The 2015/2016 El Ni\uffc3\uffb1o event caused severe changes in precipitation across the tropics. This impacted surface hydrology, such as river run-off and soil moisture availability, thereby triggering reductions in gross primary production (GPP). Many biosphere models lack the detailed hydrological component required to accurately quantify anomalies in surface hydrology and GPP during droughts in tropical regions. Here, we take the novel approach of coupling the biosphere model SiBCASA with the advanced hydrological model PCR-GLOBWB to attempt such a quantification across the Amazon basin during the drought in 2015/2016. We calculate 30\uffe2\uff80\uff9340% reduced river discharge in the Amazon starting in October 2015, lagging behind the precipitation anomaly by approximately one month and in good agreement with river gauge observations. Soil moisture shows distinctly asymmetrical spatial anomalies with large reductions across the north-eastern part of the basin, which persisted into the following dry season. This added to drought stress in vegetation, already present owing to vapour pressure deficits at the leaf, resulting in a loss of GPP of 0.95 (0.69 to 1.20) PgC between October 2015 and March 2016 compared with the 2007\uffe2\uff80\uff932014 average. Only 11% (10\uffe2\uff80\uff9312%) of the reduction in GPP was found in the (wetter) north-western part of the basin, whereas the north-eastern and southern regions were affected more strongly, with 56% (54\uffe2\uff80\uff9356%) and 33% (31\uffe2\uff80\uff9333%) of the total, respectively. Uncertainty on this anomaly mostly reflects the unknown rooting depths of vegetation.
This article is part of a discussion meeting issue \uffe2\uff80\uff98The impact of the 2015/2016 El Ni\uffc3\uffb1o on the terrestrial tropical carbon cycle: patterns, mechanisms and implications\uffe2\uff80\uff99.
", "keywords": ["El Nino-Southern Oscillation", "0207 environmental engineering", "Articles", "02 engineering and technology", "Forests", "15. Life on land", "tropical terrestrial carbon cycle", "01 natural sciences", "6. Clean water", "Carbon Cycle", "Droughts", "Soil", "13. Climate action", "El Ni\u00f1o", "Seasons", "soil moisture", "Hydrology", "gross primary productivity", "Amazon", "river discharge", "Brazil", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://royalsocietypublishing.org/doi/pdf/10.1098/rstb.2018.0084"}, {"href": "https://doi.org/10.1098/rstb.2018.0084"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Philosophical%20Transactions%20of%20the%20Royal%20Society%20B%3A%20Biological%20Sciences", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1098/rstb.2018.0084", "name": "item", "description": "10.1098/rstb.2018.0084", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1098/rstb.2018.0084"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2018-10-08T00:00:00Z"}}, {"id": "10.1098/rstb.2017.0302", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-30T16:19:07Z", "type": "Journal Article", "created": "2018-10-08", "title": "Tropical land carbon cycle responses to 2015/16 El Ni\u00f1o as recorded by atmospheric greenhouse gas and remote sensing data", "description": "The outstanding tropical land climate characteristic over the past decades is rapid warming, with no significant large-scale precipitation trends. This warming is expected to continue but the effects on tropical vegetation are unknown. El Ni\uffc3\uffb1o-related heat peaks may provide a test bed for a future hotter world. Here we analyse tropical land carbon cycle responses to the 2015/16 El Ni\uffc3\uffb1o heat and drought anomalies using an atmospheric transport inversion. Based on the global atmospheric CO 2 and fossil fuel emission records, we find no obvious signs of anomalously large carbon release compared with earlier El Ni\uffc3\uffb1o events, suggesting resilience of tropical vegetation. We find roughly equal net carbon release anomalies from Amazonia and tropical Africa, approximately 0.5 PgC each, and smaller carbon release anomalies from tropical East Asia and southern Africa. Atmospheric CO anomalies reveal substantial fire carbon release from tropical East Asia peaking in October 2015 while fires contribute only a minor amount to the Amazonian carbon flux anomaly. Anomalously large Amazonian carbon flux release is consistent with downregulation of primary productivity during peak negative near-surface water anomaly (October 2015 to March 2016) as diagnosed by solar-induced fluorescence. Finally, we find an unexpected anomalous positive flux to the atmosphere from tropical Africa early in 2016, coincident with substantial CO release.
This article is part of a discussion meeting issue \uffe2\uff80\uff98The impact of the 2015/2016 El Ni\uffc3\uffb1o on the terrestrial tropical carbon cycle: patterns, mechanisms and implications\uffe2\uff80\uff99.
