is not clear which basin is behaving more aggressively. A longitudinal profile analysis of the channels involved in the stream captures showed a local control in the drainage network. This control sets a local base level to the Iguazu river tributaries. It indicates the lithostructural limit between two different geological units: the Serra Geral group basalts and the Botucatu formation sandstones. Depending on the geographic location of this base level, channels that drain to the Iguazu (Paraná) river become more aggressive or less aggressive than the ones that drain to the Uruguai basin, and so they capture or lose area for the other basin. Therefore, it is impossible to identify a river basin that exclusively pirates the other, prevailing, in this case, a mutual competition between the Uruguai and Iguazu (Paraná) rivers basins. This fact highlights the significance of local base levels to promote stream capture processes.

Climate Change Action – What are the gaps in capacity building which is making implementation fail ?

In the recently concluded Conference of Parties (COP26) Glasgow, UK Summit 2021 the key issues focused on the 1.5 degrees Paris Agreement implementation, NDCs updating by countries, adaptation, lack of financial machinery uniformly amidst countries, mitigation and loss and damage, science based targets and nature based targets. Another mentioning was on mobilization and capacity building, which is the main attribute for climate change action failing in implementation. As per the UNFCCC capacity building portal, priority areas by activities for capacity building to channelize for getting tangible and actionable implementation at base level and to forefront include the following pointers as notings to know, upscale, upgrade and implement

A Self-Modeling Network Model Addressing Controlled Adaptive Mental Models for Analysis and Support Processes

In this paper, a self-modeling mental network model is presented for cognitive analysis and support processes for a human. These cognitive analysis and support processes are modeled by internal mental models. At the base level, the model is able to perform the analysis and support processes based on these internal mental models. To obtain adaptation of these internal mental models, a first-order self-model is included in the network model. In addition, to obtain control of this adaptation, a second-order self-model is included. This makes the network model a second-order self-modeling network model. The adaptive network model is illustrated for a number of realistic scenarios for a supported car driver.

Societal discontent will increase in Bahrain

Significance Although large-scale social protest in Bahrain has been cowed over the ten years since the ‘Arab uprisings’, small-scale demonstrations recur, reflecting a base level of discontent. Mobilising issues include economic pressures, limited political representation (especially of the Shia majority) and, most recently, ties with Israel. Impacts Despite protests, Israel’s and Bahrain’s respective ambassadors will keep up high-profile activity and statements. The authorities are likely to exaggerate the role of Iranian interference in order to deepen the Sunni-Shia divide. If Riyadh manages to extricate itself from the Yemen war, that could partly reduce the pressure on Manama.

Bedrock gorge incision via anthropogenic meander cutoff

Bedrock river-gorge incision represents a fundamental landscape-shaping process, but a dearth of observational data at >10 yr timescales impedes understanding of gorge formation. I quantify 102 yr rates and processes of gorge incision using historical records, field observations, and topographic and image analysis of a human-caused bedrock meander cutoff along the North Fork Fortymile River in Alaska (USA). Miners cut off the meander in 1900 CE, abruptly lowering local base level by 6 m and forcing narrowing and steepening of the channel across a knickpoint that rapidly incised upstream. Tectonic quiescence, consistent rock erosivity, and low millennial erosion rates provide ideal boundary conditions for this 102 yr gorge-formation experiment. Initial fast knickpoint propagation (23 m/yr; 1900–1903 CE) slowed (4 m/yr; 1903–1981 CE) to diffusion (1981–2019 CE) as knickpoint slope decreased, yielding an ~350-m-long, 6-m-deep gorge within the pre–1900 CE channel. Today, diffusion dominates incision of a 500-m-long knickzone upstream of the gorge, where sediment transport likely limits ongoing adjustments to the anthropogenic cutoff. Results elucidate channel width, slope, discharge, and sediment dynamics consistent with a gradual transition from detachment- to transport-limited incision in fluvial adjustment to local base-level lowering.

Morphologic signatures of autogenic waterfalls: A case study in the San Gabriel Mountains, California

Waterfalls can form due to external perturbation of river base level, lithologic heterogeneity, and internal feedbacks (i.e., autogenic dynamics). While waterfalls formed by lithologic heterogeneity and external perturbation are well documented, there is a lack of criteria with which to identify autogenic waterfalls, thereby limiting the ability to assess the influence of autogenic waterfalls on landscape evolution. We propose that autogenic waterfalls evolve from bedrock bedforms known as cyclic steps and therefore form as a series of steps with spacing and height set primarily by channel slope. We identified 360 waterfalls split between a transient and steady-state portion of the San Gabriel Mountains in California, USA. Our results show that while waterfalls have different spatial distributions in the transient and steady-state landscapes, waterfalls in both landscapes tend to form at slopes >3%, coinciding with the onset of Froude supercritical flow, and the waterfall height to spacing ratio in both landscapes increases with slope, consistent with cyclic step theory and flume experiments. We suggest that in unglaciated mountain ranges with relatively uniform rock strength, individual waterfalls are predominately autogenic in origin, while the spatial distribution of waterfalls may be set by external perturbations.

