There exist two large (~1000 km) dome-like structures rising from the base of the mantle in global tomographic models that exhibit low seismic wave-speeds, known as “Large Low Velocity Provinces” (LLVPs). The LLVP beneath Africa is also known as Tuzo, while the LLVP beneath the Pacific Ocean is known as Jason – two early pioneers of plate tectonics and plume theory (Wilson and Morgan, respectively). The source of these anomalously low wave-speeds is debated as both thermal and chemical heterogeneities can lower wave-speeds. These heterogeneities, however, lead to dynamically different modes of convection, where the former results in buoyant LLVPs and the latter relatively dense LLVPs. Recent studies that include dynamical modeling, Stoneley modes, and body tide constraints, are beginning to converge towards a picture where dense, chemical heterogeneities may be stored in the deepest part of the LLVPs. Many of these analyses, however, have not treated each LLVP distinctly. Considering the interdisciplinary focus of this session, we combine the unique geodetic observation of Earth’s solid body tide with methods that combine Backus-Gilbert estimation with theoretical advances in adjoint methodology, to constrain the density of each LLVP separately. This process results in the enhancement of the combined data sensitivity to a chosen region (e.g., one LLVP) while diminishing the combined data sensitivity elsewhere. We discuss the results in the context of geochemical observations unique to Tuzo and Jason and implications for the dynamics of mantle evolution.

The inversion of the focal mechanism (FM) provides an estimate of the fault plane orientation and the direction of slip of an earthquake, giving us valuable insights into the mechanical processes involved in the occurrence of an earthquake. Given the recorded first motion polarities at a set of stations, there are always two possible planes that explain the observations equally well. This so-called fault plane ambiguity is often resolved based on expert judgment, considering knowledge about the local geology and the locations of fore- or aftershocks. With seismic networks and inversion algorithms continuously improving, we can obtain large numbers of inverted FMs, even for events of low magnitudes, which calls for an automated procedure to resolve the fault plane ambiguity. Using an enhanced epidemic-type aftershock sequence (ETAS) model, we jointly invert the plausibility of each of the two fault planes specified by the inverted FM and a magnitude-dependent shape of elliptic aftershock triggering oriented in the direction of strike, based on FMs of M≥2.5 earthquakes in Southern California since 1981. Results of this inversion do not only provide an approach to resolve fault plane ambiguity but also an ETAS model which goes beyond the common assumption of spatially isotropic triggering. Preliminary results suggest that aftershocks occur predominantly in strike direction relative to their triggering events and that the shape of the ellipse describing this behaviour is magnitude-independent. We conduct pseudo-prospective forecasting experiments to compare our novel anisotropic ETAS model based on fault plane plausibility estimates to the current state-of-the-art isotropic ETAS model to test the utility of understanding source anisotropy for earthquake forecasting.

The northeastern China cold vortex (NCCV) has an important influence on the regional rainstroms over East Asia. Using the National Centers for Environmental Prediction Final (FNL) reanalysis dataset and the Global Precipitation Measurement product, an improved objective algorithm for identifying heavy precipitation NCCV (HPCV) events from 2001 to 2019 was designed. The climatological features of 208 HPCV events were investigated. The number of HPCV events showed an upward linear trend, with the highest frequency of occurrence in summer. The most active region of HPCVs was in the Northeast China Plain of 40–55° N. Most HPCV events lasted 2–5 days and had radii ranging from 250 to 1000 km. About 79% of the HPCV events was initiated (dissipated) in the definition region (35–60° N, 115–145° E). The initial position was close to the western boundary of the definition region, and the final position was mainly in the first and the fourth quadrants. The HPCV events that moved into the study region had a longer duration than those initiating in the region. The monthly variation of the strongest precipitation in the HPCV events showed a bimodal pattern, with two peaks in June and October. The location of the strongest precipitation was mostly concentrated within 2000 km southeast of the HPCV systems and it had a strong positive correlation with the center of HPCV events.

