Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “climate”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20

Physics-Dynamics Coupling in Weather, Climate, and Earth System Models: Challenges and Recent Progress

Geophysical models of the atmosphere and ocean invariably involve parameterizations. These represent two distinct areas: a) Subgrid processes which the model cannot (yet) resolve, due to its discrete resolution, and b) sources in the equation, due to radiation for example. Hence coupling between these physics parameterizations and the resolved fluid dynamics and also between the dynamics of the different fluids in the system (air and water) is necessary. This coupling is an important aspect of geophysical models. However, often model development is strictly segregated into either physics or dynamics. Hence, this area has many more unanswered questions than in-depth understanding. Furthermore, recent developments in the design of dynamical cores (significant increase of resolution, move to non-hydrostatic equation sets etc), extended process physics (prognostic micro physics, 3D turbulence, non-vertical radiation etc) and predicted future changes of the computational infrastructure (Exascale with its need for task parallelism, data locality and asynchronous time stepping for example) is adding even more complexity and new questions.

Gross, Markus↗

Gridded Sub-daily Climate Forcings for North America Based on Daymet and ERA5 (Daymet-ERA5)

To support high spatial and temporal resolution land surface modeling, this dataset provides hourly time step historic weather forcing at 1-km spatial resolution for the entire North America. The latest Daymet V4 data provides gridded historic daily weather observations at 1-km spatial resolution from 1980 to 2024. Using sub-daily temporal information from the ECMWF ERA5 reanalysis, Daymet was further temporally downscaled to hourly time steps and provided in the format required for land surface model simulations. The process of temporal downscaling preserves the relative magnitude in each hourly time step from ERA5 while maintaining the total and average values from Daymet for each day. This results in a blended 1980-2024 Daymet-ERA5 dataset. Available variables include surface air temperature, precipitation, specific humidity, shortwave and longwave radiation, wind speed, and pressure. These data can be used as a high-resolution meteorological forcing dataset to support high-resolution land surface modeling where accurate meteorological forcing datasets built from historic observations and/or reanalysis datasets are desirable.

54 ENVIRONMENTAL SCIENCES↗

Cold Climate Foundation Retrofit Energy Savings: The Simulated Energy and Experimental Hygrothermal Performance of Cold Climate Foundation Wall Insulation Retrofit Measures — Phase I, Energy Simulation

A split simulation whole-building energy/three-dimensional earth contact model (termed the BUFETS/EnergyPlus Model or BEM) can model the full range of foundation systems in the target retrofit housing stock. This model was used to extensively evaluate the results produced by the NREL BEoptE+ tool. These foundation systems that include above-grade foundation walls, diabatic floors or slabs, and lookout or walkout walls could not be modeled in BEopt version 1.1 that was used in this project.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Cold Climate Foundation Retrofit Energy Savings: The Simulated Energy and Experimental Hygrothermal Performance of Cold Climate Foundation Wall Insulation Retrofit Measures— Phase I, Energy Simulation

A split simulation whole building energy / 3-dimensional earth contact model (termed the BUFETS/EnergyPlus Model or BEM) capable of modeling the full range of foundation systems found in the target retrofit housing stock has been extensively tested. These foundation systems that include abovegrade foundation walls, diabatic floors or slabs as well as lookout or walkout walls, currently cannot be modeled within BEopt.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Summer Workshops on Climate Change Impacts and Integrated Assessment of Climate Change (Final Technical Report)

