A5045367832- Superconducting and THz Device Technology
- Radio Astronomy Observations and Technology
- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Geophysics and Gravity Measurements
- Dark Matter and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- Microwave Engineering and Waveguides
- Climate change and permafrost
- Atmospheric Ozone and Climate
- Spacecraft and Cryogenic Technologies
- Cryospheric studies and observations
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Advanced Thermodynamic Systems and Engines
- Physics of Superconductivity and Magnetism
- Ionosphere and magnetosphere dynamics
Cardiff University
2016-2025
Fermi National Accelerator Laboratory
2018-2025
Australian National University
2014-2024
Goddard Space Flight Center
2014-2024
ARC Centre of Excellence for All-sky Astrophysics
2016-2024
ASTRO-3D
2018-2024
Heliophysics
2012-2024
The University of Texas Medical Branch at Galveston
2022-2024
Centre National de la Recherche Scientifique
2020-2024
Institut National de Physique Nucléaire et de Physique des Particules
2024
The northern high latitudes have warmed by about 0.8°C since the early 1970s, but not all areas uniformly [ Hansen et al ., 1999]. There is warming in most of Eurasia, rate United States smaller than world, and a slight cooling observed eastern over past 50 years. These changes beg question, can we detect biotic response to temperature changes? Here present results from analyses recently developed satellite‐sensed normalized difference vegetation index (NDVI) data set for period July 1981...
The Fast Plasma Investigation (FPI) was developed for flight on the Magnetospheric Multiscale (MMS) mission to measure differential directional flux of magnetospheric electrons and ions with unprecedented time resolution resolve kinetic-scale plasma dynamics. This increased has been accomplished by placing four dual 180-degree top hat spectrometers around periphery each MMS spacecraft. Using electrostatic field-of-view deflection, eight species together provide 4pi-sr with, at worst,...
The NDVI3g time series is an improved 8-km normalized difference vegetation index (NDVI) data set produced from Advanced Very High Resolution Radiometer (AVHRR) instruments that extends 1981 to the present. AVHRR have flown or are flying on fourteen polar-orbiting meteorological satellites operated by National Oceanic and Atmospheric Administration (NOAA) currently two European Organization for Exploitation of Meteorological Satellites (EUMETSAT) satellites, MetOp-A MetOp-B. This long record...
We present results from an analysis of all data taken by the BICEP2, Keck Array, and BICEP3 CMB polarization experiments up to including 2018 observing season. add additional Array observations at 220 GHz 95 previous 95/150/220 dataset. The Q/U maps now reach depths 2.8, 8.8 μK_{CMB} arcmin 95, 150, GHz, respectively, over effective area ≈600 square degrees ≈400 150 GHz. achieve a signal-to-noise ratio on polarized dust emission exceeding that Planck 353 take auto- cross-spectra between...
We present results from an analysis of all data taken by the BICEP2 and Keck Array cosmic microwave background (CMB) polarization experiments up to including 2014 observing season. This includes first observations at 95 GHz. The maps reach a depth 50 nK deg in Stokes Q U 150 GHz band 127 band. take auto- cross-spectra between these publicly available WMAP Planck frequencies 23 353 An excess over lensed ΛCDM is detected modest significance 95×150 BB spectrum, consistent with dust contribution...
The South Pole Telescope (SPT) is a 10 m diameter, wide-field, offset Gregorian telescope with 966 pixel, multicolor, millimeter-wave, bolometer camera. It located at the Amundsen-Scott station in Antarctica. design of SPT emphasizes careful control spillover and scattering, to minimize noise false signals due ground pickup. key initial project large-area survey wavelengths 3, 2, 1.3 mm, detect clusters galaxies via Sunyaev-Zel'dovich effect measure small-scale angular power spectrum cosmic...
We present results from an analysis of all data taken by the bicep2/Keck CMB polarization experiments up to and including 2015 observing season. This includes first Keck Array observations at 220 GHz additional 95 150 GHz. The Q U maps reach depths 5.2, 2.9, 26 μKCMB arcmin 95, 150, GHz, respectively, over effective area ≈400 square degrees. achieve a signal noise on polarized dust emission approximately equal that Planck 353 take auto cross spectra between these publicly available WMAP...
We describe the design of a new polarization sensitive receiver, spt-3g, for 10-meter South Pole Telescope (spt). The spt-3g receiver will deliver factor ~20 improvement in mapping speed over current spt-pol. sensitivity enable advance from statistical detection B-mode anisotropy power to high signal-to-noise measurements individual modes, i.e., maps. This lead precise (~0.06 eV) constraints on sum neutrino masses with potential directly address mass hierarchy. It allow separation lensing...
