JGR–Atmospheres

Precipitation in the Southern Plains of the United States is relatively well depicted by the Community Earth System Model (CESM). However, despite its ability to capture seasonal mean precipitation anomalies, CESM consistently underestimates extreme pluvial and drought events, rendering it an insufficient tool for extending simulation lead times for exceptional events, such as the abnormally dry May 2011, which helped drive Texas into its worst period of drought in more than a century, and the abnormally wet May 2015, which led to widespread flooding in that state. Ensemble-based regional climate experiments are completed for the two extreme years using Weather Research and Forecasting model (WRF) and downscaled from CESM. WRF simulations are at convection-permitting grid resolution for improved physical representation of simulated precipitation over the Southern Great Plains. By integrating convection-permitting models (CPMs) into each individual member of a CESM ocean data assimilation ensemble, this study demonstrates that high-resolution dynamical downscaling can improve model skillfulness at capturing these two events and is thus a potentially useful tool for forecasting extremely high and extremely low precipitation events at subseasonal or even seasonal lead times.

The surface temperature-mediated change in cloud properties, referred to as the cloud feedback, continues to dominate the uncertainty in climate projections. A larger number of contemporary global climate models (GCMs) project a higher degree of warming than the previous generation of GCMs. This greater projected warming has been attributed to a less negative cloud feedback in the Southern Ocean. Here, we apply a novel “double decomposition method” that employs the “cloud radiative kernel” and “cloud regime” concepts, to two data sets of satellite observations to decompose the interannual cloud feedback into contributions arising from changes within and shifts between cloud morphologies. Our results show that contributions from the latter to the cloud feedback are large for certain regimes. We then focus on interpreting how both changes within and between cloud morphologies impact the shortwave cloud optical depth feedback over the Southern Ocean in light of additional observations. Results from the former cloud morphological changes reveal the importance of the wind response to warming increases low- and mid-level cloud optical thickness in the same region. Results from the latter cloud morphological changes reveal that a general shift from thick storm-track clouds to thinner oceanic low-level clouds contributes to a positive feedback over the Southern Ocean that is offset by shifts from thinner broken clouds to thicker mid- and low-level clouds. Our novel analysis can be applied to evaluate GCMs and potentially diagnose shortcomings pertaining to their physical parameterizations of particular cloud morphologies.

Temperature measurements by zenith-pointing ground-based Rayleigh lidars are often used to detect middle atmospheric gravity waves. In time-height diagrams of temperature perturbations, stationary mountain waves are identifiable by horizontal phase lines. Vertically tilted phase lines, on the other hand, indicate that the wave source or the propagation conditions are transient. Idealized numerical simulations illustrate that and how a wave source moving in the direction of the mean wind entails upward-tilted phase lines. The inclination angle depends on the horizontal wavelength and the wave source’s propagation speed. On this basis, the goal is to identify and characterize non-orographic gravity waves (NOGWs) from propagating sources, for example, upper-level jet/front systems, in simulated lidar observations and actual Rayleigh lidar measurements. Compositions of selected atmospheric variables from a meteorological forecast or reanalysis are thoughtfully combined to associate NOGWs with processes in the troposphere and stratosphere. For a virtual observation over the Southern Ocean, upward-tilted phase lines indeed dominate the time-height diagram during the passage of an upper-level trough. The example also emphasizes that temporal filtering of temperature measurements is appropriate for NOGWs, especially in the presence of a strong polar night jet that implies large vertical wavelengths. During two selected observational periods of the COmpact Rayleigh Autonomous Lidar (CORAL) in the lee of the southern Andes, upward-tilted phase lines are mainly associated with mountain waves and transient background wind conditions. One nighttime measurement by CORAL coincides with the passage of an upper-level trough, but large-amplitude mountain waves superpose the small-amplitude NOGWs in the middle atmosphere.

