地球科学最新文献

{"title":"Near-Earth Reconnection Contributing to Recovery Phase of Geomagnetic Storm","authors":"Terry Z. Liu, Vassilis Angelopoulos, Yukitoshi Nishimura, Yangyang Shen, Xueling Shi, Michael D. Hartinger","doi":"10.1029/2024gl112730","DOIUrl":"https://doi.org/10.1029/2024gl112730","url":null,"abstract":"Recent observations show very near-Earth reconnection (∼8–13R_E) could efficiently power the ring current during the main phase of geomagnetic storms, but whether the recovery phase might be contributed remains unclear. During the recovery phase of the May 2024 major geomagnetic storm, intense auroral brightening and geomagnetic disturbances were observed at midnight, indicative of particle injections. Current wedges observed by mid-latitude ground magnetometers around midnight suggest dipolarizing flux bundles (DFBs). The latitude of the auroral brightening was clearly lower than usual, suggesting near-Earth reconnection (NERX) was closer to Earth than during substorms (∼20–30R_E). GOES-18 at midnight detected magnetic field and plasma signatures consistent with DFBs, following an extremely thin current sheet likely compressed by strong upstream dynamic pressure. These results indicate NERX could have been close enough for resultant DFBs to penetrate geosynchronous orbit and contribute to the ring current during the recovery phase. This scenario deserves further examination in future.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"15 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atmospheric Dryness Dominates Afternoon Depression of Global Terrestrial Photosynthesis","authors":"Yue Liu, Josep Peñuelas, Alessandro Cescatti, Yongguang Zhang, Zhaoying Zhang","doi":"10.1029/2024gl110954","DOIUrl":"https://doi.org/10.1029/2024gl110954","url":null,"abstract":"Satellite observations reveal a widespread afternoon depression of photosynthesis globally. Utilizing satellite observations and eddy covariance tower-based observations worldwide, we investigated the impact of climate factors on the diurnal patterns of ecosystem gross primary production (GPP). Our analysis revealed that the increase in vapor pressure deficit (VPD) shifts the diurnal peak of GPP activity to earlier morning hours, particularly in drylands and areas with short vegetation. After disentangling the strong correlations among VPD, temperature, and soil moisture, we unraveled that VPD emerges as the dominant driver contributing to the widespread afternoon depression of photosynthesis in terrestrial vegetation globally. However, Earth System Models (ESMs) systematically underestimate the significant role of VPD in regulating photosynthesis. Eight out of 10 ESMs exhibited a clear afternoon increase in photosynthesis, which was attributed to temperature. Our findings emphasize the need to enhance the negative effects of VPD on diurnal photosynthesis in ESMs.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"28 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrodynamics of In-Stream Leaky Barriers for Natural Flood Management","authors":"Fawaz Alzabari, Catherine A. M. E. Wilson, Pablo Ouro","doi":"10.1029/2024wr038117","DOIUrl":"https://doi.org/10.1029/2024wr038117","url":null,"abstract":"Leaky barriers are in-stream natural flood management solutions designed for peak flow attenuation, whose effectiveness is dependent on their design. Flow around leaky barriers (LB) composed of three cylindrical logs were investigated using large-eddy simulation. The main LB configuration considered vertically aligned logs, with other layouts inclined at 15<span data-altimg=\"/cms/asset/9a6d17cf-81a3-4da0-ab97-23d565e42555/wrcr27598-math-0001.png\"></span><math altimg=\"urn:x-wiley:00431397:media:wrcr27598:wrcr27598-math-0001\" display=\"inline\" location=\"graphic/wrcr27598-math-0001.png\">\u0000<semantics>\u0000<mrow>\u0000<mo>°</mo>\u0000</mrow>\u0000${}^{circ}$</annotation>\u0000</semantics></math>, 30<span data-altimg=\"/cms/asset/d30c7e41-b587-41e1-bbda-4fe333c6b60d/wrcr27598-math-0002.png\"></span><math altimg=\"urn:x-wiley:00431397:media:wrcr27598:wrcr27598-math-0002\" display=\"inline\" location=\"graphic/wrcr27598-math-0002.png\">\u0000<semantics>\u0000<mrow>\u0000<mo>°</mo>\u0000</mrow>\u0000${}^{circ}$</annotation>\u0000</semantics></math>, and 45<span data-altimg=\"/cms/asset/62c6519f-affe-42aa-ba62-c05a3080f553/wrcr27598-math-0003.png\"></span><math