Abstract Linkages between diminishing Arctic sea ice and changes in terrestrial ecosystems have not been previously demonstrated. Here, the authors use a newly available Normalized Difference Vegetation Index (NDVI) dataset (a measure of vegetation photosynthetic capacity) to document coherent temporal relationships near-coastal ice, summer tundra land surface temperatures, productivity. The find that, during period satellite observations (1982–2008), within 50 km coast early breakup...
We present constraints on cosmological and astrophysical parameters from high-resolution microwave background maps at 148 GHz 218 made by the Atacama Cosmology Telescope (ACT) in three seasons of observations 2008 to 2010. A model primary secondary foreground is fit map power spectra lensing deflection spectrum, including contributions both thermal Sunyaev-Zeldovich (tSZ) effect kinematic (kSZ) effect, Poisson correlated anisotropy unresolved infrared sources, radio correlation between tSZ...
Gravitational lensing of the cosmic microwave background generates a curl pattern in observed polarization. This "B-mode" signal provides measure projected mass distribution over entire observable Universe and also acts as contaminant for measurement primordial gravity-wave signals. In this Letter we present first detection gravitational B modes, using first-season data from polarization-sensitive receiver on South Pole Telescope (SPTpol). We construct template B-mode by combining E-mode...
We present cosmological parameters derived from the angular power spectrum of cosmic microwave background (CMB) radiation observed at 148 GHz and 218 over 296 deg2 with Atacama Cosmology Telescope (ACT) during its 2008 season. ACT measures fluctuations scales 500 < ℓ 10, 000. fit a model for lensed CMB, Sunyaev–Zel'dovich (SZ), foreground contribution to spectra, including thermal kinetic SZ, Poisson radio infrared point sources, clustered sources. At = 3000, about half comes primary CMB...
Numerous studies have evaluated the dynamics of Arctic tundra vegetation throughout past few decades, using remotely sensed proxies vegetation, such as normalized difference index (NDVI). While extremely useful, these coarse-scale satellite-derived measurements give us minimal information with regard to how changes are being expressed on ground, in terms structure and function. In this analysis, we used a strong regression model between NDVI aboveground phytomass, developed from extensive...
Vegetation productivity trends for the Arctic tundra are updated 1982–2011 period and examined in context of land surface temperatures coastal sea ice. Understanding mechanistic links between vegetation climate parameters contributes to model advancements that necessary improving projections. This study employs remote sensing data: Global Inventory Modeling Mapping Studies (GIMMS) Maximum Normalized Difference Index (MaxNDVI), Special Sensor Microwave Imager (SSM/I) sea-ice concentrations,...
We present the temperature and polarization angular power spectra measured by Atacama Cosmology Telescope Polarimeter (ACTPol). analyze night-time data collected during 2013-14 using two detector arrays at 149 GHz, from 548 deg$^2$ of sky on celestial equator. use these spectra, with MBAC camera ACT 2008-10, in combination Planck WMAP to estimate cosmological parameters temperature, polarization, temperature-polarization cross-correlations. find new ACTPol be consistent LCDM model. The...
We estimate global terrestrial gross primary production (GPP) based on models that use satellite data within a simplified light-use efficiency framework does not rely upon other meteorological inputs. Satellite-based geometry-adjusted reflectances are from the MODerate-resolution Imaging Spectroradiometer (MODIS) and provide information about vegetation structure chlorophyll content at both high temporal (daily to monthly) spatial (∼1 km) resolution. satellite-derived solar-induced...
We present measurements of the $E$-mode polarization angular auto-power spectrum ($EE$) and temperature-$E$-mode cross-power ($TE$) cosmic microwave background (CMB) using 150 GHz data from three seasons SPTpol observations. report power spectra over spherical harmonic multipole range $50 < \ell \leq 8000$, detect nine acoustic peaks in $EE$ with high signal-to-noise ratio. These are most sensitive to date $TE$ at $\ell > 1050$ 1475$, respectively. The observations cover 500 deg$^2$, a...
We present a sample-variance-limited measurement of the temperature power spectrum ($TT$) cosmic microwave background using observations $\ensuremath{\sim}1500\text{ }\text{ }{\mathrm{deg}}^{2}$ field made by SPT-3G in 2018. report multifrequency measurements at 95, 150, and 220 GHz covering angular multipole range $750\ensuremath{\le}\ensuremath{\ell}<3000$. combine this $TT$ with published polarization from 2018 observing season update their associated covariance matrix to complete...
We report on 23 clusters detected blindly as Sunyaev–ZEL'DOVICH (SZ) decrements in a 148 GHz, 455 deg2 map of the southern sky made with data from Atacama Cosmology Telescope 2008 observing season. All SZ detections announced this work have confirmed optical counterparts. Ten are new discoveries. One newly discovered cluster, ACT-CL J0102−4915, redshift 0.75 (photometric), has an decrement comparable to most massive systems at lower redshifts. Simulations cluster recovery method reproduce...