In this study, a process-based lake model is used to investigate the influence of climate change on the thermodynamics of 30 large lakes over Tibetan Plateau (TP). The lake model was driven by the atmospheric forcing derived from the bias-corrected projections of three global climate models in the twenty-first century under three Shared Socioeconomic Pathways (SSPs). The hindcasts during 2000–2014 can reasonably capture the seasonality and magnitude of satellite retrieved lake surface temperature (LST). Future projections during 2015–2100 suggest a widespread increased LST, declined ice cover, and prolonged stratification, with the severity of changes in line with the climate driver shifts under different SSPs. Under the scenario with the highest level of anthropogenic radiative forcing (SSP5-8.5), the end-of-century (2086–2100) changes of LST, ice thickness, and stratification duration averaged across all studied lakes reach 4.90°C, −0.43 m, and 65.46 days, respectively. Note that the positive ice-albedo feedback can cause excess lake warming by accelerating ice break-up (30.07 days earlier) and stratification onset (46.83 days earlier). By the end of this century, more frequent, multi-seasonal thermal extremes are anticipated to push nearly half of the studied lakes into a permanent heatwave state. Together with the remarkable LST increase and winter ice loss, the lakes will mix less frequently and may shift from a dimictic to warm monomict mixing regime. Hopefully, the irreversible thermal changes can be avoided if the anthropogenic radiative forcing is controlled within the envelope outlined by the stringent climate mitigation scenario SSP1-2.6.

The South China coast (SCC) experiences frequent heavy rainfall during the warm season (May–September). Objective classification analysis on 925-hPa geopotential height shows that the majority of warm-season precipitation (>80%) occurs under three typical synoptic patterns: the southerly monsoon pattern (P1), the southwesterly monsoon pattern (P2), and the low-level vortex pattern (P3). Using 20 years of satellite observations and cloud tracking, this study highlights that mesoscale convective systems (MCSs) play a pivotal role in generating precipitation under all three synoptic patterns, while the initiation and rainfall characteristics of MCSs are strongly modulated by the background synoptic circulations. The diurnal MCS precipitation under P1 and P2 is predominantly influenced by land-sea breeze circulation, which is characterized by a morning offshore propagation and an afternoon onshore propagation. The rainfall propagation speeds, however, are strongly modulated by the prevailing low-level monsoonal flows. Under P3, MCS precipitation initiates near the coast around midnight and then propagates offshore, merging with the widespread offshore precipitation. The analysis also shows that the majority of MCSs contributing to SCC warm-season precipitation were locally initiated. This underscores the critical role of locally initiated MCSs in driving the SCC precipitation characteristics, as opposed to propagating MCSs. Statistical correlation analysis further indicates that the precipitation area and intensity of locally initiated MCSs are closely related to the lower-tropospheric moisture transport and the convective available potential energy over the upstream South China Sea, and the deep-layer wind shear (from surface to 400-hPa) over the SCC.

During atmospheric river (AR) landfalls on the Antarctic ice sheet, the high waviness of the circumpolar polar jet stream allows for subtropical air masses to be advected toward the Antarctic coastline. These rare but high-impact AR events are highly consequential for the Antarctic mass balance; yet little is known about the various atmospheric dynamical components determining their life cycle. By using an AR detection algorithm to retrieve AR landfalls at Dumont d'Urville and non-AR analogs based on 700 hPa geopotential height, we examined what makes AR landfalls unique and studied the complete life cycle of ARs reaching Dumont d'Urville. ARs form in the mid-latitudes/subtropics in areas of high surface evaporation, likely in response to tropical deep convection anomalies. These convection anomalies likely lead to Rossby wave trains that help amplify the upper-tropospheric flow pattern. As the AR approaches Antarctica, condensation of isentropically lifted moisture causes latent heat release that—in conjunction with poleward warm air advection—induces geopotential height rises and anticyclonic upper-level potential vorticity tendencies downstream. As evidenced by a blocking index, these tendencies lead to enhanced ridging/blocking that persist beyond the AR landfall time, sustaining warm air advection onto the ice sheet. Finally, we demonstrate a connection between tropopause polar vortices and mid-latitude cyclogenesis in an AR case study. Overall, the non-AR analogs reveal that the amplified jet pattern observed during AR landfalls is a result of enhanced poleward moisture transport and associated diabatic heating which is likely impossible to replicate without strong moisture transport.

