Characteristics of lightning, sprites, and human‐induced emissions observed by nadir‐viewing cameras on board the International Space Station

Farges, Thomas; Blanc, E.

doi:10.1002/2015jd024524

Cited by 11 publications

(6 citation statements)

References 70 publications

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“…Averaged across the Congo Basin, Crowhurst et al (2020) found that the best performing global climate models (GCMs) with low root mean square errors against CHIRPS2 rainfall (Funk et al 2015) have slightly higher rainfall at the November rainfall peak than the March rainfall peak. While this agrees with several studies (Haensler et al 2013;Washington et al 2013;Creese and Washington 2016), and several reanalyses ( Fig. 1a, Table 1), the CHIRPS2 data set, which has the best agreement of 10 satellite and gauge -year mean (1989-2005) seasonal cycles of a rainfall (mm day −1 ) and b evaporation (mm day −1 ) averaged over the Congo Basin (14° S-4° N, 18° E-30° E), from four reanalyses, CFSR (Saha et al 2010), ERA5-Land (Hersbach et al 2020), MERRA-2 (Gelaro et al 2017) and NCEP-2 (Kanamitsu et al 2002), and two reference data sets, CHIRPS2 rainfall (Funk et al 2015) and LandFlux-EVAL evaporation (Mueller et al 2013) rainfall products against the NIC131-Gridded rainfall dataset in the Congo Basin (Nicholson et al 2019), has a similar amount of rainfall at the two peaks ( Fig.…”

Section: Lower Evaporation In November Than March In the Congo Basinsupporting

confidence: 93%

Contrasting controls on Congo Basin evaporation at the two rainfall peaks

et al. 2020

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Evaporation is a crucial driver of Congo Basin climate, but the dynamics controlling the seasonality of basin evaporation are not well understood. This study aims to discover why evaporation on the basin-wide average is lower at the November rainfall peak than the March rainfall peak, despite similar rainfall. Using 16-year mean LandFlux-EVAL data, we find that evaporation is lower in November than March in the rainforest and the eastern savannah. The ERA5-Land reanalysis, which effectively reproduces this pattern, shows that transpiration is the main component responsible for lower evaporation in these regions. Using ERA5-Land, we find the following contrasting controls on transpiration, and therefore evaporation, at the two rainfall peaks: (a) In the northern rainforest, there is lower leaf area index (LAI) in November, driven by lower surface downward shortwave radiation (DSR), and lower vapour pressure deficit (VPD) in November, driven by lower sensible heat flux that results from lower net radiation. The combination of lower LAI and VPD explains lower transpiration, and therefore lower evaporation, in November. (b) In the southern rainforest, and in the north-eastern savannah, there is lower LAI in November, driven by lower surface DSR, and this explains lower transpiration, and therefore lower evaporation, in November. (c) In the south-eastern savannah, there is lower LAI in November, driven by lower volumetric water content (VWC), and this explains lower transpiration, and therefore lower evaporation, in November. Collectively, these contrasting controls at the two rainfall peaks explain why the basin-wide average evaporation is lower in November than March.

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Section: Lower Evaporation In November Than March In the Congo Basinsupporting

confidence: 93%

Contrasting controls on Congo Basin evaporation at the two rainfall peaks

et al. 2020

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“…This raises the possibility of connections between model biases in the Congo region and those in southern Africa. However, the lack of observational data in the Congo makes it very difficult to evaluate these biases [e.g., Washington et al, 2013], and process-based model evaluation is needed to help constrain model rainfall estimates [Creese and Washington, 2016].…”

Section: Discussionmentioning

confidence: 99%

Circulation controls on southern African precipitation in coupled models: The role of the Angola Low

Munday

Washington

2017

JGR Atmospheres

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In southern Africa, models from the latest Coupled Model Intercomparison Project produce a wide variety of rainfall climatologies. Differences between models in rainfall amount reach 70% in the rainy season (December–February; DJF), and the median model overestimates rainfall by between 15 and 40% throughout the annual cycle. This paper investigates the role of an understudied regional circulation feature, the Angola Low, in differentiating between model estimates of precipitation. In austral spring, the Angola Low is a heat low, driven by strong surface heating whereas in DJF it is more similar to a tropical low and is associated with moist instability. In the austral summer, we find that the simulated strength of the Angola Low is associated with between 40 and 60% of the intermodel variability in model mean rainfall across the subcontinent. The relationship is particularly strong along a northwest, southeast axis aligned from Angola down to the Mozambican Channel. Along this axis, models with stronger Angola Lows simulate enhanced, by up to 50 g kg−1 ms−1, northeasterly and northwesterly moisture transport. The enhanced southward moisture flux in models with relatively deep Angola Lows increases the rate of moisture convergence in central areas of the subcontinent and reduces moisture divergence across the Mozambican coast. The results highlight the need to better understand the links between the Angola Low and southern African rainfall and suggest that improving the simulation of the Angola Low can help to constrain model estimates of southern African rainfall.

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“…Another source of images of the Earth at night from the ISS is dedicated instrumentation on the ISS. For example, the experiment LRO (Lightning and Sprites Observation) (Farges et. al.…”

Section: Additional Night-time Sensors On the Issmentioning

confidence: 99%

Remote sensing of night lights: A review and an outlook for the future

Levin

Kyba

Zhang³

et al. 2020

Remote Sensing of Environment

535

247

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Remote sensing of night light emissions in the visible band offers a unique opportunity to directly observe human activity from space. This has allowed a host of applications including mapping urban areas, estimating population and GDP, monitoring disasters and conflicts. More recently, remotely sensed night lights data have found use in understanding the environmental impacts of light emissions (light pollution), including their impacts on human health. In this review, we outline the historical development of night-time optical sensors up to the current state of the art sensors, highlight various applications of night light data, discuss the special challenges associated with remote sensing of night lights with a focus on the limitations of current sensors, and provide an outlook for the future of remote sensing of night lights. While the paper mainly focuses on space borne remote sensing, ground based sensing of night-time brightness for studies on astronomical and ecological light pollution, as well as for calibration and validation of space borne data, are also discussed. Although the development of night light sensors lags behind day-time sensors, we demonstrate that the field is in a stage of rapid development.The worldwide transition to LED lights poses a particular challenge for remote sensing of night lights, and strongly highlights the need for a new generation of space borne night lights instruments. This work shows that future sensors are needed to monitor temporal changes during the night (for example from a geostationary platform or constellation of satellites), and to better understand the angular patterns of light emission (roughly analogous to the BRDF in daylight sensing). Perhaps most importantly, we make the case that higher spatial resolution and multispectral sensors covering the range from blue to NIR are needed to more effectively identify lighting technologies, map urban functions, and monitor energy use.

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Characteristics of lightning, sprites, and human‐induced emissions observed by nadir‐viewing cameras on board the International Space Station

Cited by 11 publications

References 70 publications

Contrasting controls on Congo Basin evaporation at the two rainfall peaks

Contrasting controls on Congo Basin evaporation at the two rainfall peaks

Circulation controls on southern African precipitation in coupled models: The role of the Angola Low

Remote sensing of night lights: A review and an outlook for the future

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