Climate and surface mass balance of coastal West Antarctica resolved by regional climate modelling

West Antarctic climate and surface mass balance (SMB) records are sparse. To fill this gap, regional atmospheric climate modelling is useful, providing that such models are employed at sufficiently high horizontal resolution and coupled with a snow model. Here we present the results of a high-resolution (5.5 km) regional atmospheric climate model (RACMO2) simulation of coastal West Antarctica for the period 1979–2015. We evaluate the results with available in situ weather observations, remote-sensing estimates of surface melt, and SMB estimates derived from radar and firn cores. Moreover, results are compared with those from a lower-resolution version, to assess the added value of the resolution. The high-resolution model resolves small-scale climate variability invoked by topography, such as the relatively warm conditions over ice-shelf grounding zones, and local wind speed accelerations. Surface melt and SMB are well reproduced by RACMO2. This dataset will prove useful for picking ice core locations, converting elevation changes to mass changes, for driving ocean, ice-sheet and coupled models, and for attributing changes in the West Antarctic Ice Sheet and shelves to changes in atmospheric forcing

The SPTPoL extended cluster survey

We describe the observations and resultant galaxy cluster catalog from the 2770 deg2 SPTpol Extended Cluster Survey (SPT-ECS). Clusters are identified via the Sunyaev-Zel'dovich (SZ) effect and confirmed with a combination of archival and targeted follow-up data, making particular use of data from the Dark Energy Survey (DES). With incomplete follow-up we have confirmed as clusters 244 of 266 candidates at a detection significance ξ ≥ 5 and an additional 204 systems at 4 4 threshold, and 10% of their measured SZ flux. We associate SZ-selected clusters, from both SPT-ECS and the SPT-SZ survey, with clusters from the DES redMaPPer sample, and we find an offset distribution between the SZ center and central galaxy in general agreement with previous work, though with a larger fraction of clusters with significant offsets. Adopting a fixed Planck-like cosmology, we measure the optical richness-SZ mass (l - M) relation and find it to be 28% shallower than that from a weak-lensing analysis of the DES data-a difference significant at the 4σ level-with the relations intersecting at λ = 60. The SPT-ECS cluster sample will be particularly useful for studying the evolution of massive clusters and, in combination with DES lensing observations and the SPT-SZ cluster sample, will be an important component of future cosmological analyses

Detection of CMB-cluster lensing using polarization data from SPTpol

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes Q U map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500     deg 2 survey at the locations of roughly 18 000 clusters with richness λ ≥ 10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8 σ . The mean stacked mass of the selected sample is found to be ( 1.43 ± 0.40 ) × 10 14 M ⊙ which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements

Joint analysis of Dark Energy Survey Year 3 data and CMB lensing from SPT and Planck . I. Construction of CMB lensing maps and modeling choices

Joint analyses of cross-correlations between measurements of galaxy positions, galaxy lensing, and lensing of the cosmic microwave background (CMB) offer powerful constraints on the large-scale structure of the Universe. In a forthcoming analysis, we will present cosmological constraints from the analysis of such cross-correlations measured using Year 3 data from the Dark Energy Survey (DES), and CMB data from the South Pole Telescope (SPT) and Planck. Here we present two key ingredients of this analysis: (1) an improved CMB lensing map in the SPT-SZ survey footprint and (2) the analysis methodology that will be used to extract cosmological information from the cross-correlation measurements. Relative to previous lensing maps made from the same CMB observations, we have implemented techniques to remove contamination from the thermal Sunyaev Zel’dovich effect, enabling the extraction of cosmological information from smaller angular scales of the cross-correlation measurements than in previous analyses with DES Year 1 data. We describe our model for the cross-correlations between these maps and DES data, and validate our modeling choices to demonstrate the robustness of our analysis. We then forecast the expected cosmological constraints from the galaxy survey-CMB lensing auto and cross-correlations. We find that the galaxy-CMB lensing and galaxy shear-CMB lensing correlations will on their own provide a constraint on S 8 = σ 8 √ Ω m / 0.3 at the few percent level, providing a powerful consistency check for the DES-only constraints. We explore scenarios where external priors on shear calibration are removed, finding that the joint analysis of CMB lensing cross-correlations can provide constraints on the shear calibration amplitude at the 5% to 10% level