Technology has greatly promoted ecohydrological model development, but runoff generation and confluence simulations have fallen behind in ecohydrological model development due to limited innovations. To fully understand ecohydrological processes and accurately describe the coupling between ecological and hydrological processes, a distributed ecohydrological model was constructed by integrating multisource information into MYEH. We mainly describe runoff generation and convergence modules. Based on the improved HBV model and degree-3 hour factor method, runoff generation and snow routines were constructed for semiarid grassland basins. In view of meandering and variable steppe river channels and steep hydrological relief characteristics, a confluence module was constructed; the 1-km bend radius equivalent concept was innovatively proposed to unify river channel bend degrees. The daily runoff simulation validation results obtained using two datasets were R2=0.947 and 0.932, NSE=0.945 and 0.905, and KGE=0.029 and 0.261. In the 3-hour flood simulations, the MYEH model could better restore small long-distance water flows than the confluence method that did not consider actual river lengths or bend energy losses; the MYEH model more accurately simulated the flood peak arrival time than the confluence method that did not consider overflow. The simulated mainstream overflow frequency increased by 0.84/10 years, and significant interaction periods of 10 to 13 years occurred with local precipitation, ecological status and global climate change. An approximately 2-year lag occurred in the global climate change response. This study helps us further understand and reveal the ecohydrological processes of steppe rivers in semiarid regions.

Seismic hazard assessment in active fault zones can benefit of strain rate measurements derived from geodetic data. Producing a continuous strain rate map from discrete data is an inverse problem traditionally tackled with standard interpolation schemes. Most algorithms require user-defined regression parameters that determine the smoothness of the recovered velocity field, and the amplitude of its spatial derivatives. This may lead to biases in the strain rates estimation which could eventually impact studies on earthquake hazard. Here we propose a transdimensional Bayesian method to estimate surface strain rates from GNSS velocities. We parameterize the velocity field with a variable number of Delaunay triangles, and use a reversible jump Monte-Carlo Markov Chain algorithm to sample the probability distribution of surface velocities and spatial derivatives. The solution is a complete probability distribution function for each component of the strain rate field. We conduct synthetic tests and compare our approach to a standard b-spline interpolation scheme. Our method is more resilient to data errors and uneven data distribution, while providing uncertainties associated with recovered velocities and strain rates. We apply our method to the Southwestern US, an extensively studied and monitored area and infer probabilistic strain rates along the main fault systems, including the San Andreas one, from the inversion of interseismic GNSS velocities. Our approach provide a full description of the strain rate tensor for zones where strain rates are highly contrasted, with no need to manually tune user-defined parameters. We recover sharp velocity gradients, without systematic artifacts.

In karst environments, typically characterized by peculiar hydrogeological features and high heterogeneity and anisotropy, the connection between the recharge areas and the springs is often not straightforward. Rapid infiltration underground, and the resulting network of karst conduits, are frequently at the origin of a lack of correspondence among topographic divides and underground watersheds. As a consequence, in many karst areas there is still much work to do to fully understand the groundwater flow, with the only “underground truth” often being provided by cave data. In this contribution we start from general considerations about the difficulty in comprehending hydrogeology in karst, and use them to analyze one of the most important karst areas of southern Italy, the Alburni Massif in Campania (Italy). In detail, we present data about the main karst features at the surface (dolines, endorheic basins, etc.), the most important cave systems (reaching maximum depth of about 450 m below the surface), and the main basal springs coming out at the massif borders. Integration of the different sources of data allows to hypothesize the main directions of groundwater flows, and to perform the first attempts in correlating recharge and discharge data, but such hypothesis then often prove to be wrong by data from cave and diving explorations.

Widely employed to model collisionless plasma phenomena occurring naturally in Earth’s magnetic environment, throughout the heliosphere, and in laboratory fusion devices, the Vlasov equation self-consistently describes the fundamental kinetic dynamics of plasma particles as they are accelerated through phase space via electric and magnetic forces. The Fast Plasma Investigation (FPI) onboard NASA’s Magnetospheric Multiscale (MMS) four-spacecraft mission sufficiently resolves the seven spatial, temporal, and velocity-space dimensions of phase space needed to directly observe terms in the Vlasov equation, as recently demonstrated by Shuster et al. [2021] in the context of electron-scale current layers at the reconnecting magnetopause. These results motivate novel exploration of the types of distinct kinetic signatures in ∂fe/∂t, v⋅∇fe, and (F/me)⋅∇vfe which are associated with the magnetic reconnection process, where F = −e(E + v×B) represents the Lorentz force on an electron, and fe specifies the electron phase space density. We apply this approach to characterize the structure of the velocity-space gradient terms in the electron Vlasov equation measured by MMS. Discussion of the uncertainties which arise when computing the velocity-space gradients of the FPI phase space densities is presented, along with initial validation of the (F/me)⋅∇vfe measurements by comparison to the ∂fe/∂t and v⋅∇fe terms. Successful measurement of the force term (F/me)⋅∇vfe in the Vlasov equation suggests a new technique for inferring spatial gradients from single spacecraft measurements which may be applied to improve the spatial resolution of the electron pressure divergence ∇⋅Pe necessary to understand the microphysics of the electron diffusion region of magnetic reconnection. Reference: Shuster, J. R., et al. (2021), Structures in the terms of the Vlasov equation observed at Earth’s magnetosphere, Nature Physics, doi:10.1038/s41567-021-01280-6.