Surface wind divergence is largely modulated by the sea surface temperature (SST) gradient through vertical momentum mixing and pressure adjustment. Here, the two mechanisms affecting the coupling strength between SST gradient and surface wind divergence are examined during an atmospheric front passage in the Southern Ocean. This event is also recorded by an uncrewed surface vehicle (USV). The reanalysis product (ERA5) revealed that downward momentum mixing is the dominant mechanism on the daily time scale. The coupling strength during the day when the atmospheric front passed over declined by 75%, compared to the adjacent days. This implies that the atmospheric front can partially attenuate the SST gradient effect on the surface wind divergence. Furthermore, a decade-long statistic also showed a decreasing trend of SST-wind coupling when the atmospheric fronts occur more. Additionally, after removing the mesoscale weather variation, the USV observations showed a remarkable SST imprint on the atmospheric boundary layer in the oceanic submesoscale regime, which denotes the scale below the deformation radius (∼16 km). The submesoscale air-sea interaction processes also displayed decreased air-sea coupling strength during atmospheric front passage. This is possible as the vertical velocity induced by the atmospheric front can compensate for the daily averaged uprising vertical velocity due to surface wind convergence. This analysis indicates that the atmospheric front can diminish the coupling between the SST gradient and surface wind divergence, which contrasts the existing statistical results showing that atmospheric fronts tend to enhance such coupling.

During past glacial-interglacial cycles, the boreal summer insolation is the most crucial external forcing for climate change. However, the question of whether summer insolation is a key forcing on temperatures in the boreal tropics remains under debate, hampering our understanding of climate change at low latitudes. To shed further light on this issue, we performed a series of equilibrium simulations with the NorESM-L model over the past 425 ka. Our simulations show that in the boreal tropical monsoon region, the simulated annual temperature is anti-phased towards the boreal summer insolation. This antiphase relation is also supported by some available geological data. Additional diagnostic analyses reveal that the tropical warmth throughout the year is more reliant on winter temperatures than on summer temperatures. This stands in contrast to the situation in middle to high latitudes, particularly in the Mediterranean region. Further correlation analysis and spectrum analysis suggest that the annual temperature in boreal tropics is highly linked to local winter insolation. Our results highlight complex hydrothermal configurations in the boreal tropics, suggesting a decoupling of temperature and precipitation. Specifically, variations in annual temperature and precipitation in the boreal tropics are driven by distinct patterns of seasonal insolation. We deduce that the unique hydrothermal configurations in North Africa may have influenced the dispersal of early humans out of Africa.

Residential biomass burning significantly contributes to air pollution in developing countries. However, the microscopic properties of individual particles in their emissions have not been well understood. In this study, individual primary particles from 14 kinds of biomass fuels (including firewood, crop residue, and animal dung) were collected in laboratory and field measurements, and their morphology, composition and mixing state were acquired using transmission electron microscope. These results constitute a source profile database of individual primary particles from residential biomass burning. The database reveals that different types of biomass fuels exhibit different emission characteristics, that is, residential firewood burning mainly emits pure carbonaceous particles (including organic matter (OM) and soot particles), crop residue burning mainly emits K-containing particles (including OM-K, soot(-OM)-K, and K-rich particles), and animal dung burning mainly emits pure carbonaceous particles and K-containing particles. Moreover, our results indicate that the emission characteristics obtained from laboratory and field measurements are different. Field measurements conducted in two selected villages in North China Plain exhibit a higher presence of soot particles compared to laboratory measurements, owing to their higher combustion temperatures. In contrast, field measurements conducted in one selected village in Qinghai-Tibet Plateau contain less soot particles than those from laboratory measurements in plain areas, due to the deficient oxygen supply during combustion process in the high-altitude regions. These results warn us that the emission estimation from residential biomass burning should notice the large emission differences among different biomass types and between field and laboratory measurements.

This study examines the spatial distribution and temporal variations of low-cloud top over the subtropical northeast Pacific (NEP), using observations from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). A comparison between CALIPSO observations and in-situ soundings reveals a distinct bimodal distribution of low-cloud tops, characterized by peaks near the inversion base and transition layer, corresponding to shallow cumulus clouds below the stratocumulus deck and boundary-layer decoupling phenomena. Climatologically, while traversing along a great circle from Los Angeles to Honolulu, the frequency of low cloud occurrence experiences a gradual reduction from 80% to 30%. Meanwhile, cloud top height increases from 0.6 to 1.6 km, and surface roughness varies from 50 to 300 m. This study marks the first presentation of long-term characteristics of low clouds over a vast, remote area, expanding beyond discrete field campaign observations. Accurately characterizing the marine atmospheric boundary layer (MABL) including its depth and degree of decoupling, enables further investigation into the interannual variations of low clouds, using 14 years of CALIPSO observations. Significant interannual variability in areal fraction and vertical bimodality of low clouds emerges downstream of the anomalously cold water; increased cloud cover with weakened bimodality is associated with a shallow weakly decoupled MABL. This research emphasizes the need to consider the downstream effects in studying low cloud-sea surface temperature feedback within climate models.

