Marika M. Holland | |
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Alma mater | University of Colorado Boulder |
Scientific career | |
Institutions | National Center for Atmospheric Research |
Thesis | Climate change and variability in a single column coupled sea ice/ocean mixed layer model (1997) |
Marika Holland is a scientist at the National Center for Atmospheric Research known for her work on modeling sea ice and its role in the global climate.
Holland has a B.A.[ when? ] and a Ph.D. (1997) [1] from the University of Colorado Boulder. [2] Following her Ph.D. Holland was a postdoctoral fellow at the University of Victoria until 1999 when she joined the staff at the National Center for Atmospheric Research (NCAR). [3] Holland was Chief Scientist for the Community Earth System Model (CESM) from 2012 until 2014 [4] and received the CESM Distinguished Achievement Award for her work in 2014. [5]
Holland is known for her research predicting sea ice on different time scales. Holland's modeling of sea ice began with considerations of the processes that define the actions of sea ice in climate models. [6] [7] [8] In 2003, Holland and Celia Bitz modeled how changes in the Arctic climate alter the degree of polar amplification in climate models. [9] Holland's work on future sea ice predict an ice-free Arctic Ocean by 2040, [10] research that was broadly covered in the news. [11] [12] Research by Holland and others then showed that sea ice was declining faster than the predictions. [13] Holland has also worked with biologists to assess how changes in sea ice impact Emperor penguins [14] [15] and Adelie penguins. [16] Holland has been a contributing author on the third, [17] fourth, [18] and fifth [19] assessment reports from the Intergovernmental Panel on Climate Change. In 2020 Holland was named an elected fellow of the American Geophysical Union who cited her "for sustained contributions in polar research and climate modeling". [20]
The Community Climate System Model (CCSM) is a coupled general circulation model (GCM) developed by the University Corporation for Atmospheric Research (UCAR) with funding from the National Science Foundation (NSF), the Department of Energy (DoE), and the National Aeronautics and Space Administration (NASA). The coupled components include an atmospheric model, a land-surface model, an ocean model, and a sea ice model. CCSM is maintained by the National Center for Atmospheric Research (NCAR).
Jonathan Michael Gregory is a climate modeller working on mechanisms of global and large-scale change in climate and sea level on multidecadal and longer timescales at the Met Office and the University of Reading.
The Atlantic meridional overturning circulation (AMOC) is the "main current system in the South and North Atlantic Oceans". As such, it is a component of Earth's oceanic circulation system and plays an important role in the climate system. If the strength of the AMOC changes this could have impacts on some elements of the climate system. The AMOC includes currents at the surface as well as at great depths in the Atlantic Ocean. These currents are driven by changes in the atmospheric weather as well as by changes in temperature and salinity. They collectively make up one half of the global thermohaline circulation that encompasses the flow of major ocean currents. The other half is the Southern Ocean overturning circulation.
Mikhail Ivanovich Budyko was a Soviet and Russian climatologist and one of the founders of physical climatology. He pioneered studies on global climate and calculated temperature of Earth considering simple physical model of equilibrium in which the incoming solar radiation absorbed by the Earth's system is balanced by the energy re-radiated to space as thermal energy.
Major environmental issues caused by contemporary climate change in the Arctic region range from the well-known, such as the loss of sea ice or melting of the Greenland ice sheet, to more obscure, but deeply significant issues, such as permafrost thaw, as well as related social consequences for locals and the geopolitical ramifications of these changes. The Arctic is likely to be especially affected by climate change because of the high projected rate of regional warming and associated impacts. Temperature projections for the Arctic region were assessed in 2007: These suggested already averaged warming of about 2 °C to 9 °C by the year 2100. The range reflects different projections made by different climate models, run with different forcing scenarios. Radiative forcing is a measure of the effect of natural and human activities on the climate. Different forcing scenarios reflect things such as different projections of future human greenhouse gas emissions.
Polar amplification is the phenomenon that any change in the net radiation balance tends to produce a larger change in temperature near the poles than in the planetary average. This is commonly referred to as the ratio of polar warming to tropical warming. On a planet with an atmosphere that can restrict emission of longwave radiation to space, surface temperatures will be warmer than a simple planetary equilibrium temperature calculation would predict. Where the atmosphere or an extensive ocean is able to transport heat polewards, the poles will be warmer and equatorial regions cooler than their local net radiation balances would predict. The poles will experience the most cooling when the global-mean temperature is lower relative to a reference climate; alternatively, the poles will experience the greatest warming when the global-mean temperature is higher.