altimg=\"urn:x-wiley:00431397:media:wrcr27598:wrcr27598-math-0003\" display=\"inline\" location=\"graphic/wrcr27598-math-0003.png\">\u0000<semantics>\u0000<mrow>\u0000<mo>°</mo>\u0000</mrow>\u0000${}^{circ}$</annotation>\u0000</semantics></math> in the upstream and downstream directions. Results reveal that the frontal projected blockage area of the LB leads to an increase in the upstream flow depth, with momentum being redirected toward the bottom gap, creating a primary wall-jet, whose peak velocity and coherence varied depending on LB design, however, attained a similar decay downstream. The porous LBs allowed for distinct internal flow paths that generated secondary jets, either diverting momentum upwards or downwards depending on the direction of the barrier inclination, impacting main flow features and turbulent characteristics. Turbulent kinetic energy and vertical Reynolds shear stress decreased when the barrier was inclined downstream. In the upstream inclination cases, these showed no significant variation, with magnitudes similar to those in the vertical configuration. Bed shear stress decreased with increasing barrier angle, reducing the risk of local scour and sediment mobilization. The vertical LB achieves the maximum backwater rise at the expense of promoting larger sediment bed mobilization. Structural loads on the logs vary with LB inclination, with drag forces decreasing as barrier angles increase. Hydrodynamic findings, evaluated through five design criteria, show that upstream-inclined designs, particularly with large barrier angles, exhibit improved relative performance compared to other designs.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"111 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep Nitrogen Fluxes and Sources Constrained by Arc Lava Phenocrysts","authors":"Michael R. Hudak, Peter H. Barry, David V. Bekaert, Stephen J. Turner, Michael W. Broadley, Kristina Walowski, Rebecca L. Tyne, Kan Li, Sune G. Nielsen, Joshua M. Curtice, Mark D. Kurz, Emily Cahoon, Paul Wallace, Michelle Muth, Alison M. Shaw","doi":"10.1029/2024gl111312","DOIUrl":"https://doi.org/10.1029/2024gl111312","url":null,"abstract":"Nitrogen (N) dominates Earth's atmosphere (78% N₂) but occurs in trace abundances in silicate minerals, making it a sensitive tracer of recycled surface materials into the mantle. The mechanisms controlling N transfer between terrestrial reservoirs remain uncertain because low N abundances in mineral-hosted fluid inclusions (FIs) are difficult to measure. Using new techniques, we analyzed N and He isotope compositions and abundances in olivine- and pyroxene-hosted FIs from arc volcanoes in Southern Chile, Cascadia, Central America, and the Southern Marianas. These measurements enable an estimate of the global flux of N outgassing from arcs (4.0 × 10¹⁰ mol/yr). This suggests that Earth is currently in a state of net N ingassing, with roughly half of subducted N returned to the mantle. Additionally, the N outgassing flux of individual arcs correlates with the thickness of subducting pelagic sediment, suggesting that N cycling in the modern solid Earth is largely controlled by sediment subduction.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"1 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climatic Controls on the Length and Shape of the World's Drainage Basins","authors":"Michael Bliss Singer, Stuart W. D. Grieve, Shiuan-An Chen, Katerina Michaelides","doi":"10.1029/2024gl111220","DOIUrl":"https://doi.org/10.1029/2024gl111220","url":null,"abstract":"Climate is thought to affect the structure and evolution of drainage basins, but it is not clear how climate impacts the power law scaling between channel length and drainage area. Since climate controls runoff, streamflow, and erosion regimes, we looked for dependency of drainage basin morphometrics on climate within a near-global data set. We show that increasingly arid regions have longer channels and narrower drainage basins, and power law scaling between channel length and basin area (Hack's Law) increases monotonically with aridity. We suggest these results arise due to downstream channel extension by rare large floods that erode channels into previously unchanneled terrain, yielding a morphometric signature in drylands that is preserved over long timescales due to a lack of subsequent topographic smoothing. This new understanding of drainage basin morphometrics on Earth may be used to inform interpretations of past climates on our planet and other solar system bodies.