Mesoscale convective systems (MCSs) are clusters of thunderstorms that are important in Earth's water and energy cycle. Additionally, they are responsible for extreme events such as large hail, strong winds, and extreme precipitation. Automated object-based analyses that track MCSs have become popular since they allow us to identify and follow MCSs over their entire life cycle in a Lagrangian framework. This rise in popularity was accompanied by an increasing number of MCS tracking algorithms, however, little is known about how sensitive analyses are concerning the MCS tracker formulation. Here, we assess differences between six MCS tracking algorithms on South American MCS characteristics and evaluate MCSs in kilometer-scale simulations with observational-based MCSs over 3 years. All trackers are run with a common set of MCS classification criteria to isolate tracker formulation differences. The tracker formulation substantially impacts MCS characteristics such as frequency, size, duration, and contribution to total precipitation. The evaluation of simulated MCS characteristics is less sensitive to the tracker formulation and all trackers agree that the model can capture MCS characteristics well across different South American climate zones. Dominant sources of uncertainty are the segmentation of cloud systems in space and time and the treatment of how MCSs are linked in time. Our results highlight that comparing MCS analyses that use different tracking algorithms is challenging. We provide general guidelines on how MCS characteristics compare between trackers to facilitate a more robust assessment of MCS statistics in future studies.

Contributions of the resolved waves and parameterized gravity waves to changes in the quasi-biennial oscillation (QBO) in a future simulation (2015–2100) under the SSP370 scenario are investigated using the Community Earth System Model 2 (CESM2) with enhanced vertical resolution and are compared with those from four CESM2 historical simulations (1979–2014). The maximum QBO amplitude of the future simulation is 26.0 m s−1, which is slightly less than that of the historical simulations (27.4–29.3 m s−1). However, the QBO period in the future simulation is much shorter: 21.6 months in the early-future (2015–2050) and 12 months in the late-future (2065–2100) period, than in the historical simulations (23.5–30.9 months). The shortened QBO period in the future is primarily due to increases in both resolved wave forcing and parameterized gravity wave drag (GWD) in the stratosphere, with a more significant contribution by the GWD. As convective activity becomes stronger in the future simulation, the momentum flux of parameterized convective gravity waves at the cloud top increases, resulting in stronger GWD in the stratosphere. The increases in the magnitude of westward GWD dominate those of eastward GWD in the stratosphere. This is due to a significant increase in westward momentum flux in the troposphere, especially during the descending easterly QBO, and enhanced westerlies in the lowermost stratosphere, which introduces a westward anomaly. For the resolved waves, Kelvin wave forcing is a key contributor to increased eastward forcing in the future simulation, with relatively minor contributions by other equatorial planetary waves.

Quantifying the elevation dependency of radiation partitioning in high-altitude mountains is crucial for projecting regional energy balance while remains highly uncertain. We compared the surface radiation partitioning parameters across a meadow (3,200 m), shrub (3,400 m), and forb (3,600 m) along a southern slope of the Qilian Mountains. At a daily scale, the downward shortwave radiation (R s) fluctuated minimally among the grassland types probably induced by similar site orientations. The greatest downward and upward longwave radiation (L d and L u) happened at the lowest meadow while the largest net shortwave (S n) and longwave (L n) radiation occurred at the deciduous shrub. The net all-wave radiation (R n ) of the meadow and shrub was similar and exceeded that of the forb by ∼20%. The differences in R n between the sites were jointly explained by those of upward shortwave radiation (R u) and L u, more than by R s and L d, suggesting the importance of surface attributes. The monthly normalized effective terrestrial radiation (λ, the ratio of L n to R s) varied insignificantly among the sites and averaged 0.25 ± 0.05, which was comparable to the global mean value (0.26). The smallest surface albedo (α, the ratio of R u to R s) and largest radiation efficiency (η, the ratio of R n to R s) were 0.13 ± 0.02 and 0.64 ± 0.09, respectively, both at the shrub. Grassland type dominated the spatial variations of monthly α and η. These findings highlighted the importance of grassland types to explain the spatiotemporal variations of radiation partitioning parameters in high-altitude alpine grasslands.

