Upper-tropospheric Temperature Research Articles

Lightning activity in India an important cause of increase in fatalities

With Recent increase in deaths due to lightning activity in India we are posed with a question - are these fatalities related to increase in the lightning activity owing to climate change? The IPCC report (2013) projects global warming of 1-5 °C by the end of 21st Century. The global warming is closely related to increased concentration of greenhouse gases. Previous studies have shown that on different temporal and spatial scales small increases in surface temperature leads to increase in thunderstorm and lightning activity. The lightning induced deaths are on the rise especially in the tropical south Asia and Africa but IPCC report does not explicitly deals with lightning activity and its future projection. Studies on this aspect become all the more important as the subgrid scale phenomena such as convective clouds and hence lightning are poorly resolved and taken in to account by climate models. In order to address this issue we have analyzed trends of lightning activity, surface temperature, upper tropospheric water vapour, cloud ice, Convective Available Potential Energy (CAPE) and aerosols. We also present correlation of these parameters with lightning activity using lightning flash rate data of Lightning Imaging Sensor aboard TRMM, TRMM Level -2 Precipitation Radar data, gridded temperature data of IMD, aerosol data acquired by MODIS. The result indicates that upper tropospheric temperature rise is more than surface temperature rise. This imply stable atmosphere with fewer thunderstorms. The increased convection transports additional water vapour into upper troposphere. The water vapour acts as green house has by absorbing infrared radiation emitted by the surface of the Earth. This results in more warming in the upper troposphere than at the surface and stabilizing of the atmosphere. However, results also show that within the thunderstorm the instability measured by CAPE is positively correlated with lightning activity. This paradox of stabilization of global mean atmosphere with increase in lighting activity leads us to conclude that tough thunderstorm activity has subdued but those develop are much more explosive producing more lightning activity and perhaps lead to more fatalities.

Nocturnal Extreme Rainfall over the Central Yungui Plateau under Cold and Warm Upper-Level Anomaly Backgrounds during Warm Seasons in 1980–2020

The spatiotemporal and cloud features of the extreme rainfall under the warm and cold upper-level anomalies over the central Yungui Plateau (YGP) were investigated using the hourly rain gauge records, ERA5 reanalysis data, TRMM, and Fengyun satellite data, aiming to refine the understanding of different types of extreme rainfall. Extreme rainfall under an upper-level negative temperature anomaly (cold events) presents stronger convective cloud features when compared with the positive temperature anomaly (warm events). The maximum rainfall intensity and duration in cold events is much larger than that of warm events, while the brightness temperature of the cloud top is lower, and the ratio of convective rainfall is higher. In cold events, the middle-to-upper troposphere is dominated by a cold anomaly, and an unstable configuration with upper (lower) cold (warm) anomalies is observed around the central YGP. Although the upper-level temperature anomaly is positive, the anomalous divergence and convergence of southerly and northerly winds, as well as the strong moisture center and upward motions, are also found over the central YGP in warm events. The stronger atmospheric instability and higher convective energy under the upper-level cold anomalous circulation are closely associated with the rainfall features over the central YGP. The results indicate that the upper tropospheric temperature has significant influences on extreme rainfall, and thus more attention should be paid to the upper tropospheric temperature in future analyses.

On the association of Pacific Decadal Oscillation with the interdecadal variability in Asian-Pacific Oscillation