", "keywords": ["Life Sciences & Biomedicine - Other Topics", "FLUX", "0301 basic medicine", "Hot Temperature", "550", "551", "global warming", "01 natural sciences", "Carbon Cycle", "Greenhouse Gases", "03 medical and health sciences", "[SDU.STU.CL] Sciences of the Universe [physics]/Earth Sciences/Climatology", "CHEMICAL-TRANSPORT MODEL", "carbon cycle", "INVERSION", "Biology", "TEMPERATURE", "11 Medical and Health Sciences", "0105 earth and related environmental sciences", "tropical forests", "El Nino-Southern Oscillation", "Evolutionary Biology", "Tropical Climate", "Science & Technology", "Atmosphere", "PHOTOSYNTHESIS", "EQUATORIAL PACIFIC", "Articles", "06 Biological Sciences", "15. Life on land", "[SDU.ENVI] Sciences of the Universe [physics]/Continental interfaces", " environment", "6. Clean water", "Droughts", "[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology", "13. Climate action", "PRECIPITATION", "Remote Sensing Technology", "INDUCED CHLOROPHYLL FLUORESCENCE", "CO2", "[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces", "SENSITIVITY", "environment", "Life Sciences & Biomedicine", "fire"]}, "links": [{"href": "https://eprints.whiterose.ac.uk/135234/8/Tropical%20land%20carbon%20cycle%20responses%20to%202015/16%20El%20Ni%C3%B1o%20as%20recorded%20by%20atmospheric%20greenhouse%20gas%20and%20remote%20sensing%20data.pdf"}, {"href": "https://royalsocietypublishing.org/doi/pdf/10.1098/rstb.2017.0302"}, {"href": "https://doi.org/10.1098/rstb.2017.0302"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Philosophical%20Transactions%20of%20the%20Royal%20Society%20B%3A%20Biological%20Sciences", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1098/rstb.2017.0302", "name": "item", "description": "10.1098/rstb.2017.0302", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1098/rstb.2017.0302"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2018-10-08T00:00:00Z"}}, {"id": "10.1098/rstb.2017.0408", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-30T16:19:07Z", "type": "Journal Article", "created": "2018-10-08", "title": "Widespread reduction in sun-induced fluorescence from the Amazon during the 2015/2016 El Ni\u00f1o", "description": "The tropical carbon balance dominates year-to-year variations in the CO 2 exchange with the atmosphere through photosynthesis, respiration and fires. Because of its high correlation with gross primary productivity (GPP), observations of sun-induced fluorescence (SIF) are of great interest. We developed a new remotely sensed SIF product with improved signal-to-noise in the tropics, and use it here to quantify the impact of the 2015/2016 El Ni\uffc3\uffb1o\uffc2\uffa0Amazon drought. We find that SIF was strongly suppressed over areas with anomalously high temperatures and decreased levels of water in the soil. SIF went below its climatological range starting from the end of the 2015 dry season (October) and returned to normal levels by February 2016 when atmospheric conditions returned to normal, but well before the end of anomalously low precipitation that persisted through June 2016. Impacts were not uniform across the Amazon basin, with the eastern part experiencing much larger (10\uffe2\uff80\uff9315%) SIF reductions than the western part of the basin (2\uffe2\uff80\uff935%). We estimate the integrated loss of GPP relative to eight previous years to be 0.34\uffe2\uff80\uff930.48 PgC in the three-month period October\uffe2\uff80\uff93November\uffe2\uff80\uff93December 2015.
This article is part of a discussion meeting issue \uffe2\uff80\uff98The impact of the 2015/2016 El Ni\uffc3\uffb1o on the terrestrial tropical carbon cycle: patterns, mechanisms and implications\uffe2\uff80\uff99.
", "keywords": ["0301 basic medicine", "FLUXES", "El Ni\u00f1o-Southern Oscillation", "Amazon rainforest", "sun-induced fluorescence", "El Ni\u00f1o Southern Oscillation", "drought response", "Forests", "SOUTHERN-OSCILLATION", "01 natural sciences", "Fluorescence", "Trees", "SCIAMACHY", "03 medical and health sciences", "GOME-2", "ATMOSPHERIC CARBON-DIOXIDE", "SATELLITE", "0105 earth and related environmental sciences", "El Nino-Southern Oscillation", "Amazone rainforest", "Articles", "15. Life on land", "tropical terrestrial carbon cycle", "gross primary production", "TERRESTRIAL CHLOROPHYLL FLUORESCENCE", "SIMULATIONS", "6. Clean water", "Droughts", "CLIMATE", "13. Climate action", "BALANCE", "Remote Sensing Technology", "Sunlight", "Brazil"]}, "links": [{"href": "https://royalsocietypublishing.org/doi/pdf/10.1098/rstb.2017.0408"}, {"href": "https://doi.org/10.1098/rstb.2017.0408"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Philosophical%20Transactions%20of%20the%20Royal%20Society%20B%3A%20Biological%20Sciences", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1098/rstb.2017.0408", "name": "item", "description": "10.1098/rstb.2017.0408", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1098/rstb.2017.0408"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2018-10-08T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=El+Nino-Southern+Oscillation&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=El+Nino-Southern+Oscillation&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=El+Nino-Southern+Oscillation&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=El+Nino-Southern+Oscillation&offset=3", "hreflang": "en-US"}], "numberMatched": 3, "numberReturned": 3, "distributedFeatures": [], "timeStamp": "2026-05-31T03:13:55.473876Z"}