The Relationship between ITCZ Location and Cross-Equatorial Atmospheric Heat Transport: From the Seasonal Cycle to the Last Glacial Maximum
The authors quantify the relationship between the location of the intertropical convergence zone (ITCZ) and the atmospheric heat transport across the equator (AHT[subscript EQ]) in climate models and in observations. The observed zonal mean ITCZ location varies from 5.3°S in the boreal winter to 7.2...
| Main Authors: | , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Meteorological Society
2014
|
| Online Access: | http://hdl.handle.net/1721.1/85073 https://orcid.org/0000-0001-9230-3591 |
| _version_ | 1811082085996167168 |
|---|---|
| author | Donohoe, Aaron Ferreira, David Mcgee, David Marshall, John C McGee, William David |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Donohoe, Aaron Ferreira, David Mcgee, David Marshall, John C McGee, William David |
| author_sort | Donohoe, Aaron |
| collection | MIT |
| description | The authors quantify the relationship between the location of the intertropical convergence zone (ITCZ) and the atmospheric heat transport across the equator (AHT[subscript EQ]) in climate models and in observations. The observed zonal mean ITCZ location varies from 5.3°S in the boreal winter to 7.2°N in the boreal summer with an annual mean position of 1.65°N while the AHT[subscript EQ] varies from 2.1 PW northward in the boreal winter to 2.3 PW southward in the boreal summer with an annual mean of 0.1 PW southward. Seasonal variations in the ITCZ location and AHT[subscript EQ] are highly anticorrelated in the observations and in a suite of state-of-the-art coupled climate models with regression coefficients of −2.7° and −2.4° PW[superscript −1] respectively. It is also found that seasonal variations in ITCZ location and AHT[subscript EQ] are well correlated in a suite of slab ocean aquaplanet simulations with varying ocean mixed layer depths. However, the regression coefficient between ITCZ location and AHT[subscript EQ] decreases with decreasing mixed layer depth as a consequence of the asymmetry that develops between the winter and summer Hadley cells as the ITCZ moves farther off the equator.
The authors go on to analyze the annual mean change in ITCZ location and AHT[subscript EQ] in an ensemble of climate perturbation experiments including the response to CO[subscript 2] doubling, simulations of the Last Glacial Maximum, and simulations of the mid-Holocene. The shift in the annual average ITCZ location is also strongly anticorrelated with the change in annual mean AHT[subscript EQ] with a regression coefficient of −3.2° PW[superscript −1], similar to that found over the seasonal cycle. |
| first_indexed | 2024-09-23T11:57:21Z |
| format | Article |
| id | mit-1721.1/85073 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:57:21Z |
| publishDate | 2014 |
| publisher | American Meteorological Society |
| record_format | dspace |
| spelling | mit-1721.1/850732024-05-15T03:26:56Z The Relationship between ITCZ Location and Cross-Equatorial Atmospheric Heat Transport: From the Seasonal Cycle to the Last Glacial Maximum Donohoe, Aaron Ferreira, David Mcgee, David Marshall, John C McGee, William David Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Donohoe, Aaron Marshall, John C. Ferreira, David McGee, David The authors quantify the relationship between the location of the intertropical convergence zone (ITCZ) and the atmospheric heat transport across the equator (AHT[subscript EQ]) in climate models and in observations. The observed zonal mean ITCZ location varies from 5.3°S in the boreal winter to 7.2°N in the boreal summer with an annual mean position of 1.65°N while the AHT[subscript EQ] varies from 2.1 PW northward in the boreal winter to 2.3 PW southward in the boreal summer with an annual mean of 0.1 PW southward. Seasonal variations in the ITCZ location and AHT[subscript EQ] are highly anticorrelated in the observations and in a suite of state-of-the-art coupled climate models with regression coefficients of −2.7° and −2.4° PW[superscript −1] respectively. It is also found that seasonal variations in ITCZ location and AHT[subscript EQ] are well correlated in a suite of slab ocean aquaplanet simulations with