The limited capabilities of global climate models in simulating mesoscale convective systems (MCSs) restrict our understanding of how global warming impacts MCSs. This study uses a high-resolution numerical model with large-ensemble experiments to simulate MCSs during the record-breaking extreme rainfall event in Henan Province, China, in July 2021. We compare the changes in the MCS's strength, size, and structure in a real-world simulation (RW) and a 0.8°C colder simulation (analog to no-anthropogenic-warming-world simulation, short for NAWW) to assess the response of MCSs to global warming. Our results show that the total rainfall from the MCS increased by 10.0% in RW compared to NAWW, with a 3.1% increase in area and a 6.7% increase in rainfall intensity. The development of MCS becomes more rapid in response to warming since the pre-industrial era. The warmer and wetter climate results in higher convective available potential energy, and accelerates the MCS growth, but then the narrower low-convective inhibition regions suppress the continuous growth of MCS. During the mature phase, the maximum hourly rainfall intensity (P max) can increase by up to 26.5%/K, while P max locations can either remain unchanged or shift depending on the interaction of flows and terrains. These results highlight varying responses of MCSs to global warming during its different stages and provide valuable insights into the changing characteristics of extreme rainfall events under global warming.

The historic 22–26 May 2015 flood event in Texas and Oklahoma was caused by anomalous clustered mesoscale convective systems (MCSs) that produced record-breaking rainfall and $3 billion of damage in the region. A month-long regional convection-permitting simulation is conducted to reconstruct multiple clustered MCSs that lead to this flood event. We further use the pseudo global warming approach to examine how a similar event may unfold in a warmer climate and the driving physical factors for the changes. Tracking of MCSs in observations and simulations shows that the historical simulation reproduces the salient characteristics of the observed MCSs. In a warmer climate under a high-emission (SSP5-8.5) scenario, the Southern Great Plains is projected to experience a near surface warming of 4–6 K, accompanied by enhanced moisture transport by the strengthened Great Plains low-level jet. A warmer and moister lower troposphere leads to 36%–59% larger convective available potential energy, supporting wider and more intense convective updrafts and rainfall production. Consistently, MCSs have wider convective areas and stronger rainfall intensities, producing 50% larger rain volumes during the mature stage. Extreme (99.5%) MCS rainfall frequency and amount will increase by threefold. However, MCS stratiform rain area decreases as a result of elevated stratiform cloud bases that lead to stronger sublimation and evaporation of precipitation in response to warming, resulting in reduced weak-to-moderate surface precipitation. Results suggest that global warming greatly increases precipitation intensity of clustered MCS events under strong synoptic influence, with much higher potential to produce serious floods without additional climate adaptation.

Satellites in Earth's orbit are exposed to Earth radiation, consisting of reflected solar and emitted thermal radiation, thereby exerting a non-conservative force that causes acceleration and affects the orbits. Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission aiming to retrieve the Earth's gravity potential is critically dependent on accounting for this force and all other non-gravitational forces. There are both diurnal and seasonal variations in the Earth's radiation pressure, of which the seasonal variability can be represented by climatology. Nevertheless, the daily variations in the Earth's radiation pressure, due to the transient changes in the weather; for example, clouds and their properties, are not accounted for in the orbit perturbations studies. We show here that the top-of-atmosphere radiation fluxes computed with a numerical weather prediction (NWP) model explain most of the measured short-term variations in the radial acceleration of the GRACE-FO satellite. Our physics-based modeling corrects a hitherto unexplained lack of power spectral density in the measured accelerations. For example, we can accurately model the accelerations associated with a tropical storm in the Indian Ocean in December 2020, which would not be possible when using climatological data. Our results demonstrate that using a global numerical weather prediction model significantly improves the simulation of non-gravitational effects in the satellites' orbits. In the 7-day data set, OpenIFS-simulated acceleration exhibited higher accuracy than climatological-data-simulated acceleration (2.5 compared to 2.6 nms−2) and an improved precision (2.6 compared to 3.0 nms−2). This advancement contributes to a more precise orbit determination across various applications in Earth sciences.

