NASA has released an updated near real-time global flood map product, based on twice-daily MODIS observations. The short name for the MODIS Near Real-Time (NRT) Global Flood Product is MCDWD. This updated product replaces a PI-maintained system that had delivered flood maps since 2012. The updated product is generated by a more robust processing facility, which also provides additional distribution mechanisms, including web-based global browser. The core water detection algorithm remains the same, but several improvements have been incorporated to reduce false-positives and enhance the compositing process. Additional advancements are on the horizon, including incorporation of VIIRS imagery (to replace the near end-of-life MODIS sensors), and further out, possibly Sentinel-3 OLCI.

Exposure to environmental hazards is an important determinant of health, and the frequency and severity of exposures is expected to be impacted by climate change. Through a partnership with the U.S. National Aeronautics and Space Administration, the U.S. Centers for Disease Control and Prevention's National Environmental Public Health Tracking Network is integrating timely observations and model data of priority environmental hazards into its publicly accessible Data Explorer (https://ephtracking.cdc.gov/DataExplorer/). Newly integrated data sets over the contiguous U.S. (CONUS) include: daily 5-day forecasts of air quality based on the Goddard Earth Observing System Composition Forecast, daily historical (1980-present) concentrations of speciated PM2.5 based on the modern era retrospective analysis for research and applications, version 2, and Moderate Resolution Imaging Spectroradiometer (MODIS) daily near real-time maps of flooding (MCDWD). Data integrated into the CDC Tracking Network are broadly intended to improve community health through action by informing both research and early warning activities, including (a) describing temporal and spatial trends in disease and potential environmental exposures, (b) identifying populations most affected, (c) generating hypotheses about associations between health and environmental exposures, and (d) developing, guiding, and assessing environmental public health policies and interventions aimed at reducing or eliminating health outcomes associated with environmental factors.

Submarine volcanism in shallow waters (<100 m), particularly in remote settings, is difficult to monitor quantitatively and, in the rare formation of islands, it is challenging to understand the rapid-paced erosion. However, these newly erupted volcanic islands become observable to airborne and/or satellite remote sensing instruments. NASA's ICESat-2 satellite laser altimeter, combined with visible imagery (optical and microwave), provide a novel method of evaluating the elevation characteristics of newly emerged volcanoes and their subaerial eruption products. Niijima Fukutoku-Okanoba (NFO) is a submarine volcano 1300 km south of Tokyo (Ogasawara Archipelago of Japan) that periodically breaches the ocean surface to create new islands that are subsequently eroded. The recent eruption in August 2021 is a rare opportunity to investigate this island evolution using high-resolution satellite datasets with geodetic-quality ICESat-2 altimetry. Lansdat-8 and Planet imagery provide a qualitative analysis of the exposed volcanic deposits, while ICESat-2 products provide elevation profiles necessary to quantify the physical surface structures. This investigation determines an innovative application for ICESat-2 data in evaluating newly emerged islands and how the combination of satellite remote sensing (visible and lidar) to investigate these short-lived volcanic features can improve our understanding of the volcanic island system in ways not previously possible.

Flooding affects more people than any other environmental hazard and hinders sustainable development1,2. Investing in flood adaptation strategies may reduce the loss of life and livelihood caused by floods3. Where and how floods occur and who is exposed are changing as a result of rapid urbanization4, flood mitigation infrastructure5 and increasing settlements in floodplains6. Previous estimates of the global flood-exposed population have been limited by a lack of observational data, relying instead on models, which have high uncertainty3,7–11. Here we use daily satellite imagery at 250-metre resolution to estimate flood extent and population exposure for 913 large flood events from 2000 to 2018. We determine a total inundation area of 2.23 million square kilometres, with 255–290 million people directly affected by floods. We estimate that the total population in locations with satellite-observed inundation grew by 58–86 million from 2000 to 2015. This represents an increase of 20 to 24 per cent in the proportion of the global population exposed to floods, ten times higher than previous estimates7. Climate change projections for 2030 indicate that the proportion of the population exposed to floods will increase further. The high spatial and temporal resolution of the satellite observations will improve our understanding of where floods are changing and how best to adapt. The global flood database generated from these observations will help to improve vulnerability assessments, the accuracy of global and local flood models, the efficacy of adaptation interventions and our understanding of the interactions between landcover change, climate and floods. Satellite imagery for the period 2000–2018 reveals that population growth was greater in flood-prone regions than elsewhere, thus exposing a greater proportion of the population to floods.

