As sea ice decreases, navigation in the Arctic is becoming more feasible, and new routes are likely to emerge. However, the impact of these potential routes on sea ice remains uncertain. In this study, we compare the regional impacts of two major Arctic routes: the Northern Sea Route (NSR) and the Transpolar Sea Route (TSR). Using the Community Earth System Model (CESM2), we simulate black carbon (BC) emissions until 2050 along these routes and assess their effects on Arctic sea ice (ASI). We focus on regional changes in net shortwave (SW) radiation, sea ice extent, and surface temperature. While our study does not account for other pollutants that could counteract BC effects, our results reveal significant differences in ASI's response between routes. The TSR, in particular, exerts a stronger and more widespread influence on ASI than the NSR across all seasons, especially in increasing net SW radiation over the ice.

Detection of induced polarisation (IP) effects in airborne electromagnetic (AEM) measurements does not yet have an established methodology. This contribution develops a Bayesian approach to the IP-detectability problem using decoupled transdimensional layered models, and applies an approach novel to geophysics whereby transdimensional proposals are used within the embarrassingly parallelisable and robust static Sequential Monte Carlo (SMC) class of algorithms for the simultaneous inference of parameters and models. Henceforth referring to this algorithm as Reversible Jump Sequential Monte Carlo (RJSMC), the statistical methodological contributions to the algorithm account for adaptivity considerations for multiple models and proposal types, especially surrounding particle impoverishment in unlikely models. Methodological contributions to solid Earth geophysics include the decoupled model approach and proposal of a statistic that use posterior model odds for IP detectability. A case study is included investigating detectability of IP effects in AEM data at a broad scale.

Land reclamations influence the morphodynamic evolution of estuaries and tidal basins, because an altered planform changes tidal dynamics and associated residual sediment transport. The morphodynamic response time to land reclamation is long, impacting the system for decades to centuries. Other human interventions (e.g., deepening of fairways or port construction) will add more morphodynamic adaptation timescales. Our understanding of the cumulative effects of anthropogenic interference with estuaries is limited because observations usually do not cover the complete morphological adaptation period. We aim to assess the impact of land reclamation works and other human interventions on an estuarine system by means of digital reconstructions of historical morphologies of the Ems Estuary over the past 500 years. Our analysis demonstrates that the intertidal-subtidal area ratio altered due to land reclamation works and that the ratio partly restored after land reclamation ended. The land reclamation works have led to the degeneration of an ebb and flood channel system, transitioning the estuary from a multichannel to a single-channel system. We infer that the 20th-century intensification of channel dredging and re-alignment works accelerated rather than caused this development. The centennial-scale observations show that the Ems estuary evolution corresponds to a land reclamation response following tidal asymmetry-based stability theory as it moves towards a new equilibrium configuration with modified tidal flats and channels. Considering the long history of land reclamation in the Ems Estuary, it provides an analogy for expected developments in comparable tidal systems where land reclamations were recently carried out

Bifurcations in river-dominated deltas are the main actors in the routing of water and sediments throughout the fluvial network. In spite of previous acknowledgments of their importance, we still lack a comprehensive framework on how bifurcation geometry affects the water and sediment partitioning. To investigate this issue, we firstly combine previously calibrated 2D hydrodynamic simulations on the Wax Lake Delta with a Lagrangian particle-tracking model, quantifying the partitioning of water and sediments with different buoyancy at five bifurcations and their correlations with differences in channel width, branching angle and inlet bed elevation between the downstream branches. We compare the sediment partitioning at bifurcations with available field data to validate our methodology. We then employ the same modeling tools on a simplified geometry, whose geometrical and hydraulic features resemble those of the bifurcations in the Wax Lake Delta. Model results show that the branching angle does not affect the partitioning of water and sediments. The combined effect of asymmetries in the channel width and inlet bed elevation is captured by a simple linear formula that accurately estimates the partitioning of water at bifurcations returned by the 2D calibrated hydrodynamic simulations. Our results also highlight the key role played by transverse gradients in the bathymetry of the upstream channel in determining the partitioning of sediments, suggesting that deeper portions of the cross-section of the upstream channel can cause a proportionately larger fraction of sediments with larger Rouse number to be routed towards the corresponding bifurcate.

