Preprints
Filtering by Subject: Atmospheric Sciences
Revisiting the surface-energy-flux perspective on the sensitivity of global precipitation to climate change
Published: 2018-05-23
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Climate models simulate an increase in global precipitation at a rate of approximately 1-3% per Kelvin of global surface warming. This change is often interpreted through the lens of the atmospheric energy budget, in which the increase in global precipitation is mostly offset by an increase in net radiative cooling. Other studies have provided different interpretations from the perspective of the [...]
Prognostic validation of a neural network unified physics parameterization
Published: 2018-05-18
Subjects: Atmospheric Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Weather and climate models approximate diabatic and sub-grid-scale processes in terms of grid-scale variables using parameterizations. Current parameterizations are de- signed by humans based on physical understanding, observations and process modeling. As a result, they are numerically efficient and interpretable, but potentially over-simplified. However, the advent of global high-resolution [...]
Detecting lightning infrasound using a high-altitude balloon
Published: 2018-04-17
Subjects: Atmospheric Sciences, Earth Sciences, Geophysics and Seismology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Acoustic waves with a wide range of frequencies are generated by lightning strokes during thunderstorms, including infrasonic waves (0.1 to 20 Hz). The source mechanism for these low frequency acoustic waves is still debated and studies have so far been limited to ground-based instruments. Here we report the first confirmed detection of lightning generated infrasound with acoustic instruments [...]
The role of upper level diffluence in the Tropical Easterly Jet in the formation of the recent strongest Atlantic hurricanes
Published: 2018-04-08
Subjects: Atmospheric Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
In this paper we report the evidence of the potential role of diffluence in the 200hPa wind field off the coast of West Africa in the formation of a significant number of Category 4 and Category 5 hurricanes in the recent decade. It is shown that on an average of 65% cases of hurricanes at Category 4 and above is preceded by upper level diffluence in the Tropical Easterly Jet (TEJ) by 0–3 days. [...]
Could machine learning break the convection parametrization deadlock?
Published: 2018-03-16
Subjects: Atmospheric Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Physics, Planetary Sciences
Modeling and representing moist convection in coarse-scale climate models remains one of the main bottlenecks of current climate simulations. Many of the biases present with parameterized convection are strongly reduced when convection is explicitly resolved (in cloud resolving models at high spatial resolution ~ a kilometer or so). We here present a novel approach to convective parameterization [...]
Multi-scale modeling of the urban meteorology: integration of a new canopy model in the WRF model
Published: 2018-02-16
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Urban parametrizations have been recently proposed and integrated in mesoscale meteorological models for a better reproduction of urban heat islands and to compute building energy con- sumption. The objective of the present study is to evaluate the value of the use of a module able to produce highly resolved vertical profiles of these variables. For this purpose, the Canopy Interface Model (CIM) [...]
Moisture balance over the Iberian Peninsula according to a regional climate model: The impact of 3DVAR data assimilation.
Published: 2018-01-10
Subjects: Atmospheric Sciences, Climate, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
An analysis of the atmospheric branch of the hydrological cycle by means of a 15 km resolution numerical integration performed using WRF nested in ERA Interim is presented. Two WRF experiments covering the period 2010-2014 were prepared. The first one (N) was configured as in standard numerical downscaling experiments. The second one (D), with the same parameterizations, included a step of 3DVAR [...]
Decreasing cloud cover drives the recent mass loss on the Greenland Ice Sheet
Published: 2017-11-13
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Environmental Sciences, Glaciology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Greenland Ice Sheet (GrIS) has been losing mass at an accelerating rate since the mid-1990s. This has been due to both increased ice discharge into the ocean and melting at the surface, with the latter being the dominant contribution. This change in state has been attributed to rising temperatures and a decrease in surface albedo. We show, using satellite data and climate model output, that [...]