The Asian-Pacific Oscillation (APO), featuring a seesaw pattern in the upper-tropospheric temperatures between Asia and the North Pacific, plays profound roles in the Northern Hemispheric climate anomalies. So, its variability and associated physical mechanisms are of great interest. Although progress has been achieved for the APO variability at the interannual time scale, the understanding of its interdecadal variability remains relatively poor. Based on the twentieth-century reanalysis and the simulations of the preindustrial control, Pacific pacemaker, and large ensemble experiments, this study reports a salient contribution of the Pacific Decadal Oscillation (PDO) to the interdecadal variability of the APO during summer, featured as a warm (cold) PDO phase accompanying a negative (positive) APO polarity. During the warm PDO phase, the sea surface temperature (SST) warming over the eastern Pacific is conducive to local ascending anomalies, which teleconnect with descending anomalies over the Tibetan Plateau through zonal vertical circulations. The anomalous ascent (descent) over the eastern Pacific (Tibetan Plateau) tends to strengthen (weaken) the atmospheric heating, beneficial for a warming (cooling) of the troposphere in situ. In addition, the PDO-related meridional SST gradient anomalies favor a southward shift of the subtropical jet stream, weakening the South Asian high and the North Pacific trough in the upper troposphere, which corresponds to the atmospheric situation of a negative APO phase. Quantitative analysis from the large ensemble simulations indicates that the PDO may contribute to approximately 48% of recent APO interdecadal variation from the negative phase to the positive phase in the late 1990s.

Recent autumn sea ice loss in the eastern Arctic enhanced by summer Asian-Pacific Oscillation

Recent rapid Arctic sea ice loss was documented as combined results from anthropogenic forcing and climate system internal variability. However, the role of internal variability is not well understood. Here, we propose that the Asian-Pacific Oscillation (APO), an intrinsic atmospheric mode featuring out-of-phase variations in upper-tropospheric temperatures between Asia and the North Pacific, is one driver for autumn sea ice variability in the eastern Arctic. The positive summer APO favors warming of the mid-latitude North Atlantic sea surface temperatures. This warming persists to autumn and in turn triggers strong anticyclonic anomalies over the Barents-Kara-Laptev Seas and weak lower-tropospheric cyclonic anomalies over the East Siberian Sea, enhancing moisture transport into the eastern Arctic. Such changes consequently increase lower-tropospheric humidity, downwelling longwave radiation, and surface air temperature in the eastern Arctic, thereby melting sea ice. Hence, a recent tendency of the summer APO towards the positive phase accelerates autumn sea ice loss in the eastern Arctic.

Process-Based Attribution of Summer Upper-Tropospheric Temperature Related to the South Asian Summer Monsoon

Abstract Using the ERA5 reanalysis data and the Climate Feedback Response Analysis Method (CFRAM), we attribute the mechanism of summer upper-tropospheric temperature (UTT) variations in the South Asian summer monsoon (SASM) region to several external forcing and internal feedback processes. The summer UTT in the SASM region is dominated by two modes. The first empirical orthogonal function (EOF) mode (EOF1) is a monopolar warming pattern, and the second EOF mode (EOF2) shows a meridional dipole pattern. CFRAM results show that summer UTT anomalies are mainly attributed to cloud feedback and nonradiative processes of atmospheric dynamics (ATD) and surface-related processes. For EOF1, ocean heat storage and partial cloud feedback processes contribute most UTT anomalies over the Indian Ocean. The ATD increases the UTT over East Asia through the adiabatic warming caused by anomalous anticyclone in the upper troposphere. The formation of EOF2 is closely linked to the ATD, while the cloud process partially compensates for the excessive changes in UTT caused by the ATD. The South Asian high and its circulation in the midlatitude region are significantly enhanced. The anomalous anticyclone over northern East Asia along with the anomalous easterly wind on the south side of the South Asian high favors increased warm advection and adiabatic heating, contributing to the warming of UTT. Meanwhile, adiabatic cooling resulting from the atmospheric ascent in the middle and upper troposphere leads to UTT cooling over the Indian Ocean. The quantitative attribution of UTT has great implications for better understanding future SASM variation. Significance Statement The purpose of this study is to understand the physical mechanisms of upper-tropospheric temperature (UTT) changes in the South Asian summer monsoon (SASM). Although previous studies have examined temperature variation from the perspective of atmospheric circulation, there has been limited investigation into the influence of various feedback processes. Our study reveals that the summer UTT in the SASM region is dominated by monopolar and meridional dipole modes. Utilizing a climate feedback–response analysis method, we attribute the UTT anomalies in the SASM region to the cloud feedback, oceanic heat storage, and atmospheric dynamics processes, and explore the physical mechanisms of their effects. These results have important implications for the better prediction of monsoon variability.

