ice2ice

Monthly meeting in Bergen.

Contact: Jørund

Extended PI meeting. Focus warm arctic ocean.

Wednesday in 235 at NBI and/or after lunch in 016.

Thursday in 016.

Note the new date. Meeting has been moved from 15/8 to 6/9. Updates from the Copenhagen groups.

09:00-09:30 -Sindhu: “Total air content results from Renland and preliminary interpretation”-20 min, 10 min Q

09:30-09:50-Kerim: “why am I in Copenhagen”, 20 min total

09:50:-10:30-Nicholas: “Highly temporally resolved response to seasonal surface melt of the Zachariae and 79N outlet glaciers in Northeast Greenland”, 30 min, 10 Q

10.30-10:40 Short break

10:40-11:10-Shuting/Jens “update on Idas work on nudging of the sea ice” 20 min, 10 Q

11:10-11:35-Diana: “Northern hemisphere methane realize in MIS5a as revealed by high-resolution gas measurements in ice cores.” 15 min, 10 Q

11:35-11:45-Paul: “Update on Mt. Brown project”

11:45-12:00 Update of publication list and misc. Please prepare one minute (one slide) about any new puplications/new submissions. Also let Helle know of new puplication plans. 10 min

12.00 Lunch at CIC. If you stay for lunch and is not at CIC normally please let Helle know.

Further agenda for those who are interested

• Paul: Ideas for new project about dust

• The workshop starts Wednesday Sep 20 at 12.00, and ends Friday Sep 22 at 12.00.
• A PROMICE 10-year jubilee and reception is planned for the afternoon of Sep 22.

• to present and discuss results on modeling of meltwater retention processes in snow and firn on ice sheets and glaciers;
• to plan and coordinate meltwater retention model development;
• to emphasize optical remote sensing snow parameter data comparison and data assimilation;
• to formulate a protocol for a meltwater retention model intercomparison project (RetMIP)

• Snow model development
• Meltwater retention model validation
• Meltwater retention model intercomparison project (RetMIP)
• Optical remote sensing to improve snow models

• survey and prioritize remotely sensed snow parameter data users’ requirements for global and regional snow information
• discuss how to enhance methods for estimating snow parameters, either from remote sensing or from modeling, and to evaluate advantages and disadvantages of the different approaches
• consult users about the utility/interest in other snow products suitable for studying climate-related issues.

• a protocol for a retention model intercomparison project (RetMIP) including instructions and datasets for validation.
• a list of requirements and minimum accuracy levels for models using optical remotely sensed snow parameter data
• a journal special issue like the 2016 special issue in Frontiers in Earth Science – Melt Water Retention Processes in Snow and Firn on Ice Sheets and Glaciers: Observations and Modeling, papers feeding into the IPCC Special Report on Climate change and the oceans and the cryosphere.

09:00-09:30 –Mads- The role of the Southern Ocean in the global ocean circulation and its representation in coarse resolution models-(20 min+ 10 min Q)

09:30-10:00- Andreas-The Surface Mass Balance of the Greenland Ice Sheet during the Last Interglacial (20 min+ 10 min Q)

10:00-10:10-Silje short introduction

10:10-10:20-Jonathan short introduction

Break 10:20-10:35

10:35-10:55 Peter on meltwater meeting

10:55-11:25 Martin O update on project? (20 min+ 10 min Q)

11:25-11:40 Martin S preliminary results from an analysis of Shuting’s long run using self-organizing maps.

11:40-11:50 Update of publication list. Please prepare one minute (one slide) about any new publications/new submissions. Also let Helle know of new publication plans.

11.50-12:00 Update on Future meetings

Extended PI meeting -DO theme

PhD defense by Niccoló Maffezzoli

Title: SODIUM, IODINE AND BROMINE IN POLAR ICE CORES.