Concentrations and the stable isotopic composition of bulk aerosol nitrate (NO3-) were quantified from two fall GEOTRACES cruises: 1) Alaska–Tahiti (GP15; n=22) and 2) Peru–Tahiti (GP16; n=17) to explore the hypothesis that marine emissions influence aerosol NO3- in the Equatorial Pacific. The δ15N-NO3- ranged from -14.5–0.5‰, with lowest values far from the coast and primarily reflecting a shift in sources. The δ18O- and Δ17O-NO3- were both high (65.2–85.4‰ and 21.4–30.7‰, respectively) and decreased away from continental regions, reflecting a shift in the oxidants that influence the formation of NO3-. Transport modeling and co-occurrence of low δ15N, δ18O and Δ17O provided evidence for an important influence of alkyl nitrates (RONO2) on aerosol NO3- formation. Based on the Δ17O, we quantified that the contribution of RONO2 to aerosol NO3- can be as high as 48% (range 15–48%). We were also able to estimate an average δ15N-RONO2 of -22.9 ± 19.1‰.

This article is a commentary about the state of Integrated, Coordinated, Open, and Networked (ICON) principles (Goldman et al., 2021) in Space Physics and Aeronomy and a discussion on several scopes and limitations to implementing them. The commentary focuses on the basic introduction and brief literature survey (Section 1); possibilities of implementation of ICON in Space Physics and Aeronomy (Section 2) and limitations or challenges in this field with possible solutions using ICON principles (Section 3). The Space Physics and Aeronomy section of the American Geophysical Union (AGU) comprises the interactions between solar wind, Interplanetary Magnetic Field (IMF) and different planetary magnetospheres and ionospheres. The section also deals with solar physics, mechanisms behind existence of solar magnetic fields, and evaluations of high and low speed solar winds. This field is a collection of different interdisciplinary subtopics, making this an excellent example of integrated research. Similar and transparent methodologies are adopted to solve problems all over the world which shows a coordinated approach of research. Freely available data from different space agencies and universities are also great assets for this domain which supports open research. The scopes of possible networked research with mutual benefits are also highlighted. Examples of ICON-based international collaborations and support mechanisms towards young scientists are elaborated which are helpful to mitigate limitations in this domain.

The recently selected VERITAS and EnVision missions will fly with X and Ka Band telecommunications channels, permitting dual band radio occultations of the Venus atmosphere. While signal absorption measurements during S and X Band radio occultations of Venus in the past have been used to retrieve vertical abundances of H2SO4 vapor as a function of latitude, Ka Band links have yet to be employed to sound the neutral atmosphere. Laboratory measurements and propagation models of the Venus atmosphere suggest that H2SO4 cloud aerosols/vapor and SO2 absorb radio signals differently between X and Ka bands, permitting inversion of their abundance profiles down to the attenuation limit near 45 km. Such measurements would be of great value to the study of Venus atmospheric chemistry and dynamics. While the bulk abundance of SO2 at the cloud base has been inferred from microwave/infrared radiometry and from X Band occultations, Ka Band measurements could be used to derive vertically resolved profiles at the deepest altitudes yet, spanning a region where the abundance of SO2 changes by several orders of magnitude. Vertical profiles of lower cloud bulk density could also be achieved at higher resolution than any prior remote measurements. This presentation will discuss approaches to retrieving H2SO4 vapor/aerosol, and SO2 abundances using dual X/Ka Band radio occultations of the Venus neutral atmosphere. H2SO4 vapor can be retrieved with very high accuracy, surpassing that of prior single frequency occultations. Due to the relatively low (high) X (Ka) Band opacity of both SO2 and H2SO4 aerosols, retrievals of these species from dual band occultations are highly degenerate. To improve accuracy, we find that it is necessary to incorporate the results of chemical and dynamical modeling as prior information. At lower latitudes and in regions of high abundance, preliminary results suggest retrievals of SO2 profiles can be accomplished within 15-20% uncertainty. This error increases at higher latitudes, where models of cloud bulk density span a wider range of predictions. We compare the effects of various assumptions on the accuracy of the resulting retrievals, and discuss prospects for coupling a chemical/dynamics model to the retrieval process.