Late Holocene Sedimentation on the Southern Kāpiti Coast

<p>The Kāpiti Coast is a broad low lying coastal plain on the western coast of New Zealand’s North Island. The coastal plain has formed over the last 6500 years through rapid progradation of coastal sediment, developing a distinct cuspate foreland. With numerous coastal communities across the low coastal plain, recent coastal erosion of the southern coastal plain combined with forecast sea level rise has drawn attention to coastal hazards. However, understanding these hazards has been hampered by a lack of information on the Holocene tectonic and sedimentary development of the coastal plain. This study focuses on the southern portion of the Kāpiti Coast using a geological approach to document coastal outcrops and drillcores. Using detailed sedimentological analysis including description, grainsize, composition and shape, in addition to observation of the modern environment, a detailed facies scheme and depositional model for the southern Kāpiti Coast are produced. Combining the interpreted depositional environments and age control provided by C14, OSL and well-dated pumice deposition, progressive coastal progradation and a transition from marine to terrestrial environments is reconstructed for the southern Kāpiti Coast. Records from this study reveal rapid sedimentation, at rates of up to 12.6m/1000 years within this southern limb, slowing dramatically with coastal retreat beginning within the last 400 years. Recognising the vertical offset of the beach/dune boundary as a marker of past sea level recorded in the cores and outcrops, a 1m uplift is recognised at the southernmost point of the coastal plain. In addition to constraining the penultimate movement of the Ohariu Fault, it contrasts with the tectonic stability of the central part of the coastal plain and subsidence further north. Such insight into vertical base level change across the coastal plain has implications for future coastal hazard identification.</p>

Late Holocene Sedimentation on the Southern Kāpiti Coast

<p>The Kāpiti Coast is a broad low lying coastal plain on the western coast of New Zealand’s North Island. The coastal plain has formed over the last 6500 years through rapid progradation of coastal sediment, developing a distinct cuspate foreland. With numerous coastal communities across the low coastal plain, recent coastal erosion of the southern coastal plain combined with forecast sea level rise has drawn attention to coastal hazards. However, understanding these hazards has been hampered by a lack of information on the Holocene tectonic and sedimentary development of the coastal plain. This study focuses on the southern portion of the Kāpiti Coast using a geological approach to document coastal outcrops and drillcores. Using detailed sedimentological analysis including description, grainsize, composition and shape, in addition to observation of the modern environment, a detailed facies scheme and depositional model for the southern Kāpiti Coast are produced. Combining the interpreted depositional environments and age control provided by C14, OSL and well-dated pumice deposition, progressive coastal progradation and a transition from marine to terrestrial environments is reconstructed for the southern Kāpiti Coast. Records from this study reveal rapid sedimentation, at rates of up to 12.6m/1000 years within this southern limb, slowing dramatically with coastal retreat beginning within the last 400 years. Recognising the vertical offset of the beach/dune boundary as a marker of past sea level recorded in the cores and outcrops, a 1m uplift is recognised at the southernmost point of the coastal plain. In addition to constraining the penultimate movement of the Ohariu Fault, it contrasts with the tectonic stability of the central part of the coastal plain and subsidence further north. Such insight into vertical base level change across the coastal plain has implications for future coastal hazard identification.</p>

Characterization and simulation of metagenomic nanopore sequencing data with Meta-NanoSim

Nanopore sequencing is crucial to metagenomic studies as its kilobase-long reads can contribute to resolving genomic structural differences among microbes. However, platform-specific challenges, including high base-call error rate, non-uniform read lengths, and the presence of chimeric artifacts, necessitate specifically designed analytical tools. Here, we present Meta-NanoSim, a fast and versatile utility that characterizes and simulates the unique properties of nanopore metagenomic reads. Further, Meta-NanoSim improves upon state-of-the-art methods on microbial abundance estimation through a base-level quantification algorithm. We demonstrate that Meta-NanoSim simulated data can facilitate the development of metagenomic algorithms and guide experimental design through a metagenomic assembly benchmarking task.