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Abstract Atmospheric heat transport (AHT) is an important piece of our climate system but has primarily been studied at monthly or longer time scales. We introduce a new method for calculating zonal-mean meridional AHT using instantaneous atmospheric fields. When time averaged, our calculations closely reproduce the climatological AHT used elsewhere in the literature to understand AHT and its trends on long time scales. In the extratropics, AHT convergence and atmospheric heating are strongly temporally correlated suggesting that AHT drives the vast majority of zonal-mean atmospheric temperature variability. Our AHT methodology separates AHT into two components (eddies and the mean meridional circulation) which we find are negatively correlated throughout most of the mid- to high latitudes. This negative correlation reduces the variance in the total AHT compared to eddy AHT. Last, we find that the temporal distribution of the total AHT at any given latitude is approximately symmetric. 

This paper describes how cryptographic provenance can serve as a proactive, partial solution for mitigating misinformation. Drawing on literature from human-centered computing and usable security, journalism, and cryptography, we discuss the advantages and limitations of both content-based and technical approaches to the problem of online misinformation. We argue cryptographic provenance systems designed for usability can reduce the spread of misinformation by surfacing provenance information and making this information salient and acceptable to information consumers. We highlight challenges and open research areas related to designing usable cryptographic provenance systems, specifically concerning two key stakeholder groups: journalists and news consumers. 

This paper describes how cryptographic provenance can serve as a proactive, partial solution for mitigating misinformation. Drawing on literature from human-centered computing and usable security, journalism, and cryptography, we discuss the advantages and limitations of both content-based and technical approaches to the problem of online misinformation. We argue cryptographic provenance systems designed for usability can reduce the spread of misinformation by surfacing provenance information and making this information salient and acceptable to information consumers. We highlight challenges and open research areas related to designing usable cryptographic provenance systems, specifically concerning two key stakeholder groups: journalists and news consumers. 

Abstract This study synthesizes the results of 13 high-resolution simulations of deep convective updrafts forming over idealized terrain using environments observed during the RELAMPAGO and CACTI field projects. Using composite soundings from multiple observed cases, and variations upon them, we explore the sensitivity of updraft properties (e.g., size, buoyancy, and vertical pressure gradient forces) to influences of environmental relative humidity, wind shear, and mesoscale orographic forcing that support or suppress deep convection initiation (CI). Emphasis is placed on differentiating physical processes affecting the development of updrafts (e.g., entrainment-driven dilution of updrafts) in environments typifying observed successful and null (i.e., no CI despite affirmative operational forecasts) CI events. Thermally induced mesoscale orographic lift favors the production of deep updrafts originating from ∼1- to 2-km-wide boundary layer thermals. Simulations without terrain forcing required much larger (∼5-km-wide) thermals to yield precipitating convection. CI outcome was quite sensitive to environmental relative humidity; updrafts with increased buoyancy, depth, and intensity thrived in otherwise inhospitable environments by simply increasing the free-tropospheric relative humidity. This implicates the entrainment of free-tropospheric air into updrafts as a prominent governor of CI, consistent with previous studies. Sensitivity of CI to the environmental wind is manifested by 1) low-level flow affecting the strength and depth of mesoscale convergence along the terrain, and 2) clouds encountering updraft-suppressing pressure gradient forces while interacting with vertical wind shear in the free troposphere. Among the ensemble of thermals occurring in each simulation, the widest deep updrafts in each simulation were the most sensitive to environmental influences.