​​​​​​​​​Lakes in the Arctic are important reservoirs of heat with much lower albedo and larger absorption of solar radiation than surrounding tundra vegetation. Under climate warming scenarios, we expect Arctic lakes to further accelerate thawing underlying permafrost. Previous studies of Arctic lakes have focused on ice cover and thickness, the ice decay process, catchment hydrology, lake water balance, and eddy covariance measurements, but little work has been done in the Arctic to model lake heat balance. We applied the LAKE model to simulate water temperatures in three Arctic lakes in Northern Alaska over several years. The LAKE model is a one-dimensional that explicitly solves vertical profiles of water state variables on a grid. We used a combination of meteorological data from local and remote weather stations, as well as data derived from remote sensing, to drive the model. We validated simulated water temperatures with data of observed lake temperatures at several depths. Our validation of the LAKE model completes a necessary step toward modeling changes in Arctic lake ice regimes, lake heat balance, and thermal interactions with permafrost. Our results showed that winter precipitation and lake ice plays an important role in forming water temperatures over the winter period. Our findings suggest that reduction in the lake ice thickness and ice time period could lead to more heat storage by lakes and further warming of the Arctic.

A multi-stage fuzzy inference system (FIS), a symbolic knowledge-based artificial intelligence technique, is used to delineate exploration targets for rare earth elements (REEs) associated with carbonatite-alkaline complexes in NE India. A conceptual REE mineral systems model was used to identify the following targeting criteria for REE deposits. The multi-stage FIS was structured based on the mineral systems model. The first stage of the multi-stage FIS comprised of three individual FIS to represent (1) plume-metasomatised SCLM in an extensional regime that make up fertile source regions for REE-bearing fluids and favourable geodynamic settings; (2) trans-lithospheric structures that provide favourable lithospheric architecture for the transportation of REE-enriched alkaline-carbonatite magma and (3) near-surface higher-order structures that make up a shallow crustal architecture facilitating emplacement of alkaline-carbonatite complexes. The targeting criteria were represented by their spatial proxies in the form of GIS layers derived using spatial analyses and geoprocessing tools for inputting to the FIS. The outputs of the FIS were mapped to generate prospectivity maps that were analysed to identify exploration targets for REE in the study area. The uncertainties in the outputs of the FIS were quantified using Monte-Carlo-based simulations. Exploration targets at low uncertainty levels were delineated around Sung valley and Jasra carbonatite-alkaline-complexes. Areas around the carbonatite-alkaline complex around Swangkre and to the south of the Nongstoin town were identified as high-uncertainty targets. It is recommended that ground follow-up exploration should be carried out in the former targets, and more data should be collected to increase confidence in the latter targets.

In 2015 and 2016, the AfriSAR campaign was carried out as a collaborative effort among international space and National Park agencies (ESA, NASA, ONERA, DLR, ANPN and AGEOS) in support of the upcoming ESA BIOMASS, NASA-ISRO Synthetic Aperture Radar (NISAR) and NASA Global Ecosystem Dynamics Initiative (GEDI) missions. The NASA contribution to the campaign was conducted in 2016 with the NASA LVIS (Land Vegetation and Ice Sensor) Lidar, the NASA L-band UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar). A central motivation for the AfriSAR deployment was the common AGBD estimation requirement for the three future spaceborne missions, the lack of sufficient airborne and ground calibration data covering the full range of ABGD in tropical forest systems, and the intercomparison and fusion of the technologies. During the campaign, over 7000 km2 of waveform Lidar data from LVIS and 30000 km2 of UAVSAR data were collected over 10 key sites and transects. In addition, field measurements of forest structure and biomass were collected in sixteen 1 hectare sized plots. The campaign produced gridded Lidar canopy structure products, gridded aboveground biomass and associated uncertainties, Lidar based vegetation canopy cover profile products, Polarimetric Interferometric SAR and Tomographic SAR products and field measurements. Our results showcase the types of data products and scientific results expected from the spaceborne Lidar and SAR missions; we also expect that the AfriSAR campaign data will facilitate further analysis and use of waveform Lidar and multiple baseline polarimetric SAR datasets for carbon cycle, biodiversity, water resources and more applications by the greater scientific community.