The demand for timely and accurate flood information is well understood and more urgent than ever as flooding has become the most common natural hazard worldwide, impacting people of all continents in both developed and less developed countries. Population and total exposed assets by river flooding are certain to increase in the coming century making the need for flood information even more pressing. Unlike the World Meteorological Organization (WMO), the hydrological community hasn’t been very successful in establishing a global hydrological network of observations through which model simulations and measurements and novel measurement technologies could be exploited. Countries that can afford have departments in place that are tasked to develop flood risk maps and are involved in flood forecasting and relief efforts. However, the majority of countries do not or cannot allocate sufficient funds to support such efforts, nor has there been a global initiative to identify and determine global flood risk areas. Due to the lack of objective knowledge of the impact of flooding during or after an event, first relief agency assistance is often constrained and therefore less effective. These humanitarian catastrophes could be reduced with better transformation of existing observational and modeling technologies into information useful to local populations and decision makers. Here I present new efforts to produce a state-of-the-art, globally-scoped, flood prediction, monitoring capabilities and risk evaluations platform that is interactive and includes high resolution flood information to better serve local needs. The platform builds upon already operational or quasi-operational NASA-supported global flood systems, including the DFO - Flood Observatory satellite-based hydrological gauging stations, UMD Global Flood Monitoring System (GFMS) and have these integrated with the European Commission’s GloFAS, and SAR-based high-resolution flood mapping. This with the intension to have these data layers (flood forecasting, flood extent, and flood history) available to everybody.

The structure and function of coral reef ecosystems is increasingly compromised by multiple stressors, even in the most remote locations. Severe, acute disturbances such as volcanic eruptions represent extreme events that can annihilate entire reef ecosystems, but also provide unique opportunities to examine ecosystem resilience and recovery. Here, we examine the destruction, persistence and initial recovery of reefs associated with the hydro-magmatic eruption that created Earth’s newest landmass, the Hunga Tonga–Hunga Ha’apai volcanic island. Despite extreme conditions associated with the eruption, impacts on nearby reefs were spatially variable. Importantly, even heavily affected reefs showed signs of rapid recovery driven by high recruitment, likely from local refuges. The remote location and corresponding lack of additional stressors likely contribute to the resilience of Hunga’s reefs, suggesting that in the absence of chronic anthropogenic stressors, coral reefs can be resilient to one of the largest physical disturbances on Earth.

Commercial very high-resolution (VHR) Earth observing (EO) satellites have grown into constellations with global repeat coverage that can support existing NASA EO missions with stereo and multispectral capabilities. Sub-meter data from these instruments exceeds petabytes per year and the cost for data, storage systems and compute power have all dropped exponentially. Concurrently, through agreements with the National Geospatial-Intelligence Agency, NASA-Goddard Space Flight Center is acquiring VHR EO imagery from DigitalGlobe's WorldView-1, 2, 3 Quickbird-2, GeoEye-1 and IKONOS-2 satellites. To enhance the utility of these data we are developing an Application Program Interface (API) to produce on-demand user defined science ready products to support NASA's EO missions. These enhancements include two primary foci: 1) surface reflectance 1/2° ortho mosaics - multi-temporal 2 m multispectral imagery that can be used to investigate biodiversity, horizontal forest structure, surface water fraction, and land-cover land-use at the human scale; and 2) VHR digital elevation models (DEMs) - derived with the NASA Ames Stereo Pipeline. These enhanced products benefit Earth surface studies on the cryosphere (glacier mass balance, flow rates and snow depth), hydrology (lake/waterbody levels, landslides, subsidence) and the biosphere (vertical forest structure, tree canopy height and cover) among others. Here we present current API capabilities and recent examples of derived products used in NASA Earth Science projects.

Cushion plant dominated peatlands are key ecosystems in tropical alpine regions of the Andes in South America. The cushion plants have formed peat bodies over thousands of years that fill many valley bottoms, and the forage produced by the plants is critical for native and nonnative domesticated mammals. The sources and flow paths of water supporting these peatlands remain largely unknown. Some studies have suggested that glacier meltwater streams support some peatlands, and that the ongoing loss of glaciers and their meltwaters could lead to the loss or diminishment of peatlands. We analysed the hydrologic regime of 10 peatlands in four mountain regions of Bolivia and Peru using groundwater monitoring. Groundwater levels in peatlands were relatively stable and within 20 cm of the ground surface during the rainy season, and many sites had water tables 40–90 cm below the ground surface in the dry season. Topographic and groundwater elevations in the peatlands demonstrated that the water source of all 10 peatlands was hillslope groundwater flowing from lateral moraines, talus, colluvium, or bedrock aquifers into the peatlands. There was little to no input from streams, whether derived from glacier melt or other sources, and glacier melt could not have recharged the hillslope aquifers supporting peatlands. We measured the stable water isotopes in water samples taken during different seasons, distributed throughout the catchments, and the values are consistent with this interpretation. Our findings indicate that peatlands in the study region are recharged by hillslope groundwater discharge rather than stream water and may not be as vulnerable to glacial decline as other studies have indicated. However, both glaciers and peatlands are susceptible to changing thermal and precipitation regimes that could affect the persistence of peatlands.