A document by Joanne L Wood. Click on the document to view its contents.

Coastal fast ice provides a protective barrier to continental land ice and an important biological habitat. Antarctic fast ice extent has been well quantified using satellite remote sensing but spaceborne measurement of sea ice thickness remains challenging, especially near the coast. Here, we present the first ICESat-2 laser altimeter fast ice freeboard measurements and thickness retrievals in Antarctica. In north Terra Nova Bay, ICESat-2 measured in situ validated fast ice freeboard with high accuracy, detected higher freeboard of thicker Ice Shelf Water-influenced fast ice with a sub-ice platelet layer beneath, and distinguished smooth-thermodynamic and rough-dynamic fast ice compositions. Estimates of sub-ice platelet layer thickness obtained by comparing ICESat-2 ice thicknesses with projected fast ice thicknesses and snow depths agreed with prior electromagnetic induction surveys. ICESat-2 has significant potential for large-scale assessment of fast ice thickness and for identifying regions of glacial meltwater outflow, provided snow depth is constrained.

Deep long-period earthquakes (DLPs) are often detected near volcanoes from the crust down to the upper mantle. Exhibiting coincidence with some volcanic eruptions, DLPs are recognized as potential precursors to volcanic activities yet their detection remains challenging. Meanwhile, their relation to volcanic activities and specific source mechanisms remains uncertain. In this study, we first classify earthquakes into volcano-tectonic (VTs) and long-period (LPs) earthquakes at 10 Alaskan volcanoes by frequency index (FI). The consistent differences in FI distribution between LPs and VTs across volcanoes suggest it can be leveraged for automatic classification. Presence of both VTs and DLPs in some regions suggests frequency content differences mainly arise from source effect. We then analyze 12 years of continuous waveforms by template matching and detect 20,979 DLPs. No repeating DLPs are identified below the depth of 10 km except ~1% of DLPs at Spurr Volcano, indicating source processes of DLPs at Alaskan volcanoes are primarily non-repetitive. Detections of mantle DLPs and positive correlations between DLPs and volume change rate in the magma reservoir support the involvement of magmatic activities in some DLP sources, though there is limited correlation in DLP depth distribution with magmatic water content and kinematic parameters of plate motion. In addition, only ~12% of DLP bursts occur simultaneously with VT bursts, suggesting most DLP rate anomalies are not directly linked to shallow volcanic unrests. Finally, since on average only ~26% of DLP rate anomalies coincide with eruption episodes, it is still challenging to foretell eruptions uniquely based on DLP occurrences.

Evaluating our understanding of smoke from wild and prescribed fires can benefit from downwind measurements that include both inert tracers to test production and transport and reactive species to test chemical mechanisms. We characterized smoke from fires in coniferous forest fuels for >1000 hours over two summers (2017 and 2018) at our Montana surface station and found a narrow range of key properties. DPM/DCO was 0.1070 +/- 0.0278 or about half the age-independent ratios obtained at free troposphere elevations. The average absorption Angstrom exponent across both years was 1.84, or about half the values available for very fresh smoke. Brown carbon (BrC) was persistent (~50% of the absorption at 401 nm) in both years, despite differences in smoke age and transport. DBC/DCO doubled from 2017 to 2018, but the average across two years was within 30% of recent airborne measurements. Switching from a 1.0 to a 2.5 micron cutoff increased the mass scattering and mass absorption coefficients suggesting super micron particles impact the optical properties of moderately aged smoke. O3 was elevated ~6 ppb on average over a full diurnal period when wildfire smoke was present, and smoke-associated O3 increases were highest (~9 pbb) at night suggesting substantial upwind production. NOx was almost entirely local in origin. NO2 spurred high rates of NO3 production in the presence of wildfire smoke (up to 2.44 ppb/hr) and potentially at least one nighttime BrC formation event that could have impacted next-day photochemistry.