Generating renewable bioenergy crops requires varietals that are suited to grow under varying environmental conditions necessitating the development and testing of a wide range of poplar (Populus) genotypes. Meanwhile, there is an increasing demand for refining the selection process of high-performing poplars. However, a cost-effective method is still needed to predict the productivity of various poplar genotypes. Photosynthetic capacity and leaf nitrogen are important growth-related physicochemical traits, but measuring them in the field and laboratory is expensive and time-consuming. Alternatively, remote sensing of hyperspectral leaf spectra may serve as a proxy to rapidly estimate these traits, which are associated with absorption, reflection, and transmission of solar radiation. To quantify photosynthetic traits, CO2 response curves were used to estimate Rubisco-limited carboxylation rate (Vcmax), maximum electron transport rate (Jmax), and triose phosphate utilization (TPU). From the same leaves measured for photosynthesis, leaf reflectance was measured with a handheld spectroradiometer. We measured a total of 105 leaf samples, including 6 taxa with 61 different poplar genotypes. For data analyses, Least Absolute Shrinkage and Selection Operator and Principal Component Analysis were used to determine the wavelengths that were the most useful for capturing the variability in the physicochemical data. Results showed that leaf reflectance at 758 nm and 936 nm were crucial wavelengths for predicting Vcmax (RMSPE = 31%) and Jmax (RMSPE = 32%), while 687 nm and 757 nm were important predictors for TPU (RMSPE = 31%), and 709 nm and 927 nm were important predictors for leaf nitrogen (RMSPE = 22%). The wavelengths near 687 nm and 760 nm are the oxygen absorption bands, and also overlap with the chlorophyll fluorescence emission of plants. Therefore, it is possible to apply hyperspectral reflectance models for rapid clonal screening and high-throughput field phenotyping of photosynthetic capacity parameters and leaf nitrogen of various poplar genotypes.

Lake Tanganyika, located in central East Africa, is the longest and second deepest freshwater lake on Earth. Lake Tanganyika’s diverse ecosystem and watershed are under threat today by human activities from extensive deforestation, climate change, and human-induced fires. Therefore, documenting fire and deforestation history in Lake Tanganyika’s surrounding watersheds is crucial for improving watershed management around the lake in the future. Analyzing sediment charcoal records from sediment cores provides high-resolution paleolimnological evidence that reflects the timing and impacts of fire histories and landscape conversion. Macrocharcoal, an incompletely combusted residue that remains when plants materials were burnt by fire, can be transported away from the fire sites and deposited into the lake. We sampled and calculated macro-charcoal (>61 μm) sediment flux from three sediment cores, LT-98-20MR, LT-98-15M, and TANG14-1MC-1A from the lake’s east-central coast. 20MR and 15M are 2.4 km apart, whereas 1A and 15M are 6.97 km apart. We have also compared our results with several previously studied cores from the central part of the lake. Core 15M, which is closest to the shore and has the highest sedimentation rates, showed peaks of charcoal flux from 1830 – 1850, 1896, 1910 – 1914 and 1996 AD based on correlation with a nearby core. Core 20MR, which is further offshore than 15M, has multiple sharp charcoal flux peaks at 1674, 1770, 1848 and 1881 AD, again using correlation with a nearby core. Core 1A, where the watershed has been intensively managed at Kalilani Bay in recent decades (McGlue et al., 2021), shows two significant peaks at 1668 and 1808 AD. The difference in timing of the distributions of sediment charcoal flux peaks from our study indicates these charcoal histories record localized wildfires. Some of these may correlate with the late Little Ice Age dry period in the late 18th – mid 19th C, whereas other more recent ones maybe linked to human activities such as land clearance for cassava cultivation. Low fire frequencies at most sites during the late 19th – mid 20th C may correspond to reduced human populations and disease outbreaks during that period.

