Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title><jats:p>Two air‐sea interaction quantification methods are employed on synthetic aperture radar (SAR) scenes containing atmospheric‐turbulence signatures. Quantification performance is assessed on Obukhov length <jats:italic>L</jats:italic>, an atmospheric surface‐layer stability metric. The first method correlates spectral energy at specific turbulence‐spectrum wavelengths directly to <jats:italic>L</jats:italic>. Improved results are obtained from the second method, which relies on a machine‐learning algorithm trained on a wider array of SAR‐derived parameters. When applied on scenes containing convective signatures, the second method is able to predict approximately 80% of observed variance with respect to validation. Estimated wind speed provides the bulk of predictive power while parameters related to the kilometer‐scale distribution of spectral energy contribute to a significant reduction in prediction errors, enabling the methodology to be applied on a scene‐by‐scene basis. Differences between these physically based estimates and parameterized numerical models may guide the latter's improvement.</jats:p>

<jats:title>Abstract</jats:title><jats:p>The nature of the inner core (IC) temporal changes is of great importance in understanding the deep earth dynamics. The comment by Tian and Wen (2023, <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://doi.org/10.1029/2023gl103173">https://doi.org/10.1029/2023gl103173</jats:ext-link>) on our previous paper (Yang &amp; Song, 2022, <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://doi.org/10.1029/2022gl098393">https://doi.org/10.1029/2022gl098393</jats:ext-link>) provided a new observation as evidence against the IC rotation and proposed that our observations are instead from localized rapid changes at the IC surface. Here we argue the opposite to its conclusions. The comment misinterpreted our logic and many of our observations and arguments. Its one new waveform does not contradict with the “rotation” model. The original evidence for the “surface” model is demonstrated to be an artifact from station clock errors and instrument changes. Additionally, the surface model lacks a solid physical and quantitative basis to explain existing seismic evidence. We conclude that the rotation model is currently the best interpretation and the surface model is not a viable alternative.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Mesoscale convective systems (MCSs) contribute a majority of rainfall over tropical oceans. However, our understanding of the environmental controls on tropical oceanic MCS precipitation remains incomplete. Using 20‐year of satellite observations, reanalysis data, and MCS tracking, we found that MCSs initiating in a mesoscale environment with enhanced lower‐free‐tropospheric moisture, warmer middle troposphere, stronger low‐level ascent, and stronger deep‐layer (surface‐400 hPa) wind shear tend to produce more precipitation during their lifetimes. While most of these environmental factors are correlated with one another, the deep‐layer shear is not. A rapid pickup in MCS lifetime rainfall is found when the lower‐free‐tropospheric specific humidity exceeds 10 g kg<jats:sup>−1</jats:sup>. This nonlinearity is mostly dominated by the nonlinear increase in MCS area. On the other hand, both MCS area and rain rate increase quasi‐linearly with the deep‐layer shear. The increase in rain rate is related to the enhancement of heavy precipitating convective activity with deep‐layer shear.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Yang &amp; Song (2022, <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://doi.org/10.1029/2022GL098393">https://doi.org/10.1029/2022GL098393</jats:ext-link>) first claimed existence of Earth's inner core differential rotation based on the waveform similarity of two neighboring stations AAK and KZA across an earthquake doublet and then postulated a local velocity gradient at the top of the inner core based on the difference of PKiKP‐PKIKP differential times between the stations and inferred inner core differential rotation rate. In this comment, we collectively analyze the seismic data in the region and add the data of another nearby station HORS into analysis. HORS and KZA, located in an opposite direction away from AAK, consistently exhibit high waveform similarity. Collective analysis of seismic data demonstrates the invalidity of both their logic of claiming existence of inner core differential rotation and their postulation of “a local inner core gradient” to infer differential rotation. Localized and episodic inner core surface change provides a physically consistent explanation to the seismic data.</jats:p>

<jats:title>Abstract</jats:title><jats:p>In a previous study, we investigated whether reanalysis moist static energy (MSE) transport trends over the 1980 through 2018 period are consistent (a) with each other and (b) with the finding that these transport trends are downgradient, as found in climate models. Regarding point (a), our conclusion was that MSE transport trends were dependent on the reanalysis data set. However, Cox et al. (2023) correctly point out that the reanalysis dependence is reduced dramatically if a barotropic mass flux correction is applied at a monthly mean timescale prior to computing the MSE transport trends. In our reply below, we revisit point (b) after applying this correction. We find that even after the correction, reanalysis MSE transport trends are not downgradient nor poleward in the Northern Hemisphere extratropics. However, reanalysis does show a compensation between dry static and latent energy transport trends, which has been shown in climate models historically.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Despite small direct changes to radiative forcing, solar sunspot cycles are observed in climate records because of climate system amplification that primarily affects wind and precipitation belts. We present a proxy record resolving the dominant sub‐millennial periodicities across the entire Holocene in the Southern Westerly Winds (SWW), whose migrations are linked to ocean‐atmosphere heat and carbon exchange. We use X‐ray fluorescence core scanning to examine a rapidly accumulating sediment record (6 m/kyr) recovered from the Chilean margin, yielding unprecedented &lt;2‐year resolution for the Holocene. We show that variations in terrigenous inputs to the site are linked to precipitation, which is controlled by SWW latitudinal migrations. Superimposed on a long‐term decreasing trend throughout the Holocene, we detect significant centennial cycles in the terrestrial input consistent with solar periodicities. We then propose a mechanism by which southward (northward) SWW movement in response to increasing (decreasing) total solar irradiance cools (warms) Antarctic temperatures.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Cloud‐to‐ground lightning with minimal rainfall (“dry” lightning) is a major wildfire ignition source in the western United States (WUS). Although dry lightning is commonly defined as occurring with &lt;2.5 mm of daily‐accumulated precipitation, a rigorous quantification of precipitation amounts concurrent with lightning‐ignited wildfires (LIWs) is lacking. We combine wildfire, lightning and precipitation data sets to quantify these ignition precipitation amounts across ecoprovinces of the WUS. The median precipitation for all LIWs is 2.8 mm but varies with vegetation and fire characteristics. “Holdover” fires not detected until 2–5 days following ignition occur with significantly higher precipitation (5.1 mm) compared to fires detected promptly after ignition (2.5 mm), and with cooler and wetter environmental conditions. Further, there is substantial variation in precipitation associated with promptly‐detected (1.7–4.6 mm) and holdover (3.0–7.7 mm) fires across ecoprovinces. Consequently, the widely‐used 2.5 mm threshold does not fully capture lightning ignition risk and incorporating ecoprovince‐specific precipitation amounts would better inform WUS wildfire prediction and management.</jats:p>