Spatial and Seasonal Variations of Sea Surface Temperature Threshold for Tropical Convection

Abstract Tropical rainfall variations are of direct societal relevance and drive climate variations worldwide via teleconnections. The convective rainfall tends to occur when sea surface temperature (SST) exceeds a threshold, SSTthr, usually taken to be constant in time and space. We analyze 40-yr monthly observations and find that SSTthr varies by up to 4°C in space and with season. Based on local convective instability, we develop a quantitative theory that largely explains the SSTthr variations using the climatological state of the tropical atmosphere. Although it is often assumed that spatial variations of tropical upper-tropospheric temperature are small and can be neglected, it is shown that lower climatological values favor a lower SSTthr. Similarly, a small increase in climatological surface relative humidity also leads to a decrease in SSTthr, as does a lower climatological air–sea temperature difference. Consequently, efforts to understand and predict natural or forced variations in tropical rainfall must account for, in addition to SST, the temperatures aloft and the near-surface humidity and temperature and requires improved understanding of what controls their distribution in space and time.

All‐sky infrared radiance assimilation of a geostationary satellite in the Japan Meteorological Agency's global system

AbstractAll‐sky assimilation of infrared (IR) radiances has been developed for water vapor bands of the geostationary satellite Himawari‐8 in the operational global data assimilation system. Cloud‐dependent quality control, bias correction, and observation error modeling are essential developments to effectively utilize the all‐sky radiances (ASRs). ASR assimilation increases the assimilated number of observations by 2.8 times and improves the coverage relative to the traditional clear‐sky radiance (CSR) assimilation. The additional observations better alleviate model dry biases in the middle and upper tropospheric humidity. ASR assimilation brings statistically significant improvements in the background (first guess) in humidity, temperature, and wind over the CSR assimilation. It also better improves short‐range forecasts of the middle and upper tropospheric temperature and humidity up to day 3 in the Tropics. A mixed impact in the stratospheric temperature is under investigation. The impacts of various aspects of the ASR assimilation configuration are evaluated with sensitivity assimilation experiments. The interband correlation and cloud‐dependent standard deviation of the observation error are crucial, whereas the cloud dependency of the correlation is not so important. Although ASRs at a single band were assimilated in many previous studies targeting severe weather using research‐based regional assimilation systems due to decreasing independent information in the presence of clouds, they are distinctly inferior to not only ASRs at multiple bands but also CSRs at multiple bands in a global data assimilation system that contains fewer cloud‐affected scenes. The cloud‐dependent bias correction predictors are essential in the presence of observation‐minus‐background bias that increases with cloud effects.

Trends in the atmospheric jet streams are emerging in observations and could be linked to tropical warming

Climate models predict a weak poleward shift of the jets in response to continuing climate change. Here we revisit observed jet trends using 40 years of satellite-era reanalysis products and find evidence that general poleward shifts are emerging. The significance of these trends is often low and varies between datasets, but the similarity across different seasons and hemispheres is notable. While much recent work has focused on the jet response to amplified Arctic warming, the observed trends are more consistent with the known sensitivity of the circulation to tropical warming. The circulation trends are within the range of historical model simulations but are relatively large compared to the models when the accompanying trends in upper tropospheric temperature gradients are considered. The balance between tropical warming and jet shifts should therefore be closely monitored in the near future. We hypothesise that the sensitivity of the circulation to tropical heating may be one factor affecting this balance.

