Satellites Suggest Rising Tropical High Cloud Altitude: 2002–2021

Tropical upper-troposphere clouds are expected to rise under global warming, contributing a positive radiative feedback. Here we show that Moderate Resolution Imaging Spectroradiometer (MODIS) retrievals over 2002–2021 from the Terra and Aqua satellites report tropical-mean high-cloud altitude increase of 6.9 ± 2.7 m yr−1 (±2σ), while atmospheric models 5.6 3.0 1979–2014. During their common overlap period, however, observed trend is greater than models. The also tropically confined cloud-height response El Nino, whereas cloud height peak extends into subtropics. Poleward mid-latitudes, MODIS have drifts relative each other, highlighting need for deeper investigation potential time-dependent biases in retrievals. Both sensors significant tropical increases since 2002, which statistically consistent with those simulated by climate