varying ocean mixed layer depths. However, the regression coefficient between ITCZ location and AHT[subscript EQ] decreases with decreasing mixed layer depth as a consequence of the asymmetry that develops between the winter and summer Hadley cells as the ITCZ moves farther off the equator. The authors go on to analyze the annual mean change in ITCZ location and AHT[subscript EQ] in an ensemble of climate perturbation experiments including the response to CO[subscript 2] doubling, simulations of the Last Glacial Maximum, and simulations of the mid-Holocene. The shift in the annual average ITCZ location is also strongly anticorrelated with the change in annual mean AHT[subscript EQ] with a regression coefficient of −3.2° PW[superscript −1], similar to that found over the seasonal cycle. United States. National Oceanic and Atmospheric Administration (Global Change Postdoctoral Fellowship) United States. Dept. of Energy. Office of Science 2014-02-24T16:53:20Z 2014-02-24T16:53:20Z 2013-06 2012-10 Article http://purl.org/eprint/type/JournalArticle 0894-8755 1520-0442 http://hdl.handle.net/1721.1/85073 Donohoe, Aaron, John Marshall, David Ferreira, and David Mcgee. “The Relationship Between ITCZ Location and Cross-Equatorial Atmospheric Heat Transport: From the Seasonal Cycle to the Last Glacial Maximum.” J. Climate 26, no. 11 (June 2013): 3597–3618. © 2013 American Meteorological Society https://orcid.org/0000-0001-9230-3591 en_US http://dx.doi.org/10.1175/JCLI-D-12-00467.1 Journal of Climate Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Meteorological Society American Meteorological Society |
| spellingShingle | Donohoe, Aaron Ferreira, David Mcgee, David Marshall, John C McGee, William David The Relationship between ITCZ Location and Cross-Equatorial Atmospheric Heat Transport: From the Seasonal Cycle to the Last Glacial Maximum |
| title | The Relationship between ITCZ Location and Cross-Equatorial Atmospheric Heat Transport: From the Seasonal Cycle to the Last Glacial Maximum |
| title_full | The Relationship between ITCZ Location and Cross-Equatorial Atmospheric Heat Transport: From the Seasonal Cycle to the Last Glacial Maximum |
| title_fullStr | The Relationship between ITCZ Location and Cross-Equatorial Atmospheric Heat Transport: From the Seasonal Cycle to the Last Glacial Maximum |
| title_full_unstemmed | The Relationship between ITCZ Location and Cross-Equatorial Atmospheric Heat Transport: From the Seasonal Cycle to the Last Glacial Maximum |
| title_short | The Relationship between ITCZ Location and Cross-Equatorial Atmospheric Heat Transport: From the Seasonal Cycle to the Last Glacial Maximum |
| title_sort | relationship between itcz location and cross equatorial atmospheric heat transport from the seasonal cycle to the last glacial maximum |
| url | http://hdl.handle.net/1721.1/85073 https://orcid.org/0000-0001-9230-3591 |
| work_keys_str_mv | AT donohoeaaron therelationshipbetweenitczlocationandcrossequatorialatmosphericheattransportfromtheseasonalcycletothelastglacialmaximum AT ferreiradavid therelationshipbetweenitczlocationandcrossequatorialatmosphericheattransportfromtheseasonalcycletothelastglacialmaximum AT mcgeedavid therelationshipbetweenitczlocationandcrossequatorialatmosphericheattransportfromtheseasonalcycletothelastglacialmaximum AT marshalljohnc therelationshipbetweenitczlocationandcrossequatorialatmosphericheattransportfromtheseasonalcycletothelastglacialmaximum AT mcgeewilliamdavid therelationshipbetweenitczlocationandcrossequatorialatmosphericheattransportfromtheseasonalcycletothelastglacialmaximum AT donohoeaaron relationshipbetweenitczlocationandcrossequatorialatmosphericheattransportfromtheseasonalcycletothelastglacialmaximum AT ferreiradavid relationshipbetweenitczlocationandcrossequatorialatmosphericheattransportfromtheseasonalcycletothelastglacialmaximum AT mcgeedavid relationshipbetweenitczlocationandcrossequatorialatmosphericheattransportfromtheseasonalcycletothelastglacialmaximum AT marshalljohnc relationshipbetweenitczlocationandcrossequatorialatmosphericheattransportfromtheseasonalcycletothelastglacialmaximum AT mcgeewilliamdavid relationshipbetweenitczlocationandcrossequatorialatmosphericheattransportfromtheseasonalcycletothelastglacialmaximum |