A multi‐satellite framework to rapidly evaluate extreme biosphere cascades: The Western US 2021 drought and heatwave

Abstract

The increasing frequency and intensity of climate extremes and complex ecosystem responses motivate the need for integrated observational studies at low latency to determine biosphere responses and carbon‐climate feedbacks. Here, we develop a satellite‐based rapid attribution workflow and demonstrate its use at a 1–2‐month latency to attribute drivers of the carbon cycle feedbacks during the 2020–2021 Western US drought and heatwave. In the first half of 2021, concurrent negative photosynthesis anomalies and large positive column CO2 anomalies were detected with satellites. Using a simple atmospheric mass balance approach, we estimate a surface carbon efflux anomaly of 132 TgC in June 2021, a magnitude corroborated independently with a dynamic global vegetation model. Integrated satellite observations of hydrologic processes, representing the soil–plant–atmosphere continuum (SPAC), show that these surface carbon flux anomalies are largely due to substantial reductions in photosynthesis because of a spatially widespread moisture‐deficit propagation through the SPAC between 2020 and 2021. A causal model indicates deep soil moisture stores partially drove photosynthesis, maintaining its values in 2020 and driving its declines throughout 2021. The causal model also suggests legacy effects may have amplified photosynthesis deficits in 2021 beyond the direct effects of environmental forcing. The integrated, observation framework presented here provides a valuable first assessment of a biosphere extreme response and an independent testbed for improving drought propagation and mechanisms in models. The rapid identification of extreme carbon anomalies and hotspots can also aid mitigation and adaptation decisions.

A daily gap-free normalized difference vegetation index dataset from 1981 to 2023 in China

“…The reconstructed daily NDVI dataset can provide crucial data support for better understanding the vegetation responses under climate and environmental changes, especially for rapidly occurring climate extremes 41 – 43 . Furthermore, our reconstructed daily gap-free NDVI can offer essential data support for improving the inversion reliability and temporal resolution of related vegetation parameters (e.g., gross primary productivity and net primary productivity 44 ).…”

Satellite-detected large CO2 release in southwestern North America during the 2020–2021 drought and associated wildfires

“…With future drought and heat events expected to increase (Meehl andTebaldi 2004, Zacharias et al 2014), understanding the response of terrestrial ecosystems to drought events is crucial for predicting the fate of terrestrial carbon sinks and future climate. Recently, several studies have paid attention on the impact of the southwest U.S. droughts in 2020 and (or) 2021 on terrestrial photosynthesis or gross primary production (Dannenberg et al 2022, Feldman et al 2023, Li et al 2023, yet none of them studied the impact of the full 2020-2021 event on the terrestrial net carbon uptake, which would potentially provide a more completed picture about the response of its ecosystem carbon sequestration to this event.…”

Emerging Methods to Validate Remotely Sensed Vegetation Water Content

“…Fundamental insights into plant function with global satellite VOD have been extensive. Some examples include, but are not limited to, forest drought resilience and mortality (Anderegg et al, 2020;Rao et al, 2019), carbon stocks (Brandt et al, 2018;Fan et al, 2019), tropical vegetation seasonality (Guan et al, 2014;Jones et al, 2014), ecosystem drought cascade (Entekhabi, 2023;Feldman et al, 2023), stomatal regulation strategies Liu et al, 2021a), sub-seasonal response to atmospheric variability (Harris et al, 2022), crop yields and phenology (Chaparro et al, 2018;Hornbuckle et al, 2015), and plant pulse response to rain events (Feldman et al, 2018).…”