skip to main content

Search for: All records

Creators/Authors contains: "Mukhopadhyay, S."

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Free, publicly-accessible full text available August 1, 2023
  2. Free, publicly-accessible full text available October 1, 2023
  3. Free, publicly-accessible full text available February 1, 2023
  4. Free, publicly-accessible full text available July 1, 2023
  5. Weather regime based stochastic weather generators (WR-SWGs) have recently been proposed as a tool to better understand multi-sector vulnerability to deeply uncertain climate change. WR-SWGs can distinguish and simulate different types of climate change that have varying degrees of uncertainty in future projections, including thermodynamic changes (e.g., rising temperatures, Clausius-Clapeyron scaling of extreme precipitation) and dynamic changes (e.g., shifting circulation and storm tracks). These models require the accurate identification of WRs that are representative of both historical and plausible future patterns of atmospheric circulation, while preserving the complex space–time variability of weather processes. This study proposes a novel framework to identify such WRs based on WR-SWG performance over a broad geographic area and applies this framework to a case study in California. We test two components of WR-SWG design, including the method used for WR identification (Hidden Markov Models (HMMs) vs. K-means clustering) and the number of WRs. For different combinations of these components, we assess performance of a multi-site WR-SWG using 14 metrics across 13 major California river basins during the cold season. Results show that performance is best using a small number of WRs (4–5) identified using an HMM. We then juxtapose the number of WRs selected basedmore »on WR-SWG performance against the number of regimes identified using metastability analysis of atmospheric fields. Results show strong agreement in the number of regimes between the two approaches, suggesting that the use of metastable regimes could inform WR-SWG design. We conclude with a discussion of the potential to expand this framework for additional WR-SWG design parameters and spatial scales.« less
  6. Gamma-ray detection following the inelastic neutron scattering reaction on isotopically enriched material was used to study the nuclear structure of 74 Ge. From these measurements, low-lying, low-spin excited states were characterized, new states and their decays were identified, level lifetimes were measured with the Doppler-shift attenuation method (DSAM), multipole mixing ratios were established, and transition probabilities were determined. New structural features in 74 Ge were identified, and the reanalysis of older 76 Ge data led to the placement of the 2 + member of the intruder band. In addition, a number of previously placed states in 74 Ge were shown not to exist. A procedure for future work, which will lead to meaningful data for constraining calculations of the neutrinoless double-beta decay matrix element, is suggested.