In the Andes, indigenous pastoral communities are confronting new challenges in managing mountain peatland pastures, locally called bofedales. Assessing land cover change using satellite images, vegetation survey, and local knowledge (i.e., traditional ecological knowledge) reveals the multi-faceted socio-ecological dimensions of bofedal change in Sajama National Park (PNS), Bolivia. Here, we present results from focus groups held in 2016 and 2017 to learn about the local knowledge of bofedales in five Aymara communities in PNS. Land cover maps, created from Landsat satellite imagery, provided a baseline reference of the decadal change of bofedales (1986, 1996, 2006, and 2016) and were field verified with vegetation sampling. At the park level, the land cover maps show a reduction of healthy bofedales (i.e., Juncaceae dominated peatland) cover from 33.8km(2) in 1986 to 21.7km(2) in 2016, and an increase in dry mixed grasses (e.g., Poaceae dominated land cover) from 5.1km(2) (1986) to 20.3km(2) (2016). Locals identify climate change, lack of irrigation, difficulty in water access, and loss of communal water management practices as key bofedal management challenges. Local improvement of bofedales was found in one community due to community-based irrigation efforts. Bridging knowledge of mountain land cover change helps to articulate the socio-ecological dimensions that influence local decision-making regarding bofedal management, and consideration of local actions that may be strengthened to support the sustainability of bofedales for local livelihoods in the context of climate change in the Andes.

AbstractWe have monitored a newly erupted volcanic island in the Kingdom of Tonga, unofficially known as Hunga Tonga Hunga Ha'apai, by means of relatively frequent high spatial resolution (~50 cm) satellite observations. The new ~1.8 km2 island formed as a tuff cone over the course of a month‐long hydromagmatic eruption in early 2015 in the Tonga‐Kermadec volcanic arc. Such ash‐dominated eruptions usually produce fragile subaerial landscapes that wash away rapidly due to marine erosion, as occurred nearby in 2009. Our measured rates of erosion are ~0.00256 km3/year from derived digital topographic models. Preliminary measurements of the topographic expression of the primary tuff cone over ~30 months suggest a lifetime of ~19 years (and potentially up to 42 years). The ability to measure details of a young island's landscape evolution using satellite remote sensing has not previously been possible at these spatial and temporal resolutions.

151 A severe late spring storm in central Mexico in March 2016 that struck the Monarch Butterfly Biosphere Reserve was unique because it was accompanied by high-velocity winds that eliminated the normal thermal protection provided by the Oyamel fi r forest. Temperatures throughout the forest merged with the colder open-area ambient temperatures. Th e storm was in eff ect a rain and snow storm sandwiched within a powerful and sustained wind storm, followed by lethal freezing that killed 31–38% of the butterfl ies in the Sierra Chincua and Cerro Pelón overwintering colonies. Several lines of evidence point to greater than 40% mortality of monarchs in the Rosario colony. Our estimates are a fi ve-fold increase over the 7.4% mortality reported by the press. Tens of thousands of trees were blown down and subjected to extensive salvage logging in the Core Zone of the Reserve. Th is loss of canopy cover will diminish the normal microclimatic protection provided by the intact forest. Th e unexpected eff ects of this storm may take place at greater frequency in an era of changing climate. Research summarized in Williams and Brower (2015) has shown that the intact Oyamel forest ecosystem provides microclimatic protection of the overwintering monarch butterflies (Danaus plexippus L.) by acting as a blanket that holds heat beneath the forest canopy, as an umbrella that reduces wetting of the butterfl ies clustering on the tree boughs, and as a heat source from the tree trunks radiating warmth that protects the butterfl ies clustering on the trunks from freezing. Although several past winter storms have struck the overwintering area (Calvert et al. 1983, Marriott 1996, Taylor et al. 2000, Brower et al. 2004, Taylor 2004, Brower et al. 2009), the March 2016 storm was exceptionally severe, with intense and continuous wind in combination with rain, snow, and lethally cold temperatures. In this paper, we describe this storm and how the severe wind obliterated the microclimatic protection by homogenizing sub-freezing temperatures throughout the Oyamel fi r forest ecosystem and the eff ect this had upon the butterfl ies. We also provide the fi rst quantitative estimate of butterfl y mortality caused by the storm, and we describe and address potential eff ects of the authorization to permit the salvage logging of tens of thousands of trees blown down by the storm.

As far as we are aware, the first observation in 2015 of an illegal logging operation in the Sierra Chincua overwintering area within the core zone of the Monarch Butterfly Biosphere Reserve in Mexico was made in April by a local …