South drying and north wetting over the Tibetan Plateau modulated by a zonal temperature dipole across timescales

Precipitation over the Tibetan Plateau and surrounding highlands is a crucial process in the hydrological cycle and is very important for local and downstream ecology, and previous research mainly focused on a certain range of timescales. A better understanding of the variability across various timescales, which has been largely ignored, can provide new insight on the regional weather and climate. Here, a north‒south dipole pattern of precipitation shaped by a zonal dipole of the upper-tropospheric temperature is revealed in this region. Both dipole patterns of the precipitation and the accompanied temperature exist from daily to interdecadal scales. The three-dimensional circulation anomalies connecting the temperature and precipitation dipoles are consistent across various timescales. The frequencies of daily events with opposite phases of the temperature dipole modulate the interannual and interdecadal variability in precipitation. The south drying and north wetting pattern over the Tibetan Plateau is an interdecadal manifestation of the precipitation dipole and can be ascribed to the temperature trend favourable for the positive phase of the zonal temperature dipole. The consistent dipole pattern constructs a more complete portrayal of precipitation over the Tibetan Plateau from synoptic scale to climatology.

Additional Possible Cause of the Erratic 2009 Monsoon Over South and East Asia: Large-Scale Change in the Upper Tropospheric Temperature

ABSTRACT It has been recognized by the scientific community for many years that erratic monsoon attribution should be prioritized in order to meet the growing demand for reliable monsoon forecasts. It is believed that the severe 2009 drought in the South and East Asian regions was caused by an erratic monsoon season, which has sparked enormous interest in its cause. In this study, we have identified a factor in the upper troposphere, i.e. the large-scale upper tropospheric temperature, which may have potentially functioned as a new cause. We have observed that a major change in the upper tropospheric temperature occurred, with one region over Central Asia and another over the eastern Tibetan Plateau; also observed is the interaction between these two local systems. The thermal wind link suggests that the 2009 circulations over the two different regions at 250 hPa – are characterized by a cyclone and an anti-cyclone over Central Asia and the eastern Tibetan Plateau, respectfully, and that this could be the dynamic cause of the 2009 monsoon prediction failure. Subtropical jets provide a means of connecting the dynamical systems in the two different regions, which have enhanced the convection over Central Asia and reduced the convection over South and East Asia during that period. Also revealed is the role of the thermodynamic processes, specifically the role of the vertical thermal contrast (VTC) over Central Asia and the eastern Tibetan Plateau, which is responsible for changing the convective patterns during the 2009 monsoon season. This is further substantiated by the inferred causal relationship between the upper VTC and longwave fluxes (LWFs) at the top of the atmosphere.

Changing Convection in Central Asia during the Seasonal Transitional Period and Region to Its West before and after 1999: Role of Upper Vertical Thermal Contrast

The objective of this study is to investigate and understand the changes in thermal contrast in the upper troposphere over Central Asia before and after 1999. It was observed that there was a discernible increase/decrease in upper tropospheric temperature (TT) in the 100 hPa/250 hPa over the Central Asian region during PRE99, whereas during POST99, it was found to be the other way around. A clear increase and decrease in the upper TT pattern in 100 hPa and 250 hPa can be attributed to anti-cyclonic and cyclonic circulations in the wind shear, respectively. The subtropical jet has been shown to act as a significant dynamical system generating cyclonic circulation over Central Asia, resulting in dynamical features favorable for enhancing convection during PRE99. This is evinced by the structure of the 200 hPa zonal winds, which serve as a surrogate for a subtropical jet. It can be seen that the westerly winds over the southern part and the easterly winds over the northern part of Central Asia culminate in a significant cyclonic circulation over the region. In summary, PRE99 showed an increase in convection over Central Asia and the regions to its west. The anatomy, using geopotential height, relative humidity, total cloud area (TCA) fraction, longwave fluxes (LWF), and shortwave fluxes (SWF) through the top of the atmosphere, is consistent with the above results. To further support these findings, an updated and thorough causality analysis is performed, and it is noteworthy to mention that the variation of thermal temperature contrast is found to be causally related to LWF and SWF.