In this study, we show that non-thermal collisions can play a significant role in shaping Europa's exospheric structure. Collisions between radiolytically produced O2 and the O produced via electron impact dissociation of O2 play a significant role in affecting the exospheric structure and escape rates. Specifically, O+O2 collisions lead to the production of a non-thermal O2 population, and increase the O2 escape while decreasing the O escape. These collisions are dependent on three specific physical parameters: (1) the density of O2 , (2) the electron impact dissociation rate of O2 , and (3) the O+O2 collision cross section. We demonstrate here that O+O2 collisions affect Europa's atmosphere even in the lowest limits considered. Thus, to more accurately determine the influence O+O2 collisions have on Europa's atmosphere in preparation for the forthcoming spacecraft missions, Europa Clipper and the JUpiter ICy moons Explorer (JUICE), these physical parameters need to be better constrained.

Streamflow depletion is traditionally defined as the instantaneous change in the volumetric rate of aquifer–stream exchange after a finite period of continuous groundwater extraction. In the present study an alternative metric of streamflow depletion was considered: cumulative stream depletion (CSD), which described the total volumetric reduction in flow from an aquifer to a stream resulting from continuous groundwater extraction over a finite period. A novel analytical solution for the prediction of CSD was derived, based upon an existing solution that accounted for streambed conductance and partial stream penetration. Separately, a novel numerical solution for the prediction of CSD was derived, based on the derivation of an adjoint state solution. The accuracy of the two new solutions was demonstrated through benchmarking against existing analytical solutions and perturbation-based results, respectively. The derivation of the loading term used in the adjoint state solution identified three parameters of relevance to CSD prediction. First is streambed hydraulic conductivity and thickness, both of which contribute to a lumped parameterization of streambed conductance. Second is aquifer specific yield, which controls the rate at which hydraulic perturbations propagate through an aquifer. The computational advantage of the adjoint state approach was highlighted, in which a single numerical model run can be used to predict CSD resulting from any potential groundwater extraction location. The reduction in computation time achieved was proportional to the number of potential extraction well locations. Where the number of locations is large, reductions in computation times of nearly 100 % can be achieved.

This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models and providing forecasters with information about model characteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models acharacteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models acharacteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models acharacteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models acharacteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models acharacteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models acharacteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models acharacteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models acharacteristics.This paper discusses the performance of the National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) forecast model in predicting rainfall over the Korean Peninsula caused by tropical cyclones (TCs). TCs forecasted in GFS were characterized by overestimated intensity and well-organized inner core structure during landfall, and the associated TC-induced rainfall forecast errors were examined from two perspectives: TC tracks and TC-environmental interactions. The results provide implications in three ways. First, the predicted TC track is biased to the west, bringing it closer to the Korean Peninsula landmass and contributing to an overall increase in overland precipitation. Second, the strongly simulated TC during landfall predicted rainfall only in a narrow radius around the TC center. Third, the TCs were characterized by weak upper-level TC outflow due to the well-developed TC structure, which could increase the inertial stability of the TC center during jet interaction, leading to an underestimated precipitation in outer core region of the storm. These results suggest specific sources of error in the forecast of TC precipitation over the Korean Peninsula, which can contribute to improving numerical models a

We construct a linear model of microseism power as a function of sea-ice concentration and ocean-wave activity based on seismic data for a station located on northern Ellesmere Island. We find the increase in microseism power over the last 32 years reflects the long-term loss of sea ice and increasing ocean-wave activity in the Arctic Ocean likely associated with climate change. We assess the model performance and its coefficients to determine a representative region over which sea-ice concentration and ocean-wave activity most directly influence the microseism power at the single station. We conclude that seismic data can potentially help refine in-situ observation and improve the spatiotemporal monitoring of multiyear sea ice as it changes due to climate forcing.