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"21 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microfluidics and Spectral Induced Polarization for Direct Observation and Petrophysical Modeling of Calcite Dissolution","authors":"F. Rembert, P. Leroy, A. Lassin, S. Roman","doi":"10.1029/2024gl111271","DOIUrl":"https://doi.org/10.1029/2024gl111271","url":null,"abstract":"We investigate how micro-geoelectrical monitoring is promising for studying microscale coupled processes since it facilitates the upscaling of pore-scale observations and enhances the petrophysical interpretation of the geoelectrical measurements. Microscale geophysics using microfluidics emerges and combines direct visualization of pore scale dynamics and chemical reactivity with geoelectrical monitoring. Calcite dissolution is a usual geochemical reaction considered as an analog of water–mineral interactions involved in the critical zone. We develop a numerical workflow combining image processing and geochemical simulation as inputs for the petrophysical modeling applied to a published data set of microscale induced polarization monitoring of calcite dissolution under partially saturated conditions. The successful interpretation provides the cation exchange capacity and specific surface area evolution; essential parameters in field-scale surveys.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"10 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-Frequency SuperDARN HF Radar Observations of the Ionospheric Response to the October 2023 Annular Solar Eclipse","authors":"E. G. Thomas, S. G. Shepherd, B. S. R. Kunduri, D. R. Themens","doi":"10.1029/2024gl112450","DOIUrl":"https://doi.org/10.1029/2024gl112450","url":null,"abstract":"An annular solar eclipse was visible on 14 October 2023 from 15:00–21:00 UT as its path traveled across North, Central, and South America. In this letter, we present the first multi-frequency Super Dual Auroral Radar Network (SuperDARN) observations of the bottomside ionospheric response to a solar eclipse using a novel experimental mode designed for the October 2023 annular eclipse. We compare our results from the mid-latitude Christmas Valley East radar with measurements of the vertical electron density profile from the nearby Boulder Digisonde, finding the changes in 1- and 2-hop ground scatter skip distance are well correlated with the &lt;span data-altimg=\"/cms/asset/240192fa-e88f-4ea7-b42d-4b107948997e/grl68540-math-0001.png\"&gt;&lt;/span&gt;&lt;mjx-container ctxtmenu_counter=\"45\" ctxtmenu_oldtabindex=\"1\" jax=\"CHTML\" role=\"application\" sre-explorer- style=\"font-size: 103%; position: relative;\" tabindex=\"0\"&gt;&lt;mjx-math aria-hidden=\"true\" location=\"graphic/grl68540-math-0001.png\"&gt;&lt;mjx-semantics&gt;&lt;mjx-mrow&gt;&lt;mjx-msub data-semantic-children=\"0,1\" data-semantic- data-semantic-role=\"latinletter\" data-semantic-speech=\"upper F 2\" data-semantic-type=\"subscript\"&gt;&lt;mjx-mi data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"italic\" data-semantic- data-semantic-parent=\"2\" data-semantic-role=\"latinletter\" data-semantic-type=\"identifier\"&gt;&lt;mjx-c&gt;&lt;/mjx-c&gt;&lt;/mjx-mi&gt;&lt;mjx-script style=\"vertical-align: -0.15em; margin-left: -0.106em;\"&gt;&lt;mjx-mn data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"normal\" data-semantic- data-semantic-parent=\"2\" data-semantic-role=\"integer\" data-semantic-type=\"number\" size=\"s\"&gt;&lt;mjx-c&gt;&lt;/mjx-c&gt;&lt;/mjx-mn&gt;&lt;/mjx-script&gt;&lt;/mjx-msub&gt;&lt;/mjx-mrow&gt;&lt;/mjx-semantics&gt;&lt;/mjx-math&gt;&lt;mjx-assistive-mml display=\"inline\" unselectable=\"on\"&gt;&lt;math altimg=\"urn:x-wiley:00948276:media:grl68540:grl68540-math-0001\" display=\"inline\" location=\"graphic/grl68540-math-0001.png\" xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;semantics&gt;&lt;mrow&gt;&lt;msub data-semantic-=\"\" data-semantic-children=\"0,1\" data-semantic-role=\"latinletter\" data-semantic-speech=\"upper F 2\" data-semantic-type=\"subscript\"&gt;&lt;mi data-semantic-=\"\" data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"italic\" data-semantic-parent=\"2\" data-semantic-role=\"latinletter\" data-semantic-type=\"identifier\"&gt;F&lt;/mi&gt;&lt;mn