Unexpected long-term variability in Jupiter’s tropospheric temperatures

An essential component of planetary climatology is knowledge of the tropospheric temperature field and its variability. Previous studies of Jupiter hinted at periodic behavior that was non-seasonal, as well as dynamical relationships between tropospheric and stratospheric temperatures. However, these observations were made over time frames shorter than Jupiter's orbit or they used sparse sampling. We derived upper-tropospheric (300-mbar) temperatures over 40 years, extending those studies to cover several orbits of Jupiter, revealing unexpected results. Periodicities of 4, 7 8-9 and 10-14 years were discovered that involved different latitude bands and seem disconnected from seasonal changes in solar heating. Anti-correlations of variability in opposite hemispheres were particularly striking at 16, 22 and 30 degrees from the equator. Equatorial temperature variations are also anticorrelated with those 60-70 km above. Such behavior suggests a top-down control of equatorial tropospheric temperatures from stratospheric dynamics. Realistic future global climate models must address the origins of these variations in preparation for their extension to a wider array of gas-giant exoplanets.

Robust Anthropogenic Signal Identified in the Seasonal Cycle of Tropospheric Temperature

Abstract Previous work identified an anthropogenic fingerprint pattern in TAC(x, t), the amplitude of the seasonal cycle of mid- to upper-tropospheric temperature (TMT), but did not explicitly consider whether fingerprint identification in satellite TAC(x, t) data could have been influenced by real-world multidecadal internal variability (MIV). We address this question here using large ensembles (LEs) performed with five climate models. LEs provide many different sequences of internal variability noise superimposed on an underlying forced signal. Despite differences in historical external forcings, climate sensitivity, and MIV properties of the five models, their TAC(x, t) fingerprints are similar and statistically identifiable in 239 of the 240 LE realizations of historical climate change. Comparing simulated and observed variability spectra reveals that consistent fingerprint identification is unlikely to be biased by model underestimates of observed MIV. Even in the presence of large (factor of 3–4) intermodel and inter-realization differences in the amplitude of MIV, the anthropogenic fingerprints of seasonal cycle changes are robustly identifiable in models and satellite data. This is primarily due to the fact that the distinctive, global-scale fingerprint patterns are spatially dissimilar to the smaller-scale patterns of internal TAC(x, t) variability associated with the Atlantic multidecadal oscillation and El Niño–Southern Oscillation. The robustness of the seasonal cycle detection and attribution results shown here, taken together with the evidence from idealized aquaplanet simulations, suggest that basic physical processes are dictating a common pattern of forced TAC(x, t) changes in observations and in the five LEs. The key processes involved include GHG-induced expansion of the tropics, lapse-rate changes, land surface drying, and sea ice decrease.

Features of upper tropospheric temperature fluctuations during drought years of Indian summer monsoon: results inferred from COSMIC GPS RO observations

Features of upper tropospheric temperature fluctuations during drought years of Indian summer monsoon: results inferred from COSMIC GPS RO observations

Global Changes in Water Vapor 1979–2020

AbstractGlobal‐scale changes in water vapor and responses to surface temperature variability since 1979 are evaluated across a range of satellite and ground‐based observations, a reanalysis (ERA5) and coupled and atmosphere‐only CMIP6 climate model simulations. Global‐mean column integrated water vapor increased by 1%/decade during 1988–2014 in observations and atmosphere‐only simulations. However, coupled simulations overestimate water vapor trends and this is partly explained by past studies showing that internal climate variability suppressed observed warming in this period. Decreases in low‐altitude tropical water vapor in ERA5 and ground‐based observations before around 1993 are considered suspect based on inconsistency with simulations and increased column integrated water vapor in microwave satellite data since 1979. Atmospheric Infra‐red Sounder satellite data does not capture the increased tropospheric water vapor since 2002 shown by other satellite, reanalysis, and model products. However, global water vapor responses to interannual surface temperature variability are consistent across data sets with increases of ∼4%–5% near the surface and 10%–15% at 300 hPa for each 1°C increase in global surface temperature. Global water vapor responses are explained by thermodynamic amplification of upper tropospheric temperature changes and the Clausius Clapeyron temperature dependence of saturation vapor pressure that are dominated by the tropical ocean responses. Upper tropospheric moistening is larger in climate model simulations with greater upper tropospheric warming.

