Seasonal variations of the clear-sky greenhouse effect: the role of changes in atmospheric temperatures and humidities

1993 ◽  
Vol 9 (3) ◽  
pp. 117-129 ◽  
Author(s):  
MJ Webb ◽  
A Slingol ◽  
GL Stephens
2003 ◽  
Vol 107 (2) ◽  
pp. 469-482 ◽  
Author(s):  
P. K. Pasricha ◽  
B. S. Gera ◽  
S. Shastri ◽  
H. K. Maini ◽  
T. John ◽  
...  

2015 ◽  
Vol 14 (11) ◽  
pp. 2007-2013 ◽  
Author(s):  
Nadia Diovisalvi ◽  
Armando M. Rennella ◽  
Horacio E. Zagarese

A schematic representation of the seasonal cycle of rotifer in L. Chascomús. In this figure the relative abundances of the three dominant rotifer species are expressed as fractions of the estimated clear-sky mean daily incident solar radiation.


2013 ◽  
Vol 185 (8) ◽  
pp. 6831-6846 ◽  
Author(s):  
Masumi Koriyama ◽  
Yuichi Hayami ◽  
Akane Koga ◽  
Koichi Yamamoto ◽  
Alim Isnasetyo ◽  
...  

2011 ◽  
Vol 7 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Y. Hu ◽  
J. Yang ◽  
F. Ding ◽  
W. R. Peltier

Abstract. One of the critical issues of the Snowball Earth hypothesis is the CO2 threshold for triggering the deglaciation. Using Community Atmospheric Model version 3.0 (CAM3), we study the problem for the CO2 threshold. Our simulations show large differences from previous results (e.g. Pierrehumbert, 2004, 2005; Le Hir et al., 2007). At 0.2 bars of CO2, the January maximum near-surface temperature is about 268 K, about 13 K higher than that in Pierrehumbert (2004, 2005), but lower than the value of 270 K for 0.1 bar of CO2 in Le Hir et al. (2007). It is found that the difference of simulation results is mainly due to model sensitivity of greenhouse effect and longwave cloud forcing to increasing CO2. At 0.2 bars of CO2, CAM3 yields 117 Wm−2 of clear-sky greenhouse effect and 32 Wm−2 of longwave cloud forcing, versus only about 77 Wm−2 and 10.5 Wm−2 in Pierrehumbert (2004, 2005), respectively. CAM3 has comparable clear-sky greenhouse effect to that in Le Hir et al. (2007), but lower longwave cloud forcing. CAM3 also produces much stronger Hadley cells than that in Pierrehumbert (2005). Effects of pressure broadening and collision-induced absorption are also studied using a radiative-convective model and CAM3. Both effects substantially increase surface temperature and thus lower the CO2 threshold. The radiative-convective model yields a CO2 threshold of about 0.21 bars with surface albedo of 0.663. Without considering the effects of pressure broadening and collision-induced absorption, CAM3 yields an approximate CO2 threshold of about 1.0 bar for surface albedo of about 0.6. However, the threshold is lowered to 0.38 bars as both effects are considered.


2010 ◽  
Vol 6 (4) ◽  
pp. 1337-1350 ◽  
Author(s):  
Y. Hu ◽  
J. Yang

Abstract. One of the critical issues of the Snowball Earth hypothesis is how high level of CO2 is required for triggering the deglaciation. Using Community Atmospheric Model version 3 (CAM3), we study the problem for the CO2 threshold. Our simulations show large differences from previous results (Pierrehumbert, 2004, 2005). At 0.2 bars of CO2, the January maximum near-surface temperature is about 268 K, about 13 K higher than that in Pierrehumbert (2004, 2005), but lower than the value of 270 K for 0.1 bar of CO2 in Le Hir et al. (2007). It is found that the diversity of simulation results is mainly due to model sensitivity of greenhouse effect and longwave cloud forcing to increasing CO2. At 0.2 bar of CO2, CAM3 yields 117 Wm −2 of clear-sky greenhouse effect and 32 Wm−2 of longwave cloud forcing, versus only about 77 Wm−2 and 10.5 Wm−2 in Pierrehumbert (2004, 2005), respectively. CAM3 has comparable clear-sky greenhouse effect to that in Le Hir et al. (2007), but lower longwave cloud forcing. CAM3 also produces much stronger Hadley cells than in Pierrehumbert (2005).


2018 ◽  
Vol 631-632 ◽  
pp. 1472-1485 ◽  
Author(s):  
M. Kavitha ◽  
Prabha R. Nair ◽  
I.A. Girach ◽  
S. Aneesh ◽  
S. Sijikumar ◽  
...  

2008 ◽  
Vol 1 (5) ◽  
pp. 305-308 ◽  
Author(s):  
Helen M. Worden ◽  
Kevin W. Bowman ◽  
John R. Worden ◽  
Annmarie Eldering ◽  
Reinhard Beer

2019 ◽  
Vol 123 ◽  
pp. 417-427 ◽  
Author(s):  
Ahlam H. Al Hanai ◽  
Dagmara S. Antkiewicz ◽  
Jocelyn D.C. Hemming ◽  
Martin M. Shafer ◽  
Alexandra M. Lai ◽  
...  

1976 ◽  
Vol 69 (3) ◽  
pp. 421-425 ◽  
Author(s):  
B. N. PANDEY ◽  
J. S. D. MUNSHI

SUMMARY Studies on cyclic activity of the thyroid and seasonal variations in oxygen consumption (V̇o2) under experimental conditions in which surfacing was either allowed or prevented were made in H. fossilis to try to establish a relationship between these measures and to ascertain the possible role of the thyroid in the regulation of metabolic rate. A good correlation was found between the activity of the thyroid and V̇o2 in this species. This finding was further confirmed by the administration of l-thyroxine or thiouracil to this fish. The thyroxine-and thiouracil-treated animals showed significantly higher (P < 0·05) and lower (P < 0·01) rates of V̇o2 respectively, thus indicating the probable role of the thyroid in the regulation of metabolic rate.


2012 ◽  
Vol 52 (8) ◽  
pp. 761
Author(s):  
A. Galán-Ocaña ◽  
M. J. Ramírez-Expósito ◽  
J. M. Martínez-Martos ◽  
S. Tellado ◽  
C. Azorit

The circulating renin–angiotensin system (RAS) is well known for its systemic role in the regulation of blood pressure, renal hemodynamics and fluid homeostasis. However, in mammals several organs also contain a local RAS, including male and female reproductive tissues. In the present study we analysed serum from a free-living population of red deer (Cervus elaphus hispanicus) and fallow deer (Dama dama) to determine the activity of four RAS-regulating aminopeptidases (aminopeptidase A, aspartyl aminopeptidase, aminopeptidase N and aminopeptidase B) as part of a study of annual cycles of growth and condition. Our aim was to detect seasonal variations in the activities of these aminopeptidases and their relationship to the reproductive behaviour of both species in a Mediterranean environment. In both males and females there was a maximum peak of activity in autumn. A second peak was detected in spring for males while in females activity was also higher in summer. These changes may be related to a different endocrine status according to their seasonal cycle, the decreased photoperiod in autumn and the normal timing of the seasonal growth cycle. Thus, changes in the activity of RAS-regulating aminopeptidases could reflect the functional role of angiotensins through the annual cycle of both species, also suggesting an important role of these peptide hormones in the regulation of these biological processes.


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