data-semantic-=\"\" data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"normal\" data-semantic-parent=\"2\" data-semantic-role=\"integer\" data-semantic-type=\"number\"&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;${F}_{2}$&lt;/annotation&gt;&lt;/semantics&gt;&lt;/math&gt;&lt;/mjx-assistive-mml&gt;&lt;/mjx-container&gt;-layer density response, which lags the peak obscuration by &lt;span data-altimg=\"/cms/asset/e575c9d2-22b0-4fc1-837a-fd3043ebfb14/grl68540-math-0002.png\"&gt;&lt;/span&gt;&lt;mjx-container ctxtmenu_counter=\"46\" ctxtmenu_oldtabindex=\"1\" jax=\"CHTML\" role=\"application\" sre-explorer- style=\"font-size: 103%; position: relative;\" tabindex=\"0\"&gt;&lt;mjx-math aria-hidden=\"true\" location=\"graphic/grl68540-math-0002.png\"&gt;&lt;mjx-semantics&gt;&lt;mjx-mrow&gt;&lt;mjx-mo data-s","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"4 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ground-Truth Validation of T2 Estimates From Steady-State Surface NMR","authors":"Matthew P. Griffiths, Denys Grombacher, Seyyed Reza Mashhadi, Jakob Juul Larsen","doi":"10.1029/2024gl112094","DOIUrl":"https://doi.org/10.1029/2024gl112094","url":null,"abstract":"Steady-state sequences are a new protocol for surface nuclear magnetic resonance (NMR), that can yield high quality data in a short time. In addition to faster acquisition, steady-state surface NMR purports to measure the transverse relaxation time &lt;span data-altimg=\"/cms/asset/fff6b442-b85a-49a4-8710-47f7b6a15c39/grl68642-math-0002.png\"&gt;&lt;/span&gt;&lt;mjx-container ctxtmenu_counter=\"115\" ctxtmenu_oldtabindex=\"1\" jax=\"CHTML\" role=\"application\" sre-explorer- style=\"font-size: 103%; position: relative;\" tabindex=\"0\"&gt;&lt;mjx-math aria-hidden=\"true\" location=\"graphic/grl68642-math-0002.png\"&gt;&lt;mjx-semantics&gt;&lt;mjx-mrow&gt;&lt;mjx-msub data-semantic-children=\"0,1\" data-semantic- data-semantic-role=\"latinletter\" data-semantic-speech=\"upper T 2\" data-semantic-type=\"subscript\"&gt;&lt;mjx-mi data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"italic\" data-semantic- data-semantic-parent=\"2\" data-semantic-role=\"latinletter\" data-semantic-type=\"identifier\"&gt;&lt;mjx-c&gt;&lt;/mjx-c&gt;&lt;/mjx-mi&gt;&lt;mjx-script style=\"vertical-align: -0.15em; margin-left: -0.12em;\"&gt;&lt;mjx-mn data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"normal\" data-semantic- data-semantic-parent=\"2\" data-semantic-role=\"integer\" data-semantic-type=\"number\" size=\"s\"&gt;&lt;mjx-c&gt;&lt;/mjx-c&gt;&lt;/mjx-mn&gt;&lt;/mjx-script&gt;&lt;/mjx-msub&gt;&lt;/mjx-mrow&gt;&lt;/mjx-semantics&gt;&lt;/mjx-math&gt;&lt;mjx-assistive-mml display=\"inline\" unselectable=\"on\"&gt;&lt;math altimg=\"urn:x-wiley:00948276:media:grl68642:grl68642-math-0002\" display=\"inline\" location=\"graphic/grl68642-math-0002.png\" xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;semantics&gt;&lt;mrow&gt;&lt;msub data-semantic-=\"\" data-semantic-children=\"0,1\" data-semantic-role=\"latinletter\" data-semantic-speech=\"upper T 2\" data-semantic-type=\"subscript\"&gt;&lt;mi data-semantic-=\"\" data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"italic\" data-semantic-parent=\"2\" data-semantic-role=\"latinletter\" data-semantic-type=\"identifier\"&gt;T&lt;/mi&gt;&lt;mn data-semantic-=\"\" data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"normal\" data-semantic-parent=\"2\" data-semantic-role=\"integer\" data-semantic-type=\"number\"&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;${T}_{2}$&lt;/annotation&gt;&lt;/semantics&gt;&lt;/math&gt;&lt;/mjx-assistive-mml&gt;&lt;/mjx-container&gt;, which is correlated with hydrogeological parameters like pore-size. This is in contrast to the effective transverse relaxation time &lt;span data-altimg=\"/cms/asset/0e16b890-d693-481a-aa5e-6ac1975a8827/grl68642-math-0003.png\"&gt;&lt;/span&gt;&lt;mjx-container ctxtmenu_counter=\"116\" ctxtmenu_oldtabindex=\"1\" jax=\"CHTML\" role=\"application\" sre-explorer- style=\"font-size: 103%; position: relative;\" tabindex=\"0\"&gt;&lt;mjx-math aria-hidden=\"true\" location=\"graphic/grl68642-math-0003.png\"&gt;&lt;mjx-semantics&gt;&lt;mjx-mrow&gt;&lt;mjx-msubsup data-semantic-children=\"0,1,2\" data-semantic-collapsed=\"(4 (3 0 1) 2)\" data-semantic- data-semantic-role=\"latinletter\" data-semantic-speech=\"upper