Which Is the More Effective Driver of the Poleward Eddy Heat Flux Variability: Zonal Gradient of Tropical Convective Heating or Equator-to-Pole Temperature Gradient?

Abstract Future projections of the poleward eddy heat flux by the atmosphere are often regarded as being uncertain because of the competing effect between surface and upper-tropospheric meridional temperature gradients. Previous idealized modeling studies showed that eddy heat flux response is more sensitive to the variability of lower-tropospheric temperature gradient. However, observational evidence is lacking. In this study, observational data analyses are performed to examine the relationships between eddy heat fluxes and temperature gradients during boreal winter by constructing daily indices. On the intraseasonal time scale, the surface temperature gradient is found to be more effective at regulating the synoptic-scale eddy heat flux (SF) than is the upper-tropospheric temperature gradient. Enhancements in surface temperature gradient, however, are subject to an inactive planetary-scale eddy heat flux (PF). The PF in turn is dependent on the zonal gradient in tropical convective heating. Consistent with these interactions, over the past 40 winters, the zonal gradient in tropical heating and PF have been trending upward, while the surface temperature gradient and SF have been trending downward. These results indicate that for a better understanding of eddy heat fluxes, attention should be given to zonal convective heating gradients in the tropics as much as to meridional temperature gradients.

Upper-Tropospheric Temperature Pattern Over the Asian-Pacific Region in CMIP6 Simulations: Climatology and Interannual Variability

Temperature is a most important indicator for climate change. However, compared to surface air temperature, relatively less attention has been shown to the upper-tropospheric temperature (UTT). Given that the Asian-Pacific UTT plays a remarkable role in the climate system, its future change deserves great attention. In this study, based on the Coupled Model Intercomparison Project phase 6 (CMIP6) simulations, the fidelity of 30 CMIP6 models on the Asian-Pacific UTT patterns was evaluated and their future changes under the scenarios of the Shared Socioeconomic Pathway (SSP) 2–4.5 and 5–8.5 were projected. The evaluation indicates that the CMIP6 models have a good capacity to reproduce the climatology and interannual variability of seasonal UTT during 1965–2014, with the multi-model ensemble mean (MME) outperforming individual models. The observed seesaw oscillation between the Asian UTT and the North Pacific UTT during four seasons, named Asian-Pacific Oscillation (APO), is also well performed. The MME projects a similar spatial change under both scenarios in the second half of the 21st century, with lager changes in magnitude under SSP5-8.5 than under SSP2-4.5. Compared to 1965–2014, during 2050–2099, spring, summer and autumn UTTs are projected to cool (warm) in a widespread area of Asia (the North Pacific). The projected winter UTT decreases in East Asia and most of the North Pacific. In addition, an increased interannual variability of seasonal UTT is anticipated particularly in the mid-low latitudes of the Asian-Pacific sector. The APO phenomenon is expected to still be dominant in the future climate, but its intensity (interannual variability) tends to weaken (enlarge) in each season as compared to the current.