Spaceborne lidar offers unique advantages for improving global estimates of fine particulate matter PM2.5, traditionally limited by critical data gaps in the vertical dimension. Here, we present a new method to retrieve PM2.5 relying on ensembles on aerosol extinction available within the GEOS Aerosol Data Assimilation. This study uses 1064-nm backscatter lidar data from the NASA Cloud-Aerosol Transport System (CATS) and model priors from the GEOS model. First, we developed a 1-D ensemble-based variational technique (1-D EnsVar) to perform vertically-resolved retrievals of speciated aerosol extinction and surface PM2.5. Next, we evaluated the performance of 1-D EnsVar retrievals of PM2.5 and extinction through an independent validation using measurements from spaceborne, airborne, and ground-based platforms. This approach overcomes traditional limitations by leveraging the strengths of complementary vertical aerosol information from CATS and GEOS to better resolve speciated aerosol optical properties and mass. With the advantage of active remote sensing, this approach is fully capable of performing aerosol retrievals during both daytime and nighttime scenes. Given the unique capability of CATS to process vertical profile data in near real-time, this work demonstrates the powerful utility of spaceborne lidar for improving air quality forecasting. While this pilot study is not yet performed within a cycling data assimilation system, the algorithm developed here can easily be integrated in such systems. Results presented may be useful in other applications as well, including the validation of aerosol transport models, improving passive satellite retrievals of PM2.5, and developing data assimilation techniques for future lidar platforms.

The meteorology-dependent multiscale behavior of snow depth over the Tibetan Plateau was examined via moderate-resolution datasets. By analyzing spatial variance and power spectra at specific scales (5 km, 10 km, 20 km, and 50 km) over 28 intraseasonal continuous snow cover regions, key meteorological factors affecting snow depth across different seasons were identified based upon the Kullback-Leibler distance. In spring and winter, the homogeneous power spectra highlight the significant roles of precipitation, atmospheric moisture, and temperature in snow accumulation and melt processes. Summer exhibits the highest snow depth spatial variance driven by radiation and wind dynamics. Autumn with the lowest spatial heterogeneity underscores the impact of windspeed on snow distribution through sublimation and redistribution. The alignment between spatial variance maps and spectra across these scales implies the future downscaling or upscaling without substantial loss of spatial information. These findings are essential for improving snow cover modeling and forecasting, particularly in the context of climate change, as well as for effective water resource management and climate adaptation strategies in this strategically important plateau.

On 10 May 2024, a powerful coronal mass ejection arrived at Earth at 17:05UT and caused a major geomagnetic storm. With the minimum SYM-H excursion of-497 nT (5-min data), this storm is the largest geomagnetic disturbance since March 1989, and can be categorized as a superstorm. In this work, by using a set of ground-based and space-borne instruments, we study the electrodynamic and ionospheric response to the May 2024 storm at middle and low latitudes. During the main phase of the storm, we observed a major super-fountain effect associated with an extreme ionospheric uplift. During the maximum disturbance at ~23:30UT on 10 May, the amplitude within the equatorial ionization anomaly crests reached 170 TECU in GNSS data and 130 TECU in the Swarm A data (i.e., above ~430 km of altitude). Moreover, DMSP showed the occurrence of a 2-peak density structure at ~850 km of altitude with 500-600% density increase, which is an indication of an extremely strong upward ExB drift and strong meridional thermospheric winds circulating during this storm. While the observed dayside ionospheric effects are quite significant, they are less intense than those that occurred during the 15 July 2000 and 29-30 October 2003 superstorms. During the recovery phase, a severe negative storm was observed in the American sector, driven by very strong ExB drift and composition changes. The negative deviation occurred during the recovery phase of the May 2024 storm is one of the strongest ever observed since the beginning of the GPS/GNSS VTEC era. Key-points:-during the main phase of the storm, an extreme dayside ionospheric uplift occurred driven by the PPEF and by storm-time thermospheric winds-the recovery phase was marked by significant drops in the ionospheric plasma density driven by downward ExB drift-compared to previous superstorms, the May 2024 event caused moderately intense positive ionospheric storm and the strongest negative storm

A document by Jicheng Gu . Click on the document to view its contents.

A document by Xiaochen Zhao. Click on the document to view its contents.

Harkamal Walia, Presenting Author1