- Climate Science
- Regional climate variability and change
- Global and regional climate modeling and evaluation
- Quantifiying uncertainty in modeling and projections
- Climate Services
Climate Science
At UMass Amherst, my research involves understanding climate variability and change at regional scales. I have published articles on process-based evaluation of climate model performance and projections to facilitate their use in impacts studies in the northeastern U.S. (NEUS; Karmalkar et al., 2019b), critical evaluation of how regional model ensembles represent uncertainties in projections (Karmalkar, 2018), and on broader issues of what global climate change means at regional scales to communicate the urgency for taking action (Karmalkar and Bradley, 2017).
My ongoing projects involve diagnosing the relationship between climate variability and trends in the NEUS and the Northwest Atlantic (Karmalkar and Horton, 2021), evaluating how climate model biases over Antarctica impact sea level rise projections (with Rob DeConto at UMass Amherst), and evaluation of climate model driving fields for Arctic hydrological modeling (with Mike Rawlins at UMass Amherst). I also continue collaborative work with ecologists and hydrologists on climate data use in impact studies (e.g., Siddique et al., 2020; Siren et al., under review). I am starting a directed-funded project on identifying spatio-temporal scales at which the downscaled projections are most reliable in an effort to support assessment of climate impacts in the Northeast (with Michelle Staudinger, USGS/UMass Amherst).
These current activities integrate aspects of my doctoral research at UMass Amherst focusing on regional climate modeling over Central America and the impact of climate change on biodiversity in the region (Karmalkar et al., 2008; 2011), my postdoctoral study at the University of Oxford on using regional and global climate model ensembles to study climate change in the Caribbean (Karmalkar et al., 2013), and my work at the Met Office Hadley Center (UK) on using large perturbed parameter ensembles (PPEs) to sample and quantify uncertainties in climate modeling and projections (Karmalkar et al., 2019a; Sexton et al., 2019). The PPE project at the Met Office was vast in its scope and involved: designing idealized experiments, understanding model parametrizations, running a state-of-the- art, highly complex global climate model on a supercomputer, model validation at weather and climate timescales, and statistical emulation to explore large parameter spaces.
Climate Services:
- Member, Project Advisory Committee, New York State Energy Research and Development Authority (NYSERDA) project to update the climate projections for New York State with CMIP6 data. Ongoing
- Member and Contributing Author, Greater Boston Research Advisory Group, Chapter on ‘Precipitation, Storms, and Water.’ Ongoing
- Lead Researcher, production of state-wide climate change projections for the Commonwealth of Massachusetts and dissemination through an interactive website for impacts and vulnerability assessments. Project in collaboration with the Massachusetts Office of Energy and Environmental Affairs, 2017–2018. The projections were based on a framework we developed to identify a subset of credible models for climate projections work (Karmalkar et al., 2019).
- Lead Contributor, State Climate Reports for Politicians, UMass Amherst, 2016.
- Contributor, UNDP Climate Change Country Profiles, University of Oxford, 2010-2012.
Summary of Research & Publications:
| Research Focus | Publications | |
| Research Prof. & Fellow (UMass Amherst/ NE CASC) | Regional & global climate model ensembles, Analysis uncertainty in modeling & projections, Impacts research, stakeholder engagement. Regional Focus: Northeastern US | Karmalkar & Horton, 2021 Siddique et al., 2020 Kirchhoff et al., 2019 Karmalkar et al., 2019b Karmalkar, 2018 Karmalkar & Bradley, 2017 Siren et al., under review |
| Scientist (Met Office UK) | Global climate modeling, Ensemble techniques (incl. PPEs), Uncertainty quantification | Sexton et al., 2021 Sexton et al., 2019 Karmalkar et al., 2019a Bodas-Salcedo et al., 2016 |
| Postdoc (Oxford Univ) | Regional & global climate modeling, Ensembles, Climate dynamics. Region: Caribbean | Karmalkar et al., 2013 |
| Ph.D. (UMass Amherst) | Regional climate modeling, Climate dynamics, Region: Central America | Karmalkar et al., 2011 Medina-Elizalde et al., 2010 Buytaert et al., 2010 Karmalkar et al., 2008 |