Subseasonal Variation in Neptune’s Mid-infrared Emission

Abstract We present an analysis of all currently available ground-based imaging of Neptune in the mid-infrared. Dating between 2003 and 2020, the images reveal changes in Neptune’s mid-infrared (∼8–25 μm) emission over time in the years surrounding Neptune’s 2005 southern summer solstice. Images sensitive to stratospheric ethane (∼12 μm), methane (∼8 μm), and CH3D (∼9 μm) display significant subseasonal temporal variation on regional and global scales. Comparison with H2 S(1) hydrogen quadrupole (∼17.035 μm) spectra suggests that these changes are primarily related to stratospheric temperature changes. The stratosphere appears to have cooled between 2003 and 2009 across multiple filtered wavelengths, followed by a dramatic warming of the south pole between 2018 and 2020. Conversely, upper-tropospheric temperatures—inferred from ∼17 to 25 μm imaging—appear invariant during this period, except for the south pole, which appeared warmest between 2003 and 2006. We discuss the observed variability in the context of seasonal forcing, tropospheric meteorology, and the solar cycle. Collectively, these data provide the strongest evidence to date that processes produce subseasonal variation on both global and regional scales in Neptune’s stratosphere.

CESM simulation of monsoon low pressure systems over India

AbstractMonsoon low pressure systems (LPS) during the summer monsoon season (June–September) over India are a lifeline for the agriculture‐dependent country. We use the Community Earth System Model (CESM1.2.2) to simulate the LPS characteristics (genesis, propagation direction, tracks, intensity, and precipitation) over India and the Bay of Bengal and analyse the influence of Southeast Asian mountains (SAMs) on these characteristics. CESM reproduced most of the LPS characteristics. However, a southward latitudinal shift of about 4° is simulated in the median of the tracks, which is likely due to the weaker simulated upper tropospheric meridional temperature gradient (MTG) in the Indian region. Removal of SAMs is found to have little influence on LPS characteristics. Further, it causes only a slight reduction in mean summer monsoon precipitation (by 5%) and LPS‐related precipitation (from 10.7 ± 1.0 to 10.3 ± 0.8 mm/day) over India, as SAMs have negligible influence on in situ westward propagating LPS which are the major contributors to LPS‐related precipitation. The insensitivity of LPS characteristics and precipitation over India to the removal of SAMs can be attributed to their low height and the insensitivity of MTG to the height of these mountains.

Radiative Cooling, Latent Heating, and Cloud Ice in the Tropical Upper Troposphere

Abstract The radiative cooling rate in the tropical upper troposphere is expected to increase as climate warms. Since the tropics are approximately in radiative–convective equilibrium (RCE), this implies an increase in the convective heating rate, which is the sum of the latent heating rate and the eddy heat flux convergence. We examine the impact of these changes on the vertical profile of cloud ice amount in cloud-resolving simulations of RCE. Three simulations are conducted: a control run, a warming run, and an experimental run in which there is no warming but a temperature forcing is imposed to mimic the warming-induced increase in radiative cooling. Surface warming causes a reduction in cloud fraction at all upper-tropospheric temperature levels but an increase in the ice mixing ratio within deep convective cores. The experimental run has more cloud ice than the warming run at fixed temperature despite the fact that their latent heating rates are equal, which suggests that the efficiency of latent heating by cloud ice increases with warming. An analytic expression relating the ice-related latent heating rate to a number of other factors is derived and used to understand the model results. This reveals that the increase in latent heating efficiency is driven mostly by 1) the migration of isotherms to lower pressure and 2) a slight warming of the top of the convective layer. These physically robust changes act to reduce the residence time of ice at any particular temperature level, which tempers the response of the mean cloud ice profile to warming. Significance Statement Here we examine how the amount of condensed ice in part of the atmosphere—the tropical upper troposphere (UT)—responds to global warming. In the UT, the energy released during ice formation is balanced by the emission of radiation to space. This emission will strengthen with warming, suggesting that there will also be more ice. Using a model of the tropical atmosphere, we find that the increase in ice amount is mitigated by a reduction in the amount of time ice spends in the UT. This could have important implications for the cloud response to global warming, and future work should focus on how these changes are manifested across the distribution of convective cloud types.