| dc.identifier.uri | http://hdl.handle.net/11401/77757 | |
| dc.description.sponsorship | This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree. | en_US |
| dc.format | Monograph | |
| dc.format.medium | Electronic Resource | en_US |
| dc.language.iso | en_US | |
| dc.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dc.type | Dissertation | |
| dcterms.abstract | The diurnal cycle of convection is a key to understanding the climate and weather in the context of the Earth’s energy and water cycles. Yet, the well-observed late afternoon to early evening precipitation maximum over most of inland regions still remains one of the poorly understood features of continental convection. Many numerical weather and global climate models (GCMs) have had difficulty capturing the correct diurnal cycle of convection over land. Not only does this deficiency create a concern regarding the consistency of GCMs’ physical parameterizations, but it also requires a better understating of physical processes that control the land-atmosphere interactions. Therefore, it is crucial to design models that can represent the coupling between land and atmosphere to advance our knowledge of the convection over land on subdiurnal timescales. A Simplified Land Model (SLM) has been developed to be used in the System for Atmospheric Modeling (SAM) cloud-resolving model, which can explicitly resolve convection over land with prescribed surface fluxes but lacks a realistic scheme to represent the explicit land-atmosphere interaction. By design, the SLM is considerably simpler in its formulation than other, more sophisticated land models. It uses a minimalist set of external parameters to define the vegetation and soil characteristics and physical process, and focuses mainly on the heat, moisture and momentum exchange between land and atmosphere. This allows coupled SAM-SLM model users to easily understand and modify the land surface component to meet their research requirements. Validation tests of SLM using measurements from several sites reveal that it is capable of reproducing rather well the observed surface radiation and enthalpy fluxes over various vegetated land sites. The coupled SAM-SLM model has been applied to a problem of diurnal development of clouds in the PBL over land as well as to an idealized case of the diurnal cycle of precipitation over 2D islands. The islands are of various sizes and are surrounded by an ocean using a radiative-convective equilibrium framework with prescribed and constant sea-surface temperature. The model is able to reproduce the observed timing of the precipitation maximum at 5 pm (17:00) local time for the inland regions of simulated islands far away from the sea-breeze zone. It has also been shown that the timing of precipitation can shift earlier in the case of warmer ocean. The sensitivity of the diurnal cycle of precipitation to planetary rotation as well as vegetation type and landmass size has also been tested. In particular, it has been found that, over large enough islands, changing the land cover from forest to grassland or baresoil can switch the convection regime from a regular diurnal cycle with the late-afternoon precipitation maximum to an organized propagating convection system with a timespan longer than 24-hour. | |
| dcterms.abstract | The diurnal cycle of convection is a key to understanding the climate and weather in the context of the Earth’s energy and water cycles. Yet, the well-observed late afternoon to early evening precipitation maximum over most of inland regions still remains one of the poorly understood features of continental convection. Many numerical weather and global climate models (GCMs) have had difficulty capturing the correct diurnal cycle of convection over land. Not only does this deficiency create a concern regarding the consistency of GCMs’ physical parameterizations, but it also requires a better understating of physical processes that control the land-atmosphere interactions. Therefore, it is crucial to design models that can represent the coupling between land and atmosphere to advance our knowledge of the convection over land on subdiurnal timescales. A Simplified Land Model (SLM) has been developed to be used in the System for Atmospheric Modeling (SAM) cloud-resolving model, which can explicitly resolve convection over land with prescribed surface fluxes but lacks a realistic scheme to represent the explicit land-atmosphere interaction. By design, the SLM is considerably simpler in its formulation than other, more sophisticated land models. It uses a minimalist set of external parameters to define the vegetation and soil characteristics and physical process, and focuses mainly on the heat, moisture and momentum exchange between land and atmosphere. This allows coupled SAM-SLM model users to easily understand and modify the land surface component to meet their research requirements. Validation tests of SLM using measurements from several sites reveal that it is capable of reproducing rather well the observed surface radiation and enthalpy fluxes over various vegetated land sites. The coupled SAM-SLM model has been applied to a problem of diurnal development of clouds in the PBL over land as well as to an idealized case of the diurnal cycle of precipitation over 2D islands. The islands are of various sizes and are surrounded by an ocean using a radiative-convective equilibrium framework with prescribed and constant sea-surface temperature. The model is able to reproduce the observed timing of the precipitation maximum at 5 pm (17:00) local time for the inland regions of simulated islands far away from the sea-breeze zone. It has also been shown that the timing of precipitation can shift earlier in the case of warmer ocean. The sensitivity of the diurnal cycle of precipitation to planetary rotation as well as vegetation type and landmass size has also been tested. In particular, it has been found that, over large enough islands, changing the land cover from forest to grassland or baresoil can switch the convection regime from a regular diurnal cycle with the late-afternoon precipitation maximum to an organized propagating convection system with a timespan longer than 24-hour. | |
| dcterms.available | 2017-09-20T16:53:31Z | |
| dcterms.contributor | Colle, Brian A | en_US |
| dcterms.contributor | Khairoutdinov, Marat | en_US |
| dcterms.contributor | Zhang, Minghua | en_US |
| dcterms.contributor | Vogelmann, Andy | en_US |
| dcterms.contributor | Denning, Scott A. | en_US |
| dcterms.creator | Lee, Jungmin | |
| dcterms.dateAccepted | 2017-09-20T16:53:31Z | |
| dcterms.dateSubmitted | 2017-09-20T16:53:31Z | |
| dcterms.description | Department of Marine and Atmospheric Science | en_US |
| dcterms.extent | 149 pg. | en_US |
| dcterms.format | Monograph | |
| dcterms.format | Application/PDF | en_US |
| dcterms.identifier | http://hdl.handle.net/11401/77757 | |
| dcterms.issued | 2016-12-01 | |
| dcterms.language | en_US | |
| dcterms.provenance | Made available in DSpace on 2017-09-20T16:53:31Z (GMT). No. of bitstreams: 1
Lee_grad.sunysb_0771E_12761.pdf: 14565406 bytes, checksum: 370f5f7459a93f634bc0165463663e0e (MD5)
Previous issue date: 1 | en |
| dcterms.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dcterms.subject | Atmospheric sciences | |
| dcterms.subject | continental convection, Diurnal cycle, land surface modeling | |
| dcterms.title | Development of the Simplified Land Model (SLM) and its application to the diurnal cycle of precipitation over land | |
| dcterms.type | Dissertation | |