T 2 Superscript asterisk\" data-semantic-type=\"subsup\"&gt;&lt;mjx-mi data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"italic\" data-semantic- data-semantic-parent=\"4\" dat","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"88 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Large-Scale Water Transfer Projects on the Ecological Flow and Its Value of Rivers in the Water-Receiving Area: Case Study of the Han River-to-Wei River Water Transfer Project","authors":"Zihan Guo, Ni Wang, Yin Li, Zheng Liu","doi":"10.1007/s11053-024-10441-2","DOIUrl":"https://doi.org/10.1007/s11053-024-10441-2","url":null,"abstract":"<p>The Han River-to-Wei River Water Transfer (HWWT) Project not only brings evident economic benefits to the water-receiving areas but it also generates ecological flow value (EFV) by indirectly supplementing river flows. However, the EFV resulting from water transfer is often overlooked due to its indirect nature, and traditional methods tend to overestimate it due to a lack of consideration of value growth thresholds. This paper proposes a research system to address these issues, scientifically quantifying the EFV increment after water transfer. Taking the Xianyang–Lintong river segment in the water-receiving area of the HWWT as an example, we present a holistic approach guided by river ecological issues to determine the suitable ecological flow (SEF) for the river, using it as the growth threshold for EFV. Subsequently, based on water resource allocation, changes in river flow and their relative percentages to SEF (SEF satisfaction) before and after water transfer were analyzed. Finally, an ecological value model based on SEF was employed to estimate changes in river EFV. The results indicate that the distribution of SEF varied throughout the year, correlating with the monthly water requirements of key ecological functions in the river. After water transfer, SEF satisfaction notably improved across all months except excessively wet periods. In drier years, river EFV increased significantly, reaching 31.31% at 95% flow frequency. The water purification, hydrologic cycle, sediment transport and biological diversity, contributed the most to EFV. This study provided new insights and methodologies for assessing EFV increments and formulating ecological compensation standards in the water-receiving areas after water transfer.</p>","PeriodicalId":54284,"journal":{"name":"Natural Resources Research","volume":"118 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142809751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Greenland Ice Cores Reveal a South-To-North Difference in Holocene Thermal Maximum Timings","authors":"Kaden C. Martin, Christo Buizert, Ed Brook, Olivia L. Williams, Jon S. Edwards, Ben Riddell-Young, T. J. Fudge, Farhana Mederbel, Ross Beaudette, Jeff Severinghaus, Ikumi Oyabu, Kenji Kawamura, Marie Kirk, Iben Koldtoft, J. P. Steffensen, Thomas Blunier","doi":"10.1029/2024gl111405","DOIUrl":"https://doi.org/10.1029/2024gl111405","url":null,"abstract":"Holocene temperature evolution remains poorly understood. Proxies in the early and mid-Holocene suggest a Holocene Thermal Maximum (HTM) where temperatures exceed the pre-industrial, whereas climate models generally simulate monotonic warming. This discrepancy may reflect proxy seasonality biases or errors in climate model internal feedbacks or dynamics. Using seasonally unbiased ice core reconstructions at NEEM, NGRIP, and Greenland Ice Sheet Project 2, we identify a Greenland HTM of ∼2°C above pre-industrial, in agreement with other Northern Hemisphere proxy reconstructions. The firn-based reconstructions are verified through borehole thermometry, producing a multi-core, multi-proxy reconstruction of Greenland climate from the last glacial to pre-industrial. HTM timing across Greenland is heterogenous, occurring earlier at high elevations. Total air content measurements suggest a temperature contribution from elevation changes; regional oceanographic conditions, a weakened polar lapse rate, or variable near-surface inversions may also be important sensitivities. Our reconstructions support climate simulations with dynamic Holocene vegetation, highlighting the importance of vegetation feedbacks.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"118 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}