Abstract: This research focuses on sodium, bromine and iodine in polar ice cores, with the aim of reviewing and advancing their current understanding with additional measurements and records, and investigating the connections of these tracers with sea ice and their feasibility as sea ice indicators. Modern Arctic sea ice decline clearly yields further motivation in this direction, as the reconstruction of past sea ice conditions could provide clues to the mechanisms in play nowadays and in the future projections. Inductively Coupled  Plasma Mass Spectroscopy (ICP-MS) has been applied for the determination of Na, Br and I in firn records retrieved at Law Dome and Talos Dome (Antarctica) and in the NEEM and Renland ice cores (Greenland).
The dissertation is presented as a monograph. It is structured in a way that would logically bring the reader from the broad perspective of sea ice and ice cores into the details of the physical and chemical transformations of these impurities from their emission to their deposition and finally to their determination in ice cores and interpretation of their climatic significance. This view reflects, to some extent, the thread of understanding that led to the research activities.
Chapter 2 briefly introduces sea ice, with particular focus on its salinity as a source of sea salt aerosols. Some features regarding the role of sea ice in the climate system and the differences between sea ice in the two hemispheres are described. The chapter ends with a brief summary of the state-of-the-art of the chemical tracers that are used in ice cores and marine sediment cores to reconstruct past sea ice.
Chapter 3 introduces ice cores with a geochemical perspective. The historically measured ions and compounds are described, together with their climatic relevance. The chapter ends with a description of the main analytic al techniques used to measure ionic and elemental species in ice cores.
Chapter 4 introduces sodium, bromine and iodine with a theoretical perspective and a particular focus on their connections with sea ice. Some of the physical and chemical properties that are believed to affect the sea salt aerosol signature in ice cores are described. Halogen chemistry is presented, with a particular focus on the halogen sources and radical chemistry in the polar boundary layer. The chapter continues with a historical review of the relevant atmospheric studies that have demonstrated the activation of halogen compounds and the importance of halogen chemistry at high latitudes. Finally, the use of sodium and bromine as sea ice tracers is introduced.
Chapter 5 describes the Renland ice core, drilled in coastal East Greenland in 2015 as part of ”Ice2Ice”, a project which aims at understanding the causes of past abrupt climate changes in Greenland. The study of the timescale and other glaciological parameters led to the calculation of the annual accumulation rate for the past 4000 years. Finally, a study of the potential sea salt  aerosol sources arriving at the ice core site is presented, using back trajectory analyses of the past 17 years. The results identify the aerosol source area influencing the Renland ice cap, a result necessary for the interpretation of impurity records obtained from the ice core.
Chapter 6 reviews the published ice/snow measurements of bromine and iodine at polar latitudes. Where available they are compared to atmospheric halogen measurements. A selection of sodium records from the same locations is included to provide a more complete picture. The additional measurements performed during the research activities are also displayed. With the goal of presenting and extending the state-of-the-art of knowledge of bromine and iodine in polar snow, a critical comparison between the proxies is adopted, trying to elucidate the established and the unknown features and their potential as sea ice indicators. The last section is dedicated to the measurements of sodium and bromine in the Renland core, which could provide the first ice core-based reconstruction of Arctic sea ice in the Greenland Sea for the last 125 kyr.

Supervisor
Paul Vallelonga, Centre for Ice and Climate, Niels Bohr Institute

Assessment committee
Thomas Blunier, Centre for Ice and Climate, Niels Bohr Institute
Margareta Hansson, Institutionen för naturgeografi, Stockholms Universitet
Michel Legrand, Laboratoire de Glaciologie et Géophysique de l´Environment

If interested please contact Niccoló Maffezzoli for a copy of the thesis (maffe@nbi.ku.dk)

Dear all

The dates are now fixed for the NEGIS workshop and EGRIP Steering Committee meeting 2017. I have been asking around and this seems to be the best we can do.

I would like to ask the consortia chairs to plan when they want to have their meeting (and if they need one or two blocks for the meeting). The consortia list is here: consortia-meetings-2016

After the EGRIP fieldseason, beginning of September, I will email all chairs again to finalize the program.

The NEGIS workshop is intended to be a workshop covering all activites on NEGIS – from iceridge to ocean. I would ask you to email me if you are interested in participating and also names (and emails) for researchers outside the EGRIP community we would like to invite.

the very best

Dorthe

Sunday 29 October 2017

18-22 NEGIS workshop IceBreaker

Monday 30 October 2017

9-18 NEGIS workshop

18-22 NEGIS dinner

Tuesday 31 October 2017

9-18 NEGIS workshop

13:00-15:30 EGRIP consortia meetings (1)

16:00-18:00 EGRIP consortia meetings (2)

Wednesday 1 November 2017

9:00-12:00  EGRIP consortia meetings (3)

13:00-15:30 EGRIP consortia meetings  (4)

16:00-18:00 EGRIP SC meeting

18:00 – 22:00 Icebreaker and EGRIP SC Dinner

Thursday 2 November 2017

9:00-17:00 EGRIP SC meeting

Friday 3 November 2017

9:00-17:00 ReCAP meeting

PI meeting (dinner the 8th)

Monthly meeting in Bergen.

Contact: Jørund

Francesco Muschitiello

(Lamont-Doherty Earth Observatory of Columbia University)

Title: “Deep-water circulation leads North Atlantic climate during the last deglaciation”.

Abstract: Constraining the response time of the climate system to changes in Atlantic Meridional Overturning Circulation (AMOC) is fundamental to improve climate predictability. Here we present a precise synchronization of terrestrial, marine and ice-core records that reveals for the first time the ocean-atmosphere lead-lag nature during rapid North Atlantic climate transitions of the last deglaciation. Using a continuous record of deep water ventilation from the Nordic Seas, we identify a systematic ~250-year lead of deep-water export on abrupt climate changes recorded in Greenland ice cores –in and out of the Younger Dyas stadial (YD)– in response to gradual changes in freshwater forcing. Supported by transient climate model simulations, our results also point at a delayed response of atmospheric CO₂ rise to AMOC slowdown at the onset of the YD. We conclude that variations in North Atlantic deep-water formation are precursors to large-scale climate and pCO₂ changes, which highlights the need for improved long-term future AMOC projections.