In climate science, a tipping point is a critical threshold that, when crossed, leads to large, accelerating and often irreversible changes in the climate system. If tipping points are crossed, they are likely to have severe impacts on human society and may accelerate global warming. Tipping behavior is found across the climate system, for example in ice sheets, mountain glaciers, circulation patterns in the ocean, in ecosystems, and the atmosphere. Examples of tipping points include thawing permafrost, which will release methane, a powerful greenhouse gas, or melting ice sheets and glaciers reducing Earth's albedo, which would warm the planet faster.
Climate change feedbacks are effects of global warming that amplify or diminish the effect of forces that initially cause the warming. Positive feedbacks enhance global warming while negative feedbacks weaken it. Feedbacks are important in the understanding of climate change because they play an important part in determining the sensitivity of the climate to warming forces. Climate forcings and feedbacks together determine how much and how fast the climate changes. Large positive feedbacks can lead to tipping points—abrupt or irreversible changes in the climate system—depending upon the rate and magnitude of the climate change.
Sea ice in the Arctic region has declined in recent decades in area and volume due to climate change. It has been melting more in summer than it refreezes in winter. Global warming, caused by greenhouse gas forcing is responsible for the decline in Arctic sea ice. The decline of sea ice in the Arctic has been accelerating during the early twenty‐first century, with a decline rate of 4.7% per decade. It is also thought that summertime sea ice will cease to exist sometime during the 21st century.
Professor Julienne Christine Stroeve is a polar climate scientist known for her research on remote sensing of ice and snow. She is Professor of Polar Observation & Modelling at the Centre for Polar Observation and Modelling, University College London, Senior Canada-150 Research Chair in Climate Forcing of Sea Ice at the University of Manitoba, and a senior research scientist at the National Snow and Ice Data Center within the Cooperative Institute for Research in Environmental Sciences (CIRES). She is also a member of the American Geophysical Union and an ISI highly cited researcher.
Cecilia M. Bitz is an American climatologist known for her research on sea ice and high-latitude climate change. She is a professor and chair in the Atmospheric Sciences Department, as well as the director of the Program on Climate Change at the University of Washington. She was featured on NPR's All Things Considered segment to speak about factors that lead to sea ice loss in 2007, and testified before the United States Senate committee of Energy and Natural Resources on arctic opportunities in 2015.
CICE is a computer model that simulates the growth, melt and movement of sea ice. It has been integrated into many coupled climate system models as well as global ocean and weather forecasting models and is often used as a tool in Arctic and Southern Ocean research. CICE development began in the mid-1990s by the United States Department of Energy (DOE), and it is currently maintained and developed by a group of institutions in North America and Europe known as the CICE Consortium. Its widespread use in Earth system science in part owes to the importance of sea ice in determining Earth's planetary albedo, the strength of the global thermohaline circulation in the world's oceans, and in providing surface boundary conditions for atmospheric circulation models, since sea ice occupies a significant proportion (4-6%) of Earth's surface. CICE is a type of cryospheric model.
Joellen Louise Russell is an American oceanographer and climate scientist.
Pacific Meridional Mode (PMM) is a climate mode in the North Pacific. In its positive state, it is characterized by the coupling of weaker trade winds in the northeast Pacific Ocean between Hawaii and Baja California with decreased evaporation over the ocean, thus increasing sea surface temperatures (SST); and the reverse during its negative state. This coupling develops during the winter months and spreads southwestward towards the equator and the central and western Pacific during spring, until it reaches the Intertropical Convergence Zone (ITCZ), which tends to shift north in response to a positive PMM.
Jennifer Logan is an atmospheric scientist known for her research on how human activities influence the atmosphere, particularly with respect to biomass burning and the ozone hole.
Bette Otto-Bliesner is an earth scientist known for her modeling of Earth's past climate and its changes over different geological eras.
Mary-Louise Elizabeth Timmermans is a marine scientist known for her work on the Arctic Ocean. She is the Damon Wells Professor of Earth and Planetary Sciences at Yale University.
LuAnn Thompson is the Walters Endowed Professor at the University of Washington. She is known for her work in modeling the movement of heat and chemicals via ocean currents.
Rebecca Woodgate is a professor at the University of Washington known for her work on ocean circulation in polar regions.
June-Yi Lee is an atmospheric scientist at Pusan National University known for her use of models to investigate the atmosphere and the ocean under future climate scenarios.