National Centre for Atmospheric Science

A month's worth of rain in a day?

Abstract Phrases like ‘a month’s worth of rain in a day’ make for dramatic news headlines. But how often do such events occur? Are they more likely in certain locations or seasons? And can we expect more in the future? Here we examine these questions for the UK using observations...

Satellite-based global monitoring of urban-scale methane emissions

Quantifying and understanding methane emissions of cities are of great importance given their role in current and future mitigation efforts to reduce climate-forcing emissions. However, it remains challenging to routinely and accurately characterize and verify city-scale methane...

New Constraint on Future Ocean Heat Uptake Revealed by Considering Model Spread of Radiative Forcing

Abstract Radiative forcing is the fundamental driver of ocean heat uptake ; however, its contribution to intermodel spread in has not been quantified. We address this gap by leveraging a new set of CMIP6 experiments that diagnoses time‐varying for the first time in 11 models. Amo...

The Cloud Feedback Model Intercomparison Project (CFMIP) contribution to CMIP7

Cloud processes constitute one of the key uncertainties for climate change projections. The fourth iteration of the Cloud Feedback Model Intercomparison Project, CFMIP4, contributes to the Coupled Model Intercomparison Project phase 7 (CMIP7), by providing a set of global climate...

Synoptic and large‐scale drivers of extreme precipitation events in the Himalayas

Abstract Extreme precipitation events (EPEs) in the Western Himalayas (WH) have significant cross‐sector impacts, yet understanding of their seasonal characteristics and synoptic drivers remains inadequate. This study presents an analysis of EPEs across the full annual cycle of t...

Rare events algorithm study of extreme double jet summers and their connection with heatwaves over the Northern Hemisphere

Abstract Several large scale circulation patterns have been identified in relation to extreme Northern Hemisphere summer heatwaves. Three main ones are a double jet over Eurasia, a positive phase of the summer northern annular mode, and a quasi-wave-3 geopotential height anomaly....

Extratropical teleconnections in a multi-model ensemble nudged towards the observed QBO

The Quasi-Biennial Oscillation (QBO), the dominant mode of interannual variability of monthly-mean zonal winds and temperatures in the equatorial stratosphere, has a significant influence on the circulation in other regions of the stratosphere and troposphere in boreal winter. To...

Seasonal predictability of winter PM 2.5 pollution severity in India through a strong pollution–extratropical storm connection

India suffers from severe fine particulate matter (PM 2.5 ) air pollution in winter that harms public health and disrupts economic activities. Seasonal prediction of pollution severity could facilitate proactive mitigation planning but is hindered by incomplete understanding of t...

Challenges in measuring sticky biogenic ice-nucleating macromolecules

Abstract. Ice-nucleating particles (INPs) are aerosol particles that influence mixed-phase clouds and in doing so impact weather and climate worldwide. To improve our understanding of ice production in mixed-phase clouds, we need techniques capable of accurately measuring atmosph...

A comparison of the UK 's hot, dry summers of 1976 and 2025

Abstract Summer 2025 was the warmest so far recorded for the UK, and low precipitation amounts in preceding months and through the summer led to drought conditions in many areas of the UK. The hot, dry conditions prompted many comparisons with the infamous hot, dry summer of 1976...

An energetic perspective on the impact of the Atlantic Multidecadal Variability on the West African Monsoon

Abstract. This study explores mechanisms by which the Atlantic Multidecadal Variability (AMV) drives multidecadal changes in the West African Monsoon (WAM), with a focus on Sahel rainfall. We investigate this connection through an energetic perspective using atmosphere-ocean coup...

PyActiveStorage: Energy-Efficient Workflows for Exascale Data

As climate modeling enters the exascale era, data volumes are outstripping the capacity of traditional networks. The conventional approach of transferring petabytes from remote storage to local compute is increasingly non-viable due to high latency and the unsustainable energy co...

Recent globally synchronous seasonal warm events unprecedented since 850 CE

Spatially synchronous extreme warm events can amplify environmental and societal impacts by affecting multiple regions simultaneously. However, previous studies have largely focused on June–August (JJA) events during the instrumental period, limiting understanding of their season...

The UK Clean Air Act at 70: An interdisciplinary analysis of historical air quality change

Abstract 2026 marks the 70th anniversary of the first UK Clean Air Act, a pivotal moment for air quality in modern British history. Previous narratives on this legislation have largely centred on pollution in London and monodisciplinary perspectives. This article integrates histo...

Evaluating urban heat adaptation strategies for extreme heatwaves in complex terrain: A case study of Grenoble, France

Urban heat adaptation strategies are critical for mitigating the impacts of ex- treme heat events in cities, particularly as climate change exacerbates their intensity and frequency. This study evaluates a set of adaptation strategies during the 2023 heatwave in Grenoble, France,...

Exploring the hydrogen abstraction pathway in HOM formation from α -pinene photooxidation systems under varying NO conditions

Abstract. Highly oxygenated organic molecules (HOM) are formed via autoxidation during ⚫OH-initiated oxidation of α-pinene. We investigated the relative contributions of OH-addition and hydrogen (H)-abstraction to HOM formation from α-pinene photooxidation under varying nitrogen...

Effects of surface fluxes on the moist potential vorticity distribution in the axisymmetric tropical cyclone boundary layer

Abstract This study investigates the structure and dynamics of simulated tropical cyclone boundary layers (TCBLs) using a moist potential vorticity () framework. in the boundary layer of tropical cyclones is related to the distribution of equivalent potential temperature () and a...