Joint analysis of Dark Energy Survey Year 3 data and CMB lensing from SPT and Planck . II. Cross-correlation measurements and cosmological constraints

Cross-correlations of galaxy positions and galaxy shears with maps of gravitational lensing of the cosmic microwave background (CMB) are sensitive to the distribution of large-scale structure in the Universe. Such cross-correlations are also expected to be immune to some of the systematic effects that complicate correlation measurements internal to galaxy surveys. We present measurements and modeling of the cross-correlations between galaxy positions and galaxy lensing measured in the first three years of data from the Dark Energy Survey with CMB lensing maps derived from a combination of data from the 2500     deg 2 SPT-SZ survey conducted with the South Pole Telescope and full-sky data from the Planck satellite. The CMB lensing maps used in this analysis have been constructed in a way that minimizes biases from the thermal Sunyaev Zel’dovich effect, making them well suited for cross-correlation studies. The total signal-to-noise of the cross-correlation measurements is 23.9 (25.7) when using a choice of angular scales optimized for a linear (nonlinear) galaxy bias model. We use the cross-correlation measurements to obtain constraints on cosmological parameters. For our fiducial galaxy sample, which consist of four bins of magnitude-selected galaxies, we find constraints of Ω m = 0.272 + 0.032 − 0.052 and S 8 ≡ σ 8 √ Ω m / 0.3 = 0.736 + 0.032 − 0.028 ( Ω m = 0.245 + 0.026 − 0.044 and S 8 = 0.734 + 0.035 − 0.028 ) when assuming linear (nonlinear) galaxy bias in our modeling. Considering only the cross-correlation of galaxy shear with CMB lensing, we find Ω m = 0.270 + 0.043 − 0.061 and S 8 = 0.740 + 0.034 − 0.029 . Our constraints on S 8 are consistent with recent cosmic shear measurements, but lower than the values preferred by primary CMB measurements from Planck

Sumoylation and proteasomal activity determine the transactivation properties of the mineralocorticoid receptor.

MR is a hormone-activated transcription factor that carries a strong synergy inhibitory function at its N-terminus. Using this region as bait in a yeast two-hybrid screening, we isolated major components of the sumoylation pathway, including the SUMO-1-conjugating enzyme Ubc9, and SUMO-1 itself. We found that MR interacts with both, Ubc9 and SUMO-1 in mammalian cells, and that the receptor is sumoylated at four acceptor sites which are clustered within its AF-1 domain. We observed that MR can be poly-ubiquitinated and that proteasome activity is essential for MR-activated transcription. Disruption of the SUMO-1 attachment sites abolished MR sumoylation but interfered with neither the poly-ubiquitination of the receptor nor its transactivation potential on MMTV. However, the hormone-activated mutant displayed enhanced synergistic potential on a compound promoter and delayed mobility in the nucleus. FRAP analysis further showed that proteasome inhibition immobilizes a subpopulation of unliganded MR receptors in the nucleus, a phenomenon that is significantly attenuated in the presence of aldosterone. Interestingly, the ability of the hormone to counteract the immobilizing effect of MG132 requires the sumoylation-competent form of MR. Moreover, increasing exogenously SUMO-1 cellular levels resulted in a selective, dose-dependent inhibition of the activity of the sumoylation-deficient MR. This effect was observed only on a synergy-competent promoter, revealing a mode for negative regulation of synergy that might involve sumoylation of factors different from MR. The data suggest that the overall transcriptional activity of MR can be modulated by its sumoylation potential as well as the sumoylation level of MR-interacting proteins, and requires the continuous function of the proteasome