We use the GEOS-Chem chemistry transport model to quantify the factors in the diel discrepancy of Aerosol Optical Depth (AOD) retrieved from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) satellite observations over eastern China. The GEOS-Chem simulation reveals that the AOD below 1 km is 58.5% larger at night than during the daytime, which is comparable to the counterpart of 41.3% from CALIOP (v4.2). Model sensitivity simulations show that the diurnal variation in wind barely impacts the AOD difference between daytime and nighttime, and the increase in AOD at nighttime is primarily caused by the lower temperature at nighttime compared to daytime. Further simulations demonstrate that the low temperature at night increases AOD primarily by increasing relative humidity, and hence particle hygroscopic growth, while the effect of temperature on chemical rate barely influences AOD. CALIOP also observes that the absolute difference in AOD above 1 km between nighttime and daytime is 0.105, while the counterpart in GEOS-Chem simulations is −0.031. This contrast can be partly explained by the factor that the percentage of valid CALIOP retrievals below 5 km is 15%–20% greater at nighttime than in the daytime due to the CALIOP detection limit. Removing the detection limit impact decreases the difference in the CALIOP AOD above 1 km between nighttime and daytime to 0.073.

In global forecasting systems, tropical cyclone (TC) intensity is usually underestimated, which is one of the major challenges for TC forecasting. One possible reason is the deficiency of physical parameterizations associated with ocean surface waves. To improve the TC intensity forecast, effects of two powerful wave-related processes, the spray-mediated heat flux and surface roughness, are considered in a global coupled ocean-atmosphere-wave system (CFSv2.0-WW3). Serial 24 hr forecasting experiments for all TCs from May to October 2019 are conducted, and comparisons are made against the International Best Track TC data. The results show that for strong TCs the underestimation of TC intensity in CFSv2.0-WW3 is significantly improved by the modified surface roughness parameterization and the accelerated spray heat flux parameterization based on Gaussian Quadrature. For major hurricanes with initial wind speeds above 30 m/s, the error of TC maximum wind speed decreases by about 34.4%. To understand the associated dynamic and thermodynamic processes, a series of 120 hr simulations for major hurricane Hagibis is conducted. The effect of spray-mediated heat flux accounts for 91.7% of the TC intensity improvement. The increased heat fluxes offset the negative contributions of vertical advection and ventilation, leading to enhanced entropy. The low-level pressure is then decreased, resulting in enhanced convergence of absolute vorticity, which overpowers the negative effects of frictional dissipation and vertical momentum advection. The study indicates that the application of these two wave-related parameterizations can potentially improve the global forecast and reanalysis of TC intensity.

South America is a large continent situated mostly in the Southern Hemisphere (SH) with complex topography and diverse emissions sources. However, the atmospheric chemistry of this region has been historically understudied. Here, we employ the Multi-Scale Infrastructure for Chemistry and Aerosols, a novel global circulation model with regional refinement capabilities and full chemistry, to explore the sources and distribution of the carbon monoxide (CO) tropospheric column in South America during 2019, and also to assess the effect that South American primary emissions have over the rest of the world. Most of the CO over South America can be explained either by non-methane volatile organic compounds (NMVOC) secondary chemical production or by biomass burning emissions, with biomass burning as the main explanation for the variability in CO. Biomass burning in Central Africa is a relevant contributor to CO in all of the continent, including the southern tip. Biogenic emissions play a dual role in CO concentrations: they provide volatile organic compounds that contribute to the secondary CO production, but they also destroy OH, which limits the chemical production and destruction of CO. As a net effect, the lifetime of CO is extended to ∼120 days on average over the Amazon, while still being in the range of 30–60 days in the rest of South America.

Land surface temperature anomalies can be linked to changes in local surface energy balance, although the relationship between surface temperature variability and individual radiative processes remains unclear. In this paper, we quantify the contributions of surface radiative effects and non-radiative heat fluxes to the variance of monthly land surface temperature using European Centre for Medium-Range Weather Forecasts Reanalysis v5 data and Coupled Model Intercomparison Project Phase 6 simulations. The surface energy budget equation is used to link changes in surface radiation, surface heat fluxes and land surface temperature. Subsequently, surface radiation is decomposed into the radiative effects of clouds, air temperature, surface albedo and relative humidity using radiative kernels. The contributions of these radiative processes, including their coupling effects, are quantified using covariance matrices. The results reveal the air temperature radiative effect to be the most significant contributor to the variability of land surface temperature. In addition, the covariance terms reveal important coupling effects. For example, the contribution from the cloud radiative effect is found to be substantially dampened by its coupling with surface heat fluxes. The air temperature radiative effect is further decomposed into a forcing component and a feedback component using different regression methods, in an attempt to separate the air temperature radiative effect as the driver of the surface temperature variability. The cloud radiative effect becomes the primary contributor to the variance of surface temperature after separating the air temperature feedback, while the contribution of the air temperature radiative forcing remains important.