There is an increased interest in geoscience virtual field trips (VFTs) coinciding with an expansion of online learning and growing concerns about the lack of diversity, inclusion, and equity in many STEM fields. Motivated by this interest, we built a VFT of Coastal Maine using Unity software, traditionally a game development platform, and piloted a web-based desktop VR (dVR) and headset immersive VR (iVR) version of the VFT in an introductory physical geology class (total n=25, dVR=14, iVR=11) at a small liberal arts college in spring 2021. Our primary goals of the pilot study were to assess if students would demonstrate (1) learning outcomes within an accessible virtual environment as they would in a real-world geology field site lab experience and (2) equivalent proficiency in lab goals in dVR and iVR conditions as measured by response accuracy. Within the VFT, participants were shown a series of overview maps across several spatial scales to help them geolocate the field site. They were then placed in the model at ground level and asked to perform several tasks to learn to navigate the environment and use the compass for orientation and spatial reasoning tasks. Participants observed prompted geologic features and answered multiple choice and short answer questions with the aid of augmented information (i.e., real-world site images, photomicrographs) embedded within the VFT. There was no statistically significant difference in response accuracy between the dVR and iVR conditions, which suggests the potential for VFT access and scalability without requiring iVR equipment. However, there was a marked decrease in accuracy on lab responses (i.e., identifying rocks, assessing rock orientation, and interpreting collision processes) when compared to previous in-person field experiences. We hypothesize higher resolution images and more realistic field site rendering could address this issue in the future. Encouragingly, when compared to in-person field experiences, we qualitatively observed an increase in independent exploration and reasoning and an increase in student comfort using the augmented compass within the VFT environment. Student feedback was overwhelmingly positive regardless of VFT condition and 100% of participants indicated they wanted access to more VFT experiences.

Critical research questions such as how geomorphic and sedimentary systems modulate sediment movements and what are the timing, controls, and duration of significant sediment transport and deposition over submillennial to millennial timescales are still poorly understood, especially in the semi-arid Southern California. Although several sediment tracing and chronometric methods are available to address these questions, we still do not know well about the dominant controls and durations of sediment transport from the upper catchment source to the downstream sink. To examine this issue, here we used luminescence ages from K-feldspar sand grains from the range-front nested alluvial fans to the ~12-km-downstream in the flood plains of the Mission Creek catchment, Southern California. From a total of 29 sediment samples with >1,400 single grain (175–215 µm sizes) luminescence ages, we identified at least six depositional periods both in the upstream and downstream deposits in the catchment with no significant lag during the Holocene. Additional six significant depositional periods are also identified during the late Pleistocene (since the last ~100 ka) in the upstream alluvial fan deposits. These depositional periods correspond reasonably well with the late Pleistocene and Holocene intervals of wetter-than-average climate conditions based on hydroclimatic proxies from nearby locations. We, therefore, reinforces the concept that climate, especially wetter intervals, likely plays the first-order control on significant sediment deposition on submillennial to millennial timescales in the Mission Creek catchment. We also applied a detailed multi-elevated-temperature post-IR IRSL (MET-pIRIR) dating and bleaching experiment to examine whether sediment migration from the upstream to the downstream produces any significant changes in luminescence measurement (equivalent dose) signals. Any substantial changes in MET-pIRIR signals will be used to quantify the sediment movement characteristics (i.e., repeated flooding and burial events) within the catchment system.

Sparse rain gauge networks and declining observations in Africa limit climate research in the region. However, the proliferation of satellite-rainfall products (SRPs) and the growth of citizen-science-driven in-situ observations driven by cheaper data collection technologies have provided a pathway to overcoming the data scarcity problem. In this paper, we used rain gauge data from 596 stations operated by the Trans-African Hydro-Meteorological Observatory (TAHMO) across Africa to evaluate the performance of two widely-utilized satellite-based rainfall products: the Climate Hazards InfraRed Precipitation with Stations (CHIRPS) and the Tropical Applications of Meteorology using Satellite data (TAMSAT), and two under-validated and underutilized products: the satellite-only Global Satellite Mapping of Precipitation (GSMaP) and the gauge-corrected GSMaP version (GSMaP_Gauge). We also inter-compared the performance of the four products over Africa, East Africa, Southern Africa and West Africa at daily, pentadal, and monthly timescales. Our findings indicated that the GSMaP products had better performances at daily timescales whereas CHIRPS and TAMSAT matched or outperformed the GSMaP products at pentadal and monthly timescales. GSMaP_Gauge daily rainfall detection was almost 1.5 times the CHIRPS detection scores at the same temporal scale. The Pearson correlation coefficient increased with temporal aggregation but the volumetric errors increased for all products. Additionally, all the products overestimated (underestimated) low (high) intensity rainfall events. Our analysis adds to a growing number of validation studies in Africa and presents an opportunity for developers of satellite-rainfall products to integrate the new TAHMO observations in bias-correction algorithms to improve the accuracy of SRPs in the region.