This grant supported a long sequence of summer workshops in Snowmass, Colorado that began in 1996. The last workshop in this sequence was held in the summer of 2016. This annual event was a centerpiece in the Department of Energy’s support for the creation and maintenance of a community of practice in integrated multi-sector dynamics research and modeling. These workshops brought together key members of the multi-sector dynamics modeling community with other researchers engaged in relevant research on multi-sector (energy, water, land, etc., dynamics) research to participate in discussions of cutting-edge research topics and develop collaborative approaches for addressing open research challenges. This grant provided funds to leverage BER and other federal research investments in the development of appropriate multi-sector dynamics modeling methods by expanding interactions and promoting collaborations between the community of researchers engaged in this research and those involved in other energy and environmental systems research programs. This process is augmented through various outreach activities including periodic presentations and web-based and other internet-based methods for disseminating key scientific findings and to otherwise engage broader participation in pre- and post-workshop discussions and information exchange. The main goals of the summer workshop series were to: Build and support an integrated multi-sector dynamics (iMSD)research community of practice; Infuse best-in-class science into iMSD research activities; Exchange international iMSD research perspectives and information; Accelerate research integration among the iMSD, the sectoral impacts, and earth and environmental systems modeling communities; Develop collaborative scientific perspectives on significant iMSD research challenges; Build collaborations in addressing the challenges; and Develop processes to share information more broadly within the iMSD and the associated family of research communities. The funding provided for this workshop series has helped the energy and environmental systems modeling research community in general - and the multi-sector dynamics research community in particular - make progress on addressing these and other significant research and community building challenges.

54 ENVIRONMENTAL SCIENCES↗

Early climate on earth-reduced gas models and early climate on Mars-reduced gas and obliquity models

At high obliquity, Martian polar ground temperatures could exceed the melting point of ice for considerable periods of time (approximately 90 Earth days). Under special conditions ice itself might melt. Carbon dioxide adsorbed on the Martian regolith is not expected to buffer the seasonal pressure wave except in the unlikely event that the soil pore size is very large (50 micron). For a basaltic soil composition the maximum CO2 that could be desorbed over obliquity time scales due to thermal forces is a few millibars. At low obliquities the atmospheric pressures may drop, desorbing the soil. The only means to achieve higher CO2 pressures is to have much higher planet-wide temperatures due to some greenhouse effect, or to be at an epoch before the regolith or carbonates formed. The water ice budget between north and south polar caps was considered and summer sublimation rates imply that the ice could be exchanged between the poles during obliquity cycles. A critical factor in the polar cap water budget is the interaction of water and dust. The origin of the Martian polar laminae is probably due to variations in this interaction.

Toon, O. B.↗

Climate model calculations of the effects of volcanoes on global climate

An examination of the Northern Hemisphere winter surface temperature patterns after the 12 largest volcanic eruptions from 1883-1992 shows warming over Eurasia and North America and cooling over the Middle East which are significant at the 95 percent level. This pattern is found in the first winter after tropical eruptions, in the first or second winter after midlatitude eruptions, and in the second winter after high latitude eruptions. The effects are independent of the hemisphere of the volcanoes. An enhanced zonal wind driven by heating of the tropical stratosphere by the volcanic aerosols is responsible for the regions of warming, while the cooling is caused by blocking of incoming sunlight.

Robock, Alan↗

Maynard Participation in Alaska Forum on the Environment Panel Discussion on Increasing Input to the US National Climate Assessment (NCA) and the Intergovernmental Panel on Climate Change (IPCC) Processes from Alaska, with Emphasis on Indigenous Peoples Issues

Dr. Nancy Maynard was invited by the Alaska Forum on the Environment to participate in a Panel Discussion to discuss (1) background about what the US NCA and International IPCC assessments are, (2) the impact the assessments have on policy-making, (3) the process for participation in both assessments, (4) how we can increase participation by Indigenous Peoples such as Native Americans and Alaska Natives, (5) How we can increase historical and current impacts input from Native communities through stories, oral history, "grey" literature, etc. The session will be chaired by Dr. Bull Bennett, a cochair of the US NCA's chapter on "Native and Tribal Lands and Resources" and Dr. Maynard is the other co-chair of that chapter and they will discuss the latest activities under the NCA process relevant to Native Americans and Alaska Natives. Dr. Maynard is also a Lead Author of the "Polar Regions" chapter of the IPCC WG2 (5th Assessment) and she will describes some of the latest approaches by the IPCC to entrain more Indigenous peoples into the IPCC process.

Maynard, Nancy G.↗